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    Volume 28,2020 Issue 5
    • CHEN Ze-hui, WU Xun, ZHU Yun-fang, WANG An-gui, GUO Xiang-yang, LIU Peng-fei

      2020,28(5):1-7, DOI: 10.13597/j.cnki.maize.science.20200501

      Abstract:

      Heterosis is a common phenomenon in biology, which has been widely used in commercial breeding practice. It often shows the difference of heterosis among individuals derived from the first generation of a cross between pair-populations(lines). However, the genetic basis of heterosis' formation is still in the stage of hypothesis, mainly including dominant hypothesis over-dominant hypothesis, epistasis heterosis gene, allele specific expression and other theoretical explanations. In this paper, different reviews of heterosis hypotheses were summarized, and the utilization of the practicability of HF1dy2 was clarified, when combined reported heterosis hypotheses with current maize inbred line and hybrid breeding practice. Based on this, the complementary theory of parental gene frequency difference in the formation of heterosis was discussed. One viewpoint about inbred selection and hybrids crossed between groups was proposed. In addition, some breeding practices of maize improving and innovating for heterosis groups were also discussed.

    • SUN Qi, LU Shou-ping, LI Wen-cai, YU Yan-li, ZHAO Meng, LI Wen-lan, MENG Zhao-dong

      2020,28(5):8-13, DOI: 10.13597/j.cnki.maize.science.20200502

      Abstract:

      Parental inbred lines of pedigree information of maize hybrids released by Pioneer Corporation in China from 2001 to 2019 were collected and sorted out. The pedigree map of parental inbred lines was drawn including SS and NSS populations. The results indicated that 53 maize hybrids from Pioneer Corporation were most released in Huanghuai plan summer maize region focused on Shandong and Henan province and Northeast spring maize region focused on Jilin province during the past 19 years. The background of SS population includes B73 and PHG39, the most as derivative inbred lines of PHG39.Basing backbone line PH09B and its derivative line PH890, eight inbred lines, PH6WC, PH6JM, PHJEV, PHTEF, PH11V8, PH18Y6, PH1JP8, PH12P3 were originated. These inbred lines combined 14 released hybrids. The background of NSS population includes OH07, Iodent and Lancaster germplasm, priority to OH07. The backbone inbred lines PHN46 and PH4CN formed 9 derivative inbred lines, PH4CV, PH2N1, PH5AD, PHPM0, PH1N2D, PH11YB, PH11VR, PH12RP, PH12TB. These inbred lines combined 18 approved hybrids.

    • WANG Xing-chuan, FEI Ji-fei, LIU Dong-sheng, GAO Fei, WANG Ai-fen, YUAN Zhi-qiang, CHEN Rui-jie, SUN Zhao, ZHANG Chang-zheng, WANG Yi-bo

      2020,28(5):14-19, DOI: 10.13597/j.cnki.maize.science.20200503

      Abstract:

      Lantron808 is a corn hybrid created in 2012 using CT3566 and CT3354 as female and male parents respectively, which satisfies the trait breeding goals of Mid-early maturity, high yield potential, lodging resistance, high density planting, disease resistance, fast dehydration, machine-harvesting, and wide adaptability. Lantron808 has been approved in five national trials for commercial corn production in four major corn production regions and five maturity zones including Huang-Huai-Hai summer corn region, Northeast region(in both Northeast medium maturity zone and East Huabei medium and late maturity zone), Northwest region, and Southwest region. The yield performance of Lantron808 in national and regional multi-location trials, and production trials were reported, along with its excellent characteristics in agronomic traits, lodging resistance, density tolerance, and feed quality of silage. According to the performance of Lianchuang808 and the experience of the breeding process, related issues on commercial breeding were discussed. In particular, the pyramiding breeding of favorite traits, the assignment of heterotic group and their implications to heterosis.

    • LIU Jie, ZHANG Chun-xiao, LI Shu-fang, CAO Tie-hua, LIANG Xuan-he, LIU Xue-yan, MA Yong-xin, ZHENG Da-hao, LI Xiao-hui

      2020,28(5):20-26,31, DOI: 10.13597/j.cnki.maize.science.20200504

      Abstract:

      The appropriate temperature for the identification of chilling tolerance at maize germination stage was established as 10℃, based on a statistical analysis of the average ground temperature of 10 cm underground in Gongzhuling, Jilin during April 20 th to May 10 th, 2009-2018. The germination rate, germination index, average germination time and relative values of 81 maize hybrids were measured under low temperature stress. Principal component analysis was used to calculate the comprehensive cold tolerance D value. Based on D value and relative germination rate, chilling tolerance of maize hybrids was comprehensively evaluated. The results showed that six single indicators at germination stage were synthesized into two independent comprehensive indicators by principal component analysis. Based on the D value of comprehensive evaluation of cold resistance and the relative germination rate, 81 hybrids were all divided into 5 categories by cluster analysis, which included excellent cold resistance, strong cold resistance, medium cold resistance, weak cold resistance and very weak cold resistance. Both have a high degree of coincidence. Five hybrids with strong cold resistance were screened out, including Xianyu1225, Shengyuan 80, Heyu 35, Xiangyu998 and Liangyu 66. A strategy was finally proposed to combine the rough evaluation based on relative germination rate with the precise evaluation based on comprehensive cold tolerance D value.

    • TAO Rui, HOU Jia-xian, LIU Hong-xia, SANG Jian, WANG Xin-qi, YUE Yao-hai, SUN Chuan-bo

      2020,28(5):27-31, DOI: 10.13597/j.cnki.maize.science.20200505

      Abstract:

      Eleven waxy maize materials were induced by haploid inducers (Jiyou 101) to study the effect of silk length, pollinating date on haploid inducing rate and different approaches on haploid doubling. The results of haploid inducing indicated that, the average haploid inducing rate of long silk pollination was 13.47%, short silk pollination was 5.75%, after summer pollination was 12.86%, summer pollination was 6.22%. The results of haploid doubling indicated that, the average loose powder rate of dipping shoot was 10.66%, dipping root was 6.20%, dipping seed was 4.34%, spontaneous was 1.05%, the best way of haploid doubling was dipping shoot.

    • WANG Shuai, QI Mao-dong, WEI Feng-ju

      2020,28(5):32-38, DOI: 10.13597/j.cnki.maize.science.20200506

      Abstract:

      Heat shock protein 70(HSP70s) are found extensively in prokaryotic and eukaryotic and one of the most conserved molecular chaperones. In this study, a member of the HSP70 family was isolated from maize. Its fulllength coding sequence was 1 992 bp, and its open reading frame is 2 352 bp. The encoded protein with molecular weight is about 75.0 kD. Through protein structure prediction and homologous alignment analysis, the gene encodes a protein containing ATPase site and HSP70 conserved domain. It is highly similar to Arabidopsis thaliana AtHSP70-12 sequence, so it is named ZmHSP70-12. Subcellular localization analysis showed that the ZmHSP70-12 protein was expressed in the endoplasmic reticulum. Real-time quantitative PCR analysis revealed ZmHSP70-12 has an obvious response to abiotic stress, such as high temperature and drought. Therefore, it speculates that ZmHSP70-12 is a stress-related gene in maize stress.

    • SI Wei-na, WANG Heng-sheng, DONG Jin-lei, LI Ling-ling, CHEN Jin-wu, CHENG Bei-jiu, GU Long-jiang

      2020,28(5):39-46, DOI: 10.13597/j.cnki.maize.science.20200507

      Abstract:

      Growth-regulating factors(GRF) is an important type of transcription factors, which were specifically identified in plant kingdom. Several homologs of GRF genes have been demonstrated to be key regulators that could affect the development of plant height in model plants, such as Oryza sativa and Arabidopsis thaliana. In the present study, weighted gene co-expression network analysis(WGCNA) was used to explore the potential key hub ZmGRF genes via previously published high-throughput RNA-seq dataset. A total of nine candidate ZmGRF genes exhibited significant co-expression mode with functionally characterized genes in maize. Moreover, 8 out of 9 candidate gene could form robust gene pairs within maize or between maize and rice genomes via microsynteny analysis. The ratio of Ka to Ks for each gene pair indicated that all ZmGRF genes were undergone stringent purifying selection, indicating the conversation of molecular function of ZmGRF genes in maize. Finally, ZmGRF genes showed clearly diverse expression profiles in different maize lines or developmental stages.

    • CHU Kun, NIE Xiao-xiong, FENG Hua-jie, HAN Gui-li, LIANG Xue-lian

      2020,28(5):47-52, DOI: 10.13597/j.cnki.maize.science.20200508

      Abstract:

      The ultrasonication-assisted Agrobacterium treatment method was modified with the addition of emery to increase the treatment intensity to the apical meristem cells of germinating seeds. Ninety three plants from 800 control seeds were sprayed three times with glyphosate solution, and 27 of them survived, their leaves were taken with a PCR electrophoresis test and 23 shown positive, which suggested that epsps gene was introduced into the corn cultivar, and the transformation rate was 29%. Finally, which has been shown that the method has the advantages of circumventing the tedious tissue culture procedures and being easy to apply.

    • JIANG Ao-nan, YAN Jing-qi, LU Hai-bo, ZHAO Hai-chao, HUANG Zhi-hong

      2020,28(5):53-59, DOI: 10.13597/j.cnki.maize.science.20200509

      Abstract:

      In order to compare different section folding strength of spring maize varieties, in cold and arid regions of northwest nine spring maize varieties as the research object, through the determination of maize base in the third section flexural strength, microstructure and by using an optical microscope to observe the internodes, section microscopic indicators of vascular bundle and folding strength related analysis, the research section of spring maize folding strength and stem the relationship between the microstructure. The results showed that the joint folding strength of different spring maize varieties reached a significant level. Statistical analysis on the microscopic indexes of vascular bundles showed that the variation coefficient of vascular bundle sheath thickness and epidermal cell thickness was the largest, reaching 34.8% and 23.2% respectively. The increase of the number of vascular bundles in stem segment was not conducive to the improvement of the nodule folding strength(r=-0.945**, r=-0.927**), while the increase of the mean area of vascular bundles and phloem area was beneficial to the increase of the nodule folding strength(r=0.831*, r=0.799*, r=0.733*, r=0.786*). Diameter analysis showed that the number of vascular bundles had the largest direct effect on the strength of the stem folding, followed by the thickness of epidermal cells, and the largest area of vascular bundles, the thickness of vascular bundle sheath, phloem area and other indicators also had an indirect effect on the strength of stem folding through the number of vascular bundles. Among the tested varieties, the number of vascular bundles was less, the average area of vascular bundles and phloem area was larger, the stalk folding strength was higher, and the lodging resistance was better than other varieties.

    • ZENG Xu-hui, PENG Hong, JIANG Hou-liang, ZHANG Jie, WANG Bo

      2020,28(5):60-66, DOI: 10.13597/j.cnki.maize.science.20200510

      Abstract:

      In order to evaluate the yielding ability and stability, and adaptability of different maize varieties, as well as the discrimination and representativeness of test sites in maize regional trial, the GGEBiplotGUI package of free and open-source R language was used to analyze 18 varieties(including Zhengdan958 as the control) and 10 test sites in Huaibei, Jiangsu Province in 2018. The results showed that the 10 test sites were divided into three small"ecological zones", among which Fengxian, Tongshan, Pizhou and Shuyang were the first group, Huai'an, Suining and Suqian were the second group, Binhai, Gangbu farm of Lianyungang and Jingsetianhua of Huai'an were the third group. Ruiyou288, HT736, X1601 and Ly1666 had high yields, among which the yield of Ruiyou 288 was high and stable, and the yields of the other three weren't stable. Three test sites, Huai'an, Suining and Shuyang had good discrimination and representativeness. Gangbu farm of Lianyungang and Jingsetianhua of Huai'an had strong discrimination but poor representativeness. The test site of Suqian had strong representativeness but poor discrimination.

    • HU Cong-hui, SHI Wen-jun, LI Liang, SHA Ye, QIAN Chun-rong, QI Hua, MI Guo-hua

      2020,28(5):67-76, DOI: 10.13597/j.cnki.maize.science.20200511

      Abstract:

      In order to get high-yield, nitrogen-efficient maize cultivars so as to improve nitrogen use efficiency in Northeast China, a two-years experiment in three locations and two nitrogen application levels were conducted in Lishu of Jilin province, Tieling of Liaoning province and Harbin of Heilongjiang province in 2017 and 2018. Twenty maize cultivars were used in each of the three experimental sites each year, and their yield and yield components were analyzed. The results showed that, in Lishu, Liangyu918 and Demei 1 were double-efficient cultivars which showed high yield under both low and high nitrogen input in both years. Xianyu335 and Difeng 128 were high-yielding cultivars which got high yield only at high nitrogen input. In Tieling, double-efficient cultivars were Hongshuo899, Jinhua299, Shenyu 21 and Dika159. Xianyu335 was a high-yielding cultivar. In Harbin, Jingke728, Tiannong 9, Yucheng 1, Xianyu335 were double-efficient cultivars, and Deyu919 and Yinongyu 10 were high-yielding cultivars. Compared to the average yield level of all the tested cultivars, across the three locations, the use of double-efficient increased maize yield by 12.8% and 16.2% under high and low nitrogen input, respectively. The high-yielding cultivars increased maize yield by 6.4% under high nitrogen input. The double-efficient cultivars had more grains per ear. High-nitrogen efficient cultivars had more ears per area and grain numbers per ear only under high nitrogen input. Under low-nitrogen levels, low-nitrogen efficient cultivars had more grain numbers per ear only under low-nitrogen supply.

    • WANG Ya-nan, JIAN Jun-shuai, JIA Kai, BAI Lan-fang, WANG Rui, ZHANG Xiang-qian, WANG Yu-fen

      2020,28(5):77-85,92, DOI: 10.13597/j.cnki.maize.science.20200512

      Abstract:

      Thirty-four maize cultivars were used in a field experiment for this study. During silage harvest period of maize, the mechanical properties, variety differences and index correlation of different maize varieties were compared and analyzed after the investigation of field lodging rate, plant height, ear height, stalk diameter, rind penetration strength(RPS) and crushing strength(CS). All of these can provide a theoretical basis for screening silage maize varieties with strong lodging resistance and suitable mechanical harvesting properties. The results showed that both of the RPS and CS at the bottom of the stem gradually decrease with the increase of the internode; and this indicator has a significant positive correlation with plant height; stem breakage during silage harvesting was the key factor that would lead to maize lodging; Among all tested maize cultivars, 32D22, Xianyu1692, Dongdan606 and KXA4574 showed stronger comprehensive lodging-resistance.

    • SHENG De-chang, WANG Yuan-yuan, HUANG Shou-bing, TAO Hong-bin, WANG Pu

      2020,28(5):86-92, DOI: 10.13597/j.cnki.maize.science.20200513

      Abstract:

      Using heat-sensitive maize variety ZY 309 as the material, two high-temperature treatments were set up to study the effects of different days of high temperature on maize yield and panicle traits, material production and transport, and grain storage capacity. The results showed that HT1 had no significant effect on maize yield, but HT2 significantly reduced maize seed setting rate and yield. The plant height of plants was decreased under HT2, and the leaf area was HT2 > CK > HT1. The high-temperature stress at flowering stage significantly decreased the net photosynthetic rate of panicle leaves, but had no significant effect on chlorophyll content; HT2 decreased the number of kernels and the total dry matter weight, increased the dry matter content of stem, leaf and loquat leaves in the mature stage, and the total weight of dry matter in the plant was increased. The high-temperature stress increased the crude protein content, soluble sugar content and starch content. The results showed that under HT1 treatment, maize increased its translocation capacity to cope with high-temperature stress, while HT2 reduced the grain storage capacity by significantly reducing the number of kernels, which caused irreversible damage and affected maize source(leaf area) and flow(material transport and distribution).

    • XIAO Wan-xin, WANG Yan-bo, YE Yu-sheng, ZHAO Hai-yan, LIU Jing, SUI Yang-hui, WANG Yong-jun, JIA Yu-ying

      2020,28(5):93-101, DOI: 10.13597/j.cnki.maize.science.20200514

      Abstract:

      This study was conducted by using PVC pipe in the field with the split block design, which split plot was inbred lines, the split plot was water treatments from 2016 to 2017. The root morphology traits, root-to-shoot growth ratio, and yield were measured. Compared with CML58, the root angle of available brace roots of Huangzaosi was increased obviously, the negative response time to water stress of the number of root, root length, root surface area and other root traits of Huangzaosi was earlier than that of CML58, which distribution ratio of root length, root surface area and the number of root tips was higher at 40-90 cm soil layer after water stress. Root growth redundancy of Huangzaosi was less than that of CML58, especially 0-20 cm soil layer after R3 stage. The ratio of total root length to plant height and total root surface area to plant leaf area of Huangzaosi was higher than that of CML58 under different water treatments. However, the ratio of root dry weight to biomass and brace roots angle to leaf angle of Huangzaosi was lower than that of CML58. Compared with CML58, Huangzaosi could regulate the growth angle of available brace roots better under water stress, the matter transformation efficiency was enhanced by duly adjusting rootto-shoot growth from horizontal and vertical direction, maintaining the architecture and function of main distribution zone of the root, increasing root distribution ratio at deep soil layer and decreasing root growth redundancy.

    • LI Hong-yan, LI Lu-lu, WANG Yong-hong, ZHAO Ru-lang, ZHANG Wen-jie, MING Bo, WANG Ke-ru, XIE Rui-zhi, HOU Peng, ZHANG Wan-xu, LIU Wan-mao, XUE Jun, LI Shao-kun

      2020,28(5):102-109, DOI: 10.13597/j.cnki.maize.science.20200515

      Abstract:

      Eight cultivars with different growth stages and dehydration rates in Yinchuan, Ningxia(spring maize region) and Xinxiang, Henan(summer maize region) were used to study the dynamic difference of kernel moisture content and dehydration rate in the different parts of maize ear. We divided the maize ear into five parts vertically, then measured the kernel moisture content and calculated the kernel dehydration rate in different parts periodically. The results showed that during the middle and late stages, the kernel moisture content in the upper part of the ear was lower than that in the middle and lower parts. The differences of kernel moisture content in various parts of the ear were lower before physiological maturity than that after physiological maturity. The range of different parts of the kernel moisture content was less than 3% in test maize cultivars on 20 d before physiology maturity. The range at maturity was 0.6%-5.2%, and the maximum range was 6.2% after physiological maturity. The dehydration rate gradually decreased from the top to the bottom of the ear, and there were differences in different cultivars. The kernel dehydration rate in different parts of the ear was great in Xianyu335, Dika517 and Dika519. The range of kernel moisture content in different parts was negatively correlated with the dehydration rate of middle kernels and total ear.

    • DONG Wan-lin, CHENG Lu, SUN Zhi-gang, ZHANG Li-zhen, HU Qi, LI Shi-ji, HE Qi-jin, PAN Xue-biao

      2020,28(5):110-118, DOI: 10.13597/j.cnki.maize.science.20200516

      Abstract:

      In order to quantify the spatiotemporal change of summer maize yield and yield components and explore the change of the year of climate type, the data of multipoint field experiments with the same summer maize cultivar were analyzed in summer maize growing region in China from 2004 to 2013. The result showed that, summer maize yield of the regional average was 9 055 kg/ha; the seasonal difference of the yield was 1 635 kg/ha, the site difference of it was 4 258 kg/ha; the seasonal and site variation of it was 18.1% and 47.1%, respectively; 1 000-kernel weight of the regional average was 313 g with 13.1% seasonal variation and 27.8% spatial variation. Kernel number of the regional average was 479. Kernel number presented 18.0% seasonal variation and 38.7% spatial variation. Summer maize yield increased significantly with the increase of 1 000-kernel weight. The large fluctuation and spatiotemporal variation of summer maize yield were caused by kernel number decreasing significantly and the large spatiotemporal variation. In low yield sites, the change of climate factors significantly impacted yield and yield components of summer maize. In the mean yield sites, temperature and the days of maximum temperature above 33℃ influenced these significantly. And in the high yield sites, significantly affected by precipitation.

    • XU Xiao-hong, DU Yan, WANG Hong-jun, CHE Bao-yu, YANG Shuang, WANG Hong-li, SHU Kun-liang

      2020,28(5):119-123,130, DOI: 10.13597/j.cnki.maize.science.20200517

      Abstract:

      Taking Taobei District of Baicheng in the west of Jilin province as the research area. Nine indexes about the main body's approval factor and the agricultural sustainability factor were selected to establish the suitability evaluation system of dry land corn cultivation technology model. The data of nine indexes come from the measured data and the survey data, and the method of Projection Pursuit was used. The results of evaluation showed that among the four straw mulching modes, four straw mixing modes and two conventional modes adopted in the study area the "no tillage + straw rough crushing and returning to row mulching" was the most suitable model to be promoted and applicated in the study area. The main advantages of this model were the highest ratio of production to investment, the least labor, the lower operating cost and long-term straw mulching can improve soil nutrients and physical and chemical properties.

    • WU Wen-ming, CHEN Hong-jian, ZHANG Lin, CHEN Xiang, PENG Chen, JING Li-li, WANG Shi-li

      2020,28(5):124-130, DOI: 10.13597/j.cnki.maize.science.20200518

      Abstract:

      Field experiments were carried out to investigate the relationship between grain moisture content and effective accumulated temperature of different hybrids in the main production areas of the Huaibei Plain. Combining with meteorological data to determine the suitable planting and harvesting dates which suitable for the machining. The results showed that the earlier planting date, the higher the yield, and the yield of the LY9105 was significantly higher than that of the DK517, but the grain dehydration rate of the DK517 was faster than that of the LY9105. The effective accumulated temperatures required to 28% moisture content of the DK517 and LY9105 are 873.0℃ and 943.9℃, respectively, and the targeted 25% moisture content are 914.1℃ and 992.3℃, respectively. In order to ensure the mechanical grain harvest and high yield, when the middle maturing hybrid comparable to LY9105 are planted at June 5th, and the harvest date is about October 5th, 100% of the year can guarantee the machine grain harvesting. When the planting date postponed to June 15th, the early-maturing hybrids comparable to DK517 are planted, and the harvesting date around October 5th, 72.7%-90.9% of the year can guarantee the grain machine harvest. Therefore, in the Hubei plain, the reasonable combination of hybrids and planting date can achieve mechanical harvesting, high and stable grain yield.

    • LIU Fang-ming, DOU Jin-gang, GAO Yu-shan, SUN Yun-yun, HOU Zhong-hua, LIU Hui-tao

      2020,28(5):131-136, DOI: 10.13597/j.cnki.maize.science.20200519

      Abstract:

      The determination of maize varieties suitable for mechanical kernel harvest is one of the important contents for constructing the technical model of high yield and increasing efficiency of maize in the dry irrigation area in western areas of Jilin province. From 2018 to 2019 the maize cultivars suitable for mechanical kernel harvest test were carried out under drip irrigation in western regions of Jilin province. The harvest grain moisture content and yield for 38 maize cultivars were tested. According to grain moisture content and yield level, the two-way average method was used to make graphs for classifying cultivars. The results showed that 5 maize cultivars including Dika159, Fulai 77, Jinong108, Jinongda889 and Youdi919 suitable for mechanical kernel harvest under drip irrigation are preliminarily selected. According to the cultivars analysis on comprehensive characters, it is found that Jinongda889 was the best, followed by Dika159, both can be used for recommended cultivars for high yield and high efficiency cultivation under drip irrigation in western areas of Jilin province.

    • LÜ Tian-fang, XU Tian-jun, ZHAO Jiu-ran, WANG Rong-huan, LIU Yue-e, CAI Wan-tao, ZHANG Yong, LIU Xiu-zhi, CHEN Chuan-yong, WANG Yuan-dong, LIU Chun-ge

      2020,28(5):137-141, DOI: 10.13597/j.cnki.maize.science.20200520

      Abstract:

      In this experiment, Jingnongke828 (National registration 20190009) was used as the research material. Research on the mechanical grain yield quality of Jingnongke828 was carried out in Jing-Jin-Ji area, to provide technical support for the demonstration and promotion of the variety. The results showed that, Jingnongke828 was able to reach physiological maturity normally from September 21 to October 12 from June 1 to 20. The average growth period of Jingnongke828 was 107 d. The average moisture content of Jingnongke828 is 25.5% at 9-15 d after physiological maturity; the average broken rate, average impurity rate and grain loss rate of Jingnongke828 is 4.3%, 2.0% and 3.5%. The average yield of Jingnongke828 was 10 559.8 kg/ha, and the highest yield is 11 373.0 kg/ha at the Beili village, Dongshiduan, Xushui county, Hebei province. The yield of Jingnongke828 was negatively correlated with the field loss rate(r=-0.61**, n=22). There was a very significant positive correlation between the moisture content and the percentage of broken grains(r=0.80**, n=22), and a significant positive correlation between the moisture content and the percentage of impurities(r=0.45*, n=22), which indicated that the moisture content of grains was the main factor affecting the mechanical grain yield quality of maize.

    • YANG Yun-shan, GUO Xiao-xia, LIU Hui-fang, HOU Peng, LIU Guang-zhou, LIU Wan-mao, MING Bo, XIE Rui-zhi, WANG Ke-ru, LI Shao-kun

      2020,28(5):142-147, DOI: 10.13597/j.cnki.maize.science.20200521

      Abstract:

      The experiment was conducted in the field by setting a shading test throughout the whole growth period. The influence of shading on the grain moisture content of kernels at maturity was analyzed. The grain moisture content showed a same tendency, Denghai618 was the lowest, Xianyu335 was the second and Zhengdan958 was the highest under the treatment of CK, S1 and S2, respectively. Denghai618 was 4.36% higher than Xianyu335 under S3 treatment. The grain moisture content increased with increasing levels of shading, the grain moisture content of S1 (85% of natural light), S2(70% of natural light) and S3(50% of natural light) was 2.79%, 4.43% and 23.83% higher than that of CK(natural light), respectively. The weak light stress by shading delayed the maturity of maize, the maturity of S1, S2 and S3 were delayed by 4.0, 4.0 and 6.5 days compared with CK, which may be the reason for the increase of grain moisture content. It is suggested that selecting cultivars with earlier maturity and faster kernel dehydration rate will meet the requirement of grain moisture for mechanical grain harvesting in the areas where kernel dehydration rate was slowly caused by frequently rainy and lightless weather.

    • LIU Shuo-ran, YING Fei-yu, CUI Shuai, ZHONG Sheng-hao, LI Zhen-chao, ZHANG Xing-yu, CHEN Li-dong, WANG Yin, GAO Qiang

      2020,28(5):148-154, DOI: 10.13597/j.cnki.maize.science.20200522

      Abstract:

      The effects of nitrogen and sulfur interaction on plant growth and nutrient uptake in maize seedlings were studied by a pot experiment. The results showed that nitrogen application and sulfur application had an impact on the growth and nutrient uptake of maize seedlings, and interaction between the two was significant. The plant height, stem diameter, SPAD value, net photosynthetic rate, dry matter accumulation and nitrogen accumulation of N2 treatment were higher significantly than those of N0 treatment with different value of 48.7%, 30.0%, 28.3%, 18.5%, 47.4% and 285.3%, respectively. Furthermore, above parameter indexes of N1 treatment were lower than N2 treatment as well as higher than N0 treatment. Sulfur application significantly promoted the growth of maize seedlings, and showing interaction effect of nitrogen and sulfur significantly. Without nitrogen fertilization(N0), sulfur application significantly raised the dry matter accumulation of plant. Under low nitrogen condition(N1), maize growth and nitrogen uptake were promoted with sulfur application; Under high nitrogen condition(N2), the sulfur fertilization effect was similar to that of low nitrogen application. In conclusion, superior dry matter accumulation, the highest sulfur utilization and superior nitrogen utilization were observed in N2S1 treatment. Therefore, N2S1 fertilization is the most effective nitrogen and sulfur nutrition management measure for maize seedlings growth.

    • ZHAN Wen-jie, LIU Jian-zhao, LIANG Yao, YUAN Jing-chao, ZHANG Hong-xi, LIU Song-tao, CAI Hong-guang, REN Jun

      2020,28(5):155-161, DOI: 10.13597/j.cnki.maize.science.20200523

      Abstract:

      Using XY335 as test material, the agronomic measures were optimized. Four agricultural operation and funding models were tested:Local agronomic cultivation(CK), Optimize management mode 1(Opt-1), Optimize management mode 2(Opt-2), Optimize management mode 3(Opt-3). To compare and analyze the yield and composition factors, dry matter accumulation and distribution, nutrient absorption and utilization characteristics and photosynthetic characteristics of maize under different agronomic management modes. The results showed that the average yields of Opt-1, Opt-2, Opt-3 were 25.7%, 48.9%, 44.5% higher than the CK. The total dry weight of Opt-1, Opt-2, Opt-3 were 9.5%, 37.2%, 16.3% higher than the CK. Opt-2's nitrogen content is 300kg/ha, 33.3% higher than Opt-3. However, there was no significant difference in grain nutrient accumulation between opt-3 treatment and opt-2 treatment, and there was no significant difference between its fertilizer partial productivity and CK treatment. Under Opt-3 treatment, leaf area index(LAI) at flowering stage was higher and LAI decline rate after flowering was slowed down. Net photosynthetic rate and stomatal conductance were increased by 22.0% and 5.6%, respectively compared with CK. In addition, Opt-3 treatment increased the planting density to 7.0 million plants/ha, which further enhanced the photosynthetic performance of maize leaves.

    • CHEN Qiang, ZHANG Jin-long, LEI Shuai, LI Qiang, ZHANG Xiao-ming, CHEN Guo-hua

      2020,28(5):162-168, DOI: 10.13597/j.cnki.maize.science.20200524

      Abstract:

      The damage status of maize aphids on different maize varieties was recorded by 5-point sampling method under the natural susceptibility condition in the field. The aphid resistance of 21 varieties was identified by aphid-to-aphid ratio method, and the feasibility of aphid-to-aphid resistance of maize was analyzed by aphid-toaphid ratio in peak period. The results showed that there were significant differences in aphid resistance among different maize varieties. Guidan203, Qingqing601, Zhenhe978, Zhouyu913, Beiyu 10, Puyu 3, Shuijinyu 8, and Yunhe 2 were highly resistant varieties. The number of natural enemies of maize aphids was consistent with the population of maize aphids. The ratio of benefit to the harm of maize varieties to aphids was a power function. The benefitharm ratio decreased with the increase of aphid population ratio.

    • LI Xiang, WANG Huan-huan, GUO Qiu-cui, LI Xu, LI Xin-yu, ZHANG Hui-wen

      2020,28(5):169-175, DOI: 10.13597/j.cnki.maize.science.20200525

      Abstract:

      Corn stalk rot caused by Fusarium graminearum can lead to serious yield reduction of maize. Screening efficient antagonistic strains were particularly important for controlling corn stalk rot. Eight hundred and ten strains of bacteria were isolated from soil by dilution culture method. Antagonistic bacteria were screened by plate confrontation method, and their molecular identification was conducted through 16S rDNA sequence analysis. A total of 23 antagonistic bacteria were isolated, which accounted for 2.84% of the total bacteria isolated. The inhibition zone diameter was 10.12-27.56 mm. These bacteria were mainly distributed in three phyla:Firmicutes, Proteobacteria and Actinobacteria and five genera:Bacillus, Pseudomonas, Streptomyces, Acinetobacter and Arthrobacter. Among the five genera, Bacillus was the most abundant genus and had relatively strong antagonistic ability. Furthermore, Bacillus siamensis had the strongest antagonistic activity, which indicated that it had great potential for biocontrol and was worth further exploration. Twenty-three strains isolated from the experiment had good antagonistic activity against Fusarium graminearum and had potential application value in the prevention and control of corn stalk rot.

    • XU Zhi-peng, LI Hui-xia, LI Wen-hao, NI Chun-hui, LIU Yong-gang, XU Xue-fen

      2020,28(5):176-184, DOI: 10.13597/j.cnki.maize.science.20200526

      Abstract:

      The corn root systems and the rhizosphere soil samples were collected according to symptoms of dwarf and earlier withering plants to learn the damage of plant nematodes in the seed corn production areas of Zhangye city, Gansu Province in 2018, a population of cyst nematode was isolated. The pathogen was confirmed as Heterodera elachista by identification of morphological characteristics and molecular biology analysis. The pathogenicity test results showed that the symptoms such as shortness of the corn plants and yellowing of the leaves were caused by this nematode population using artificial inoculation. The effects on the hatching of the nematode in different temperatures and hatching solutions corn root exudates, corn root juice, and soil infusion were studied, and the survival of the newly hatched juveniles and the second-stage juveniles(J2) at different temperatures. The results showed that the suitable hatching temperature for the cyst nematode was 28℃. At 28℃, the survival time of J2 was 22 d; at 25℃, the survival time of J2 was 24 d; at 5℃, the survival time was more than 30 d, and the mortality of J2 was the lowest. Corn root exudates, soil infusion and 20 times corn root juice could obviously promote the hatching of the Heterodera elachista, while 5 times corn root juice and 4 mmol/L zinc chloride solution inhibited hatching.

    • YANG Zhi-wu, XU Ze-min, LI Qing, WANG Feng-shan

      2020,28(5):185-190, DOI: 10.13597/j.cnki.maize.science.20200527

      Abstract:

      The relationship between financing gap and the main production efficiency of maize planting scale was studied with CD production function model and Transcendental logarithmic production model based on 1805 field survey data of maize planting scale operators in Heilongjiang province. The results showed that whether CD production function model or Transcendental logarithmic production model, the financing gap has a significant negative impact on the average yield. The financing gap of large-scale corn farmers in Heilongjiang affects their normal production and operation. It is necessary for financial institutions to establish new financial services related to agricultural production and to solve the seasonal financing gap of large-scale operators.

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    • wangyinghua, Zhongfei Sheng, Shujie Qu, Aiguo Zhu, Wengang Li

      Abstract:

      The convective weather occurs frequently in maize growing season in the Huang-Huai-Hai plain, and maize lodging risk is greater. Spraying plant growth regulators at the jointing stage of maize is considered to be an ideal cultivation technique to reduce the maize lodging rate. In this experiment, Zhengdan 958, which was widely planted in the Huang-Huai-Hai plain, was used as the test material to study the effect of spraying EDAH on maize lodging resistance and photosynthetic capacity. The results of two years of research indicate that EDAH increased maize grain yield by an average of 11.34%, mainly due to the significant increase in the number of harvestable ears and thousand kernel weights of maize. EDAH can also reduce the plant height, ear height and center of gravity of the maize, and improve the quality of maize base internode, thereby reducing the maize lodging rate from 10.31% to 3.36%. EDAH can also increase the SPAD value and net photosynthetic rate of maize by increasing the light environment of the ear leaves position, thus ensuring the formation of maize grain yields. To sum up, the plant growth regulator treatment can improve the summer maize yields improving the lodging resistance of maize and the photosynthetic capacity of maize ear leaves.

      • 1
    • GAO Jia-qi, WANG Kun, Xu Mei-yan, BI Wen-wen, TAN Jing

      Abstract:

      The key to maize breeding is the developing of inbred lines. The pure lines can be quickly obtained and the breeding’s efficiency can be greatly improved by using haploid breeding technology. But the haploid inducing rate is normally low and the application of haploid technology to fresh corn has been less studied. Therefore, it’s of great significance to study the influence factors of the haploid inducing rates in fresh corn, which will accelerate the application of haploid technique and improve the breeding’s efficiency of fresh corn. In the study, different genotypes of fresh corn (including normal sweet corn, super sweet corn, sugary enhanced corn, and waxy corn ), a total of 15 materials as female and four different inducers as male were selected, the crosses were made during different pollination period in Jing Hong winter season and Kunming summer season respectively, and the induced haploid offspring were statistical analyzed, finally tried to reveal the influence of different genetic background, different inducer genes, different ecological conditions and different pollination period on haploid inducing rate. The main results were as followed: different genetic background, inducer genes, ecological conditions and pollination periods had important influence on the haploid induction, the haploid inducing efficiency in Kunming summer season was significantly higher than that of in Jing Hong winter season, pollination during early stage was significantly higher than that of in late stage, inducers 1 and 2 was significantly higher than that of inducers 3 and 4. Therefore, it can be concluded that the haploid inducing rate can be greatly increased by using inducers 1 and 2, making pollination during early stage in Kunming summer season for fresh corn breeding.

      • 1
    • Wang Hao

      Abstract:

      To explore the response of soil inorganic nitrogen and spring maize root system to the input of controlled release urea(CRU) in the arid area of southern Ningxia. In this research, the cultivar “Xianyu698” was applied as research material. Five nitrogen application regimes: No nitrogen was applied as the control(CK), Conventional urea(U) supply UR: 100% U, 1/3 U base application, 1/3 U flare opening period application, CRU1: 1/3 CRU+1/3 U base application, 1/3 U flare opening period application, CRU2: 2/3 CRU+1/3 U base application, CRU3: 100% CRU base application were set to analyze the effects of CRU on the spatial and temporal distribution of soil inorganic nitrogen and root growth distribution, nitrogen uptake efficiency and grain yield of maize. The results indicated that the content of soil nitrate nitrogen and ammonium nitrogen in CRU significantly increased at late stage of spring maize compared with UR. Additionally, CRU2 had the most obvious effect in CRU. UR and CRU have different effects on root system parameters in different periods. UR in the early stage is beneficial to root growth, while CRU after anthesis has a greater impact on root length and root weight density of 0-80 cm soil layer. The path analysis is further It shows that the change of corn root length and root weight density is one of the important reasons for increasing yield. CRU input significantly increased the nitrogen content of the plant and the grain yield during the whole growth period. Among them, 15 days after flowering, CRU increased grain nitrogen content compared with UR. The outstanding one is CRU2, which is not only the grain has high nitrogen content, but also high yield. CRU2 grain yield was 14.65 t/hm2, which was 32.70%, 5.78%, 1.52% and 5.17% higher than CK, UR, CRU1 and CRU3, respectively. Consequently, through 2/3 CRU+1/3 U basal application can effectively increase the nitrate and ammonium nitrogen content in topsoil, promote the growth and development of maize roots which ensure the supply and demand of nutrients during the growth period of maize, it is realized to high yield and high efficiency cultivation of spring maize.

      • 1
    • lanchang, wangshaojie

      Abstract:

      【Objective】In order to understand the effects of nitrogen regulation on nitrogen utilization and ammonia volatilization from maize farmland in black soil region of Northeast China,【Method】Field experiments were conducted in Lishu county of Jilin province in 2018 and 2019. Six treatments were set up: no nitrogen as control (N0), conventional nitrogen application (Nconv), optimized nitrogen application (Nopt), controlled-release nitrogen fertilizer application (Nctrl), organic fertilizer addition (FM) and straw returning (SR). The ammonia volatilization fluxes under different managements were determined in situ by venting method, and nitrogen use efficiency and nitrogen balance were calculated. 【Result】 The results showed thatcompared with the Nconv treatment, the nitrogen use efficiency was significantly increased by 14.1%, 15.6%, 24.2% and 27.1% in thetreatments Nopt, Nctrl, FM, and SR, respectively. Compared with N0, NConv, NCtrl, and SR, the NOPT and FM treatments significantly increased the total ammonia volatilization, accounting for 3.2% and 4.2% of the nitrogen fertilizer application rate, respectively. The estimated results of nitrogen balance showed that the Nopt reduced the apparent nitrogen losses by 46.2%and the nitrogen surplus by 30.1%.【Conclusion】The nitrogen use efficiency can be greatly improved while the yield is stable by regulating the amount, period and type of nitrogen fertilizer. The application of controlled-release nitrogen fertilizer can significantly reduce the loss of ammonia volatilization. Therefore, in this study area, the management of "controlled-release nitrogen fertilizer application + straw returning" is more conducive to increase maize yield and nitrogen efficiency, and reduce the risk of environmental pollution.

      • 1
    • LU Xinchu, ZHENG Yongzhao, CHEN Xu, HAN Xiaozeng, ZOU Wenxiu, YAN J un

      Abstract:

      Albic soil is one of the main agricultural soils in the northeast of China. The acid, sticky, thick, heavy were the main character of these soil that had detrimental effects on the crop yields. The physicochemical properties and maize yield were analysed under different biochar application rate and organic fertilizer for 2 consecutive years in present study. The tillage layer was shallow, organic matter content was low, the available nitrogen, phosphorus, potassium content, exchangeable hydrogen and exchangeable aluminum content was high, soil pH as low as 3.88, and yield of maize was 5866.7-8735.8 kg/hm2 of the C0 treatment due to long-term fertilizer application. The C1 treatment with 15000 kg/hm2 of biochar application was not a significant increase the yield compared with the C0. While the yield could be increased 6.6-31.3% in C3 treatment and OM treatment. The soil pH, content of soil organic matter, total N and available potassium could be increased with the increased biochar application rate. Therefore, the application of 30,000 kg/hm2 of biochar to ameliorate the Albic soil is most effective.

      • 1
    • yehaotian

      Abstract:

      Based on the carbon flux data over an agroecosystem in Jinzhou field station of Shenyang Atmospheric Environment Research Institute of China Meteorological Administration, the change of CO2 flux in the growing seasons of the maize farmland ecosystem was analyzed. The average nocturnal respiration rate was 0.17, 0.18, 0.15, 0.19 mgCO2·m2·s-1 and the average daytime net carbon exchange rate was -0.43, -0.43, -0.39, -0.39 mgCO2·m2·s-1 during the growing season in 2008?2011, the interannua variability was not significant. The 8-day accumulation of net carbon exchange was U-shaped and the maximum carbon absorption intensity was -81.6, -75.2, -64.8, -59.7 gC·m-2·8d-1. The CO2 flux changed significantly in different phenological stages, and the change was the largest from jointing stage to milk ripening stage. During the four years, the ecosystem showed carbon sink in the growing season, and the proportion of carbon consumed by respiration to fixed carbon in photosynthesis was not different. The cumulative carbon exchange capacity was -513.37, -489.86, -482.06, -398.67 gC·m-2, respectively. There was a linear correlation between the nocturnal ecosystem respiration and EVIs×Ws (EVIs and Ws are the functions of enhanced vegetation index and land surface water index on photosynthesis, respectively) (R2=0.73), and L-T equation (R2=0.39) was satisfied with land surface temperature. The results showed that the respiration model based on remote sensing data was effective in estimating ecosystem respiration (R2=0.92), which played an important role in carbon budget assessment of Maize Farmland Ecosystem in Northeast China.

      • 1
    • Guoxiaoxu, Yanghengshan, Taijicheng, Mariliang, Mengde

      Abstract:

      Abstract:In order to explore new ways of reducing nitrogen and increasing efficiency of spring maize,from 2018 to 2019,in the Inner Mongolia Horqin Agricultural Hi-tech Demonstration Park,using conventional topdressing urea as a control,studied the effect of shallow burial drip irrigation combined with reduced application of urea combined with UAN on root system,yield and benefit of spring maize.The result showed,Appropriate reduction of urea and application of UAN can promote corn root growth,enhance SOD and POD enzyme activities of root during silking and milking stages,reduce MDA content,slow down the senescence of the root system,conducive to the formation of yield in the later growth periods.The contents of ammonium nitrogen and nitrate nitrogen in each soil layer showed that CK(conventional topdressing urea) were significantly higher than that of urea reduction with UAN treatment,UAN could promote the absorption and utilization of soil nitrogen by roots.The yield of N2U treatment (reduction of urea by 25%,combined with UAN 75kg / hm2) were not significantly different from that of CK,but they were significantly higher than that of N1U treatment (reduction of urea by 51%,combined with UAN 75kg / hm2).N2U treatment has the highest economic benefits in two years,they were 15543.35 yuan / hm2 and 18088.13 yuan / hm2.Shallow buried drip irrigation technology facilitates field operations of urea reduction with UAN of maize,combined application of UAN and reduction of urea was an effective way to reduce nitrogen and increase efficiency of spring maize in the irrigation area of Xiliaohe Plain.

      • 1
    • YANG Chen, HE Kang-Lai, WANG Zhen-Ying

      Abstract:

      Abstract: Results showed that the holes of 1st generation was mainly in the middle portion of the corn stalks for 69.6%, the 2nd generation mainly in the lower portion for 41.2%, the distribution of overwintering larvae of the Asian corn borer were mainly in the middle portion and the lower portion for 40.6% and 36.6% in Qiqihar, respectively. The distribution of holes of 1st and 2nd generation was mainly in the middle portion of the stalk for 47.3% and 47.7%, the overwintering larvae was mainly in the lower portion for 63.2% at harvest, and in the lower portion increased to 69.2 % in December of 2018, in the root portion increased to 24.3% in April of 2019, respectively. The results showed that the distribution of holes caused by Asian corn borer in the 2nd generation was lower than that of holes in the 1st generation, the overwintering larvae of Asian corn borer mainly distributed in the middle and lower portion of the stalk and had a downward trend.

      • 1
    • Tang Ji-hua, Guo zhanyong, Xie Hui-ling, Chen Wei-cheng

      Abstract:

      In this paper, we propose that under the station of new seed law put into effect and the situation of agricultural supply side reform, as well as maize production season is facing a changing climate conditions and seed industry is facing severe pressure of competition in China, maize breeders and seed company manager should select a variety of hybrids to construct varieties group for meeting the market demand according to different ecological types, different environments and market demand, it can be resolve the potential risks of maize production and seed company owing to single or several variety, and provide support for usage of variety diversity and corn production.

      • 1
    • ZENG Zi-hao, YUAN Jing-chao, ZHANG Shui-mei, CHENG Song, ZHANG Chang, LIANG Yao, LIU Song-tao, REN Jun, LIU Jian-zhao, CAI Hong-guang

      Abstract:

      To provide theoretical basic for rational fertilization in black soil area of Jilin Province, two years stationary field experiment was carried out to study the yield, nitrogen absorption and utilization of maize under different fertilization methods. The result showed that yield, biomass and nitrogen uptake of maize with increasing application of nitrogen fertilizer, increased 121.97% ~ 177.88%, 95.08% ~ 127.77%, 206.18% ~ 295.46%, respectively. The biomass and nitrogen accumulation of both one-time base application of nitrogen fertilizer (N1) and multiple application of nitrogen fertilizer (N2) were fastest-growing from V12 to R1. Compared to N1, the dry matter accumulation of N2 increased 30.18% and the nitrogen accumulation of N2 increased 105.53%. The contribution rate of nitrogen accumulation of N2 was 68.13% ~75.00%, which was significantly higher than N1. Comprehensive two years, compared to N, the yield, dry matter and nitrogen accumulation of N2 increased 7.60%, 4.56% and 3.19%, respectively. Nitrogen utilization rate, physiological utilization rate, partial productivity and agronomic efficiency of N1 increased 6.13%, 10.22%, 3.83% and 12.58%, respectively. Therefore, it ensured the nitrogen supply of maize after flowing, improved the efficiency of nitrogen applicaiton and increased maize yield of N2.

      • 1
    • Wang Zhou, JIAO Yunfei, LI Qiang, GAO Hongjun, ZHANG Xiuzhi, ZHU Ping, PENG Chang

      Abstract:

      In view of the west of northeast plain region soil arable layer shallow, the plough, tight, and poor permeability change problem, to improve regional farmland soil structure, raise soil water storage ability to keep moisture, improve land productivity of farmland and farmers increase production, half arid areas in western jilin province has carried out subsoiling patterns on soil physical properties and the effects of maize yield research. Four treatments including no-tillage, subsoiling between planting rows, subsoiling on planting rows, and subsoiling between planting rows and on planting rows were set up in the experiment. The results showed that, compared with no-tillage, subsoiling could significantly reduce the soil bulk density in 0-40cm soil layer, and subsoiling between planting rows and on planting rows had the best effect, with soil bulk density decreasing by 0.17g /cm3 on average. The total porosity and water content of the soil also showed similar trends, among which subsoiling between planting rows, on planting rows, and on planting rows increased by 8.3%, 9.6%, 15.5%, 9.78%, 10.83%, and 14.65%, respectively, compared with the control no-tillage. Moreover, subsoiling was more obvious than the no-tillage soil to move down, 17.5cm and 5-15cm, respectively, in two years. Moreover, after subsoiling the economic yield, components and economic benefits of corn also showed a trend of synchronous increase. Combined with economic benefits and yield/investment ratio, deep tillage on planting lines was a better mode of deep tillage in western corn fields of Jilin province.

      • 1
    • YU Jiao-jiao, SHEN Tao, ZHANG Xiao-dong, WANG Ya-ni

      Abstract:

      Histone acetylation modification as key epigenetic factors in regulating the expression of genes in multiple aspects of plant growth, development and plant response to abiotic or biotic stresses. A better understanding of how histone acetylation modification fine-tunes its physiological and developmental processes to fluctuating N concentrations in the soil is needed to improve N use efficiency in maize production. N limitation generally inhibited ear growth. The ear was 16.2%-19.7% shorter from 1 to 2 weeks after silking (OAS; TAS) under N limitation compared to that with suf?cient N supply. During the same time, the dry weight (DW) of the N de?cient ear was 35.6%-44.4% less than that of the N suf?cient ear. The N concentration abruptly dropped in the maize ear at TAS, with an approximately 13.3% decrease. qRT-PCR amplification were conducted to analyze maize seedling stage and key period of maize ear developmnet, how nitrogen deficiency affects the expression level of histone acetylases (GCN5 and HAT-B) and deacetylases (HD1b, HD2, HDA101, HDA102, HDA106 and HDA108). During the seedling stage, all HTAs and HDACs were dierentially regulated in response to low nitrogen treatment for 8 days, except HAT-B, which did not respond to nitrogen deficiency. the expression of HDA102 and HDA108 decreased in response to low nitrogen treatment for 12 h relative to the control, while the expression of HAT-B, HDA101, HD1b and HD2 increased after 36 h of nitrogen deficiency treatment. In addition, the expression of HD1b was also significantly up-regulated after 4 d of nitrogen deficiency. After low nitrogen treatment for 2 days, the expression of HDA106 and HDA108 were down-regulated. At silking stage, except HAT-B, HD1b and HD2 genes, all genes had a higher expression levels under nitrogen deficiency. At one week before silking, the expression of HDA101 and HDA106 were significantly up-regulated due to nitrogen deficiency. However, the expression of HD1b and HD2 were significantly down-regulated at two week after silking. Instead, the expression of HDA101 was up-regulated in nitrogen-deficient ear at two week after silking. In addition, the expression of HDA106 decreased in response to low nitrogen at one week after silking. The regular expression of histone acetylases and deacetylases under nitrogen deficiency indicated that an important role of histone acetylation modification in maize’s adaptation to nitrogen deficiency stresse during growth and development.

      • 1
    • Wang Zhi-wei, Wu Fei, Sun Wei-wei, Song You-hong

      Abstract:

      Maize silk's dynamic extension is important in determining silking and subsequent fertlization. However, there are few studies on the dynamic characteristics of silk extension thus far, so it is necessary to describe the dynamic characteristics of silk extension. In this experiment, the relationship between the silk extension at the bottom, middle and top of and the female cob for two main cultivars i.e. ZhongDan909 (ZD909) and AnNong591 (AN591), was studied. The results showed that the bottom and middle silk of ZD909 and AN591 were development, silking and abscission earlier than upper silk. When there were 18 and 19 visible leaves (12 and 13 fully expanded leaves), and the cob reaches about 10% of its final length. When there were 19 and 20 visible leaves (18 and 20 fully expanded leaves), and the cob reaches about 50% of its final length, bottom and middle silk start silking, and bottom, middle and top silk develop to about 70%, 60%, 30% of the final length, respectively. The length of silk development before and after the silking stage accounted for more than 65% of the total length, which is the key period for silk to emerge from the bract. When all the leaves were fully expanded and the cob develops to about 80% of the final length, the bottom and middle silk were completely developed and abscission. The above-mentioned relationship between the two varieties showed consistency. Then, the Logistic model was used to fit the dynamic extension of silk and cob, and the development process of silk and cob was quantified. In conclusion, silk and cob extension characteristics were accurately described in this paper, and the results can be applied to the simulation of silk and cob extension development.

      • 1
    • FENG Guang, ZHAO Hong-xu, WANG xiao-jie, YAO Yong-xiang, CHEN Zeng-qi, WANG Xiu-feng, YU Bing, CAO Zu-bo

      Abstract:

      Five second cycle inbred lines M5861, M5862, M5864, M5866 and M5867 were bred based on Zheng58×PH6WC as the tested inbred lines, crossed with 4 different heterosis groups test lines(PH4CV, Dan3140,Chang7-2 and Jing92) by incomplete diallel crossing(NCⅡ), it analyzed the main agronomic characters and yield combining ability effect. The results showed that: GCA effect value of different characters of tested lines M5861and M5866 were higher, of SCA effect value of four hybrids M5861×PH4CV, M5864×Dan3140, M5866×PH4CV and M5866×Dan3140 were higher, three hybrids M5861×PH4CV, M5861×Dan3140 and M5866×PH4CV were higher on total combining ability effect which expression was consistent with actual planting, it explained the total combining ability effect could more accurately reflect the comprehensive performance of hybrids.The study showed that second cycle inbred lines of Zheng58×PH6WC had a better heterosis effect with the pioneer paternal inbred lines.

      • 1
    • ZOU Cheng-lin, ZHAI Rui-ning, QIN Jie, TAN Hua, HUANG Ai-hua, WEI Xin-xing, HUANG Kai-jian, MO Run-xiu, HUANG Yan-fen

      Abstract:

      In order to investigatethe effects of drought stress using different concentration PEG ongerminationcharacteristics of hard kernel maize seeds, and screen anoptimumvalue of PEG for drought stress simulation on maize. Three hard kernel maize varieties in Guangxi were used as test materials, they were drought stressed in cultural solutions under different concentrations of polyethylene glycol (PEG): 0%, 5%, 10%, 15%, 20%, 25%, 30% were compared in the experiment, 12 characters of the average germination speed, germination rate,? length of radical and plumule, and translocation rate of storage materials, etc., were analyzed. The results showed that different degree of drought stress had significant effects on seed germination characteristics of all varieties, the days of the first and peak germination and average germination speed was reduced with the concentration increase of PEG. The germination energy, germination percentage and germination index showed a decreasing tendency, they weremarkedly affected by soaking with 15% PEG, and were decreased significantly by soaking with 25% PEG. With the increase of PEG concentration, the growth inhibition of maize radical and plumule was more obvious, the inhibition was most obvious at 20% concentration, and reached its limit at 25% concentration; PEG could inhibit the movement of storage materials in maize seed, dry weight of radical and plumule, storage reserve transformation rate of maize decreased evidently with the increase of PEG concentration, and reached its limit at 25% concentration. It seemed that the increase of PEG concentration can delay the germination time of maize seeds, reduce the germination ability, and limit the growth and development of radical and germ, results in reducing storage material transfer rate of maize. 12 indexes mentioned can be used to evaluate the drought resistance of maize seeds. When simulating mild, moderate and sever drought stress, PEG concentration was suggested be set to 5% or 10%, 15% or 20%, 25%.

      • 1
    • Li Mu, Lu Shi, Gao Ting-Ting, Zheng Shu-Bo, Zhou De-Long, Wang Min, Li Chen-Yan, Lu Ming

      Abstract:

      Sixty inbred lines in northeast maize breeding were selected as test materials. The correlation between seed storability and growth period was analyzed for the first time through high-temperature and high-humidity methods and field trials. The results showed that the maize inbred lines of different genotypes had obvious differences in traits such as germination potential, germination rate, emergence stage, tasseling stage, loose powder stage, spinning stage, and maturity stage. The germination potential of seeds after aging treatment showed a significant negative correlation with the traits of each growth period (-0.253~-0.321), maximum correlation with maturity (-0.321); the germination rate showed a very significant negative correlation with the traits of each growth period (-0.376~-0.429), maximum correlation with maturity (-0.429), indicating that the maize inbred lines with relatively short growth periods may have aging resistance It is superior to the maize inbred line with longer growth period, which provides a valuable reference for the breeding, genetic improvement and mechanism analysis of maize varieties suitable for storage at suitable maturity in the future.

      • 1
    • Wangjiaxu, 姜文野, 赵彬, 满艳苹, 张旷野, 刁玉霖, 朱康宁

      Abstract:

      In view of the increase of planting density and promotion of dense planting maize varieties, the effects of different patterns on dry matter accumulation and distribution of maize yield formation were explored,which may lay a theoretical foundation for high-yield cultivation of spring maize. In this study, maize hybrid line Liangyu 99 was used as the material from 2018 to 2019. We designed general settings planting (row spacing) (as CK) and three non-uniform planting patterns, two row of big ridge, partial ridge-narrow/wide row and 2-0 culture, respectively, to find out the effects of different planting patterns on the photosynthesis parameters, dry matter accumulation,transshipment and distribution of population, and the yield of maize. The results of the two years indicated that the net photosynthetic rate of population, transpiration rate, and stomatal conductance increased by1.39% ~ 36.55%, 2.78% ~ 18.98% and 5.88% ~ 45.75% in three non-uniform planting patterns compared with CK.We also found that the dry matter accumulation of population increased by 3.36% ~ 13.89%, at the same time, the dry matter transport rate of leaves, stems and leaf sheaths increased by 1.92% ~ 23.08%, 5.48% ~ 34.31% and 19.56% ~ 53.39%, respectively. We then noticed that the contribution rate of grain yield increased by 3.50% ~ 62.50%. It was worth noting that the three non-uniform planting patterns significantly increased the grain yield of maize, and the yield increased by 14.16% ~ 30.34% in 2018, and 4.19% ~ 9.28% in 2019. The reason for the large increase in yield of 2018 was the decline in the empty bar rate (In 2018, the empty bar rate decreased by 1.79% ~ 13.29%, and in 2019 the rate was 0.05% ~ 0.43%).This result further indicated that non-uniform planting patterns in drought years showed a greater yield increase advantage. Among the three types of non-uniform planting patterns, the two row of big ridge had the highest grain yield in two years, reached 6264.68 kg?hm-2 (2018) and 12449.40 kg?hm-2 (2019).

      • 1
    • YAO QiLun, Fang Ping

      Abstract:

      There are close relationships among plant height, lodging resistance and planting density of maize, as dwarf is a goal trait of maize to gain a high yield. In this study, using a dwarf maize mutant Hii-015, its wild type W015 and 16 inbred lines, we analyzed phenotype characteristics, hereditary model and the combining ability of main traits to explore the utilization of maize dwarf genes. The results indicated that the dwarf of the mutant Hii-015 resulted from shorten internodes. Excluding the dwarf trait, the economic traits of the mutant Hii-015 exhibited no differences when compared with those of the wild type W015. The dwarf trait of the mutant Hii-015, which is controlled by a single recessive gene, can inherit. For the general combining ability of Hii-015, the most negative effects were found in plant height, ear height, internode length and the number of internodes, while positive effects were recorded in kernel numbers per row, 100-kernel weight and yield per plant. It can be concluded that the mutant Hii-015 is a excellent line in dwarf maize breeding.

      • 1
    • Sa-ru-la

      Abstract:

      In order to improve the alkalized soil, maize straw was returned to the field in 2018 on the basis of the alkalized soil in the West Liaohe Plain Irrigation Area, and the experiments of applying Zhongnong Lukang maturing agent and Renyuan straw maturing agent, mixing sand and mixing furfural residue were carried out. The yield of spring maize, root characteristics of maize and soil available nutrients and enzyme activities were measured by conventional testing methods. The effects of different improvement measures on alkaline soil characteristics and maize growth were studied. The results showed that compared with the conventional mixed sand treatment in saline-alkali soil, the combined application of Zhongnonglukang and Renyuan straw maturing agent could significantly increase the dry weight of maize roots by 37.41% and 31.94%, increase SOD and POD activities of roots and decrease MDA content of roots, and significantly increase the content of soil alkali-hydrolyzed nitrogen at silking stage by 21.32% and 39.18% respectively. The content of soil available phosphorus increased by 121.89% with the application of Renyuan straw decomposing agent, 171.28% of ammonium nitrogen was increased by Zhongnong lvkang straw decomposition agent;The combined application of Zhongnong Lukang significantly increased soil cellulase activity, and the combined application of Zhongnong Lukang straw maturing agent significantly increased maize yield by 17.65%. Corn straw returning to the field in alkaline soil combined with Zhongnong Lukang straw ripening agent had better effect.

      • 1
    • SHI Hai-chun

      Abstract:

      43 maize hybrid combinations and their parents were used as materials. A simulate drought stress experiment was conducted using 20% PEG-6000 solution to study the heterosis performance of drought resistance at the seedling stage of Maize, and to investigate the correlation with its parents. The results were as follows: 12 combinations showed positive super-parent advantage and 18 combinations showed positive mid-parent advantage. 13 combinations showed positive control heterosis compared with Zhongdan808. The drought resistance and control heterosis of the maize hybrid combination at the seedling stage were consistent with the maternal, male, high-value parent, low-value parent and the mean of the parents, while none reached a significant level, indicating that there was no significant correlation between drought resistance and control heterosis of maize hybrids at seedling stage and their parents. The drought resistance of hybrids cannot be predicted simply based on the drought resistance of their parents in the practices of breeding. These results provide a reference for maize drought resistance breeding.

      • 1
    • wangjunqiang, zhaoxiumei

      Abstract:

      In this study, we evaluate the resistance to Fusarium ear rot of 40 backbone maize inbred lines in Heilongjiang Province between 2018 and 2019, so as to reasonable make use of these inbred lines in breeding and breed new maize hybrids with good characteristics. The results showed that average resitance to Fusarium graminearum or Fusarium verticilloides of the inbred lines were different. The resistance to both strains of 83J03 and Suixi617 was highest, indicating that they should be utilized in breeding of ear rot resistance, while the resitance to ear rot of HB1124 and N5 was lowest, indicating that they should not be used in areas with a high incidence of ear rot. This study provided material basis and theoretical support for breeding of resistance to Fusarium ear rot and genetic improvement.

      • 1
    • 刘迪发

      Abstract:

      With nineteen maize standard varieties as experimental material, referring to the assignment in the guide, analysising on difference of the expression of characteristics of maize standard varieties for DUS testing in Hainan by coefficient of coincidence(COC). The results showed that, Huang C, Huangzaosi's performance in Hainan were quite different from the assignment in the guide, the standard varieties of measurement types of QN can't be used,testing in Hainan. U8112, Dan340, Ji833, Ye107, Zao49, Yedan4's performance in Hainan were basically consistent with the assignment in the guide, the corresponding standard varieties of measurement types of QN can consider to be used,testing in Hainan. However, U8112 and Ye107 should not be used as the standard varieties for the character of silking stage.The expression of characteristics of the length of the main shaft of the lowest lateral branch and leaf width were quite different from the assignment in the guide, considering to replace the corresponding standard varieties, testing in Hainan; the expression of characteristics such as pollinating period,silking stage,the number of the primary lateral branches of the tassel,the length of lateral branch of the tassel,plant height (inbred line),ear length(inbred line),ear diameter (inbred line),ear row number (inbred line) and other were basically consistent with the assignment in the guide, will give priority to the adoption of corresponding standard varieties,testing in Hainan.However,Ye 478 should not be used as a standard variety for the character of pollination period, Fe 7922 should not be used as a standard variety for the character of plant height (inbred line).

      • 1
    • weipengcheng

      Abstract:

      The main meteorological factors influencing the stem traits of Spring Maize in Guizhou Province and their influence degree were explored, which provided scientific basis for the layout and high-yield cultivation regulation of Guizhou spring maize. Four maize varieties Xianyu 1171, xinzhongyu 801, Jinyu 838 and Xingyu 3 were used as test materials in five maize sub regions of Guizhou Province. The relationship between main meteorological factors and maize stalk traits was studied by means of grey correlation degree and correlation analysis. The results showed that the effective accumulated temperature had the greatest influence on the bending strength and cellulose content. When the effective accumulated temperature was 1293.82 ℃·D and 1470.10℃·D, the maximum values of the bending strength and cellulose were 296.64N and 21.92%, respectively; the sunshine hours had the greatest influence on the length and flattening ratio of internode. When the sunshine hours were 638.55h and 752.14h, the internode length and flattening ratio reached the maximum 50 cm and 0. 092 respectively. The daily average temperature and precipitation had the greatest impact on the puncture intensity and cross-sectional area respectively. When the average temperature was 19.23℃·D, the puncture intensity reached the minimum value, which was 32.53N. When the precipitation was 819.01mm, the cross-sectional area reached the minimum value, which was 4.03cm2.

      • 1
    • zengzhi

      Abstract:

      This paper uses the 2004-2018 panel data of 19 major corn producing regions and provinces in my country, and uses the double difference method to analyze the impact of the price-compensation separation policy on farmers" income from growing grains, and conducts a robustness test. The study found that the price-compensation separation policy restrained the growth of farmers’ income from growing grain in the three northeastern provinces and Inner Mongolia. The study found that the production effect mechanism inhibited the increase in farmers’ income from growing grain, and the industrial structure and market linkage mechanism promoted farmers’ income from growing grain. . And the conclusions of this article have good robustness. Improve the production subsidy mechanism, increase urban financial support to rural and professional farmers, provide farmers with a variety of skills training, increase public finances to tilt toward "agriculture, rural areas, and farmers". The agricultural industry structure must focus on the growth of agricultural product revenue and efficiency. The entry point to promote the growth of farmers’ income from growing grain.

      • 1
    • SI Wei-na, WANG Heng-sheng, DONG Jin-lei, LI Ling-ling, CHEN Jin-wu, CHENG Bei-jiu, GU Long-jiang

      Abstract:

      Growth-regulating factors (GRF) is an important type of transcription factors, which were specifically identified in plant kingdom. Several homologs of GRF genes have been demonstrated to be key regulators that could affect the development of plant height in model plants, such as Oryza sativa and Arabidopsis thaliana. However, if there were ZmGRF genes that were involved in the transcriptional regulation network of plant height in maize remains elusive. In the present study, weighted gene co-expression network analysis (WGCNA) was used to explore the potential key hub ZmGRF genes via previously published high-throughput RNA-seq dataset. A total of nine candidate ZmGRF genes exhibited significant co-expression mode with functionally characterized genes in maize. Moreover, 8 out of 9 candidate gene could form robust gene pairs within maize or between maize and rice genomes via microsynteny analysis. The ratio of Ka to Ks for each gene pair indicated that all ZmGRF genes were undergone stringent purifying selection, indicating the conversation of molecular function of ZmGFR genes in maize. Finally, ZmGRF genes showed clearly diverse expression profiles in different maize lines or developmental stages. The present study could provide a modest comprehensive analysis of ZmGRF genes in maize and may help characterizing its molecular function in regulation of plant height in future.

      • 1
    • ZHANG Qi-ming, SHI Hai-chun, YU Xue-jie, YANG Shu, ZHAO Chang-yun, XU Xiu-lan, KE Yong-pei

      Abstract:

      In order to dig up genes (ORFs) related to CMS-C sterility in maize, The sequences of mitochondrial genome of four materials, sterile line K932S and K169S, maintainer line K169 and restorer line K932R, were comparatively analyzed by using next-generation sequencing technology. The results showed that the mitochondrial genome length of sterile cytoplasm K932S, K169S and K932R were 739676bp, 739723bp and 739765bp, respectively; and that of normal cytoplasm K169 was 569617bp; 33 protein coding genes ,15-16 tRNA genes and 3-4 rRNA genes were annotated. There were 19 and 10 repetitive sequences longer than 100bp in the sterile cytoplasmic and normal cytoplasmic genomes, respectively, and repetitive sequences shorter than 100bp presented little differences; Among the three sterile cytoplasmic genomes , the homologous fragments are arranged in the same order, with a collinearity of 99 %, however, three reversed fragments were found in the normal cytoplasm, and the arrangement order also changed, with a similarity of 95%. Among the four genomes, 145-151 ORFs were found, there were 13 differential genes (ORFs) between K169S and K169, but only 1 of that was extracted between K932S and K932R, 8 unique ORFs was discovered in K169S mitochondrial genome. In summary, the mitochondrial genome size of maize CMS-C is obviously larger than that of the normal cytoplasm,

      • 1
    • zhaoqiang, ChenZeHui

      Abstract:

      T32 and Qi319 were used as parents to construct 118 F2:3 families. Ear related traits of different families were evaluated, and genotype of each plants were identified by using high-density SNP markers. QTL mapping was conducted for 5 Ear-Related traits (ear length, ear diameter, ear row number, kernel number per row, ear barren tip) by using composite interval mapping method in IciMapping4.2 software. A total of 16 QTLs were detected, wherein 3, 2, 4, 2 and 5 QTLs were detected to be related with ear length, ear diameter, ear row number, kernel number per row and ear barren tip, respectively. A single QTL could explain phenotypic variation of 2.92% ~ 13.53%. Based on the public database, 5 suspected key candidate genes related with spike related traits were screened by using bioinformatics analysis, which including genes of Zm00001d031906, Zm00001d02721, Zm00001d002762, Zm00001d002768. These results would provided much more genetic locus for the genetic improvement of ear traits in corn, and some reliable candidate regions for the exploration of candidate genes' function.

      • 1
    • Liu Dan, Liu Mei-yan, Sun Jian, Zhang Xian-bao, Pan Zi-wang, Zhang Jian

      Abstract:

      Spermidine (Spd) is important plant growth regulators that play vital roles in the environmental stress tolerance of crops. In this study, the effects of Spd against chilling stress was investigated in maize seedlings. Low temperature treatment inhibited seedling growth, while the production of superoxide radical (O2.-) and hydrogen peroxide(H2O2) and the level of membrane lipid peroxidation was increased, and the content of chlorophyll was decreased in chilled maize leaves. However, leaves spraying with Spd markedly alleviated chilling stress-induced growth inhibition,

      • 1
    • SUN Shu-feng, ZHANG Xi-hua, SHI Zhen-sheng

      Abstract:

      A system research on the test content and methods of popcorn quality,for which the problems of technical requirements and quality inspection of the popcorn industry in China.The result shows that the greater error in the measured value,when the specification reaches 1000mL or more, the measured value tends to be stable;Corn flake volume testing,the smaller the size, the greater the error.The measured value tends to be stable when the specifications of the conical measuring cylinder reach 500mL or more,while there are still large differences until the specifications of the straight measuring cylinder reach 2000mL.For the measuring of unit weight,the relevant standard of corn "GB 1353-2018" stipulates that measuring unit weight with grain unit weight device. This test shows that the results of straight measuring cylinder and grain unit weight device for measuring the unit weight of popcorn has little difference.Using a straight measuring cylinder to measure the unit weight of popcorn can not only ensure its accuracy, but also measurement of a small amount of samples that cannot be measured by the grain unit weight device.After the introduction of unit weight indicators, the comparison between different index units at home and abroad can be achieved through the relationship between the expansion ratio and CC / g.

      • 1
    • zhangye, 张艳, 邢跃先, wangziyu, wenjing, haodongyun, lishijie

      Abstract:

      A recessive ligamentless mutant was found in the self-crossing population of a maize inbred line Huangzao4 in 2008, and then a homozygous and stable hereditary ligamentless inbred line (Huangzao4lg) was gained through continual self-crossing. In order to explore and make full use of the elite genetic resources of maize ligamentless trait, and to improve population production of maize, five ligamentless maize inbred lines (JiV203 lg, K10 lg, JiV088 lg, JiV152 lg and Zhe461 lg) were obtained by back-crossing the inbred lines(JiV203, K10, JiV088, JiV152 and Zhe461) as recurrent parents to Huangzao4lg as donor parent, respectively. That is, 5 near isogenic lines of maize ligamentless trait were obtained, too. In this study, 5 pairs of near-isogenic lines were used as the mapping population, which was genotyped by Affymetrix 5H90K SNP chip, and then the gene of the ligamentless trait was mapped. In addition, candidate genes were primarily analyzed according to B73 reference sequence. The results showed that the maize ligamentless gene was located in the physical region of about1.12 Mb on the 2.01-2.02 bins, and there are 64 genes totally in this interval, of which 28 genes encoded functional proteins and 38 genes encoded putative proteins and unknown proteins,.

      • 1
    • GAO Hong-jun

      Abstract:

      The effects of combined straw returning and applying nitrogen fertilizer on yield of spring maize, accumulation of inorganic nitrogen in soil profile, nitrogen balance and nitrogen use efficiency were studied in a field experiment for eight years. The results showed that t the optimum nitrogen application rates for 2012-2019 were 202.7, 193.7, 182.2, 171.2, 163.6, 156.1, 150.7 and 150.5 kg/hm2 respectively, according to the linear regression equation. Both apparent nitrogen loss and residual mineral nitrogen increased significantly with the increase of nitrogen application rate, and there was a significant positive correlation between them and nitrogen application rate. For applying nitrogen amounts of 100kg/hm2 , the residual mineral N and the apparent loss of N increased by 9.09-10.34 and 5.89-7.34 kg/hm2 respectively. When the nitrogen application rate exceeded 150 kg/hm2, there was no significant difference in nitrogen uptake, but the apparent loss of N and residual mineral N in soil was significant among different treatments. With the increase of N application rate, N use efficiency increased at first and then decreased. When N application rate reached 150 kg/hm2, N use efficiency reached the highest (75.2% and 92.3%). In the range of 210-330 kg/hm2 nitrogen application, the residual inorganic nitrogen increased significantly, which resulted in the accumulation of inorganic nitrogen in deep soil (60-100cm).

      • 1
    • lirui, 杨恒山, 薛明强

      Abstract:

      In order to explore effects of optimized nitrogen application on the greenhouse gas emissions in spring maize fields under the shallow drip irrigation in the Xiliaohe Plain, characteristics of CO2, N2O and CH4 emission during the growth period of the constant nitrogen topdressing (T1) and optimized nitrogen topdressing (T2: 70% constant nitrogen topdressing) under shallow drip irrigation were determined using method of static dark box-gas chromatography and adopting conventional irrigation with conventional constant nitrogen topdressing as a control (CK) in the Agricultural High-tech Demonstration Park of Horqin District, Tongliao City, Inner Mongolia in 2019. The results showed that there was no significant difference in maize yield between T1 and T2 treatments under shallow drip irrigation, both of which were significantly higher than CK (P<0.05). Compared with the traditional irrigation under the same nitrogen application, the N2O emission of shallow drip irrigation increased by 11.78% and the CH4 uptake was reduced by 34.78%, but there was no significant difference in CO2 emissions during the growth period of maize; compared with T1, the CO2 and N2O emissions of T2 reduced by 13.15% and 20.27% respectively, but there was no significant difference in CH4 absorption under the shallow drip irrigation. Under the same nitrogen application, the shallow drip irrigation reduces the intensity of greenhouse gas emission (P<0.05) compared with traditional irrigation, and the intensity of greenhouse gas emission of T2 decreases by 10.46% compared with that of T1; there was no significant difference in comprehensive warming potential between shallow buried drip irrigation and traditional irrigation, both of which were significantly higher than that of T2 under the shallow drip irrigation (P<0.05); there was also no significant difference in net ecosystem economic budget between T1 and T2 under shallow drip irrigation, both of which were significantly higher than that of CK (P<0.05). In general, compared with traditional irrigation, the shallow drip irrigation increases N2O emissions and reduces CH4 absorption under the same nitrogen application; the treatment of T2 reduces greenhouse gas emission intensity and comprehensive warming potential, and ensure higher maize yield and net ecosystem economic budget, which is a water and nitrogen management model for maize in the Xiliaohe Plain that combines high yield, high efficiency and ecology.

      • 1
    • 崔文芳, 陈静, 鲁富宽, 秦德志, 王利平

      Abstract:

      【Objectives】For plain irrigation area of Inner Mongolia soil quality decline limit the core issue of spring maize nitrogen efficiency, to further improve the efficiency of nitrogen spring maize population as the core goal, under the condition of biochar combined with the reduction of nitrogen, nitrogen efficient maize nitrogen efficiency, at the same time, through the biological carbon and nitrogen reduction regulation, research to promote the efficiency of nitrogen utilization rate and reduce nitrogen. 【Methods】Split zone test design was adopted for the test. Nitrogen fertilizer was the main zone, varieties were the secondary zone, and the main treatment was: C0 (CK, pure N 20 kg/mu), C1 (200 kg/mu biochar pure N + 20 kg/mu), C2 (200 kg/mu biochar pure N + 17 kg/mu), the C3 (biochar 200 kg/mu pure N + 14 kg/mu), C4 (200 kg/mu biochar pure N + 11 kg/mu), deputy processing for varieties of nitrogen efficiency and inefficiency, zheng 958 respectively (lh-zd) and jade first 508 (XY), respectively, in the big stage, spinning stage, filling stage, the ratooning buds, la ripe stage, determination of sampling fresh dry weight of each organ, The samples were used to determine nitrogen content to calculate nitrogen accumulation, absorption efficiency, utilization efficiency and nitrogen efficiency. 【Results】The dry matter accumulation, nitrogen accumulation capacity and nitrogen efficiency of biochar were all outstanding in the treatment of 200kg/ mu and pure N 11 kg/ mu, while the yield of biochar was the highest in the treatment of 200kg/ mu and pure N 14 kg/ mu, which was significantly higher than that of biochar in the treatment of 200kg/ mu and pure N 11 kg/ mu. Therefore, when biochar is applied in combination with nitrogen fertilizer, it is recommended that the appropriate amount of nitrogen fertilizer be pure N 14 kg/ mu or pure N 11 kg/ mu. When 200kg/ mu of biochar was applied in combination with pure N 11 kg/ mu, the dry matter accumulation capacity, nitrogen accumulation capacity, nitrogen efficiency and yield of zhengdan 958 were all better than those of xianyu 508, and the difference was significant. 【Conclusions】In Inner Mongolia plain irrigated area, under the condition of biochar and nitrogen fertilizer reduction, 200kg/ mu of biochar applied in mu and pure N 14 kg/ mu or pure N 11 kg/ mu could achieve 30%-45% nitrogen saving. Nitrogen efficiency of nitrogen efficient maize varieties increased by 52.78-93.33%, which could better play the nitrogen absorption capacity and nitrogen utilization capacity of nitrogen efficient varieties, which was conducive to achieving both high yield and high efficiency.

      • 1
    • Xie Yan-bo, Tan Xi-Chang, Xing Zhen-juan, Xia Wei, Li Cong-cong, Long Li-kun, Liu Na, Li Fei-wu

      Abstract:

      To study the tolerance of transgenic corn ZZM030 developed by China Seed Group Co., Ltd. to target herbicides glufosinate, glyphosate and four other non-target herbicides, atrazine, nicosulfuron, quizalofop-p-ethyl and sethoxydim. The target trait effectiveness and tolerance to non-target herbicides of this transgenic corn line were evaluated. Using farmland experiments, the plots were randomly arranged in groups, and the transgenic corn ZZM030 and the corresponding non-transgenic control Xiang 249 were sprayed with different amounts of glyphosate, glufosinate, and non-target herbicides. Investigate and record the seedling rate, plant height, and symptoms of phytotoxicity at 14 and 28 days. ZZM030 showed no phytotoxicity when spraying the middle dose and 2 times the amount of glufosinate. After spraying 4 times the medium dose of glufosinate, a slight phytotoxicity was found within 1 week, and the toxic damage disappeared after 4 weeks of application One week after spraying glyphosate, slight phytotoxicity occurred at 1 times, 2 times and 4 times the amount, and the phytotoxicity had disappeared after 2 weeks of application. Spraying different doses of glufosinate and glyphosate had no significant effect on the subsequent growth and major agronomic indexes of transgenic corn plants. There was no significant difference in seedling rate and plant height between different treatments. After spraying the non-target herbicides atrazine and nicosulfuron, ZZM030 did not produce the same phytotoxicity as the control after spraying atrazine and nicosulfuron, and there was no significant difference in plant height and seedling rate; and After spraying quizalofop-p-ethyl and sethoxydim, ZZM030 corn and control corn dwarfed severely, with a phytotoxicity grade of 4-5. The difference between the plant height and the treatment without spraying herbicide was significant. GM corn ZZ030 has good tolerance to glufosinate and glyphosate, ZZM030 corn has good tolerance to other herbicides atrazine and nicosulfuron, but it cannot tolerate corn sensitive The herbicides quizalofop-p-ethyl and sethoxydim. This study provides data support for the environmental safety assessment of ZZM030 corn.

      • 1
    • 王晨光, 赵美娟, peiwendong, 王国兴, 张宏军, 雷格丽, zhangrenhe

      Abstract:

      Reasonable application of nitrogen is an important way to improve the yield and quality of maize. To explore the effect of nitrogen application on grain yield, nitrogen use efficiency and feed quality of spring maize, and to provide basis for high-quality, high-yield and efficient cultivation of forage maize in spring sowing area of Northern Shaanxi. From 2017 to 2018, the field experiment was carried out with shaanke 9 as the material. The effects of different nitrogen fertilizer ratels (0, 90, 180, 270 and 360 kg/hm2) on the leaf area index, yield, feed quality and nitrogen utilization rate of maize. The results showed that nitrogen application significantly increased leaf area index, SPAD value and biomass. Nitrogen application increased maize yield by 64.4%, compared to N0. Nitrogen use efficiency increased first and then decreased with the increase of nitrogen application, and the increase of grain yield and nitrogen use efficiency was the largest under 268 kg/hm2 treatment. The maximum crude protein, starch and fat content of the N270 treatment increased by 2.4%, 13.7%, and 22.5% respectively, compared with N0. The NDF and ADF content of the N270 treatment increased by20.4% and 18.1% respectively, compared with N0. The crude protein and IVDMD of the N270 treatment increased by 22.5% and 17.6% respectively, compared with N0. It can be concluded that proper application of nitrogen fertilizer can improve the quality of corn population, increase the yield and nitrogen utilization rate, and improve the feeding value. Therefore, 268 kg/hm2 is recommended as the suitable nitrogen fertilizer for grain and forage maize production in the North Shaanxi irrigation area.

      • 1
    • Zhang Meiwei, Qu Junfeng, Zhang Panpan, Li Chuan, Zhao Xia, Niu Jun, Huang Lu, Chen Jinglun, Yu Ting, Liu Jingbao, Qiao Jiangfang

      Abstract:

      In order to study the effects of nitrogen fertilizer reduction on grain yield and dry matter accumulation of summer maize in different plant densities, a two-factor randomized block test design was conducted with Zhengdan 1002, which analyzed the plant morphological characteristics, grain yield, nitrogen utilization efficiency (NUE) and dry matter accumulation of summer maize. The results showed that, higher panting density and nitrogen application both increased plant height and spike position, but nitrogen fertilizer reduction (N2,N3,N4) had no significant effects on plant morphological characteristics, compared with normal fertilizer application (N1). D2 increased summer maize yield by 24.74%, significantly. And N2 declined yield of summer maize in this planting density. While the treatments of N3 and N4 had no significant influence on yield of summer maize both in D1 and D2 planting densities. D2 significantly increased dry matter accumulation of silking and maturation stages, and amount of dry matter after anthesis, while it decreased contribution proportion of post-anthesis dry matter to grain. The influences of N2, N3 and N4 treatments had no significant different with N1 on dry matter accumulation characteristics. In additionally, treatments of N2,N3 and N4 significantly increased nitrogen partial factor productivity by 16.00%~22.90% under two planting densities, while the nitrogen agronomy efficiency only obtained significant higher increased by 16.32% in the treatment of D2N4. In conclusion, summer maize could achieve high yield and high efficiency aims with 75000 plant/hm2 planning density and nitrogen fertilizer reduction by 20% (180 kg/hm2) combined application with organic fertilizer.

      • 1
    • KANG Cai-rui, XIE Jun-hong, LI Ling-ling, WANG Jin-bin, WANG Jia-nan, GUO Xi-jun, PENG Zheng-kai, Setor kwami Fudjoe, WANG Lin-lin

      Abstract:

      To maintain the sustainable improvement of maize yield and explore reasonable soil amendments. The effects of soil amendments on chlorophyll content(SPAD), photosynthetic characteristics, leaf area index, dry matter accumulation and yield under full film double ridge were studied relied on the positioning test set up in 2012 at the loess plateau rainfed farming area. There were five treatments: CF, chemical nitrogen fertilizer ; SC, chemical nitrogen fertilizer + organic fertilizer ; SM, organic fertilizer; MS, maize straw and NA, no nitrogen fertilizer. The results showed that the photosynthetic characteristics of maize were significantly enhanced by CF and SC, and the photosynthesis rate, transpiration rate and stomatal conductance of CF and SC were higher than those of other treatments in 2018-2019. All four soil amendment treatments increased the chlorophyll content and leaf area index of maize leaves. Treatments CF, SC, SM and MS increased the chlorophyll content and leaf area index by 74.6% and 80.0%, 64.5% and 74.0%, 18.9% and 28.9%, 12.9% and 25.8% compared to NA, respectively. In each growth period, dry matter accumulation under CF and SC treatment was significantly higher than that under NA treatment, but there was no significant difference between CF and SC treatment. All soil amendment treatments increased maize yield, with CF and SC most effective inincreasing yield. Treatments CF and SC increased yield and biomass by 148.7% and 118.4%, 119.1% and 105.0% compared to NA respectively, but there was no significant difference between CF and SC. In conclusion, chemical nitrogen fertilizer and chemical nitrogen fertilizer + organic fertilizer under the same N input level can improve photosynthesis by increasing leaf chlorophyll content and leaf area index, thus increasing maize yield, and in order to make the yield of maize sustainable, the suitable soil amendment of plastic film fully mulched ridge-furrow planting maize is chemical nitrogen fertilizer + organic fertilizer.

      • 1
    • YI HONG MEI, 张云龙

      Abstract:

      Seed purity is one of the core indicators of seed quality. Molecular markers have a good application prospect in seed purity identification because they are not limited by environment and season, and have a good discrimination ability. In this study, a combination of eight pairs of primer was selected from the industry standards suitable for purity assessment which had high heterozygosity and variety discrimination ability could identify more than 90% of approved varieties, and 96% of approved varieties have more than four heterozygous loci. SSRs and plant inspection were used to compare their ability to assess seed purity, 38 maize samples collected from national seed market were both tested by field planting and SSR purity. An average rate of 0.6% of inbred seedlings and 1.8% of off-types was detected by 8 SSR markers combination, and compared with the average rate of 1.4% for inbred seedlings and 0.6% for off-types in field planting identification. The purity values detected by the two methods had good correlation. The result of field inspection was consistent with SSR for identifying off-types and typical individuals, and SSR could accurately distinguish weak seedlings and diseased plants that were difficult to identify in the field. Significant separation of genotypes and phenotypes were observed in 7 samples with grade 3-5 of uniformity detected by SSR markers. Atypical seedlings caused by poor uniformity are difficult to identify in variety purity assessment both for SSR and field inspection.

      • 1
    • SUN Xuan, JI Yu-long, ZHANG Ru-yang, WANG Ji-dong, WANG Xia-qing, SONG-Wei, ZHAO Jiu-ran

      Abstract:

      In this experiment, Huang gai group inbred lines Jing2416, Jing92 and 213 improved inbred lines were used as experimental materials, and Jing464, Jing724, JingMC01 were used as testers to combine 645 hybrid combinations by NCII hybrid design method, The analysis of the combining ability and genetic parameters of kernel water content at harvest were carried out. The results showed that 68 inbred lines such as Jing2416J92-049, Jing2416J92 -074, Jing2416J92-101 were excellent than high-value parent in general combining ability. 177 hybrid combinations such as Jing2416J92-192×Jing464, Jing2416J92-210×Jing724, Jing2416J92-009×JingMC01 were excellent than high-value parent in special combining ability. Based on GCA and SCA, 57 excellent hybrid combinations such as Jing2416J92-192×Jing464, Jing2416J92-210×Jing724, Jing2416J92-200×JingMC01 were selected. According to the analysis of genetic parameters, the generalized heritability of kernel water content at harvest was 73.70%, and the narrow heritability was 65.82%, so this trait should be selected in the early generation. This study provided important guiding significance for the selection of excellent inbred lines from Huang gai group, hybrid combinations for mechanized harvesting of grain, and improved breeding efficiency.

      • 1
    • 刘方明, 孙云云, Wu Haiyan

      Abstract:

      In recent years, atrazine as a widely used herbicide with the increase of time, area and quantity has caused great pressure on the environment, food safety and human health. Therefore, it is of great practical significance to isolate and screen efficient functional strains that can degrade atrazine. In this study, a bacterial strain (W24) capable of utilizing atrazine as sole nitrogen source for growth was isolated from the soil of maize fields by enrichment culture. The isolate was identified as Paenarthrobacter sp. according to its biochemical characterization and 16S rRNA sequence analysis. When the substrate concentration was 100 mg/L, the degradation rate of atrazine was above 40% under the suitable temperature (20℃~35℃) and pH 6~9. The degradation rate reached 94.2% at the optimum temperature (30℃) and pH 7 for 72 h. The degradation rate of atrazine still reached 40.4% while the concentration of atrazine was 500 mg/L. The results of bioremediation showed that the degradation rate of the strain was 83.5% after incubation for 35 d while the concentration of atrazine in contaminated soil was 50 mg/kg. The strain W24 showed good potential for bioremediation of atrazine-contaminated soil.

      • 1
    • XING Zhen-juan, DONG Li-ming, LONG Li-kun, LIU Na, XIA Wei, XIE Yan-bo, LI Cong-cong, LI Fei-wu

      Abstract:

      Sequence analysis of 23 transgenic corn events showed that CaMV35s promoter, NOS terminator, Cry1Ab/Ac gene, and Pat gene covered 21 events, except DAS40278-9 and BLVA430101. In this study a series of experiments, including primer combination screening, reaction system optimization, sensitivity test, and applicability test were conducted. Consequently A five-plex fluorescent PCR system and a duplex fluorescent PCR system were established based on five common elements and two event-specific sequences respectively. This assay can greatly improve the detective throughput to screen genetically modified ingredients of the crops, in which the detection sensitivity can reach 0.05%. These two multiplex fluorescent PCR detection systems established in this study is characterized by strong specificity, high sensitivity, and good stability. which providing a more efficient technical means for the safety supervision and identification of genetically modified crops.

      • 1
    • wangcong, Maqingmei, Guoxinmei, Zhaomeiai, Songxiyun, Peiyuhe

      Abstract:

      In order to assist the lodging resistance breeding of maize stems and understand the genetic characteristics of lodging resistance related characters of maize stems, six generations (P1, P2, B1, B2, F1, F2) of reciprocal crosses of K12 and A7110 were analyzed by major gene-polygene mixed inheritance model . The results showed that the optimal model of stem diameter orthogonal combination was D-1 model (one major gene and additive-dominant polygene), and the optimal model of stem diameter reciprocal cross combination was E-1 model (two major genes with additive-dominance-epistatic effects plus polygenes with additive-dominance effects). The most suitable model of thrust resistance combination was C model (additive-dominant epistatic polygenes). The polygenic heritability of backcross generation was 6.22% and 19.94%, respectively, and the polygenic heritability of backcross generation was 68.81% and 52.78% in reverse cross .In the process of maize breeding, according to the characters mainly controlled by polygenic inheritance, the method of recurrent selection in the generation with high heritability can enrich the target genes, which is conducive to improving the breeding efficiency.

      • 1
    • Xu He

      Abstract:

      The 2016 corn purchasing and storage system reform pushed the corn price policy to a new stage. An important sign is the marketization of corn prices, which ended the long-term dependence of corn prices on policies. Since the reform of the purchasing and storage system was implemented, has the corn production situation in Jilin Province changed significantly due to the drop in corn prices? How liquid is the corn market? Has the operating rate and profitability of processing enterprises improved? The development of the corn industry under policy changes is worthy of further exploration. Through the analysis of this research, it is found that the overall corn sown area and yield in Jilin Province remain stable. The corn sown area and yield are relatively stable before and after the reform of the purchasing and storage system in the dominant corn production area, while the non-dominant production area has achieved a reduction in the corn sown area. A certain effect has been achieved, but there has been a phenomenon of multiple cropping. The circulation of corn has increased, but the circulation cost has increased. The fall in corn prices has activated the vitality of downstream corn processing companies and increased their operating rates. The companies turned losses into profits but their profitability methods have not been fundamentally changed. Maize processing enterprises in the province still focus on primary corn processed products, and their deep processing capacity is insufficient. In this regard, this study puts forward reasonable suggestions to promote the sustainable development of the corn industry in view of the shortcomings in the current development of the corn industry in Jilin Province.

      • 1
    • 赵逍遥, 张倩倩, 杨子怡, 刘美玉, 赵佳丽, 张金玥, 曹志艳, 刘宁, 董金皋

      Abstract:

      Setosphaeria turcica is an important pathogenic fungus in corn. Metabolites can provide important information for revealing the growth and development of pathogenic fungi and their pathogenic mechanisms. In this study, UPLC-MC was used to analyze the metabolome of S. turcica, and the extraction and detection conditions were optimized by orthogonal experiments. The results showed that the extraction condition was 80% methanol and ultrasonic extraction at 4 °C for 30 min, and the total ion chromatogram detected by UPLC-Triple TOF/MS had good peak shape and uniform distribution. 12,323 features in were obtained, and the number of compounds identified in positive ion mode is more than that in negative ion mode. Compounds with the relative standard deviation less than 20% accounted for more than 89.607%. The compounds related to lipid metabolism, amino acid metabolism and nucleotide metabolism, and heterocyclic compounds such as furan, can be identified and used for untargeted metabolomics studies of S. turcica.

      • 1
    • dongwenfeng, liangjingang, lixiaying, liupengcheng, wanghaoqian, zhangxudong, chenziyan, zhangxiujie

      Abstract:

      Genetically modified maize (Zea mays L.) C0010.2.2 was developed by Beijing DaBeiNong Biotechnology Co., Ltd. through Agrobacterium-mediated transformation which transformed epsps and pat gene to maize DBN567 characterized by resistance to glyphosate and glufosinate. The purpose of this study is to develop the qualitative detection method of genetically modified maize C0010.2.2. A series of specific PCR primers were designed on the right and left of the foreign gene inserted binding site, and a qualitative detection method for genetically modified herbicide-tolerent maize C0010.2.2 was established according to primer screening, specificity testing, sensitivity testing, primer concentration testing and annealing temperatures testing. The method was verified that has a good specificity and repeatability with the limit of detection (LOD) and sensitivity 0.1% by 8 external laboratories.

      • 1
    • LIU Fang-ming, DOU Jin-gang, GAO Yu-shan, SUN Yun-yun, HOU Zhong-hua, LIU Hui-tao

      Abstract:

      The determination of maize varieties suitable for mechanical kernel harvest is one of the important contents for constructing the technical model of high yield and increasing efficiency of maize in the dry irrigation area in western areas of Jilin province.. From 2018 to 2019 the maize cultivars suitable for mechanical kernel harvest test were carried out under drip irrigation in western areas of Jilin province. The harvest grain moisture content and yield for 38 maize cultivars were tested. According to grain moisture content and yield level, the two-way average method was used to make graphs for classifying cultivars. The results showed that 5 maize cultivars including DiKa 159, FuLai 77, JiNong 108, JiNongDa 889 and YouDi 919 suitable for mechanical kernel harvest under drip irrigation are preliminary selected. According to the cultivars analysis on comprehensive characters, JiNongDa 889 are much superior followed by DiKa 159 were founded, which can be used for recommended cultivars for high yield and high efficiency cultivation under drip irrigation in western areas of Jilin province.

      • 1
    • LIU Xiao-dan, 徐国良, 才 卓

      Abstract:

      This paper briefly introduces the National corn yield contest in America in 2019. This paper studies the results of the competition, analyzes the distribution area of the winners in the United States, the selection of seed brands and information, and then analyzes the reasons for the high yield of corn, so as to put forward the enlightenment and suggestions of the high yield competition of corn in the United States for China's corn production.

      • 1
    • Qing Liu, Yang Liu, Yang Hu, Yexin Nan, Jie Liu, Xiangguo Liu, Dongyun Hao, Jia Guo, Yuejia Yin

      Abstract:

      Rapid screening of the transgenic events by visual phenotype analysis can improve the efficiency of transformation and gene function verification. In this study, a new method of screening transgenic maize was established. We constructed a new plant expression vector pcambia3300-DsRed by using the specific expression promoter LTP2 of callus and aleurone layer and the visual red fluorescent protein coding gene DsRed. After the infection of maize HiII immature embryos by Agrobacterium mediated method, the red callus was induced, and identified as positive transgenic event by PCR. The visual screening method made tissue culture screening more effectively and reduced the screening time. That the positive red seeds and negative white seeds were visible in T0 generation improved the efficiency of transformation while reducing the molecular identification cost of the transgenic events.

      • 1
    • WEN Jingru, KE Yongpei, YU Xuejie, REN Shangxiang, QUBI Wuhe, XIA Wei, SHI Haichun

      Abstract:

      45 maize hybrid combinations as research materials and 20% PEG-6000 solution were used to simulate drought stress at germination and seedling stages, of which 7 indicators such as germination rate and germinability were investigated at germination stage, and 9 indicators such as plant height and root-shoot ratio were investigated at seedling stage. Principal component analysis and membership function were used to analyze the drought resistance performance and explore the comprehensive drought resistance at the germination stage and seedling stage. The results have showed that the test combinations can be divided into 4 categories according to the resistance at germination stage, including, 2 test combinations belong to strong drought resistance type such as Ruiyu 617, 16 belong to drought resistance type such as Zhenghong006, 23 belong to medium drought resistance type such as Zhenghong 507, and 4 belong to drought sensitivity type such as ZH719; According to the drought resistance at seedling stage, the test combinations can be divided into 3 categories, including, 9 belong to drought resistance type such as ZH733, 34 belong to medium drought resistance type such as Zhenghong 412, and 2 belong to drought sensitivity type such as ZH606; According to the comprehensive drought resistance at germination and seedling period, the test combinations can be divided into 3 categories: drought resistance, medium drought resistance and drought sensitivity, including,14 belong to drought resistance type such as Ruiyu 617, 28 test combinations belong to medium drought resistance type such as Zhenghong 613, and 3 belong to drought sensitivity type such as ZH719. The analysis has concluded that it is of more practical guiding significance to evaluate the drought resistance of the maize hybrid combination at germination stage and seedling stage at the same time, which is beneficial to the selection of suitable sowing conditions and drought resistance management at seedling stage specifically.

      • 1
    • wuhaiyan

      Abstract:

      Straw-returning is an important agricultural method to improve soil fertility and achieve waste utilization. The straw-returning method and microbial decomposing inoculums would affect the straw decomposition rate, and soil nutrients and maize growth. In this study, three straw-returning methods and two microbial decomposing inoculums treatments were established. And two control treatments were established. One is with straw return but without microbial inoculum, and the other one is without straw return or microbial inoculum). The straw decomposition rate, soil nutrient content, maize biomass and yield of different treatments were measured after maize harvest. The results showed that the straw decomposition rate in rotary tillage and deep tillage were higher than in moldboard plowing. Deep tillage could significant increase deep layer soil (0~60 cm) nutrient content and maize yield compared with rotary tillage and moldboard plowing. Microbial inoculum application could significantly increase straw decomposition rate in moldboard plowing and rotary tillage. And microbial inoculum could increase maize biomass in deep tillage. All results indicated that microbial decomposing inoculum could promote straw decomposition and maize growth, but the application effect was different in different straw-returning methods.

      • 1
    • SUN Bao-long, WANG Yong-jun, YAO Dan, LUO Yang, LV Yan-jie

      Abstract:

      To study the effects of long-term different tillage measures on soil respiration and carbon and nitrogen changes in maize fields in the black of Northeast China, is an important issue to protect black land and ensure the sustainable development of national food security. In this study, the soil respiration rate of conventional rotary tillage(CT), high stubble row to row subsoiling-reduced tillage(RT), no-tillage(NT) and deep ploughing(PT) were compared by in-situ method on the basis of 37a different tillage system. The relationship between soil temperature and moisture, the change characteristics of soil total carbon and inorganic nitrogen, microbial carbon and nitrogen, microbial activity and root biomass were analyzed. The results showed: Under the condition of long-term cultivation, the soil respiration in the field during the growth period of spring maize presented a mono-peak dynamic change, and reached the maximum at the flowering period of maize. The average respiration rate in the growing season was RT>NT>CT>PT. There was a significant exponential relationship between soil temperature and soil respiration rate under different tillage treatments, and the soil temperature at 10cm could explain 45.2%-67.8% of soil respiration rate variation, and the variation range of Q10 is 2.1-5.3; After long-term cultivation, the carbon content of NT and RT in 0-20cm soil was significantly higher than that of other treatments, and the inorganic nitrogen content in different soil layers was significantly higher than that of CT and PT. Compared with other treatments, RT treatment has higher microbial activity and microbial carbon content in 0-20cm soil, while the root biomass is the lowest level of all tillage methods. RT treatment improves the responsiveness of soil respiration to temperature. Long-term conservation tillage RT and NT treatment can effectively increase the total carbon and nitrogen content of farmland upper soil and improve farmland soil quality. It is of great significance to promote conservation tillage as a better management measure.

      • 1
    • LV Tian-fang, XU Tian-jun, ZHAO Jiu-ran, WANG Rong-huan, LIU Yue-e, CAI Wan-tao, ZHANG Yong, LIU Xiu-zhi, CHEN Chuan-yong, WANG Yuan-dong, LIU Chun-ge

      Abstract:

      Mechanical grain harvesting has become an inevitable trend in the development of corn production in China. In this experiment, Jingnongke828 (National registration 20190009) was used as the research material. The research on the mechanical grain yield quality of Jingnongke828 was carried out in Jing-Jin-Ji area, in order to provide technical support for the demonstration and promotion of the variety. The results showed that: (1) Jingnongke828 was able to reach physiological maturity normally from September 21 to October 12 from June 1 to 20. The average growth period of Jingnongke828 was 107 d. (2) the average moisture content of Jingnongke828 is 25.5% at 9-15 d after physiological maturity; the average broken rate, average impurity rate and grain loss rate of Jingnongke828 is 4.3%, 2.0% and 3.5%. (3) The average yield of Jingnongke828 was 10559.8 kg hm-2, the highest yield is 11373.0 kg hm-2.at the Bei li village, Dong shi duan, Xushui county, Hebei province. (4) The yield of Jingnongke828 was negatively correlated with the field loss rate (r=-0.61**, n=22). There was a very significant positive correlation between the moisture content and the percentage of broken grains (r=0.80**, n=22), and a significant positive correlation between the moisture content and the percentage of impurities (r=0.45*, n=22), which indicated that the moisture content of grains was the main factor affecting the mechanical grain yield quality of maize. It can be seen that the Jingnongke828 can reach mature normally from June 1 to 20, and the broken rate and impurity rate are lower than the national standard when grain mechanical harvesting, so the effect of harvesting seeds by machine is good.

      • 1
    • YANG Zhi-wu, XuZemin, LI Qing

      Abstract:

      This paper studies the relationship between financing gap and the main production efficiency of maize planting scale with CD production function model and Transcendental logarithmic production model based on 1805 field survey data of maize planting scale operators in Heilongjiang Province. The results show that whether CD production function model or Transcendental logarithmic production model, the financing gap has a significant negative impact on the average yield. The financing gap of large-scale corn farmers in Heilongjiang affects their normal production and operation. It is necessary for financial institutions to establish new financial services related to agricultural production and to solve the seasonal financing gap of large-scale operators.

      • 1
    • LI Min, GOU Fang qi, TAN Xiao ting

      Abstract:

      Using the tracked field survey data of corn producers in Cainiu town, Tieling city, Liaoning province in 2018 and 2019, the paper analyzed the adoption and economic effect of high yield technology of spring corn strip cultivation and close planting, technical efficiency was evaluated by stochastic frontier production function model method(SFA).The result is as follow: Those households with large production scale such as big farming household and cooperation were more likely to adopt the high yield technology .The households which were highly educated and whose agricultural income accounting for a large number of the total income were prone to adopt the high yield technology . The proportion of ordinary households adopting technology was low. The high yield technology of spring corn strip cultivation and close planting has significantly improved the economic benefit and technical efficiency of corn production. Compared with normal years, the high yield technology of spring maize strip tillage and close planting can play the advantages of improving economic benefits and technical efficiency in disaster years. Therefore, the government should intensify the propaganda of this technology, improve farmers" professional quality, encourage a large scale production, and increase technical subsidies to improve the adoption of the high yield technology of spring maize strip tillage and close planting.

      • 1
    • Zhai Juan, Xue Jun, Zhang Yuanmeng, Zhang Guoqiang, Shen Dongping, Wang Qun, Liu Chaowei, Li Shaokun

      Abstract:

      In order to clarify the effect of nitrogen application rate on the lodging resistance of densely planted maize stalks under the conditions of water and fertilizer integration and nitrogen fertilizer application, in 2019, nine nitrogen fertilizer levels were set up in Qitai, Xinjiang and Tongliao, Inner Mongolia to investigate the maize stalk breaking resistance, plant morphology, basal internode puncture strength and dry matter accumulation under different nitrogen application rates, and establish the relationship between nitrogen application rate and these indicators. The results showed that in a certain range of nitrogen application, with the increase of nitrogen application, the resistance to break, RPS and DWUL of maize stalk increased gradually. When nitrogen application reached a certain amount, the resistance to break, RPS and DWUL of maize stalk basal internode did not increase. The plant height, ear position height and ear position coefficient also increased with the increase of nitrogen application. Correlation analysis showed that the stem breaking resistance was negatively correlated with plant height, ear height and ear coefficient, and positively correlated with RPS and DWUL of basal internode. The results show that under the condition of water and fertilizer integration and nitrogen fertilizer application, increasing nitrogen application can improve the mechanical strength and the lodging resistance of maize stalk by increasing the dry matter accumulation in maize stalk.

      • 1
    • WANG Qun, XUE Jun, ZHANG Guo-qiang, WANG Feng, CHEN Jiang-lu, XIE Rui-zhi, MING Bo, HOU Peng, WANG Ke-ru, LI Shao-kun

      Abstract:

      In order to clarify the effect of irrigation on the stalk lodging resistance of close planting maize under the conditions of drip irrigation under plastic film, two years experiments on the interaction between irrigation amount and planting density were tested, and the changes with the irrigation amount in maize stalks breaking force, plant height, basal internodes morphology and mechanical strength were studied under different planting densities. The results showed that the lodging resistance of stalks decreased with the increase of planting density. The effect of the change of drip irrigation amount under different densities on the stalk lodging resistance is not completely consistent. At density of 7.5 ′104 plants ha-1, stalk breaking force of 480 mm irrigation is higher than 360 mm, continue to increase the irrigation to 600 mm, the stalk breaking force decreased. At the density from 9.0 to 10.5 ′104 plants ha-1, with the increase of irrigation amount, the stalk breaking force is increasing. At the density of 12 to 13.5 ′104 plants ha-1, there were no significant differences among each irrigation treatments above 480 mm. Therefore, after the increase in planting density, the appropriate increase in irrigation amount (480-540 mm) can improve the material accumulation of basal internodes and stalk diameter, and enhance the stalk mechanical strength; while increasing the irrigation amount continue, the effect of lodging resistance of stalk is not significant. Therefore, under the condition of mulch drip irrigation, the reasonable select of irrigation amount is important in stalk lodging resistance.

      • 1
    • 陈  琦, 段  云, 徐永伟, 陈 莉, 沈海龙, 刘 迪, 范志业, 侯艳红, 黄建荣, 李世民

      Abstract:

      The developmental duration, survival rate, reproduction and age-stage life table of M. separata reared feeding on wheat and maize were carried out under laboratory conditions of 15℃-25℃ (average18℃), RH 70% and a photo period of 12 L:12 D. The results showed that, compared with those fed on wheat, the developmental duration and the pre-oviposition period of M. separata fed on maize were significantly shortened 1.168±0.337 d and 1.063±0.435, respectively. The oviposition period per female was prolonged 2.692±0.991d. The oviposition quantity increased 240.533±153.965, and the pupae weight and the generation survival rate were significantly increased. The life table parameters indicated that the net reproductive rate (R0), intrinsic rate of increase (rm) and finite rate of increase(λ) of M. separata fed on maize were 573.96, 0.10 and 1.10, which higher than those fed wheat (304.05, 0.08 and 1.09). The mean generation time (T) and double population time(td)of M. separata fed on maize were 66.59 and 7.27, lower than those fed on wheat (67.37 and 8.17). The development and reproduction of M. separata reared on wheat and maize exhibited significant difference. Maize was more suitable for growth and development of M. separata than wheat, and this provided one of possible reasons for the outbreak on maize field.

      • 1
    • wang yu feng

      Abstract:

      The effect from harvest time to storage time on the quality of fresh maize were studied.12 Waxy corns and 6 sweet corns were used as the materials,the effect of the fresh-eaten maize was placed at room temperature(28 ℃) 0 h、8 h、16 h、24 h and 32 h on sugar content, starch content,protein contentand and Sucrose-metabolic enzyme activity in grain after harvest were studied.The result showed the soluble sugar content,the sucrose content,fructose content,, reducing sugar content,starch content ,soluble protein content and sucrose metabolic enzyme activities of the grain showed a downward trend. The quality change of waxy corn was greater than that of sweet corn.Therefore, in order to ensure the grain quality of fresh-eaten maize, it is recommended to freeze storage within 8 hours after harvesting of maize; in sweet maize, Syngenta OVERLAND is stored frozen within 16 hours after harvesting, Jingketian 183, Hetian 1, Hetian 1, Syngenta Damigo and Zhengtian 66 were stored frozen within 8 hours after harvesting.

      • 1
    • shilei, lvning, chenyun, liangfei

      Abstract:

      This study aimed to explore the effect of accumulation and translocation of dry matter and nutrient on the spring maize yield under different irrigation stategies, and screen out the appropriate irrigation amount of maize in northern Xinjiang. Maize cultivar of Zhengdan 958 was used as the test material, and a field experiment was conducted to investigate the effects of flood irrigation amount (4800, 7200 m3/hm2, marked as MI1 and MI2, respectively) and drip irrigation amount (4200, 4800, 5400 and 6000 m3/hm2, marked as DI1, DI2, DI3 and DI4, respectively) on accumulation and distribution of dry matter and nutrient in different organs at the reproductive stage. The relevance between dry matter, nutrient and grain yield of maize was calculated by Pearson correlation coefficient. The results showed that 1) different irrigation amount had significant impact on maize dry matter, the order of the dry matter weight of aboveground plant was MI2>DI3>DI4>MI2, DI2>DI1, and the dry matter accumulation in tassel was significantly higher than that in stem and leaf in each irrigation treatment and which was obviously improved with irrigation amount increasing; the dry matter weight of DI3 was highest and which was 16.62% ~ 45.51% greater than that of other irrigation treatments. 2) with the increase of irrigation amount under different irrigation treatments, the N and K nutrient uptake of aboveground plants were significantly improved, but the P nutrient had no significant changes; P accumulation content in leaf and stem of flood irrigation treament was significantly higher than that of drip irrigation treament, and the accumulation effect of N and K in tassel was more significant under drip irrigation treament. 3) the grain yield of maize under drip irrigation was significantly higher than that under flood irrigation, yet which was not increased with the drip irrigation amount; the grain yield of DI3 treatment was the highest and the average yield reached to 17920.8 kg/hm2, and the increased yield was attributed to the increased of tassel diameter, tassel grain column number and 1000-grain weight. 4) it was found that the accumulation of dry matter and K nutrient in tassel were extremely positively correlated with grain yield of maize by Pearson correlation analysis. According to the dry matter accumulation, nutrients content in different organs and the maize yield, the appropriate irrigation amount of spring maize was suggested to be 5400 kg/hm2 under drip irrigation in areas of northern Xinjing. The findings might provide a reference for optimizing irrigation system of water-fertilizer integrated for spring maize in Xinjiang.

      • 1
    • liujiang

      Abstract:

      In this study, a maize gene named ZmCPB1 was cloned from maize Qi319 inbred lines. The full length cDNA of ZmCPB1 was 1446bp that encoded a protein of 481 amino acid with predicted molecular weight of 54.05KD and a theoretical isoelectric point of 8.59. Bioinformatics analyses showed that ZmCPB1 was a transmembrane protein with a membrane-spanning domain in N-Terminal. The secondary structure of ZmCPB1 protein contained 48.44% of alpha helix, 4.99% of beta turn, 10.60% of extended strand and 35.97% of random coil. The result of Plant-mPLoc prediction indicated that ZmCPB1 protein was located in endoplasmic reticulum. Sequence alignment showed that ZmCPB1 contained a highly conserved region of VKFVHRKALK. The phylogenetic analysis revealed ZmCPB1 protein was highest related to homologous proteins of Sorghum bicolor, Setaria italica, Oryza sativa and Hordeum vulgare, which belonged to the same branche. Furthermore, quantitative Real Time Polymerase Chain Reaction(qRT-PCR) asssy was performed to analyze the expression pattern of ZmCPB1 in different tissues and developmental stages of maize. The results showed that the expression level of ZmCPB1 was lower in root, stems, leaces and bract, but higher in ear. At different stages of maize grain development, the expression pattern of ZmCPB1 showed a certain regular change.The expression of ZmCPB1 increased continually from one day to ten days after pollination, and reached the highest level at the 10th day, then decreased significantly. These results demonstrated that ZmCPB1 is involved in maize grain development, which laid a foundation for further research of the biological function of ZmCPB1.

      • 1
    • xuxinying, shaochangxiu, sunzhigang, longbuju, dongwanlin

      Abstract:

      Global climate change, mainly characterized by climate warming and extreme climate, has a significant impact on agricultural production and directly threaten to global food security. With the development of technology and the change of social demand for food, maize has become the first food crop in China. Adverse effects of heat stress has on physiological and biochemical characteristics of maize and its growth and development, which leads to the reduction of maize yield and quality. In this paper, physiological and biochemical effects of heat stress on yield - related organs of maize, and effects of heat stress on maize growth and yield at different growth stages were summarized: heat stress had negative effects on cell membrane and antioxidant system of maize, leaf photosynthesis and related enzyme activity, tassel branching and pollen activity, spikelet spinning and filament activity, and starch synthesis related enzyme activity in grains; heat stress at different growth stages has different effects on yield and its components, and the sensitivity of maize to heat stress during the growth period was from high to low as follows: flowering stage > grain filling stage > earing stage > seedling stage. The heat stress in the same growth period was also different among different maize varieties.Understanding the research progress on effects of heat stress on physiology and biochemistry of maize and the effects of heat stress on maize yield in different growth stages, has important theoretical and practical significance for breeding and popularizing high temperature tolerant varieties, adjusting planting system and structure, and promoting maize agricultural production to adapt to climate change.

      • 1
    • Zehui Chen

      Abstract:

      Heterosis is a common phenomenon in biology, which has been widely used in commercial breeding practice.?However, the genetic basis of heterosis has been still at the stage of hypothesis, mainly including dominant hypothesis, super dominant hypothesis, epistasis, heterosis gene, allele specific expression and other theoretical explanations.?Based on the theory of quantitative genetics, the mathematical expression of heterosis was defined as HF1=Σdy2.?Based on the breeding practice of maize inbred lines and hybrids, this paper had summarized different heterosis hypotheses, expounded the practicability of HF1=Σdy2. Except that, the possible effect of epistasis on heterosis was also discussed, and the guiding role of HF1=Σdy2 in maize breeding was discussed in depth.

      • 1
    • zhouyujie, hanjienan, wangmeijuan, liuxiaoli, limingshun

      Abstract:

      The mutation of Opaque2 (O2) significantly affect protein body formation, starch content, and amino acid composition in the endosperm of maize kernels, and the increasing of lysine content significantly improves nutrition quality. Through the backcrossing scheme, we constructed near isogenic lines of 17 waxy maize backgrounds with the o2 mutation gene. By analyzing the trait of the kernel, including appearance, pericarp thickness, 100-kernel weight and crude starch content, we found that the kernels of 16 near isogenic lines were shrunken significantly and their endosperm changed to opaque obviously compared to the controls. Pericarp thickness of 6 lines increased, and the 100-kernal weight of 11 lines decreased significantly, crude starch content of 12 lines decreased significantly. It indicated that the introduction of o2 mutant gene mainly have a negative effect on kernel appearance, yield and crude starch content with waxy maize, but the degree of influence is related to maize background.

      • 1
    • zhangmingwei, yanghengshan, fanxiuyan

      Abstract:

      Effect of reduction of nitrogen and irrigation on dry matter accumulation, utilization efficiency of water and nitrogen and yield of spring Maize in shallow drip irrigation were studied by using the traditional border irrigation cooperated with the conventional nitrogen application as the control in irrigation areas of the West Liaohe plain of Inner Mongolia from 2017 to 2018. The experiment was adopted a split plot design, in which the irrigation level was the main treatment including 60% of conventional irrigation, 50% of conventional irrigation and 40% of conventional irrigation and the nitrogen application level was the secondary treatment including 50% of conventional nitrogen fertilization, 70% of conventional nitrogen fertilization and conventional nitrogen fertilization. The results showed that the dry matter accumulation of each treatment improved with the increase of irrigation and nitrogen level, and the dry matter accumulation of W3N3, W3N2 and W2N3 was no significant difference with CK; the dry matter accumulation rate of each treatment was lower than CK in silking stage and slightly higher than CK after silking stage except for W1N1 in 2018. The dry matter transportation rate of stem sheath and leaf and the contribution rate of dry matter translocation to grain both improved with the increase of irrigation and nitrogen level, and there was no significant difference between the dry matter transport capacity of W3N3, W3N2 and W2N3 treatments with CK; the contribution rate of leaf translocation to grain was lower than CK in drip irrigation, and the contribution rate of stem sheath translocation to grain was lower than CK at low irrigation and nitrogen level in drip irrigation. The change regulation of nitrogen accumulation, translocation and contribution rate to grain of plant with irrigation and nitrogen changing rules was basically consistent with dry matter. The grain yield of W3N3 was the highest under shallow drip irrigation and there was no significant difference with W3N2, W2N3 and W2N2, which were all significantly higher than that of other treatments and CK. Utilization efficiency of irrigation water of each treatment was significantly higher than that of CK; nitrogen partial productivity of N1 and N2 was significantly higher than that of CK while there was no significant difference with CK under the N3 level under the same drip irrigation quota; efficiency of nitrogen absorption of W3N2 was the highest, which were significantly higher than other treatments and CK, except for W3N1 and W2N1. The analysis above shows that the shallow drip irrigation of maize has obvious effect of water saving and nitrogen reducing, which is a high-yield and high-efficiency technology suitable to be popularized in West Liaohe plain and its ecological similar areas.

      • 1
    • SuiYanghui

      Abstract:

      Nitrogen rate and planting density have been the two main factors for high maize yield. At present, excessive nitrogen input and low planting density are the main problems in the main maize production areas in China. Therefore, reasonable increased density and nitrogen reduction are important ways to improve the yield and the efficient utilization of nitrogen fertilizer of spring maize in Northeast China. A new maize hybrids released in China, Liaodan575, was used as experiment materials. Three plant densities (60, 67.5 and 75 thousand plants per hectare) and three nitrogen rates (135, 180 and 225 kg/hm2) were designed by random experiment in 2017 and 2018. The results showed that compared with D6.00, D6.75 and D7.50 dry matter accumulation of maize significantly increased by 14.9% and 17.6% in 2017, 0.4% and 11.3% in 2018. Compared with N135, N180 and N225 nitrogen accumulation were higher, increased by 0.2% and 0.9% (in 2017), 9.3% and 8.1% (in 2018), respectively. During the 2017 and 2018, the highest maize yield was obtained under the treatment of D6.75 and N225. The maize yield of D6.75N225 in 2017 as well as D6.75N180 and D6.75N225 in 2018 was significantly higher than that of other treatments, and the interaction effect of planting density and nitrogen application amount significantly affected maize yield, indicated that increased plant density with reduced N rate properly was an important way to synergistic improve maize yield. The highest harvest index, nitrogen harvest index and nitrogen partial productivity were obtained under D6.75 treatment in 2017 and 2018. Therefore, it is recommended for Liaodan575 that suitable planting density should be increased from the conventional density to 67.5 thousand plants per hectare, and the amount of nitrogen application should be 225 kg/hm2 in the first year, and then to 180 kg/hm2 in the next year. It can achieve the goal of reducing nitrogen, increasing density and increasing maize yield.

      • 1
    • LI Guang-fa

      Abstract:

      Using 336 DH lines bred by haploid breeding from F1of PH4CV × A6 were male parents, and 336 hybrid combinations were made with ph6wc as female parent. Three repeated identification tests were carried out for 14 combinations with better comprehensive characters and Xianyu 335 (PH6WC × PH4CV) and Tongyu 99 (PH6WC × A6) after 2-year identification and elimination. Variance, genetic coefficient and cluster analysis were carried out for the additive dominant effect of 10 characters. The results showed that plant height, ear height, grain moisture, 100 grain weight and bulk density had super high parent and super low parent heredity, the ratio of grain to ear had super high parent heredity, and the grain weight per ear had no super high parent heredity. The effect of path coefficient of each character on the grain weight per ear was: 100 grain weight > ear row number > ear length > bulk density > plant height > ear height and the negative effect was (absolute value): grain moisture > grain ear ratio> bald tip length. 14 DH lines can be divided into 3 groups, The chi square distance of PH4CV and A6 is 3.45, and that of D752 and A6 is 1.96. In this round of haploid breeding practice, only D752 ear grain weight additive dominant effect should reach PH4CV level, while taking into account the low plant height, low ear height and other excellent characters, the improvement efficiency is 0.30%.

      • 1
    • XU Jia-yi, SUI Shi-jiang, KANG Yue, CHEN Yue, ZHANG Yan-jun, GONG Liang, NIU Si-wei

      Abstract:

      To determine the characteristics of nitrogen (N) and phosphorus (P) loss in the dry farmland of Liaohe River plain, the field experiment was conducted to in-situ monitor the water flow and N and P loss by runoff and leaching under the different treatments from 2016 to 2017. The results showed that the runoff and leaching events mainly occurred from June to August, which was closely related to rainfall. The dissolved N and P were the main forms of N and P in the leaching and runoff water (excluding P in runoff water). N concentrations in the leaching water were higher than runoff, whereas P concentrations in the runoff water were more than leaching. N leaching loss was higher than runoff in both 2016 and 2017, while greater runoff P loss was determined in 2016 and approximately equivalent P loss by leaching and runoff these two approaches in 2017. Compared to the conventional fertilization (CF) and optimized fertilization treatment (OF), the water flow of runoff and leaching was decreased in the optimized fertilization combined with straw incorporation treatment (OFS), especially with 20.3% and 14.9% lower runoff flow in OFS than CF and OFS in 2016 (p<0.05). The average concentrations of total N, dissolved N, NO3-–N, and NH4+–N were compared among the different treatments as follow: CF>OF>OFS, while there was little difference of P concentrations among the three treatments. Compared to CF, both OF and OFS treatments reduced N and P loss, especially with 31.0% lower runoff N loss and 19.3% lower runoff P loss in OFS than CF in 2016 (p<0.05). In conclusion, N leaching were main contribution to the nutrients loss in the dry farmland of Liaohe River plain, and straw incorporation based on optimized fertilization had the potential on controlling N and P loss.

      • 1
    • WU Wen-ming, CHEN Hong-jian, ZHANG Lin, CHEN Xiang, PENG Chen, JING Li-li, WANG Shi-li

      Abstract:

      Field experiments were carried out to investigate the relationship between grain moisture content and effective accumulated temperature of different hybrids in the main production areas of the Huaibei Plain. Combining with meteorological data to determine the suitable planting and harvesting dates which suitable for machine. The results showed that the earlier the sowing date, the higher the yield, and the yield of the middle-maturing hybrid was significantly higher than that of the early-maturing hybrid, but the grain dehydration rate of the early-maturing hybrid was faster than that of the middle-maturing hybrid. The effective accumulated temperatures required to of the early and middle-maturing hybrids are 873.0 ° C and 943.9 ° C, respectively, and to the targeted 25% moisture content are 914.1 ° C and 992.3 ° C, respectively. In order to ensure the mechanical grain harvest and high yield, when the middle maturing hybrid are planted at June 5th, and the harvest period is about October 1st, 81.8% of the year can guarantee the machine grain harvesting. When the planting date postponed to June 15th, the early-maturing hybrids are planted, and the harvesting date around October 5th, 72.7-90.9% of the year can guarantee the grain machine harvest. Therefore, due to the uneven distribution precipitation in the main production area of ??Anhui province, in order to ensure the mechanical grain harvest and higher yield, the hybrid must be reasonably matched with the environment to form the new cultivation idea of ??"plating date is determined by soil moisture, variety is sown by planting date

      • 1
    • ZHOU Wen-Qi, LIAN Xiao-Rong, ZHOU Yu-Qian, Wang Xingrong, YANG Yan-Zhong, LIU Zhong-Xiang, WANG Xiao-Juan, HE Hai-Jun, KOU Si-Rong

      Abstract:

      Maize germplasm resource innovation plays an important role in maize breeding and artificial mutagenesis is an important method of crop germplasm resource innovation. In this study, a maize mutant library with 2 206 maize mutant libraries was constructed by mutagenesis of corn inbred line B73 and K22 pollen, which was treated with 0.5 mg?L-1 ethyl methanesulfonate solution (EMS). A series of mutants with phenotypic variation including plant type, leaf type, leaf color, fertility, resistance and epidermal morphogenesis, were screened from M2 and M3 progeny. The E16, E199 and W594 mutants with potential breeding application were mainly described which could be used for breeding new varieties of dwarf, low-ear and high density and lodging resistance dense-tolerant. In addition, epidermal morphological and developmental pattern identification and genetic analysis were performed on E88 and sep-1 (smooth epidermal pavement cell lobes-1) mutants regulating epidermal morphogenesis of plants. Subsequently, F2:3 isolates population were constructed and candidate genes regulating epidermal morphogenesis will be clone by mapping. This study will provide a method and dose reference of EMS mutagenesis for the creation of new germplasm resources of different maize inbred lines, and more important, it provide stable genetic materials for the selection and breed of new maize varieties, it also provides genetic resources for expanding the study of maize genomics.

      • 1
    • wangzhidan

      Abstract:

      Agricultural technological progress is the main driving force for the growth of China""s grain production capacity. By using the E-S model and C-D production function, the panel data of 13 provinces at three advantage regions of maize in China from 2004 to 2016, the leading technological progress mode of maize production was analyzed and proposed from the aspects of inter annual changes, development stages and regional differences. The results showed that: the substitution effect of mechanical input on labor input was increasing, the promotion effect of biochemical input on maize production was relatively limited, maize production was mainly based on mechanical technological progress presently. There were significant differences in the technological progress patterns among the three advantage regions. The northern part and the Huang-Huai-Hai plain were obviously higher than the southwestern part in elastic coefficients of mechanical input, the northern part was comparatively lower than the Huang-Huai-Hai plain and the southwestern part in elastic coefficients of biochemical input.

      • 1
    • WEN Jing-ru, KE Yong-pei, YU Xue-jie, LIANG Xue, ZHAO Chang-yun, LI Ren-fei, SHI Hai-chun

      Abstract:

      In this study, 54 maize inbred lines were used as materials, and 20% PEG-6000 solution was used for drought stress at the seedling stage, and 9 indicators such as plant height and root-shoot ratio were investigated. Indexes were selected by principal component analysis, and then the comprehensive drought resistance value D was calculated using the membership function method, and their drought tolerance was evaluated and clustered according to the D value. The main results are: 7 inbred lines such as K186 and K123 are grouped with Zheng 58 and belong to a drought-resistant inbred line; 25 inbred lines such as K121 and K182 are grouped with Chang 7-2 and are a moderate drought-resistant self Inbred lines; 20 inbred lines such as K101 and G2490 are grouped into one class, and they are drought-sensitive inbred lines. The results can provide reference for the utilization of these inbred lines in maize drought-resistant.

      • 1
    • WANG Long-fei, YANG Qian, LI Guang-hao, LU Wei-ping, LU Da-lei

      Abstract:

      The effects of drought stress at different post-silking stages (grain formation stage and grain filling stage) on grain yield and starch quality of waxy maize were studied using Suyunuo 5 (SYN5) and Yunuo 7 (YN7) as materials. The soil relative moisture contents were 75% and 55% under control and drought conditions, respectively. The grain yield was significantly reduced by drought at different stages, and the reduction was severe when water deficit occurred at grain formation stage. Drought stress significantly decrease the starch content, increase the contents of total protein, globulin and glutelin, enlarge the average starch granule size, rise the proportion of long amylopectin chains, and improve the relative crystallinity, and the effect of grain formation stage was greater than that of grain filling stage. Flour peak viscosity was unaffected by grain filling stage drought stress but significantly decreased when plants suffered water deficit at grain formation stage. The flour gelatinization enthalpy was decreased and increased when drought occurred at grain formation and filling stages, respectively. Drought stress decreased the retrogradation percentage of SYN5 and the decrease was larger when plants suffered drought at grain filling stage. The retrogradation percentage of YN7 was not affected by drought at grain formation stage but was increased by drought at grain filling stage, respectively. In conclusion, low starch content, high protein content, large starch granule size, long amylopectin chains and high relative crystallinity under the drought stress affected the starch pasting and thermal properties, and the affects was severe when drought occurred at grain formation stage.

      • 1
    • WU Shuyue, LI Qiuzhu, LI Wenying, CUI Zhengguo, ZHANG Yubin, WANG Hongyu, CUI Jinhu

      Abstract:

      The northeast region is one of the most areas that produce food crops. The problem of lodging is the main limiting factors for crop production, which seriously restricts the mechanized harvesting process of corn in the region. The mechanized production of corn requires that the stalks remain erect at harvest, and increasing the planting density will affect the ecological environment of the corn population, change the stalk traits of the corn, and increase the lodging rate to some extent. Hongyu 236, Xiangyu 998 and Jiamei 2 were used as materials. The rate of nitrogen application was 150, 180, 210, 240 and 270 pure N kg/hm2. Planting density was 60, 70, 80, 90 and 100 thousand plants/hm2. The purpose of this research is to explore the rate of nitrogen application and density on dry matter accumulation and compressive strength of stems at the base of maize, and to analyze the correlation with the thrust strength, in order to provide a basis for the anti-inverted mechanized production of maize close planting. The results showed that: Inter-node dry matter increased first and then decreased when density and nitrogen fertilizer increased, and the interaction between density and nitrogen fertilizer was positive. However, when density was more than 80000 plants per hectare, inter-node dry matter decreased irreversibly. Crushing strength decreased when density increased, and effect of nitrogen fertilizer was not significant. Besides, the 3rd to 5th inter-node dry matter per centimeter and the 3rd inter-node crushing strength could be used to evaluate lodging resistance of maize.

      • 1
    • QIAN Chun-rong, WANG Rong-huan, YU Yang, XU Tian-jun, GONG Xiu-jie, HAO Yu-bo, JIANG Yu-bo, LI Liang, LV Guo-yi, YANG Zhong-liang, ZHAO Jiu-ran

      Abstract:

      In this study, 9 maize varieties differing in maturity were used as experimental materials, and experiments were conducted in Harbin and Beijing in 2014 and 2015 to study the dry matter accumulation, transport and distribution characteristics. The results showed that the dry matter accumulation, the dry matter accumulation rate before and after silking, the number of kernel per ear, the weight of 100 grains and the yield of maize varieties had significant or extremely significant differences among different ecotypes and cultivars, and there were significant interaction effects among ecotypes, cultivars and years. There was no significant difference in the proportion of dry matter distributed to the organs of grains, leaves, sheath, bracts and cobs in different ecological zones, but there was a significant difference in the proportion of dry matter distributed to the stems, which was 3 percentage points higher in Harbin than in Beijing. With the extension of maturity, the dry matter accumulation rate before silking tended to decrease, and the dry matter accumulation rate after silking tended to increase. The dry matter accumulation rate before silking in Beijing ecological zone was higher than that in Harbin, and the dry matter accumulation rate after silking in Harbin was higher than that in Beijing. The dry matter transport of maize organs was significantly different in different ecological intervals. In the Harbin ecological area, there was no transfer and output of stem and sheath dry matter, and only leaf dry matter showed as transfer and output. The dry matter of stem, sheath and leaf in Beijing ecological area is transported and exported. Compared with the two ecological zones, the leaf dry matter transfer rate in Harbin ecological zone was 6 percentage points higher than that in Beijing, and the contribution rate of leaves to grains in Harbin was 1.8 percentage points higher than that in Beijing. The above results indicated that maize yield in the cold region was mainly due to the assimilation products after silking rather than the material transport of nutrient organs. Therefore, in the corn planting area in the cold region of Heilongjiang province, the excessive growth in the early stage should be controlled, so as to reduce the redundancy of dry matter, strengthen the nutrition in the flowering period, and promote the photosynthetic production after flowering, so as to increase the yield of corn.

      • 1
    • xiaozhanwen, wangduocheng

      Abstract:

      In order to explore the optimal agronomic measures for super-high-yield cultivation of grain feeding general corn in the inland irrigation area of Hexi, a four-factor five-level secondary universal rotation combination design was used to study the main cultivation factors of density (X1) and nitrogen fertilizer (X2), phosphate fertilizer (X3), and potassium fertilizer (X4). The effect on the yield of tolerance-tolerant and resistant maize Zhengde 305 was established by a regression mathematical model between yield and 4 factors. The optimization of the model analysis showed that the four factors had the following effects on the yield of maize: nitrogen fertilizer>density>potassium fertilizer>Phosphate fertilizer, and density and nitrogen fertilizer have significant effects on yield. Under the conditions of this test, the optimal agronomic measures to obtain a yield of≥16000 kg/hm2 are: a density of 101000 to 108000 plants/hm2, an N application of 264.3 to 289.95 kg/hm2, and a P2O5 application of 155.48 to 187.80 kg/hm2 The amount of K2O applied was 152.6~166.5kg/hm2.The verification of 653.3hm2 high-yield demonstration field proved that the model constructed was accurate and could provide technical support for super high-yield cultivation of corn.

      • 1
    • Zhao Xin, Chen Baoyu, Wang Hongjun, Wang Nan, Sun Mengqi, Liang Xuanhe, Cao Tiehua

      Abstract:

      In order to find out the drought threshold of maize in different growth periods under the condition of no tillage under straw mulching, so as to scientifically guide supplementary irrigation and avoid water resource waste. Our team conducted drought experiments with different gradients in the artificial awning from 2018 to 2019. The results showed that,?with 5% reduction as the critical point, the drought threshold under no-tillage coverage was 0.609 during the period from jointing to tasseling, which was significantly higher than 0.551 under the condition of open rotary tillage, but there was no significant difference between tasseling and milk ripening (0.524 and 0.512, respectively). In terms of the time of occurrence of drought threshold, the coverage was 6.1 days later than that of bare land during jointing to tasseling, but the difference was reduced to 3.7 days between tasseling and milk ripening. These results indicated that straw mulching could significantly improve the drought resistance of maize and extend the interval of necessary water replenishment (especially from jointing to tasseling), so as to reduce the number of water replenishment during the whole growth period of maize with the same yield.

      • 1
    • XU Hong-le, SU Wang-cang, LENG Qiu-li, XUE Fei, SUN Lan-lan, WU Ren-hai

      Abstract:

      In the present study, the whole-plant bioassay method was conducted to study the herbicidal activity of pyroxasulfone against the main gramineous weeds in the autumn crop fields, such as Digitaria sanguinalis, Eleusine indica, Echinochloa crusgalli and Setaria viridis. Furthermore, the safety of pyroxasulfone to corn, sorghum and millet was also evaluated. The results showed that the soil treatment of pyroxasulfone had good control effects on Digitaria sanguinalis, Eleusine indica, Echinochloa crusgalli and Setaria viridis. When the application dosage was 120 g a.i.hm-2, the fresh weight inhibition rates of pyroxasulfone to the four weeds were 98.76%, 97.77%, 100% and 100%, respectively. The GR90 values of Digitaria sanguinalis, Eleusine indica, Echinochloa crusgalli and Setaria viridis were 120, 73.30, 13.88, 20.72 g a.i.?hm–2, respectively. Pyroxasulfone had good safety to corn, but the bad safety to sorghum and millet. The fresh weight GR10 of corn, sorghum and millet were 602.01, 1.56, 0.34 g a.i.?hm–2, respectively. The fresh weight selectivity index of pyroxasulfone was not less than 8.21 between maize and four weeds, but not more than 0.11 between sorghum, millet and four weeds. Pyroxasulfone can be used as an ideal soil treatment herbicide in corn field, and also can be further registered and popularized.

      • 1
    • lihongxin, tanxiaoting

      Abstract:

      The paper uses the field survey data of 240 maize farmers, measures the technical efficiency of maize farmers with translog stochastic frontier production function, and analyzes the influence of land trust on the technical efficiency of maize farmers.The research shows that the heterogeneity of maize farmers'' production technical efficiency in the surveyed area is obvious, ranging from 0.28 to 0.98, and the average technical efficiency is 0.91.To participate in land hosting corn farmers average technical efficiency than not to attend land hosting the average technical efficiency increased by 6%, in addition, corn growers householder age, sex, cultural level, family is engaged in the agricultural population, family farm income accounted for, whether to receive government support is have a significant effect on technical efficiency, based on the above research conclusion, finally puts forward relevant policy suggestions.

      • 1
    • ZHOU Shenghui, ZHANG Lei, LV Xinze, HUANG Jinguang

      Abstract:

      In this study, bioinformatic methods were emplored to identify all GLR family genes in the genome of maize inbred line B73. Multiple sequence alignment showed that the GLRs of maize were highly conservation, including two Glu receptor binding regions (GlnH1 and GlnH2) and four transmembrane regions (M1, M2, M3, M4). Phylogenetic analysis showed that the GLR family of maize can be divided into two categories: ZmGLRII and ZmGLRIII. The GLR family genes of maize were located on 4 different chromosomes (2, 4, 5 and 7) and the corresponding amino acid sequences share quite similar motifs. Prediction of subcellular distribution revealed that the GLRs were mainly located in endoplasmic reticulum and mitochondrion. Expression patterns in different tissues demonstrated that multiple GLR genes were only detected in specific tissues. Environmental stresses, such as drought and high temperature, have different effects on the expression of GLR family genes in maize. These data laid a solid foundation for further comprehensive analysis of the biological activities of GLRs in maize.

      • 1
    • LIle, Luyang, Chanyuming, Xuwenjing, Yangzhi, Zhaoyu, Zhangzhengkun, Liqiyun

      Abstract:

      The biological characteristics of Beauveria bassiana?have a significant correlation with its virulence against the target pests, which is of great significance for the preliminary screening of fungal strains with high virulence. Ten stains of B. bassiana, randomly isolated and identified from a muscardine?cadaver?of corn borer larva collected from maize field. The sporulation quantity, conidiophores germination rate, colony growth rate and the virulence of the strains against corn borer third instar?larvae were measured, respectively, all of them displayed significant differences among different stains. On this basis, the correlation between biological characteristics and virulence of all stains was analyzed. The results showed that for all fungal stains, the colony growth rate was positively correlated with virulence, the conidiophores?germination rate showed no correlation with the virulence, while the sporulation quantity was negatively correlated with virulence. Therefore, the colony growth rate can be used as a preliminary evaluation index for high virulence strains screening of B. bassiana.

      • 1
    • GAOSong, LIU Hong-wei, HE Huan, LV Qing-xue, ZHOU De-long, XING Yue-xian, ZHAO Xing-yan, ZHANG Zhi-jun, ZHANG Jian-xin, ZHONG Yi, XIA Yuan-feng, SONG Guang-shu

      Abstract:

      205 inbred lines from 7 groups, such as Reid group, Lancaster group, LRC group, SPT group, PA, PB group and Tropical group, were used as materials.6973 high quality SNP markers were used to analyze population genetic structure, genetic diversity and genetic relationship between groups.The results showed that 205 samples could be divided into 7 groups, the average frequency of main alleles was 0.726, the average gene diversity was 0.344, and the average value of heterozygosity was 0.274. the average PIC value of 0.723.In the 6973 SNP markers ,3750 SNP marker gene diversity was 0.45~0.50, and 53.8% of the total,which had a high level of polymorphism.Through cluster division and selection of inbred lines with ideal plant type and excellent resistance in the field, the hybrid combinations were prepared according to incomplete diallel crossing design, and a new corn variety Jidan 563 was selected and approved.

      • 1
    • Hang LIU, Lexin HOU, Fangming WANG, Yuqiang Zhang, Jiansheng LI, Ning DING

      Abstract:

      Silage maize becomes one of the important directions for maize production in the new era, China. In order to make clear the breeding direction of silage maize at the present stage in China and approach strategies of further improving for silage maize. Heterosis group and heterosis model of 28 nationally examined silage maize varieties released from 2004 to 2017 were analyzed, and 6 heterosis group and 8 heterosis model were divided with the method of pedigree analysis, in which 4 heterosis model that of Temperate-tropic I group × Raid yellow group, LD group × Temperate-tropic I group,Raid yellow group ×Tropical germplasm and Temperate-tropic I group × High oil were the most representative. There were most 16 inbred lines belonged to the Temperate-tropic I group, and 14 varieties contained its consanguinity, accounting for 50% of the 28 varieties; in which the quality standards of 13 varieties reached to the first class. Biomass and fiber quality are two major breeding purposes of silage maize improvement. In the future improvement of silage maize, silage type and grain combining silage type should be main types, and forage type is supplement one. The silage varieties having high biomass, good fiber quality, resistance to lodge and disease should be selected. Collecting excellent germplasm resources and broadening the basis of genetic improvement as well as establishing modern genetic improvement technology platform should be paid more attention to. Regarding varieties types, single cross is dominant, triple cross and double crosses are secondary.

      • 1
    • DI Hong

      Abstract:

      Head smut was one of the major diseases in spring maize area in northern China, and caused total loss of the crop yields. Five molecular markers closely linked to major resistance loci of head smut in bin2.09 area, were used in this study including 3 STS markers and 2 dCAPS markers. The resistant near-isogenic line 1JD006, which was developed from the susceptible line Huangzao4 and the resistant line Mo17 carrying the major resistance QTL, was used as the resistant donor to improve the susceptible line Chang 7-2 combing the marker assistant selection and backcross breeding method. The results showed that 3M1-25 was the optimal molecular marker with the highest selection efficiency, and next was marker MZA6393. Six plants with high background recovery rates (>87.5%) in BC2F2 population were selected. Twelve plants were selected from BC3F2 population with the recovery rates above 96.92%. The field incidence of them were below 40%. Except line 4JZ574-01, the main agronomic traits of the other lines in BC3F3 population were similar to Chang 7-2. The results should be benefit to marker-assisted selection breeding for maize head smut resistance.

      • 1
    • HONG Defeng, ZHANG Xueshun, MA Yi, WEI Feng, MA Junfeng, WEI Xiaoyi, YAN Yuxin, WANG Jiamu

      Abstract:

      Xin 01A3 and sib-line Xin 6 were both elite inbred lines in maize, which were breeding by used maize hybrid (production test variety A in 2000) as basis material, hybridization with the tropical germplasm 8085 Thai, backcross with Chang 7-2, and then selfing through many generations. Xin 01A3 and Xin 6 belong to TangSiPingTou heterosis group, with the characteres of mid-early maturity, high resistance, high combining ability, good quality and so on. Directly using Xin 01A3, Xin 6 and their improved inbred lines as parents, many excellent maize hybrids were breeding which were approved by provincial and national test. Among them, Xindan 68 is the first group variety suitable for mechanized harvesting approved by Henan province. Xindan 58, Xindan 65, Xindan 68 and Xindan 88 are all approved by national test, these varieties are suitable for Huang-huai-hai summer maize planting, and suitable for mechanized operation in the whole maize production. Xindan 33, Xindan 36, Xindan 38, Xindan 61 and Yudan 606 are all ordinary maize varieties with the characteristic of good quality, high yield and high resistance. Their new varieties breeding by Xin 01A3, Xin 6 and their improved inbred lines have laid a solid foundation for advancing maize production and improving its competitiveness.

      • 1
    • YAO Qi-lun, HUO Shi-Ping

      Abstract:

      Comparative physiological and transcriptomic analyses of tropical and temperate maize lines were performed in order to understand physiological and molecular responses of different maize germplasms subjected to water deficits at the stage of seedling. The results indicated that there were considerable increases in POD and SOD activities, and MDA, soluble carbohydrate, and soluble protein contents under drought stress. In contrast, the chlorophyll content and four chlorophyll fluorescence parameters (Fv/Fo, Fv/Fm, ΦPSII, and QP) decreased in all four lines in responses to drought stress. Additionally, the tropical maize lines maintain relatively higher values for the chlorophyll content and four chlorophyll fluorescence parameters than those of the temperate lines. On average, after the raw data had been filtered, the RNA-Seq experiments yielded between 44.56 and 52.58 million paired-end reads per sample. For the four different maize lines under drought stress, 20126 differentially expressed genes (DEGs) were identified and 21 GO terms are commonly overrepresented. There are differential responses of different maize inbred lines subjected to drought stress at physiological and molecular levels. It can be concluded that the tropical maize germplasm conferred potential resistance to water deficits as compared to the temperate maize germplasm.

      • 1
    • Dong huaiyu

      Abstract:

      The phenotypic resistance to stalk rot and lodging resistance of 83 maize varietiesfor mechanical grain-harvestwere investigated in this research. There are 49 maize varieties that showed moderately resistant, resistant or highly resistant. Lodging rate of 16 varieties is less than or equal to 5%, however, there are 29 varieties whose lodging rate is less than or equal to 8%.Based on the phenotypic resistance to stalk rot and lodging resistance, 25 varieties are screened for mechanical grain-harvest that are suitable for the central and northern maize production areas of Liaoning Province. They can alleviate the lack of suitable matching varieties for the promotion of mechanical grain-harvest technology in Liaoning maize production area。

      • 1
    • LU Jun-tian, REN Li-li, YUE Hui, WANG-Liang, Lu Bao-liang, WANG Xiao-jie, Sun Jiu-chao

      Abstract:

      Early maturing Iodent was used to improve Lvdahonggu germplasm resources, Using NCⅡ genetic mating design, Improve offspring and Hybrid combination were used as the test material to study the combing ability and heterosis of key traits in suitable machines. The results showed that Iodent improved Dan 598 and Dan Huang 34 had better comprehensive harvesting traits, and the highest combination with PH6WC, forming a strong dominant combination, which was a suitable hybrid combination for mechanical harvesting. The grain water content is extremely positively correlated with the breakage rate of the grains, which is a key trait that limits grain yield. Correlation analysis showed that the grain moisture content, lodging rate, growth period, number of ears, and stem rot rate have a significant positive correlation between the damage rates of harvested kernels, which is the key characters should be selected during breeding to improve breeding efficiency.

      • 1
    • lvguangde, Mi Yong, Chen YongJun, Sun YingYing, Wang Chao, Mu QiuHuan, Wu Ke, Qian ZhaoGuo

      Abstract:

      In order to determine the effects of fractional fertilization and nitrogen application on dry matter accumulation and distribution, nitrogen accumulation characteristics and maize yield, field nitrogen fertilizer operation experiments were carried out in 2015-2016 maize growing season. The experimental material of maize is' zhengdan 958 ', and the two-factor splitting area is adopted, the main area is the way of nitrogen application, and the secondary area is the amount of nitrogen application. In the main area, there are 2 nitrogen application methods: all nitrogen base application (A1), 50% nitrogen base application +50% nitrogen application in Large trumpet stage (A2); Four nitrogen application rates were set in the sub-area: 68 kg?hm-2 (B1), 113 kg?hm-2 (B2), 181 kg?hm-2 (B3), and 249 kg?hm-2 (B4). No nitrogen fertilizer was applied as control (CK). The effects of dry matter accumulation and nitrogen accumulation on maize yield and yield structure were systematically analyzed by measuring the changes of dry matter and nitrogen accumulation under different nitrogen fertilizer operation. Results show that the V6 and V12 stage, one-time basal score corn fertilizing nitrogen and high dry matter accumulation, However, after the initial topdressing of VT, the accumulation of nitrogen and dry matter in multiple fertilization was higher than that of the one-time basal application. The accumulation of nitrogen and dry matter in the whole growth period about multiple fertilization was higher than that in the one-time basal application, and reached the maximum under the condition of the application of 181 kg?hm-2. The accumulation of dry matter and nitrogen in the mature period showed the same pattern, and the difference was significant. The nitrogen fertilizer operation effect of maize significantly affected the grain yield and yield structure, and there was a significant difference between treatments. Under the treatment of A2B3, the maximum yield of maize was 9250.12 kg?hm-2. Through the simulation equation of fertilizer application and yield, the maximum theoretical yield was 9288.95 kg?hm-2, and the maximum theoretical yield was 202.93 kg?hm-2. Based on the above results, the effect of separate fertilization is more significant than that of one-time fertilization, and the nitrogen accumulation characteristics and dry matter accumulation distribution of maize under the treatment of A2B3 are the maximum, and the effect is significant. It is suggested that the nitrogen fertilizer operation with benq application of 90.5 kg?hm-2+ topdressing of 90.5 kg?hm-2 can obtain higher yield of maize and can be used as a theoretical reference in maize agricultural production.

      • 1
    • Li Yang, Zhang Jie, Bai Ju, Xu Fang-lei, Bo Qi-fei, Yue Shan-chao

      Abstract:

      Screening high-yield and high nitrogen use efficiency varieties is an important measure for reduce nitrogen fertilizer application and increase nitrogen fertilizer use efficiency. In this experiment, 16 maize varieties were used to compare the yield of different types of varieties and their potential N fertilizer input reduction under two nitrogen levels. The results showed that JY18, DH605, and XY335 have the potential to increase production by more than 5%, and potential N fertilizer input reduction is 15.48% to 18.39% (2018) and 14.26% to 29.47% (2019) in two years. According to their grain yield in the 225 kg/ha N (N225) treatment and in the zero N control (N0), the 16 maize varieties were divided into four categories, analysis of its biomass and nitrogen accumulation and transport characteristics showed that high-yield and high nitrogen use efficiency have higher dry matter accumulation of post-silking periods and higher nitrogen uptake on the basis of ensuring a general level of nitrogen transport.

      • 1
    • PAN Li-wen, ZHU Nuan-nuan, YANG Yu-long, LIU Tian-xue

      Abstract:

      The production efficiency of maize - soybean intercropping under mechanization production condition was studied to provide the theoretical basis for optimizing maize - soybean intercropping pattern. We conducted a field experiment including four planting patterns, maize monoculture (MM), soybean monoculture (SM), maize - soybean intercropped with row ratio 2:4(2/4I) and maize-soybean intercropped with row ratio 4:4 (4/4I) to explore the crop yield, economic efficiency and soil greenhouse gas emission. The results showed that, compared with MM, the yield of maize in the 2/4I and 4/4I modes decreased by 2949 kg/hm2 and 2253 kg/hm2,respectively, while the yield of soybean increased by 1998 kg/hm2 and 1419 kg/hm2, respectively. Compared with SM, the yield of soybean in the 2/4I and 4/4I decreased by 1802 kg/hm2 and 2380 kg/hm2, respectively, while the yield of maize increased by 7017 kg/hm2 and 7712 kg /hm2, respectively. Both 2/4I and 4/4I had intercropping advantages, and the land equivalent ratio was 1.24 and 1.15, respectively. Compared with MM, the cost of production in both 2/4I and 4/4I reduced by 1663 yuan/hm2 and 1133 yuan/hm2, respectively. Compared with SM, the cost of production in 2/4I reduced 168 yuan/hm2, while 4/4I increased 362 yuan/hm2. Compared with MM and SM, the output value of 2/4I increased by 3275 yuan/hm2 and 3140 yuan/hm2, respectively, and the economic benefit increased by 54.34% and 43.60%, respectively. The output value of 4/4I increased by 2073 yuan/hm2 and 2818 yuan/hm2, respectively, the economic benefit increased by 35.27% and 25.10%, respectively. With the Intercropping pattern, the emission fluxes of soil CO2 and N2O also reduced in farmland. Compared with SM, in mature stage, the emission flux of soil CO2 and N2O significantly reduced by 20.84% and 73.11%, respectively. Compared with MM, in the 9-leaf stage, the N2O emission flux significantly reduced by 34.13%. Comprehensive comparison of production efficiency and ecological efficiency in two maize - soybean intercropping pattern, the intercropping advantage of 2/4I was greater than that 4/4I.

      • 1
    • Zhanghaoyu, Mengchaoran, Zhangfenglin, Liudi, Weichangzhou

      Abstract:

      【Objective】The effect of different base-topdressing ratios of phosphate fertilizer on nutrient absorption and yield of drip irrigation corn was studied through field plot experiments, which provided a experimental basis for efficient phosphorus application technology of drip irrigation maize. 【Method】The experiment has a total of 5 treatments. P0(no phosphate fertilizer), Pb100(base: topdressing at 1:0), Pb50(base: topdressing at 1:1), Pb25(base: topdressing at 1:3), Pb0(base: topdressing at 0:1). 【Result】Under the same phosphorus application, base-topdressing ratios of phosphate fertilizer have different effects on P uptake amount, yield and phosphate recovery rate of drip-irrigated maize. P applied with 25% base fertilizer and 75% topdressing performance best P recovery rate and corn grain yield. The P absorption in the middle and late growth stages of maize was higher than the other four treatments. Yield increased by 18.05%, and phosphate recovery rate was 23.90%. The research found that the N and P uptake peak were at middle and late stages of maize growth (spinning to filling stage). And the absorption of phosphorus and nitrogen by maize showed significant positive correlation during silking and filling stages. It showed that increasing the proportion of P applied in the later stage is conducive to driving N absorption by mazie. 【Conclusion】Under the condition of drip irrigation, 25% phosphate base and 75% topdressing is the best P application strategies, it guarantee the P supply of the maize during the various growth periods, promote the growth of maize and the formation of yield.

      • 1
    • TAO Jin-ming, LIU Shuo-ran, SI Yan-ling, LI Xiao-yu, GAO Qiang

      Abstract:

      Agricultural ammonium polyphosphate (APP), as a new type of liquid nitrogen-phosphorus compound fertilizer, has the characteristics of good slow release, strong nutrient activity, and high absorption and utilization. In this experiment, the yield and phosphorus utilization efficiency of spring corn in a typical black soil region of Northeast China were studied through field experiments to determine the optimal application rate of ammonium polyphosphate in corn production. The results of the two-year test showed that when the phosphorus nutrient input was 75 kg/hm2, the corn yield, dry matter quality, and phosphorus accumulation were at high levels, and the two-year phosphorus fertilizer utilization rates were 25.0% and 24.5%; When it exceeds 75 kg/hm2, the yield will no longer increase significantly, but the utilization rate of phosphate fertilizer will gradually decrease. For this reason, it is necessary to determine the reasonable amount of ammonium polyphosphate. Comprehensive analysis of yield, fertilizer utilization rate and farmland phosphorus surplus rate found that the application of ammonium polyphosphate 75~90 kg/hm2 can meet the high-yield planting of local corn, and phosphate fertilizer can be reduced by 15% -20%.

      • 1
    • WANG Lai-gang, HE Jia, LI Bing, YANG Xiu-zhong, WANG Li-jun, GUO Yan

      Abstract:

      The objectives of this study were to explore the application effect and ability about the Unmanned Aerial Vehicle (UAV) remote sensing in maize (Zea mays L.) growth monitoring. The experiments were carried out during 2018~2019 at Experimental Bases Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang, China, and study the estimate models of leaf area index and yield of maize derived from Unmanned Aerial Vehicle (UAV) multispectral remote sensing in different growth stages, and then mapping the leaf area index and yield of maize in demonstrative?region based on these models. The result?showed that: there were accuracy and stability of the estimate model about leaf area index based on NDVI, EVI and GNDVI. There was the highest accuracy of the yield estimate model based on vegetation indexes in tasseling stage, followed by the silking stage, and the lowest jointing stage. Compared the accuracy of the yield estimation model, the cumulative vegetation index from 3 growth stages was higher than the single growth stage, and the determination coefficient (R2) is 0.87, root mean square error (RMSE) is 405.42 kg·hm-2. The monitoring model of UAV remote sensing in this research, could monitoring and evaluation for growth potential and yield of maize by quickly and effectively, which has accumulated experience for precision agriculture based on UAV, and it is great significance for the management and control of precision agriculture on a large scale.

      • 1
    • dongpengfei

      Abstract:

      In order to screen out the ear character of suitable mechanical grain harvest of maize, 17 maize varieties were used as experimental materials, the main ear traits, covering bract traits and grain traits of harvesting were measured, and the mechanical harvest quality of different maize varieties was evaluated. Based on the quality of mechanical harvest, the relationship between ear characters and mechanical grain quality was analyzed using stepwise regression. The results showed that there were significant difference in mechanical grain

      • 1
    • Cheng Weidong

      Abstract:

      Since 2015, the Ministry of Agriculture and Rural Affairs has organized the third action of national survey and collection of crop germplasm resources, and Guangxi was one of the first provinces to participate in the operation. The experimental materials of germplasm resources used in this study were 367 landraces of maize collected in Guangxi over the past four years, of which 203 were field corn landraces, 145 were wax corn landraces and 19 were pop corn landraces. The protein content, fat content and starch content were measured using the DA7200 near-infrared grain analyzer made by Perten in Sweden, and the observations were repeated 3 times. The result shown: among the 367 maize landraces of Guangxi tested for quality detection, the average protein content was 12.61%, the coefficient of variation was 7.12%, and the content range was 10.44%-15.19%. The average fat content was 4.45%, the coefficient of variation was 9.27%, and the content range was 3.48%-5.89%. The average starch content was 68.01%, the coefficient of variation was 2.88%, and the content range was 59.35%-71.79%. The content range and variation coefficient are fat content>protein content>starch content. The protein content and fat content of most of maize landraces of Guangxi are medium and low value types, and the starch content of only some of maize landraces of Guangxi is medium to high value type. A few number of landraces germplasm resource in Guangxi have quite high protein content meanwhile with quite high fat content, and some of landrace germplasm resources in Guangxi has quite high fat content meanwhile with quite high starch content. No landrace resources with high protein and starch content were found, and no landrace resources with high protein, fat and starch content were found.

      • 1
    • LIN Miao, ZHANG Qiu-zhi, SHI Li-yu, LIU Bei, WANG Hong-wu, PAN Jin-bao

      Abstract:

      SNeutral Detergent Fiber (NDF) is an important index to measure the fiber quality of silage maize. In this study, 341 maize inbred lines were evaluated for NDF in 2018 in Shenyang and Tongliao experimental stations. These inbred lines were subjected to whole genome sequencing, generating a total of 6,276,612 high quality SNPs. GWAS analysis detected 49 SNPs using the threshold of P < 0.000001 and 10 SNPs using the threshold of P < 0.00000001. Eight candidate genes were identified based on the GWAS, the biological functions of these genes mainly involved in cell growth and development, stress response, DNA repair damage. These results would be useful for researching on the genetic and molecular mechanism of NDF, and for the development of silage maize cultivars.

      • 1
    • peiwendong, zhangrenhe, wangguoxing, leiwenni, leigeli, gaomin, zhanghongjun

      Abstract:

      The aim of this study was to explore the canopy characteristics for high yield under increased plant density and determine the suitable planting densities in the irrigated region of north Shaanxi. Four plant density 45000, 60000, 75000 and 90000 plantshm-2were designed during 2018 and 2019 growing seasons. Two maize cultivars SK 9 and DF 30 were used to explore the effects of planting density on leaf area index, leaf direction value, light energy interception rate, photosynthetic characteristics and yield traits of maize. The results showed that the grain yield of the two cultivars increased then decreased with the increase of density, and the highest yield was obtained at the density of 75000 plantshm-2, the average yield of the two years was 14.1 t hm-2 and 13.2 t hm-2, respectively. The number of productive ear was remarkably increased with the increasing of planting density, but the seed numbers per ear and 100-kernel weight decreasedwith the increase of planting density. With the increase of planting density, the two cultivars can adjust the leaf angle of upper ear, plant type becomes compact, the leaf layer of ear position receives more light energy, improving the photosynthetic performance of population, and resulting in making more accumulation of photosynthetic production; but the coordination morphological structure and physiological function of SK 9 is better than DF 30 under the higherplant density, indicating that the grain yield potential of SK 9 is higher than DF 30. We conclude that properly increasedplant density couple with density tolerant cultivars is potential way to improve the maize yield in the irrigation area of Northern Shaanxi. The optimal planting density of maize is 75000 plantshm-2, which is suitable for the large-scale promotion in this area.

      • 1
    • wangyingyan

      Abstract:

      To provide theoretical basis for promoting high yield and efficiency production of spring maize, the comprehensive effects of fertilization level, fertilizer type and farming managements on grain yield were explored by analyzing the root distribution, dry matter accumulation and yield components under various cultivation patterns. A two-year (2017—2018) field experiment was conducted at Tieling county in Liaoning, the variety ‘Zhengdan 958’ was employed as the test material, the experiment was set as four treatments including rotary tillage without fertilization with equal row-space (T1), rotary tillage with one-time fertilization and equal row-space (T2), nitrogen fertilizer operation and equal row-space under plow tillage with straw returning (T3) and organic fertilizer input and nitrogen fertilizer operation with 2:0 row planting under plow tillage (T4), the planting density was 67500, 52500, 67500, 82500 plants hm-2, respectively. The results indicated that significant impacts on grain yield of spring maize were found between different cultivation patterns. Compared with T1, T2, T3 treatments, the grain yield of T4 in 2017 and 2018 were increased by 23.76%, 23.17%, 15.55%, and 34.59%, 28.05%, 17.19%, respectively. There was a significant difference between treatments for the above-ground dry matter accumulation and nitrogen accumulation during the whole growth period, it was showed with a trend as T4> T3> T2> T1 consistently, and the proportion of them under T3 treatment after silking stage was found with the highest values. Soil water content under T3 and T4 treatments were higher beneath 30 cm soil depth than those from T1 and T2 treatments. At 0-10 cm soil layer, soil nitrate nitrogen content in T2, T3, and T4 treatments was increased by 3.4%, 19.75%, and 55.97% compared with that in T1 treatment, respectively. Root length density (RLD), root surface area density (RSD), and root dry weight density (RWD) from T1 treatment at 0-10 cm soil layer were significantly higher than those from other three treatments (P <0.05), they exhibited a trend as T1> T2> T4> T3. The leaf area index (LAI) under T3 and T4 treatments were larger than those from T1 and T2 treatments, while root surface area index (RAI) was found with converse trend between them. In conclusion, the managements of increasing the planting density, using plow tillage, adjusting the nitrogen fertilizer management and selection of fertilizer variety could be considerable for increasing the grain yield of spring maize in this study area.

      • 1
    • ZONG xianchun, ZHANG zhenjun, GUAN Fachun, HOU ligang, ZHANG yongfeng, liping

      Abstract:

      The factors influencing corn yield under different production modes were compared and analyzed, in order to develop the strategy of increasing corn yield under the mode of "raising geese in corn field". The results showed that kernel number per row, grain weight per ear and yield of RGC-E treatment were significantly lower than those of the control (P<0.05).The correlation coefficient between grain weight and hundred grain weight of RGC-E was 0.453 lower than that of the CK, the correlation coefficient between grain weight and row number was 0.279 higher than CK, and the correlation between grain weight, row number and hundred grain weight was significantly affected by the RGC-E measures; The positive indirect effect of hundred grain weight on yield is the largest through kernel number per row in the CK (indirect path coefficient was 0.475), but the positive indirect effect of row number on yield is the largest through kernel number per row in the RGC-E(indirect path coefficient was 0.301). Therefore, the role of factors of corn yield components changed in the yield components, the heritability of row number should be enhanced to increased corn yield on the basis of increasing of the kernel number in the future.

      • 1
    • li zhong nan

      Abstract:

      According to 8 F1 materials of purple sheath inbred lines × green sheath DH lines of maize, 607 DH lines were induced by hybridization and doubled by self pollination in Hainan Province. The suitability of purple sheath DH lines and green sheath DH lines, pollution rate, average number of polluted plants, and the number of polluted plants by purple sheath and green sheath in green sheath DH lines were tested and analyzed. The results showed that the pollen viability of double haploid with purple leaf sheath was stronger than that of double haploid with green leaf sheath.

      • 1
    • Liu Qiang, Deng Yan, Wang Lujun, Zhao Li, Guo Hongxia, Zhang Liguang, Wang Chuangyun

      Abstract:

      In this study, single sequence repeat(SSR)marker sites were identified based on transcriptome sequencing of teosinte(Z.mays. ssp. parviglumis).Results showed that a total of 14 099 SSR were obtained, and the SSRs occurrence frequency f was 13.31%.Trinucleotides and single nucleotides were the main types of repeats,accounting for 42.12% and 25.65% of the total SSRs, respectively;hexanucleotide repeats was the lowest which was 0.43%.Transcriptome results showed that a total of 38 repeat elements were found in the teosinte SSR, and single nucleotide repeat A / T exhibited the highest frequency,accounting for 21.058% of the total SSRs;followed by AG / CT and GCC / GGC,accounting for 6.76% and 5.53% respectively.The number of 5 repeat SSRs was the most,which was 3 927(27.85%).The results should contribute to researches

      • 1
    • MU Xinyuan, CHENG Sixian, LIU Tianxue, LIU Weiling, LI Na, WU Jian, YANG Li, ZHAO Yali, LI Chaohai

      Abstract:

      In order to determine the suitable tillage depth and establish a reasonable topsoil of Lime Concretion Black Soil, a multi-year experiment with four tillage depths of subsoiling [30 cm (S30), 40 cm (S40), 50 cm (S50) and 60 cm (S60)] and rotary tillage (RT, 15 cm) as the control was carried out to study the effects of different tillage depths on soil porosity, soil respiration rate, and root growth, biomass accumulation, nutrient absorption and grain yield of summer maize. The results showed that, the increase of tillage depth could not only improve the soil porosity and soil environmental quality, but also promote the root growth, biomass accumulation and nutrient absorption of summer maize, so as to improve the grain yield of summer maize. With the increase of soil tillage depth, the soil pore condition improved continuously, but the grain yield, biomass accumulation and nutrient absorption of summer maize increased first and then decreased. Among the four tillage depths, the S50 treatment was the best. Compared with rotary tillage, the soil porosity and surface area of soil pores at 40-50 cm soil layer under S50 treatment increased by 27.8% and 24.8% respectively, the soil respiration rate increased by 63.7%, the root mass density, dry matter accumulation, nitrogen accumulation, phosphorus accumulation and potassium accumulation of plant increased by 89.0%, 13.2%, 15.5%, 20.7% and 9.0% respectively, and the grain yield of summer maize increased by 11.0%. Therefore, the suitable tillage depth should not exceed 50 cm for summer maize production in Lime Concretion Black Soil.

      • 1
    • ZHAN chao, CHEN guo-shuang, SHAO qing-chun, LUO na-na, WANG min-ling, WANG pi-wu

      Abstract:

      Using molecular marker technology to divide the population of maize inbred lines and identify kinship can effectively provide technical support for cross breeding. In this experiment, 30 pairs of SSR markers with good polymorphism were used to genotype and classify 259 maize inbred lines. A total of 228 alleles variants that vary from 4 to 13 were detected in 259 inbred lines, with an average of 7.57 detected per primer pair. The polymorphism information content ranged from 0.37 to 0.86, with an average of 0.69, and the average of genetic diversity index was 0.73. By UPGMA cluster analysis method, 259 maize inbred lines were divided into 5 major groups, which were named the Reid,the Lu da Red Cob,the Sipingtou,the Lancaster,the Zi 330 subgroup. The results are mainly based on the four groups of the Reid, the Lu da Red Cob, the Sipingtou and the Lancaster.The division of population was basically consistent with the genealogy. At the same time, the maize inbred lines with complicated genealogy sources were divided to clarify the belonging of the inbred lines.

      • 1
    • LUO Yi, WU La-ping

      Abstract:

      Reducing food losses are becoming an important mean of saving resources and increasing food supply. Based on the survey data of 1196 households in 23 provinces, this paper measured the corn storage losses of different sizes, and used the Fractional Logit model to study the causes and determinates of corn storage losses in different sizes. The result shows, with the increase of scale, the corn storage loss rate decreased first and then increased, and the corn storage loss rate of middle-scale farmers was the lowest. The empirical analysis result shows that expand the corn storage scale and adopt advanced corn storage facilities can reduce the corn storage loss of different sizes. In addition, rodent damage will increase corn storage losses for large and medium-sized farmers. Compared with other measures, physical control is positively related to corn storage losses for large and small farmers. Increase the land scale will increase the corn storage loss of large and small-scale farmers; the variety is positively related to the corn storage loss of large and medium-sized farmers.

      • 1
    • WU Yuan, 易婧

      Abstract:

      Based on the core journal articles of 721 silage maize researches published in CNKI database from 1992 to 2019, using literature analysis method and drawing knowledge map with CiteSpace software, visually analyze the literature distribution, journal distribution, research institutions, core authors, research hotspots and trends of silage maize research in China, aiming at comprehensively grasping the development process of silage maize research in China, and providing valuable reference for theoretical research of silage maize in China. The results show that in the past 30 years, the research on silage maize in China has shown a wave-like development trend, 10 publications in the core area, At present, institutions engaged in silage corn research are widely distributed, but they are mainly concentrated in areas with developed herbivore and animal husbandry industries such as North China and Northeast China. The co-occurrence network between them is low, and cooperation needs to be improved. Finally, through the analysis of high-frequency keywords and emergent words in the literature, it is concluded that the research hotspots of silage maize in China mainly focus on the selection of silage maize, the nutritional value of silage maize, the use of silage maize, how to increase silage maize yield, the economic benefits of silage maize; its development trend is mainly concentrated on silage maize fermented varieties, whole plant silage maize production technology, silage quality and planting density and sowing date, variety and planting pattern, fertilization method and soil type, cultivation method and sowing the impact of the way on the yield of silage maize.

      • 1
    • Hou Liangyu, Wang Keru, Han Dongsheng, Li Shaokun

      Abstract:

      In this study, based on such technical procedures as planting variety, planting density, total mechanization operation, storage and drying, a survey was carried out on the progress of maize production in 71st farm, 4th Agriculture Division, XPCC, China. According to the analyzed result, it is shown that, the maize production technology based on dense planting for high yield, lied in mechanical grain harvesting, and emphasized on green prevention and straw returning, has constantly achieved the nationwide high yield records of maize at large area (700hm2) in 71st farm in the irrigation production area of maize, Northwestern China, respectively,which were identified by the experts from the ministry of agriculture and rural affairs of PRC in 2012(16701 kg/hm2), in 2014(18414 kg/hm2), and in 2017(18447 kg/hm2). With a net profit over 15000Yuan/ hm2, it has realized the coordinative improvement between high yield and high efficiency, as well as green sustainability of maize production, thereby, thus setting a representative mode of modern maize production.

      • 1
    • LiuJie, Zhang Chun-xiao, Li Shu-fang, Cao Tie-hua, Liang Xuan-he, Liu Xue-yan, Ma Yong-xin, Zheng Da-hao, Li Xiao-hui

      Abstract:

      The appropriate temperature for the identification of chilling tolerance at maize germination stage was established as 10℃, based on statistical analysis of the average ground temperature of 10 cm underground in Gongzhuling, Jilin during April 20th to May 10th, 2009-2018. The germination rate, germination index, average germination time and relative values of 81 maize hybrids were measured under low temperature stress. Principal component analysis was used to calculate the comprehensive cold tolerance D value. Based on D value and relative germination rate, chilling tolerance of maize hybrids was comprehensively evaluated. The results showed that six single indicators at germination stage were synthesized into two independent comprehensive indicators by principal component analysis. Based on the D value of comprehensive evaluation of cold resistance and the relative germination rate, 81 hybrids was all divided into 5 categories by cluster analysis, which included excellent cold resistance, strong cold resistance, medium cold resistance, weak cold resistance and very weak cold resistance. Both have a high degree of coincidence. Five hybrids with strong cold resistance were screened out, including Xianyu 1225, Shengyuan 80, Heyu 35, Xiangyu 998 and Liangyu 66. A strategy was finally proposed to combine the rough evaluation based on relative germination rate with the precise evaluation based on comprehensive cold tolerance D value.

      • 1
    • DONG WANLIN

      Abstract:

      Long-term and multipoint field experimental data with the same cultivar provides effective data support for research spatiotemporal variations of crop yield. This study aimed to quantify the spatiotemporal change of summer maize yield and yield components and explore the change of the year of climate type. The data of multipoint field experiments with the same summer maize cultivar (Zhengdan958) were analyzed in summer maize growing region in China from 2004 to 2013. Summer maize yield of the regional average was 9055 kg ha-1. The seasonal difference of the yield was 1635 kg ha-1, the site difference of it was 4258 kg ha-1. The seasonal and site variation of it was 18.1% and 47.1%, respectively. 1000-kernel weight of the regional average was 313 g with 13.1% seasonal variation and 27.8% spatial variation. Kernel number of the regional average was 479, and decreased significantly (P≤0.01). Kernel number presented 18.0% seasonal variation and 38.7% spatial variation. Summer maize yield increased significantly with the increase of 1000-kernel weight. The large fluctuation and spatiotemporal variation of summer maize yield were caused by kernel number decreasing significantly and the large spatiotemporal variation. The days of maximum temperature above 33 oC was the main reason for summer maize yield greatly reduction during growth stage.

      • 1
    • jiangaonan

      Abstract:

      In order to compare different section folding strength of spring maize varieties, in cold and arid regions of northwest 9 spring maize varieties as the research object, through the determination of corn base in the third section flexural strength, microstructure and by using optical microscope to observe the internodes, section microscopic indicators of vascular bundle and folding strength related analysis, research section of spring corn folding strength and stem the relationship between the microstructure. The results showed that the joint folding strength of different spring maize varieties reached a significant level. The statistical analysis on the microscopic indexes of vascular bundles showed that the variation coefficient of vascular bundle sheath thickness and epidermal cell thickness was the largest, reaching 34.8% and 23.2% respectively. The increase of the number of vascular bundles in stem segment was not conducive to the improvement of the nodule folding strength (r=-0.945**, r=-0.927**), while the increase of the mean area of vascular bundles and phloem area was beneficial to the increase of the nodule folding strength (r=0.831*, r=0.799*, r =0.733*, r=0.786*).Diameter analysis showed that the number of vascular bundles had the largest direct effect on the strength of the stem folding, followed by the thickness of epidermal cells, and the largest area of vascular bundles, the thickness of vascular bundle sheath, phloem area and other indicators also had an indirect effect on the strength of stem folding through the number of vascular bundles. Among the tested varieties, the number of vascular bundles was less, the average area of vascular bundles and phloem area were larger, the stalk folding strength was higher, and the lodging resistance was better than other varieties.

      • 1
    • Yang Yunshan, Guo Xiaoxia, Liu Huifang, Hou Peng, Liu Guangzhou, Liu Wanmao, Ming Bo, Xie Ruizhi, Wang Keru, Li Shaokun

      Abstract:

      Grain moisture content of maize at harvest is the key factor that affects the grain quality, storage and processing which has been an important issue of technique and economic. The experiment was conducted in the field by setting a shading test throughout the whole growth period. We analyzed the influence of shading on grain moisture content of kernels at maturity. The grain moisture content showed a same tendency, Denghai 618 was the lowest, Xianyu 335 was the second and Zhengdan 958 was the highest under the treatment of CK, S1 and S2, respectively. In addition, the average grain moisture content of Zhengdan 958 was 2.26% and 9.43% higher than Xianyu 335 and Denghai 618; Xianyu 335 was 7.01% higher than that of Denghai 618. Denghai 618 was 4.36% higher than Xianyu 335 under S3 treatment. The grain moisture content increased with increasing levels of shading, the grain moisture content of S1 (85% of natural light), S2 (70% of natural light) and S3 (50% of natural light) was 2.79%, 4.43% and 23.83% higher than that of CK (natural light), respectively. With the planting density increased from 75000 to 120000 plants ha- 1, the grain moisture contents of Denghai 618, Xianyu 335 and Zhengdan 958 increased by 6.63%, 1.62% and 1.53%, respectively. The increase degree of grain moisture content of Denghai 618 was significantly higher than that of Xianyu 335 and Zhengdan 958. The weak light stress by shading delayed the maturity of maize, the maturity of S1, S2 and S3 were delayed by 4.0, 4.0 and 6.5 days comparing with CK, which may be the reason for the increase of grain moisture content. It is suggested that selecting cultivars with earlier maturity and faster kernel dehydration rate will meet the requirement of grain moisture for mechanical grain harvesting in the areas where kernel dehydration rate was slowly caused by frequently rainy and lightless weather.

      • 1
    • lihongyan, lilulu, lishaokun, xuejun, wangyonghong, wangkeru, xieruizhi

      Abstract:

      In order to define the dynamic difference of kernel moisture content and dehydration rate in the different parts of maize ear, this study used eight cultivars with different growth stages and dehydration rates in Yinchuan, Ningxia (spring maize region) and Xinxiang, Henan (summer maize region). We divided the maize ear into five parts vertically, then measured the kernel moisture content and calculated the kernel dehydration rate in different parts periodically. The results showed that during the middle and late stage, the kernel moisture content in the upper part of ear was lower than that in the middle and lower parts. The differences of kernel moisture content in various parts of ear was lower before physiological maturity than that after physiological maturity. The range of different parts of the kernel moisture content was less than 3% in test maize cultivars on 20 d before physiology maturity. The range at maturity was 0.6%-5.2%, and the maximum range was 6.2% after physiological maturity. The dehydration rate gradually decreased from the top to the bottom of ear, and there were differences in different cultivars. The kernel dehydration rate in different parts of ear was great in Xianyu 335, Dika 517 and Dika 519. The range of kernel moisture content in different parts were negatively correlated with dehydration rate of middle kernels and total ear.

      • 1
    • DI Hong

      Abstract:

      In this study, two pairs of hybrids and their parental inbred lines of maize which planted in early-maturing and very early-maturing in Heilongjiang were used, Demeiya 2 (low moisture content) and Keyu 17 (high moisture content), Demeiya 3 (low moisture content) and Zhedan 37 (high moisture content), which were significant difference in grain moisture content at harvest. The dynamic changes of grain moisture content, dehydration rate, and filling rate were investigated to find the relationship with the moisture content of harvest. The results showed that the grain moisture content of Demeiya 2 and Demeiya 3 were significant higher than Keyu 17 and Zhedan 37 at harvest stage respectively. The grain moisture content of maize hybrids showed no significant difference in varieties until physiological maturity stage, then the difference gradually increased. The grain filling rate of two varieties with low moisture content (Demeiya 2 and Demeiya 3) were 0.12g/d quicker than other two hybrids with high moisture content (Keyu 17 and Zhedan 37). The difference was derived from female inbred lines. Three days difference from pollination to physiological maturity were detected between hybrids with low and high grain moisture content at harvest, which were derived from the female inbred lines. The dehydration rate became quicker, which were detected in the male and female inbred lines. There were the extremely significant and significant negative correlation between the grain moisture content at harvest and the grain dehydration rate and the grain filling rate respectively. The results should be benefit for maize hybrid breeding and innovation of resource with low grain moisture content at harvest, quick dehydration and completely mechanized production.

      • 1
    • Xu Zhi-peng, Li Hui-xia, Li Wen-hao, Ni Chun-hui, Liu Yong-gang, Xu Xue-fen

      Abstract:

      The corn root systems and the rhizosphere soil samples were collected according to symptoms of dwarf and earlier withering plants to learn the damage of plant nematodes in the seed corn production areas of Zhangye city, Gansu Province in 2018, and a population of cyst nematode was isolated. The pathogen was confirmed as Heterodera elachista by identification of morphological characteristics and molecular biology analysis. The pathogenicity test results showed that the symptoms such as shortness of the corn plants and yellowing of the leaves were caused by this nematode population using artificial inoculation. The effects on the hatching of the nematode in different temperatures and hatching solutions corn root exudates, corn root juice, soil infusion were studied, and the survival of the newly hatched juveniles and the second-stage juveniles(J2) at different temperatures. The results showed that the suitable hatching temperature for the cyst nematode was 28 ℃. At 28 ℃, the survival time of J2 was 22 d; at 25 ℃, the survival time of J2 was 24 d; at 5 ℃, the survival time was more than 30 d, and the mortality of J2 was the lowest. Corn root exudates, soil infusion and 20 times corn root juice could obviously promote the hatching of the Heterodera?elachista, while 5 times corn root juice and 4 mmol/L zinc chloride solution inhibited hatching.

      • 1
    • denghaoliang

      Abstract:

      It has been a long-term focus that the response of spring maize growth characteristics, yield performance and water use efficiency to different mulching planting patterns in field production. To detect a better cultivation techniques of spring maize in semi-arid region in Loess Plateau, the spring maize cultivars used was‘JK-3’, Six treatments experiment were conducted in 2015 and 2016, respectively, included non-contoured seedbed with film mulching (WM), non-contoured seedbed with half film mulching (HM), ridge-furrow with polyethylene film and straw mulching (MRM), ridge-furrow with full film mulching (WRF), ridge-furrow with straw mulching (SM) and non-contoured seedbed without mulching as the control (CK). We measured the growth characteristics, yield and its components and water use efficiency (WUE) of spring maize during the different growth stages, and the dynamic of each growth index during the whole growth period. The results showed that the ridge and furrow with mulching rainwater harvesting planting can significantly improve the growth of spring maize and dry matter accumulation. In addition, it can optimize the structure of the ear, with better yield components such as ear length, ear diameter, grain number and 100-grain weight. WRF and MRM treatments increased the average grain yield and WUE by 171.40%, 155.05% and 142.80%, 125.44% in compared to CK over two growing seasons respectively, especially on the basis of sole WRF treatment. Taken together, WRF was the superior choice for high and stable yield of maize in semi-arid region in Loess Plateau due to its good production characteristics.

      • 1
    • wangfeng, 陈江鲁, 李少昆

      Abstract:

      In order to study the effect of irrigation amount on maize grain dehydration after physiological maturity. The research set up irrigation experiment and interaction experiment between irrigation amount and planting density. Maize cultivars Xianyu 335 and Jiushenghe 2468 were used in this experiments. The changes of moisture content of maize grains from physiological maturity to drying by standing in the field. The results showed that, in the experiment of equal amount irrigation and distribution irrigation in growth period, the moisture content were increased after physiological maturity with the increased of irrigation amount at the planting density of 9×104 ha-1and 12×104 ha-1; with the increased of the irrigation amount from 3600 m3 ha-1 to 7200 m3 ha-1, the moisture content of maize grains increased by 0.94-2.87 percent respectively. And it shows that the greater the amount of irrigation, the slower the rate of dehydration in maize grains. In the auxiliary experiment of irrigation amount and planting density, at the planting density from 6×104 ha-1to 13.5×104, with the increased of the irrigation amount from 3000 m3 ha-1 to 6000 m3 ha-1, the moisture content of maize grains increased by 2.97, 1.60, 5.00, 5.57, 3.66 and 2.64 percent respectively with significant differences. At 3000 m3 ha-1 and 6000 m3 ha-1 irrigation amount, the moisture content of maize grains were significant difference from 6×104 ha-1to 13.5×104, however, there is no obvious increase or decrease trend. There were no significant difference in the moisture content of maize grains among all planting densities at 4500 m3 ha-1 irrigation amount. To sum up, the moisture content of maize grains were sensitive to the change of irrigation amount, but the response to planting density was irregular.

      • 1
    • PAN Guang-tang, YANG Ke-cheng, LI Wan-chen, HUANG Yu-bi, GAO Shi-bin, LAN Hai, LI Lu-jiang, CAO Mo-Ju, TANG Qi-lin, FU Feng-ling, ZHOU Shu-feng, WU Yuan-qi, LU yan-li, LIN Hai-jian, SHEN Ya-ou, RONG Ting-zhao

      Abstract:

      The establishment of heterotic groups and patterns is crucial to a successful maize hybrid breeding programme. We systematically summarized the recent researches and application on heterotic groups and patterns, as well as unitization of tropical maize germplasm during maize breeding process in Southwestern China. As early as the 1980s, a novel insight that inbred lines could be directly developed from tropical maize germplasms, and hybrids could be further crossed from temperate and tropical inbred lines by incorporating their respective advantages, was firstly proposed by Sichuan Agricultural University. Under this concept, inbred line S37 (Su37) was successfully selected from the Suwan-1 tropical population, and also several popular hybrids were bred using the heterotic pattern of "temperate germplasm × tropical germplasm". Along with the successful practices in Southwest China, more experiences of maize breeding were summarized continuously. For example, the maize germplasms could be divided into three groups, namely Reid, Non-Reid and Tropical. The hybrids can be produced from a single cross using inbred selected from two of the all three groups, which was called as a "triangle" heterotic pattern. Furthermore, we found that the pattern of "Reid × Non-Reid" was more suitable for areas of shallow hills and river valley, and patterns of "Reid × Tropical" and "Non-Reid × Tropical" were more suitable for deep hills and mountains. According to the development requirements of maize industry and improvement of breeding technology, deeper exploration and innovation of tropical maize germplasms in the future is proposed in the review, which will be helpful to realize a relatively fixed pattern of maternal and paternal groups, and heterotic patterns for maize breeding in specific ecological regions.

      • 1
    • Wang Ya-nan, Jian Jun-shuai, Jia Kai, Bai Lan-fang, Wang Rui, Zhang Xiang-qian, Wang Yu-fen

      Abstract:

      Thirty-four maize cultivars were used in a field experiment for this study. During silage harvest period of corn, the mechanical properties, variety differences and index correlation of different corn varieties were compared and analyzed after the investigation of field lodging rate, plant height, ear height, stalk diameter, rind penetration strength (RPS) and crushing strength (CS). All of these can provide theoretical basis for screening silage corn varieties with strong lodging resistance and suitable mechanical harvesting properties. The results showed that both of the RPS and CS at the bottom of the stem gradually decrease with the increase of the internode; and this indicator has a significant positive correlation with plant height; stem breakage during silage harvesting was the key factor that would lead to corn lodging; Among all tested corn cultivars, 32D22, Xianyu 1692, Dongdan 606 and KXA4574 showed stronger comprehensive lodging-resistance.

      • 1
    • LU Jun-tian, REN Li-li, Lv Chun-bo, Qu Jiang-bo, Liu Zhong-jie, Xu Xiao-hui

      Abstract:

      Using iodent germplasm to improve the resource of Luda Red Bone, analyzed the Combining ability and heterosis of the main agronomic traits of five improved lines by using NC II genetic mating design。25 cross combinations were obtained by using PB-2, PB-3, PB-7, PB-8, PB-10 as female parent and Dan988, Tie0322, M54, Mo17 and Tie7922 as test varieties with strong superiority to the inbred lines. The results showed that the improved lodging line population of iodent germplasm had great utilization value. It could effectively reduce the plant height, ear height, row number of ears, increase the yield, lodging resistance, grain quality and ear length of hybrid. The parents of the improved population of Dan598 and Dan99 had high general combining ability and high yield specific combining ability, which were easy to use. Combination of high-yielding hybrid combinations has great application value in breeding.

      • 1
    • 展文洁, 刘剑钊, 梁尧, 袁静超, 张洪喜, 刘松涛, CAI Hong-guang, 任军

      Abstract:

      The objective of this study was to clarify the characteristics of soil physical and chemical properties, root system distribution, nutrient accumulation, and yield under different soil plough layer construction mode, including four modes, T1 (stubble cleaning and seeding), T2 (Seedbed compaction after subsoiling), T3 (seedbed compaction with inter-row subsoiling), T4 (seedbed and inter-row subsoiling with seed bed compaction). This experiment chose common maize Zhengdan 958 as the plant material. The result indicated that the biomass, nutrient accumulation and grain yield were increased significantly in T2 and T3 treatments, and the grain yield increased by 20.2% and 28.1%, respectively, and the accumulation of nitrogen, phosphorus, and potassium in grain increased over 15.0% on average. The soil structure was improved in T2 and T3 treatments, and the three phase ratio and soil moisture content were higher than that in T1 treatment. The total root dry weight,total root length and total root surface area in T2 and T3 treatments were increased by 10.6%-55.7%, 32.6%-43.6%, and 23.1%-38.9%, respectively. The root distribution among different soil layers was more reasonable, and the ability of roots to absorb and utilize soil nutrients was improved. In a summary, subsoiling of seedbed or row with compaction in seedbed can improve soil structure, increase soil water content, the proportion of liquid and the gas phases in the soil, and then promote the development of maize root system, increase the absorption of nutrients in deeper soil, thus resulting higher grain yield and nutrient efficiency.

      • 1
    • Guo Ya-nan, Xue Jun, Ming Bo, Hou Jun-feng, Fan Ying-hu, Dong Peng-fei, Wang Ke-ru, Xie Rui-zhi, Hou Peng, Li Shao-kun

      Abstract:

      High kernel broken rate is a main factor to limit promotion of mechanical maize kernel harvesting technology. Maize kernel hardness is the direct factor to affect breakage. This study located in two ecological planting areas, and set different cultivars and sowing dates experiments. The hardness of embryo, endosperm and top of kernel were measured using the hand portable push-pull meter under different moisture content condition. To determine the change of hardness during the dehydration process of maize kernel, and to analyze the relationship between kernel moisture content and hardness. The results show that hand portable push-pull meter can measure puncture strength of kernel embryo, endosperm and top of different maize cultivar under moisture content variation. The penetration strength can be used to characterize the hardness of kernel. The endosperm of kernel had the highest hardness, followed by the top, and the hardness of embryo is the lowest. Kernel hardness increased as the decreasing of moisture content. The hardness of embryo was the most sensitive to moisture content changing, however, the hardness of top was the least sensitive to moisture content changing. The response of endosperm hardness to moisture content is different among different cultivar. The selection of suitable cultivars and the determination of optimal harvesting period can be carried out by the hardness of the endosperm in maize production.

      • 1
    • XueJun

      Abstract:

      Lodging is a common problem during maize production. Lodging increases the difficulty and costs of harvesting. The experiment treatments included maize cultivars, plant density and fertilizer were conducted. The rate of stalk lodging, root lodging, ear and kernel loss were investigated to determine the quantitative relationship of lodging rate with grain loss in mechanical grain harvest. The effect of different harvesting methods on yield loss are clarified by changing the header height and harvest direction. The results showed that, the ear loss was a major part of grain yield loss. The stalk lodging had a greater impact on maize ear loss than root lodging in mechanical grain harvest. Ear loss ra/te increased by 0.28% when stalk lodging rate increased each 1%, ear loss rate increased by 0.17% when root lodging rate increased each 1%. The ear loss was higher in lower position of stalk broken than that in higher position. Lowering the harvester header decreased ear loss rate, but this was easily to cause blockage of the header, this greatly reduced harvest efficiency. When the harvesting direction was opposite to the direction of plant lodging, the ear loss was lowest, however, this was also easily to cause the blockage of the header.

      • 1
    • tan guo bo, bian shao feng, Yang Xiao-Hui, zheng hong bing, yan wei ping, zhao hong xiang, zhang li hua, sun ning, meng xiang meng, yang da hai, qi hua

      Abstract:

      Using maize as experimental material, the cultivation patterns of simplified drip irrigation, drip irrigation under plastic film and furrow irrigation were studied. The results showed the maize leaf area index, dry matter accumulation, yield and soil moisture utilization of the simplified drip irrigation were lower than that of drip irrigation under plastic film. The maize leaf area index, dry matter accumulation, yield and soil moisture utilization of the simplified drip irrigation were higher than that of the furrow irrigation. The sowing, fertilization and drip irrigation pipe laying of the model were completed at one time. Corn is not cultivated while it is growing. The technology mode is convenient to operate and simple to use. This model solves the problem that drip irrigation under plastic film cannot be completely cleaned and easily causes white pollution. It solves the problem of traditional furrow irrigation that nitrogen fertilizer is not easy to apply in different stages and the uniformity of irrigation water is not consistent. Water saving, increase production, increase income and increase efficiency have been realized in the simplified drip irrigation of maize. which can be applied and popularized in areas with irrigation conditions in the semi-arid regions of northeast China.

      • 1
    • Xu Chen Wu

      Abstract:

      The ideal ear and kernel type of maize are the key to improve maize yield. In this study, 32 teosintes, 68 landraces and 294 inbred lines from a wide range of sources were used as materials. Based on the simplified genome sequencing of 294 maize inbred lines, 11 ear- and kernel-related traits were analyzed by GWAS. The results showed that a total of 44 SNP loci were detected for 11 traits, of which 28 loci were associated with 6 ear-related traits and 16 loci were associated with 3 kernel-related traits. In order to understand whether these associated sites through domestication and improvement, we further integrated the associated loci with sequence data of 32 teosintes and 68 landraces. It is found that a total of 29 SNP shared among the three populations. By Fisher’s exact test, it is found that the allele frequency of 7 SNPs had significant difference between teosinte and landrace, that of 14 SNPs had significant difference between landrace and inbred line, and that of 3 SNPs had significant difference among teosinte, landrace and inbred line. The result suggested that these loci might undergo the domestication or/and artificial improvement in the history of corn evolution. The results laid a foundation for further excavation of candidate genes related to ear and kernel of maize and development of functional molecular markers.

      • 1
    • LI Chun-lei

      Abstract:

      Tropical maize germplasm CML493 were artificial inocuting setosphaeria turcica in this study. The leaves surface present bit spot then gradually increase and enlargement along the extension of time. Methylation-sensitive amplification polymorphism (MSAP) technique and transcriptome sequencing (mRNA -seq) technique were used to analyze the DNA methylation pattern, DNA methylation level and mRNA expression of CML493. The results showed that the methylation sensitive amplification polymorphisms of each treatment group were 78.21% and 76.13%, and the methylation sensitive amplification polymorphisms of each treatment group were 21.79% and 23.87%. The total methylation rate increased by 5.49%, the total methylation rate increased by 14.24%, and the semi-methylation rate increased by 6.11%. When inoculated with bacteria solution after 6 days, the total methylation rate increased by 6.40%, the total methylation rate increased by 16.73%, and the semi-methylation rate increased by 5.57%. When inoculated with the bacteria solution on 12d, A total of 2298 coexpressed genes, 1434 coexpressed up-regulated genes and 769 coexpressed down-regulated genes were detected. The number of upregulated genes was significantly higher than that of down-regulated genes according to the volcanogram. A total of 5 gene IDs were screened out to be possibly involved in the regulation of inoculated Setosphaeria turcica. The total methylation and total methylation were closely related to the number of differentially expressed genes and down-regulated genes with the extension of the infection time.The number of hemimethylation was closely forecast related to the number of up-regulated genes .

      • 1
    • YANG Jin-sheng, LI Guang-qun, LAN Jin-hao, LIU Guang-yao, BAI Wen-bin, WANG Qin-di, Zeylan Abdumijiti

      Abstract:

      In 1979, China began to implement the corn variety approval system, in order to better understand the situation of corn variety approval in the past 40 years. The datum of 11803 new maize varieties authorized from 1979 to 2018 were collected in this article. These datum included the units, the frequency, the parental origin, the characteristics and so on. The varieties with a total promotion area of more than 40 million mu and an annual promotion area of more than 10 million mu were summarized. The changing trend and the spreading cycle of the main maize varieties since the reform and opening up were analyzed by these datum. It will provide reference for maize breeding.

      • 1
    • LI Song, HAN Wei, ZHANG Kai, YI Yan-li

      Abstract:

      Rotary tillage is adopted in maize planting in western Liaoning province for a long time, which is one of the important reasons that lead to shallower top-soil and lower maize yield. Therefore, it is of great significance to explore a tillage method that is suitable for maize cultivation in western Liaoning. In this study, the soil physical properties, distribution of maize roots and maize yield were measured by field experiments under three-year continuous rotary tillage, plowing tillage and deep loosening, respectively. The results showed that, compared with plowing tillage and rotary tillage, deep loosening significantly increased the top-soil thickness and decreased the subsoil thickness. In the middle and lower layers of soil, deep loosening also reduced soil compaction and bulk density, improved soil porosity, and was conducive to the downward growth of maize roots. Thus the maize roots in the middle and lower layers of soil are not only richer, but also account for a higher proportion of the total root quantity. This study indicates that deep loosening is beneficial to improve soil structure and promote maize growth, which provides a theoretical basis for constructing reasonable top-soil and high yield of maize in cinnamon soil area in western Liaoning.

      • 1
    • ZHANG Feng-qi, ZHANG Jun, ZHANG Ying-ying, DING Yong, QI Jian-shuang, GU Li-min, MU Xin-yuan, ZHAO Fa-xin, MA Zhi-yan, XIA Lai-kun, TANG Bao-jun

      Abstract:

      Kernel rehydration rate is one of the main factors affecting kernel moisture content at maturity in maize. The study used 14 inbred lines from home and abroad, following the complete diallel crossing, and had obtained 182 combinations as materials. By employing AUDDC (Area Under the Dry Down Curve) method, we were respectively carried out the calculation of the kernel dehydration rate at 35~40d, 40~50d, 50d~maturity, 40d~maturity and 35d~maturity after pollination and the genetic analysis. The results indicated that variance of general combining ability of kernel dehydration rate at each development stage for the 14 inbred lines were all reached very significant level, in which the inbred lines LH202 had the smallest effect value at all development stages. Special combining ability variance of 182 combinations at all development stages were also reached very significant level. At each individual development stage, the heredity of kernel dehydration rate was mainly additive effect, and the heritability of kernel dehydration rate at 40d~maturity after pollination was the highest, and could be stable heredity. There were significantly positive correlation among 40~50d, 50d~maturity, 40d~maturity and 35d~maturity after pollination of kernel rehydration rate, and they were also respective significantly positive correlation with kernel moisture content at maturity, and the combinations for the kernel dehydration rate at these stages showed significant positive relation with their parents’. The results will provide theoretical basis for kernel rehydration rate identification and genetic improvement of maize varieties.

      • 1
    • ZHANG Bi-zhou, GAO Ju-lin, YU Xiao-fang, BORJIGIN Qinggeer, HU Shu-ping, HAN Sheng-cai, BORJIGIN Naoganchaolu, WANG Zhen

      Abstract:

      【Objectives】The aims of the study were to isolate the low-temperature cellulose degradation microbes from GF series of microbial consortium which had obtained through low-temperature acclimation in low-temperature in our lab, establish the low-temperature and high-efficiency composite microbial system for corn stover degradation and analyze the its degradation effects.【Methods】Using Congo red medium, we isolated the single strain with obvious hydrolyzation circle through spread plate method at 15℃, then did effective pair based on its own characteristic. With 3 culture types (liquid state cultivation, solid state cultivation and simulation environment cultivation), we conducted microbial consortium selection and effect evaluation by determining filter paper enzymes (FPA) activity and corn stover degradation rate.【Results】Twenty-nine single strains were obtained after isolation and purification, and 11 strains showed obvious hydrolysis circle in cellulose Congo red medium. Also, we obtained 10 conjugate pairs strains, while conjugate pairs strain A, D and G degraded filter paper after 15 days culture at 15℃. The conjugate pairs strain had a better degradation ability than the single strain. The order of corn stover degradation rate of conjugate pairs strain at three different culture types is, simulation environment cultivation>solid state cultivation≥liquid state cultivation, while conjugate pairs strain G showed the best degradation performance at simulation environment cultivation. The FPA was 32.96 U/ml with a 20.98 U/ml increase compared to CK, and the corn stover degradation rate of G was 47.56% with a 21.56% increase compared to CK. After 16SrDNA identification, the results showed that conjugate pairs strain G consisted of Pseudomonas sp., Cellulosimicrobium cellulans, Achromobacter marplatensis and Pseudomonas fuscovaginae.【Conclusions】The degradation performance of the conjugate pairs strain was significantly better than that of the single strain, while conjugate pairs strain G showed best. It provides us a new way for corn stover microbial inoculum research and utilization.

      • 1
    • Huangzhaofu

      Abstract:

      Grain moisture content at the physiological maturation stage is highly correlated with that at the harvest stage. It is of great significance to clarify the changing characteristics and influencing factors of grain moisture content at the physiological maturation stage of spring maize and determine the appropriate harvest date. During 2017 to 2018, the experiment was conducted in Kailu, Inner Mongolia and Tieling, Liaoning to observe grain moisture content of 8 common varieties at the physiological maturity stage, and to analyze the effects of accumulated temperature changes at the mature stage(15d before physiological maturity) of grain dehydration. The results showed that: the same varieties in different locations and different years had different grain moisture content at physiological maturity. The differences of the 8 varieties at different location reached an average of 2.31 (ranging from 0.8 to 4.3) percentage point, and the differences between different years reached an average of 2.91 (ranging from 0.7 to 5.4) percentage point. Environmental factors had effects on the date of physiological maturity and the moisture content, and there existed significant interaction effects between varieties and environments. There was no significant correlation between the grain moisture content at the physiological maturity stage and the length of the growth stage, but the longer the growth stage (x) was, the larger the difference (y) in the grain moisture content at the physiological maturity stage between different locations and different years, which fit y = 0.1619 x-21.454, R2= 0.736** (n=16). The accumulated temperature at the mature stage of grain dehydration had a significant influence on the dehydration rate and the grain moisture content at the physiological maturity stage. The moisture contents at the physiological maturity stage were relatively high in the areas with low temperature and slow dehydration.

      • 1
    • Wang Feng, Wang Yufeng, Xu Xiaoxuan, Li Jiaxin, Ding Dong, He Lin, Li Zuotong, Xu Jingyu

      Abstract:

      The maize variety 344 was used as the experimental material, and the physiological characteristics data and the transcriptome differential gene expression data of maize seedlings under low phosphorus stress were analyzed. To deciphers the molecular regulation of physiological changes in maize Leaves under low phosphorus stress, and preliminarily identified the key genes involved in physiological response under low phosphorus stress. The results showed that under low phosphorus stress, chlorophyll fluorescence parameters (FV/FM) and chlorophyll content of maize leaves decreased in varying degrees, chlorophyll synthesis related genes were mostly down-regulated, and chlorophyll degradation related genes were mostly up-regulated. Most of the genes related to photosynthetic characteristics of maize leaves were down-regulated, and photosynthetic efficiency was significantly reduced. Under phosphorus stress, the activities of SOD and POD increased gradually with the increase of treatment time, and most of the genes encoding the two enzymes were up-regulated. At the same time, eight key genes of MDA synthesis LOX were detected,and seven of them were up-regulated under phosphorus stress. Meanwhile, the content of MDA increased gradually during low phosphorus treatment.

      • 1
    • zhaoxinzhe, wanghongwei

      Abstract:

      25 expired proprietary (ex-PVP) U.S. maize inbred lines were crossed to two elite tester inbred lines CA193 and CA749 by NCII genetic design. These crosses and two hybrid checks Jidan27 and Xianyu335 were evaluated for main agronomic traits in Gong zhuling of Jilin province and Harbin of Heilongjiang province to analyze the breeding potential of 25 ex-PVP U.S. inbred lines. The results showed that 13 inbred lines, including 2MCDB, LH198, PHR63, LH184, PHHH9, MBWZ, PHJR5, LH186, PHT47, LH217, PHMK0, PHEG9 and LH218, had high general combining abilities (GCA) effects for grain yield. Four of the 13 elite lines, 2MCDB, LH184, LH186, PHJR5 and PHT47, also showed the potential of reducing moisture content in harvest time. The inbred line PHT47 and PHJR5 had the best breeding potential for increasing ear row number and shortening growth period in the study. The two cross, CA193×PHT47 and CA749×2MCDB, could be used to develop new lines targeting to the two lines CA193 and CA749, since they showed moderate yield and more row number per ear. The three high-yielding crosses comparing to Jidan27 hybrid, CA193×PHT47, CA193×2MCDB and CA193×PHJR5, could be tested to develop new hybrids.

      • 1
    • maqing

      Abstract:

      WRKY proteins were reported to participate in regulating plant development and adapting to diverse environmental stresses. In this study, WRKY11 encoding a WRKY transcription factor was cloned from maize. ZmWRKY11 expression was induced by salt stress. It is a nuclear located protein with no transcriptional activation ability in yeast. The interaction between ZmWRKY11 and ZmCaM2 was proved using yeast two hybrid assay. To validate the function of ZmWRKY11, we constructed an overexpression vector pCAMBIA1301-ZmWRKY11 and transformed the vector into Arabidopsis. Heterologous overexpression of ZmWRKY11 in Arabidopsis significantly enhanced plant tolerance to salt stress, as determined by physiological indicator such as cotyledons greening rate, malondialdehyde (MDA) content, relative electrolyte leakage (REL) and proline content. These findings suggested that ZmWRKY11 may function as a positive factor in plant salt stress response.

      • 1
    • XU Tian-jun, LYU Tian-fang, LIU Yue-e, CAI Wan-tao, WANG Yuan-dong, ZHANG Chun-yuan, LIU Xiu-zhi, XING Jin-feng, LIU Hai-wu, ZHAO Jiu-ran, WANG Rong-huan

      Abstract:

      Eight maize varieties (four certified as special silage maize and four certified as cereal grain maize) were used in order to study and clarify the dynamic changes of the grain and whole plant water content for different types of silage maize varieties. The results showed that (1) At the milk line position of 1/4, 2/4, 3/4 and 4/4, the tested eight varieties were averaged 36.3, 44.0, 53.5 and 63.3 d after pollination, respectively. The averaged grain water content was 49.5%, 38.8%, 33.3%, 30.8%, and the corresponding averaged whole plant water content was 76.9%, 69.4%, 58.9% and 53.1%, respectively. (2) The duration of the whole plant water content for the tested eight varieties decreased from 70% to 60% averaged 14.1 d, and the special silage maize varieties averaged 16.5 d which 5.4 d longer than that of the cereal silage maize varieties (averaged 11.1 d). (3) The decreasing rates of grain and whole plant water content of special silage varieties Jingkeqingzhu516 and Yayu26, cereal silage varieties Zhengdan958 and Jingke968 were lower than those of other varieties of the same type during the grain milk line 1/2-3/4 and the whole plant water content from 70% to 60%. In conclusion, the period of the whole plant water content from 70% to 60% of the tested silage maize varieties during the suitable harvest period was corresponding to 1/2-3/4 of the grain milk line position; the suitable harvest period of the special silage varieties was about 5 d longer than that of the cereal silage varieties; the relative lower values of the grain physiological precipitation rate and the decreasing rate of the whole plant water content during the suitable silage harvest period were the main reasons for the relative longer suitable harvest periods of Jingkeqingzhu516 and Yayu26, Zhengdan958 and Jingke968.

      • 1
    • WANG Xiuping, FANG Wensong, DU Zixuan, LIU Tianxue

      Abstract:

      The aim of this paper is to quantify comparative analysis of heat damage during flowering stage of summer maize, and detailed evaluation the spatial and temporal distribution of heat damage during flowering stage of summer maize. Time span of flowering stage was analyzed based on observed growth stages by agrometeorological experiment station during 1981 to 2018. Average high temperature days during flowering stage, frequency of high temperature days over 3 days and 5 days during flowering stage in a different period in Henan province according to the daily maximum temperature during 1970 to 2018. Temperal and spatial distribution of high temperature during summer maize flowering stage were analyzed. The result indicated that high temperature days from 1970 to 1999 kept steadily, and high temperature days from 2000 to 2009 were least among the three periods, high temperature days increased obviously since 2010. Then the area of Henan province was divided into five sections: the eastern part of Henan, the southern part of Henan, the western part of Henan, the northern part of Henan and the middle of Henan. While the high temperature days in the southern part of Henan are the most, followed by the eastern part of Henan, the middle of Henan, the western part of Henan and the northern part of Henan. The average high temperature days were 4 to 6 days in most part of Henan province, 2 to 4 days in parts of the northern part and the western part of Henan, and 6 to 8 days in part of the southern part of Henan. The frequency of high temperature days over 5 days was highest in the southern part of Henan with 2 to 3 time per ten years. The frequency of high temperature days over 5 days was declined with the date pushed back. Ten-year recurrence rate of high temperature days over 5 days was below 1 time between 9th august and 18th august in most parts of Henan.

      • 1
    • Kong Fan-lei, Zhao Bo, Zhou Mao-Lin, Song Bi, Lei En, Li Zhong, Li Xiao-Long, Chen Xiang, Yuan Ji-Chao

      Abstract:

      Mechanical grain harvesting is the way to realize the leap development from artificial harvest to grain harvest in southwest maize region. Based on the mechanical grain harvest experiments carried out in four provinces and cities in southwest China from 2017 to 2018, this paper analyzed the current quality of mechanical grain harvesting and the main factors that affected the grain harvest quality in southwest maize region. The results showed that, high grain breakage rate and loss rate were the main quality problems of maize mechanical harvesting in southwest China. The average grain breaken rate was 7.41%, and the average total grain loss rate was 5.84%. The grain breaken rate and total grain loss rate were both higher than the national standard of 5% [“Technical requirements for maize combine harvester" (GBT-21961-2008). The average impurity rate was 2.18% which was lower than the national standard of 3%. The distribution range of harvesting grain moisture content was from 14.40% to 57.54%, with an average of 26.66%. There was significant positive correlation between the grain breakage rate, impurity rate and the grain moisture content, while ear loss rate and total grain loss rate were significantly negative correlation with grain moisture content. Reducing the grain moisture content was beneficial to reduce the grain breakage rate and impurity rate, while it increased the ear loss rate and total grain loss rate. Mechanical grain harvesting quality of maize was different among regions, varieties and combine harvesters. The average broken rate of sichuan summer maize, sichuan spring maize, chongqing spring maize, guizhou spring maize and yunnan summer maize were 6.23%, 5.33%, 5.56%, 11.26% and 8.87%, while the average ear loss rate were 6.00%, 3.72%, 5.91%, 6.45%, 3.47% and 5.63%, respectively. Using the same combine harvest machinery with similar grain moisture content, variety Guohaoyu 7 had the highest grain breakage rate and impurity rate while the highest grain loss rate was invariety Yanke 288. There were significant differences in grain breakage rate, impurity rate and falling grain loss rate between different combine harvest machinery, while the variable coefficient of the ear loss rate and grain total loss rate was not significant. According to the ecological characteristics of maize production region, Carrying out the research on suitable varieties, harvesting conditions and grain harvesting machines were the key measurements to promote the rapid development and application of maize mechanical grain harvesting technology.

      • 1
    • WANG Zhao, MU Cong, LI Yun-meng, GAO Jing-yang, SONG Yun-xia, DONG Chao-pei, MA Pei-pei, HE Ke-wei, XU Jing, DONG Hua-fang, SUN Xiao-dong, HAN Ya-nan, ZHOU Zi-jian, CHEN Jia-fa, WU Jian-yu

      Abstract:

      As an important pathway, cob can affect the infection and spread of Fusarium verticillioide in maize ear. In order to study the cob resistance to Fusarium verticillioide and to understand the difference between kernel resistance and cob resistance in maize, the identification system of cob resistance was optimized. In addition, 164 inbred lines were surveyed to establish the cob resistance identification system and to select excellent resistance inbred lines in two years and two locations. By analyzed of the four indexes (surrounding infected length, internal infected length, infected area and relative infected area), the surrounding infected length was identified as optimal, which has better repeatability in same inbred line and can easier distinguish the resistance between different inbred lines. Fifty-eight inbred lines with high resistance of cob were identified, such as CML27, BT-1, CML274, etc. At the same time, elite inbred lines BT-1, CML173, CML193 and other eight inbred lines with high resistance to ear rot in both kernel and cob were screened out. These results laid a foundation for disease resistance breeding and resistance inheritance research.

      • 1
    • wanglulin

      Abstract:

      Epicuticular waxes play an important role in preventing water loss, ultraviolet damage and coping with various stress. Water-holding capacity is the performance of wax content in leaf epidermis and becomes an important measurement of wax content in leaf epidermis. To identify candidate genes controlling and regulating epicuticular wax biosynthesis, the association panel of 218 inbred lines composed with temperate, subtropical, and tropical materials, were used. Their water-holding capacity was surveyed with three replications in Yuanyang. A

      • 1
    • hanjienan

      Abstract:

      Starch content is an important trait of maize (Zea mays L.) kernels as it accounts for the seed yield and quality. Analysis starch content accurately at the population level is the important foundation when we study genetic and physiological of starch quality. In this paper, 230 maize inbred lines were set as samples, using the method of polarimeter and pre-treatment of the first derivative add minus one line separately to establish and optimize a Near-infrared spectroscopy (NIRS) model of maize starch content successfully, which can improve the accuracy of the prediction significantly. Of the model, the calibration standard deviation (RMSEE) is 0.609, the cross-validation standard deviation (RMSECV) is 0.722, the external verification standard deviation (RMSEP) is 0.738, the calibration correlation coefficient (R2cal) is 0.909, the cross-validation correlation coefficient (R2cv) is 0.864, and the external verification correlation coefficient (R2cv) is 0.854. Of the model, the deviation between the predicted value and the chemical value can be controlled within 1.7%, which can improve the accuracy largely when it was used in quantitative analysis of grain starch content and then can be applicated in breeding inbred line selection or crude starch content analysis at the group level.

      • 1
    • SHI Yong, JIN Wei-huan, Ren Zhen-zhen, Guo Sha, Dong Shi-feng, CHEN Yan-hui, Wen Yan-peng

      Abstract:

      Photoperiod sensitivity is the main limiting factor for the introduction of tropical and subtropical maize germplasm resources in temperate zones. To break through the obstacle, cloning related genes and studying their functions to construct the gene regulation network of maize photoperiod sensitivity trait, are the major approaches. Photoperiod sensitive regulating mechanisms in different plants are with conservatism and differences. Based on the present studies on photoperiod sensitive regulating mechanism in Arabidopsis thaliana and Oryza sativa, we reviewed the genetic characteristics, gene mapping, gene functional characterization of maize photoperiod regulation mechanism and summarized the existing problems.

      • 1
    • Chen Qiang, Zhang Jinlong, Lei Shuai, Li Qiang, Zhang Xiaoming, Chen Guohua

      Abstract:

      In order to effectively implement integrated management of maize pests, the difference of aphid resistance among maize varieties was clarified and aphid resistant varieties were screened. The damage status of maize aphids on different maize varieties was recorded by 5-point sampling method under the natural susceptibility condition in the field. The aphid resistance of 21 varieties was identified by aphid-to-aphid ratio method, and the feasibility of aphid-to-aphid resistance of maize was analyzed by aphid-to-aphid ratio in peak period. The results showed that there were significant differences in aphid resistance among different maize varieties. Guidan 203, Qingqing 601, Zhenhe 978, Zhouyu 913, Beiyu 10, Puyu 3, Shuijinyu 8 and Yunhe 2 were high resistant varieties. The number of natural enemies of maize aphids was consistent with the population of maize aphids. The ratio of benefit to harm of maize varieties to aphids was power function. The benefit-harm ratio decreased with the increase of aphid population ratio.

      • 1
    • SUN Qi, Lu Shou-ping, LI Wen-cai, YU Yan-li, ZHAO Meng, LI Wen-lan, MENG Zhao-dong

      Abstract:

      Parental inbred lines and their pedigree origination of approved Pioneer seed industry maize hybrids from 2001to 2019 in China were collected and sorted out. The pedigree map of each heterotic population were made. The result indicated that 53 maize hybrids of Pioneer seed industry were approved most in Huanghuai plan and Northeast China during the 19 years. The background of female population includes B73 and PHG39, most as derivative inbred lines of PHG39. The backbone inbred line PHB09 formed 8 derivative inbred lines,PH6WC, PH6JM, PHJEV, PHTEF, PH11V8, PH18Y6, PH1JP8, PH12P3. The derivative inbred lines combined 14 approved hybrids. The background of male population includes OH07, Iodent and Lancaster germplasm, priority to OH07. The backbone inbred lines PHN46 and PH4CN formed 9 derivative inbred lines, PH4CV, PH2N1, PH5AD, PHPM0, PH1N2D, PH11YB, PH11VR, PH12RP, PH12TB. These inbred lines combined 18 approved hybrids. The Pioneer seed industry selected inbred lines adaptive to Chinese ecological environment basing original germplasm background.

      • 1
    • Wang Xingchuan, Fei Jifei, Liu Dongsheng, Gao Fei, Wang Aifen, Yuan Zhiqiang, Chen Ruijie, Sun Zhao, Zhang Changzheng, Wang Yibo

      Abstract:

      Lantron 808 is a corn hybrid created in 2012 using CT3566 and CT3354 as female and male parents respectively, which satisfies the trait breeding goals of Mid-early maturity, high yield potential, lodging resistance, high density planting, disease resistance, fast dehydration, machine-harvesting, and wide adaptability. Lantron 808 have been approved in five national trials for commercial corn production in four major corn production regions and five maturity zones including Huanghuaihai summer corn region, Northeast Region (in both Northeast medium maturity Zone and East Huabei Medium and Late Maturity Zone), Northwest region, and Southwest region. The yield performance of Lantron 808 in national and regional multi-location trials, and production trials were reported, along with its excellent characteristics in agronomic traits, lodging resistance, density tolerance, and feed quality of silage. According to the performance of Lianchuang 808 and the experience of the breeding process, related issues on commercial breeding were discussed, in particular, the pyramiding breeding of favorite traits, the assignment of heterotic group and their implications to heterosis.

      • 1
    • Wang Shuai, Qi Maodong, Wei Fengju

      Abstract:

      Heat shock protein 70 (HSP70s) are found extensively in prokaryotic and eukaryotic and one of the most conserved molecular chaperone. In this study, a member of the HSP70 family was isolated from maize. It’s full-length coding sequence was 1992bp, and it’s open reading frame is 2352bp. The encoded protein with molecular weight is about 75.0kD.Through protein structure prediction and homologous alignment analysis, the gene encodes a protein containing ATPase site and HSP70 conserved domain. It is highly similar to Arabidopsis AtHSP70-12 sequence, so it is named ZmHSP70-12. Subcellular localization analysis showed that the ZmHSP70-12 protein was expressed in the endoplasmic reticulum. Real-time quantitative PCR analysis revealed ZmHSP70-12 has obvious response to abiotic stress, such as high temperature and drought.Therefore, it was speculated that ZmHSP70-12 is a stress-related gene in maize stress.

      • 1
    • zengxuhui, 彭宏, wangbo

      Abstract:

      In order to evaluate the yielding ability and stability, and adaptability of different maize varieties, as well as the discrimination and representativeness of test sites in maize regional trial, the GGEBiplotGUI package of free and open source R language was used to analyze 18 varieties(including Zhengdan 958 as the control ) and 10 test sites in Huaibei, Jiangsu Province in 2018. The results showed that the 10 test sites were divided into three small "ecological zones", among which Fengxian, Tongshan, Pizhou and Shuyang were the first group, Huai'an, Suining and Suqian were the second group, Binhai, Gangbu farm of Lianyungang and Jingsetianhua of Huai'an were the third group. Ruiyou 288, HT736, X1601 and Ly1666 had high yields, among which the yield of Ruiyou 288 was high and stable, and the yields of the other three weren’t stable. The three test sites, Huai'an, Suining and Shuyang had good discrimination and representativeness. The test sites, Gangbu farm of Lianyungang and Jingsetianhua of Huai'an had strong discrimination but poor representativeness. The test site of Suqian had strong representativeness but poor discrimination.

      • 1
    • Liushiwei, Peiyuhe, Xuyingying, Zhukaili, Songxiyun

      Abstract:

      In order to determine the contents of lignin, cellulose and hemicellulose more rapidly and accurately, the near-infrared reflectance spectroscopy(NIRS) models of fiber composition in corn stalk were constructed with 200 maize inbred lines as experimental materials. The results showed that the NIRS models of lignin, cellulose and hemicellulose content in maize stalk established in the spectral regions of 4017.94~8053.28, 4017.94~8067.89 and 4027.08~8928.20 were the best. The calibration model was established by partial least square regression (PLS), and the corrected correlation coefficients (RMRSQ) of lignin, cellulose and hemicellulose were 0.9329, 0.9251 and 0.9265, and the corrected standard deviation (RMSEC) were 1.57, 1.68 and 1.18, respectively. In order to verify the model, 30 corn stalk samples were selected as test set. The external correlation coefficients (RSQ) of lignin, cellulose and hemicellulose were 0.9389, 0.8911 and 0.9050, respectively, and the prediction standard deviations (SEP) were 1.57, 2.14 and 1.49, respectively. The models were also cross-validated with 30 stalk samples, and the cross-validation correlation coefficients (1-VR) were 0.8973, 0.9442 and 0.8918, respectively, and the standard deviation of cross validation (SECV) ware 1.87, 2.32 and 1.43, respectively. The results showed that the models have good quality and can determine the contents of lignin, cellulose and hemicellulose in corn stalk quickly and accurately, which will provide technical support for corn lodging resistance breeding research.

      • 1
    • Cao zhongyang, Tang Bin, Guo Huan Le, Chen Song Lin, Chen Zhi Hui

      Abstract:

      In this study, the high temperature environment at the late stage of maize grain?dehydration in the South Area of Middle Reaches of Yangtze River was used to explore the characteristics of different stages of dehydration rate of maize cultivars with different dehydration rates , especially in the later stage, in order to provide theoretical guidance for breeding and screening maize varieties with fast dehydration. In 2018, three varieties of Xianyu 335 (XY335), Denghai 605 (DH605) and Zhengdan 958 (ZD958) with different dehydration rates were used as materials, planted in Changsha on three sowing dates. The characteristics of dehydration of maize grain at different stages and the relationship between grain dehydration and filling and meteorological factors were analyzed. The results showed that the dehydration rates of the three varieties sown at three different times all increased firstly and then decreased, further followed a rapid increase/rise at the later stage. The rate of grain dehydration before and after the rapid rise of the late stage showed different characteristics. We took the starting point of the rapid increase of the grain dehydration rate in the later period as the separation point, the early stage was the T1 stage, and the later stage was the T2 stage. At the T1 stage, the grain dehydration rate was significantly positively correlated with the grain filling rate (r=0.845**), but no significant correlation with meteorological factors, showing physiological dehydration characteristics; T2 stage, grain dehydration rate were significantly positively correlated with temperature-related meteorological factors and average sunshine hours, and significantly negatively correlated with rainfall, showing net dehydration characteristic. The difference of grain dehydration rate among varieties was mainly reflected at the later stage: i.The grain dehydration rate of XY335 and DH605 were higher than ZD958 at the later stage; ii. When the grain moisture content was used as the evaluation scale, the dehydration rate of XY335 and DH605 increased rapidly earlier than ZD958 at the late stage. The results showed that grain dehydration rate of maize at the later stage was affected by genotype and meteorological factors, the varieties with low moisture content at harvest stage had the characteristics of earlier rapid dehydration and faster dehydration at the later stage.

      • 1
    • YangShuTian, Du Tianqing

      Abstract:

      In order to explore the physiological mechanism of the effect on foliar spraying selenium in waxy corn,determine the optimum concentration of selenium foliar spraying on waxy corn ,and select the waxy corn varieties with high absorption and utilization of selenium. Two-factor split-plot design method was used to comparative study the different physiological indexes and grain selenium content of four main extension planting waxy maize varieties under five selenium levels. The results showed that 60 g? hm-2 spraying selenium level on waxy corn could not only increase the POD activity,GSH content and reduce MDA content,but also effectively increase the chlorophyll content and chlorophyll a/b value. Compared with Se0,the content of selenium in grain of four cultivars increased significantly at this concentration. There were significant differences in the effects of variety,concentration and interaction on grain selenium content. The contribution of each factor to total variation was concentration > variety > interaction between variety and concentration. Compared with respective Se0 treatments,the grain average selenium contents of the four cultivars were increased 118.0545,139.3179,162.9583 and 87.1647 g?kg-1. CTN1965 and JN20 had stronger selenium enrichment ability. The leaf spraying selenium concentration was 83.8636 g?hm-2,which was the limit value of the experiment. Under the spraying selenium concentration,the average selenium content of grains could reach the safety upper limit of 300g?kg-1.

      • 1
    • ZHAN Wen-jie, LIU Jian-zhao, LIANG Yao, YUAN Jing-chao, ZHANG Hong-xi, CAI Hong-guang, REN Jun

      Abstract:

      【Objectives】The objective of this study was to investigate a agronomic management mode which could coordinately increase both grain yield and nutrient use efficiency of maize. 【Methods】A maize cultivar, XY335, was used as tested material in a field experiment. Four agronomic management modes were tested: Local agronomic cultivation(CK), Optimize management mode 1 (Opt-1),Optimize management mode 2 (Opt-2),Optimize management mode 3 (Opt-3). Analyze the characteristics of grain yield formation under different cultivation patterns and their nutrient absorption and utilization efficiencies. 【Result】The results showed that the average yields of Opt-1, Opt-2, Opt-3 were 25.7%, 49.0%, 44.5% higher than the CK. The main factor affecting yield was the number of ears harvested. The total dry weight of Opt-1, Opt-2, Opt-3 were 9.5%, 37.2%, 16.3% higher than the CK. Opt-2’s nitrogen content is 300kg/hm2, 33.3% higher than Opt-3. However, its grain nutrient accumulation was not significantly higher than opt-3,and there was no significant difference between its fertilizer partial productivity and CK treatment. Under opt-3 treatment, leaf area index (LAI) at flowering stage was higher and LAI decline rate after flowering was slowed down. Net photosynthetic rate and stomatal conductance were increased by 22.0% and 5.6% respectively compared with CK. In addition, opt-3 treatment increased the planting density to 7.0 million plants /hm2, which further enhanced the photosynthetic performance of maize leaves.【Conclusion】The results indicated that higher grain yield and higher nutrient use efficiency can be coordinately achieved through integrating and optimizing cultivation techniques in maize production.

      • 1
    • chu kun, nie xiaoxiong, feng huajie, han guili, liang xuelian

      Abstract:

      Over the past decade, agrobacterium mediated genetic transformation has been widely used in breeding and molecular biology research because of its stability and efficiency. However, when using traditional agrobacterium mediated transformation in corn, the transformation of agrobacterium tumefaciens is limited, and it has many disadvantages, such as complex operation, low conversion rate, and so on. Biologists have found that the use of ultrasonic-assisted agrobacterium-mediated transformation in germinating corn seed can improve the agrobacterium mediated transformation rate. In this study, the ultrasonication-assisted Agrobacterium treatment method was modified with the addition of emery to increase the treatment intensity to the apical meristem cells of germinating seeds. The emerged 93 plants from 800 control seeds were sprayed three times with glyphosate solution, and 27 of them survived, their leaves were taken with a PCR electrophoresis test and 23 shown positive, which suggested that epsps gene was introduced into the maize cultivar, and the transformation rate was 29%. Finally, which has been shown that the method has the advantages of circumventing the tedious tissue culture procedures and being easy to apply.

      • 1
    • Lu Yuan

      Abstract:

      In order to improve the utilization efficiency of waxy maize germplasm in excellent germplasm resources exploitation and waxy maize variety improvement. A genome-wide scan was performed on 5 crop maize inbred lines, which represent crop maize germplasm resources in China respectively, and 44 waxy maize inbred lines from different sources with SNP-Chips. A total of 34,257 SNPs with Polymorphic Information Content (PIC) ranged from 0.02 to 0.56, with an average of 0.32; and a minimum allele frequency (MAF) ≥ 0.03 were used for genetic diversity analysis. The identity-by-state (IBS) of the 49 inbred lines ranged from 0.59 to 0.99 with an average value of 0.68. 5 groups were divided from 49 maize inbred lines by Neighbor-joining (NJ) clustering method based on IBS, including 19, 9, 4, 9, and 3 materials. Waxy maize inbred lines with unknown pedigree were divided into different groups, so their relatedness with other inbred lines was defined. This study provides basic materials and a theoretical basis for heterosis utilization, germplasm innovation and evolutionary genetics analysis of waxy maize.

      • 1
    • LIU Shuo-ran, YING Fei-yu, CUI Shuai, ZHONG Sheng-hao, LI Zhen-chao, ZHANG Xing-yu, CHEN Li-dong, WANG Yin, GAO Qiang

      Abstract:

      The effects of nitrogen and sulfur interaction on plant growth and nutrient uptake in maize seedlings were studied by pot experiment. The results showed that nitrogen application and sulfur application had an effect on the growth and nutrient uptake of maize seedlings, and interaction between the two was significant. It is obvious that nitrogen deficiency severely impeded the growth of maize. The plant height, stem diameter, SPAD value, net photosynthetic rate, dry matter accumulation and nitrogen accumulation of N0 treatment were lower significantly than those of N2 treatment with difference value of 32.7%, 29.9%, 22.1%, 15.6%, 32.2% and 74.0% respectively. Furthermore, the above parameter indexes of N1 treatment were higher than N0 treatment as well as lower than N2 treatment. Sulfur application significantly promoted the growth of maize while the effects of sulfur application were different under various nitrogen application conditions. Without nitrogen fertilization (N0), sulfur application improved maize growth, and significantly raised the dry matter accumulation of maize seedlings. Under low nitrogen condition (N1), maize growth and nitrogen uptake were promoted with sulfur application; meanwhile nitrogen utilization of N1S2 treatment was 52.9% better than that of N1S0 treatment. Under high nitrogen condition (N2), the sulfur fertilization effect was similar to that of low nitrogen application, but the improvement of fertilizer utilization rate of nitrogen is not significant with further addition of sulfur fertilizer. In conclusion, superior dry matter accumulation (82.03 g/plant), the highest sulfur utilization (9.24%) and superior nitrogen utilization (31.84%) were observed in N2S1 treatment which had the most significant nitrogen and sulfur interaction. Therefore, N2S1 fertilization is the most effective nitrogen and sulfur nutrition management measure for maize seedlings growth.

      • 1
    • Kong Lili, Hou Yunpeng, Liqian, Yin Caixia, Qin Yubo, Wang Meng, Yu Lei, Liu Zhiquan

      Abstract:

      Abstract: In order to clarify the reasonable phosphorus (P) management patterns in semi-arid region of Jilin province, a field experiment was conducted to investigate the effects of different P application periods and proportions on maize yield, matter production, P absorption and utilization among the same amounts of P fertilizer under mulched drip irrigation in 2014-2015. The treatments included P1 (100% basal fertilizer), P2 (40% basal fertilizer + 60% jointing fertilizer), P3 (40% basal fertilizer + 40% jointing fertilizer + 20% belling fertilizer) and P4 (40% basal fertilizer + 20% jointing fertilizer + 20% belling fertilizer + 20% flowering fertilizer). The results showed that maize yields of split P application treatments (P2, P3 and P4) were better than that of P1 treatment, respectively. The yield of P4 treatment was significantly higher 8.9% (2014) and 7.4% (2015) than that of P1 treatment(P<0.05). P fertilizer application could improved the amounts of dry matter and P absorption from silking stage to maturing stage significantly, in which P1 treatment arrived at the highest at silking stage, and P4 treatment was the highest from filling stage to maturing stage. Compared with P1 treatment, split P application treatments (P2, P3 and P4) reduced P translocation amount, its rate and contribution rate of translocation P to kernels before silking stage of maize. Split P application improved contribution rate of accumulation P to kernels after silking stage significantly, and P4 treatment reached the highest value. Correlation analysis showed that the grain yield was significant or extremely significant correlated positively (r=0.6302-0.8761) with the dry matter and P absorption around silking stage of maize, and the correlation coefficients after silking stage were higher than them before silking stage. Compared with P1 treatment, P recovery efficiency, agronomic efficiency and partial factor productivity were increased under split P application treatments (P2, P3 and P4) by 4.1%-18.2%, 21.8%-58.9%, 3.3%-8.9% (2014) and 6.0%-26.9%, 22.2%-43.9%, 3.7%-7.4% (2015), respectively, and which of P4 treatment was the highest value. In conclusion, the optimum P application schedule was obtained by 40% basal fertilizer, 20% at jointing stage, 20% at belling stage, 20% at flowering stage with 90 kg/hm2 of phosphorus fertilizer under mulched drip irrigation in this area.

      • 1
    • XIAO Wan-Xin, WANG Yan-Bo, YE Yu-Sheng, LIU Jing, JIA Yu-Ying, SUI Yang-Hui, ZHAO Hai-Yan, WANG Yong-Jun

      Abstract:

      This study was conducted by using PVC pipe in the field with split block design, which main plot was 2 inbred lines, split plot was 2 water treatments under 3 water stresses at different reproductive growth stage from 2016 to 2017. The root morphology, root-to-shoot growth ratio, harvest index and kernel weight of the plant was measured. The result showed that, compared with CML58, the root angle of available brace roots of Huangzaosi was increased obviously, the negative response time to water stress of number of root, root length, root surface area, average diameter of root, root volume, number of root tips, ratio of total root length to plant height (ROL) and total root surface area to plant leaf area (ROSA) of Huangzaosi was earlier at R1 growth stage than that of CML58 at R3 and R5 growth stage, which distribution ratio of number of root, root length, root surface area and number of root tips was higher than that of CML58 at 40-90cm soil layer after water stress. Root growth redundancy of Huangzaosi was less than that of CML58, especially in the 20-90cm soil layer at R1 and 0-20cm soil layer at R3 and R5. The ROL and ROSA of Huangzaosi were higher than that of CML58 under different water treatments. However, the ratio of average of total root angle from vertical direction of available brace roots to average of total leaf angle from the main stem above available ear node (ROA) of Huangzaosi was 39.4% lower than that of CML58. The harvest index of Huangzaosi was higher than that of CML58 at R6, and the average of kernel weight per plant of 2 years of Huangzaosi was 96.9% higher than that of CML58. The ROL was significant positive to kernel weight per plant at R1. The ROA was significant negative to kernel weight per plant at R1 and R3. This study concluded that, compared with the maize inbred line with low drought tolerance, the maize inbred line with high drought tolerance could regulated the growth angle of available brace roots better under water stress at reproductive growth stage, the matter transformation efficiency was enhanced by adjusting and controlling roots growth, maintaining the architecture and function of main distribution zone of root, increasing root distribution ratio at deep soil layer, adjusting root-to-shoot growth from horizontal and vertical direction and ratio of root angle to leaf angle, and decreasing root growth redundancy, which got a higher yield finally.

      • 1
    • yucaihong

      Abstract:

      The male sterile lines were obtained through transgenic methods, creating basic materials for the application of male sterile lines in maize hybrid seed production. The plant expression vector MS26 RNAi were constructed, and the immature embryonic tissue (Zong31) has been used as the receptor for the agrobacterium -mediated transformation. Transgenic plants were obtained from transformation using mannose as selectable marker. 18 single copy T0 plants were identified from TaqMan assay, 12 of which showed to be male sterile in the I2-KI Dyeing analysis. In the field trials, all single copy T1 plants of the five events showed 100% male sterility at the pollen-shattering stage, while the other agronomic traits were the same as those of wild type. The target MS26 RNAi gene has integrated into maize genome. Real-time PCR analysis showed that the expression of MS26 gene was significantly decreased in MS26 RNAi transgenic maize plants It demonstrated that the T-DNA has been fully integrated into maize genome and resulted in the complete male sterility.

      • 1
    • ren zuo li, 张继峯, 杨文杰, 陈潇洁, jiazhecheng

      Abstract:

      In order to study the physiological growth characteristics of weak light stress in different growth stages and reduce the yield of maize, the effects of severe weather and light intensity on the physiological growth of maize were simulated. The Xinjiang main breed variety Xinyu No.9 was used as the tested variety. Artificial light control was used to simulate the light conditions of different intensities, and 20%, 50% and 70% shading treatments were carried out in the whole growth period, the silking stage and the maturity stage respectively, and the photosynthesis of maize under weak light stress in different growth stages was described. Physiological mechanism. The results showed that after shading treatment, the chlorophyll relative SPAD value of corn leaves increased significantly, the fluorescence parameters ΦPSII, Fv/Fm and qP increased, NPQ decreased, and the change was more significant with the increase of shading degree. After treatment, it gradually returned to the control (CK) level. After shading treatment, the dry matter accumulation and yield of maize were reduced to different extents. The plant height, stem diameter, leaf area and yield of shaved corn in the whole growth period were significantly reduced, and the changes of maize ears during shaving and maturity were observed. Significantly, plant height, stem diameter and leaf area did not change significantly. Compared with CK, the whole growth period, shading, shading and shading at maturity also have a significant impact on the growth and development of maize. The shading period during the whole growth period and the shaving period of the males delay the growth of maize, mature stage The shade has advanced the corn growth process. It can be seen that the yield of maize decreased significantly under low light stress, while the shading of silking stage had the most significant effect on corn yield. This study can provide a reference for the development of stable maize in the climatic environment where the field corn is exposed to insufficient light in different growth periods. Keywords: corn; drip irrigation; weak light stress; chlorophyll fluorescence; yield

      • 1
    • LI Rong-gai, LI Xing-hua, SONG Wei, WANG Jiang-hao, ZHANG Quan-guo, Wang Li-wei

      Abstract:

      Cultivated maize (Zea mays L., 2n=20) is the most widely grown and the highest total output crop in the world, and is also an important raw material for the feed, chemical, fuel, and pharmaceutical industries. Aphids are one of the main insect herbivores that reduced maize production. In China, the corn leaf aphid (Rhopalosiphum maidis Fitch) is the major aphid that damages maize production. In recent years, the risk of the corn leaf aphids in the northern spring maize planting area and the Huanghuaihai summer maize growing area is on the rise, while the maize germplasm resources with resistance to aphids are not abundant. So far maize resources that is completely immune to aphids have not been found. The inheritance patterns of resistance to aphids in maize are complex, of which, most were characterized in recessive manners, and controlled by one, two, or multiple genes. So far, only few resistant QTLs and genes have been mapped. The physiological and biochemical mechanisms of resistance to aphids have been preliminarily studied. This paper focuses on the previous research results and proposes possible future study on aphid resistance in maize.

      • 1
    • ZHANG Lei, KONG LiLi, HOU YunPeng, YU Lei, Wang LiChun

      Abstract:

      In order to clarify the relationships between the characteristics of dry matter accumulation, translocation and distribution, the dynamic change of soil nitrogen and yield after anthesis of maize under different nitrogen application levels, a field experiment was conducted to study the effects of different nitrogen application levels (0, 70, 140, 210, 280, 350 kg/hm2) on maize yield, the characteristics of dry matter accumulation, translocation and distribution, and the dynamic change of soil inorganic nitrogen after anthesis of maize at the main producing areas of central Jilin province for two years (2015-2016). The result showed that maize yield was increased significantly (P<0.05) by 12.3%-37.8% (2105) and 13.9%-47.0% (2016) through nitrogen fertilizer application than that of no nitrogen treatment, and the highest value was at nitrogen fertilizer application of 210 kg/hm2. Dry weight of stem and leaf were increased respectively, but dry weight of kernel was increased at first and decreased later with increasing of nitrogen application levels. Nitrogen fertilizer application improved the translocation amount, translocation rate to kernels derived from dry matter accumulation in different organs and contribution rate to kernels from vegetative organs after anthesis of maize significantly (P<0.05), and also increased the distribution proportion of dry matter in kernel. And the highest values were at nitrogen fertilizer application of 210 kg/hm2 respectively than them of no nitrogen treatment. Nitrogen application could enhance inorganic nitrogen content at 0-20 cm soil significantly (P<0.05) from flowering stage to mature stage than no nitrogen application treatment. Soil inorganic nitrogen content increased with the increment of nitrogen application levels, and the highest value was at nitrogen fertilizer application of 350 kg/hm2. The correlation analysis indicated that maize yield and its components had significantly or extremely significantly positive correlations with the amounts of dry matter accumulation and translocation at mature stage except maize spike number. It had extremely significantly quadratic curve between soil inorganic nitrogen content and yield after anthesis of maize. In conclusion, the appropriate amount of nitrogen fertilizer could improve maize yield by increasing inorganic nitrogen content in soil, dry matter accumulation and translocation after anthesis of maize, and distribution proportion to kernel.

      • 1
    • Li Wen-Duan, Han Bing, Cao Xiao-Xiong, Li Yan-Jiao, Wei Ao-song, Cheng Wen-Hua, Wang Yun-He, Guo Jin-Jie, Yang shuo, Chen Jing-Tang

      Abstract:

      Determination of Water absorption rate of 63 Maize inbred lines by gravimetric method, the average seed water absorption rate of the different heterosis groups were analyzed by variance analysis, and the inbred lines with high water-absorption rate of the seeds in each group were selected. A total of 36 inbred lines with seed water absorption rate greater than 0.6mg/h were selected in the experiment 48 hours after water absorption treatment. The inbred lines were divided into five heterosis groups: P group, Lvdahonggu(LRC), Reid, Lancaster and Tangsipingtou(TSPT). The average water absorption rate of the seeds 48 hours after water absorption was 0.73mg/h for Lancaster group, 0.71mg/h for Lvdahonggu group, 0.62mg/h for Reid group, 0.57mg/h for P group and 0.56mg/h for Tangsipingtou group. The results showed that the water absorption rate of the seed particles did not differ significantly between the different groups, but there were significant differences between the water absorption times. The objective of this paper is to study the characteristics of the water absorption rate of maize inbred lines in different heterosis groups and to select the inbred lines with high seed water absorption rate.

      • 1
    • shengdechang

      Abstract:

      Using heat-sensitive corn variety ZY 309 as material, two high-temperature treatments were set up to study the effects of different days of high temperature on corn yield and panicle traits, material production and transport, and grain storage capacity. The results showed that HT1 had no significant effect on maize yield, but HT2 significantly reduced maize seed setting rate and yield. The plant height of plants was decreased under HT2, and the leaf area was HT2>CK>HT1. The high temperature stress at flowering stage significantly decreased the net photosynthetic rate of panicle leaves, but had no significant effect on chlorophyll content; HT2 decreased the number of kernels and the total dry matter weight, increased the dry matter content of stem, leaf and loquat leaves in the mature stage, and the total weight of dry matter in the plant was increased. The high temperature stress increased the crude protein content, soluble sugar content and starch content. The results showed that under HT1 treatment, maize increased its translocation capacity to cope with high temperature stress, while HT2 reduced the grain storage capacity by significantly reducing the number of kernels, which caused irreversible damage and affected maize source (leaf area) and flow (material transport and distribution).

      • 1
    • Li Yangyang, Fan Zuowei, Zhang Liming, Wang Yanguo, Zhao Yang, Liu Xiaoying, Li Xiaoqiu, Wu Haiyan

      Abstract:

      Northeast China is one of the major grain producing areas in China. The use of herbicides in large quantities is the main means of weeding in crop cultivation. Atrazine is a highly effective herbicide widely used in farmland, but because of its excessive use and long residual period, it is harmful to human health and ecological environment. Therefore, isolation and screening of highly efficient functional strains capable of degrading atrazine is of great practical significance for agricultural product safety and soil environmental remediation. In this study, a degrading strain W11 was isolated from the surface soil of maize field by enrichment method, which could use atrazine as a sole nitrogen source to grow. Based on its biochemical characterization and 16S rRNA gene sequence, strain W11 was identified as Paenarthrobacter sp. It could degrade 97.1% of atrazine (100 mg/L) in the medium within 60 h. Its optimum temperature and pH range for growth were 25℃~35℃ and 6~9, respectively; Its optimum temperature and pH were 30℃ and 7, respectively. Glucose was the most suitable carbon source for its growth and atrazine degradation. Additional nitrogen sources did not affect the degradation of atrazine. Strain W11 has a great potential for bioremediation of atrazine-contaminated soil.

      • 1
    • GUO Wen-lei, FENG Li, CUI Ye, WU Dan-dan, ZHANG Tai-jie, ZHANG Chun, TIAN Xing-shan

      Abstract:

      In order to explicate the application prospect in sweet corn fields, 30% nicosulfuron?atrazine?mesotrione oil dispersion (OD) was applied at different leaf stages of sweet corn under field conditions, through which the weed control effect and the safety to sweet corn were evaluated. When applied at 3~4 leaf stage or 6~7 leaf stage, 30% nicosulfuron?atrazine?mesotrione OD showed high safety to the sweet corn breed Yuetian 28 in the doses of 900~1575 g a.i./hm<sub><sup>2</sup></sub>. Compared with the conventional herbicide 38% atrazine suspension concentrate (SC), which applied pre-emergence at 2160 g a.i./hm<sub><sup>2</sup></sub>, 30% nicosulfuron?atrazine?mesotrione OD had higher weed control efficacy and significant effect on increasing yield. Based on the results, 30% nicosulfuron?atrazine?mesotrione OD was recommended to spray at 3~5 leaf stage of sweet corn, with the dose 900~1350 g a.i./hm<sub><sup>2</sup></sub>.

      • 1
    • HU Cong-hui, SHI Wen-jun, LI Liang, SHA Ye, QIAN Chun-rong, Qihua, MI Guo-hua

      Abstract:

      In order to get high-yield, nitrogen-efficient maize cultivars so as to improve nitrogen use efficiency in Northeast China, a two-year experiment in three locations and two nitrogen application levels were conducted in Lishu of Jilin Province, Tieling of Liaoning Province and Harbin of Heilongjiang Province in 2017 and 2018. Twenty maize cultivars were used in each of the three experimental sites each year, and their yield and yield components were analyzed. The results showed that, In Lishu, Liangyu 918 and Demei 1 were double-efficient cultivars which showed high yield under both low and high nitrogen input in both years. Xianyu 335 and Difeng 128 were high-yielding cultivars which got high yield only at high nitrogen input. In Tieling, the double-efficient cultivars were Hongshuo 899, Jinhua 299, Shenyu 21 and Dika 159. Xianyu 335 was a high-yielding cultivar. In Harbin, Jingke 728, Tiannong 9, Yucheng 1, Xianyu 335 were double-efficient cultivars, and Deyu 919 and Yinongyu 10 were high-yielding cultivars. Compared to the average yield level in all the tested cultivars, across the three locations, the use of double-efficient increased maize yield by 12.8% and 16.2% under high and low nitrogen input, respectively. The high-yielding cultivars increased maize yield by 6.4% under high nitrogen input. The double-efficient cultivars had more grains per ear. High-nitrogen efficient cultivars had more ears per area and grain numbers per ear only under high nitrogen input. Under low nitrogen levels, low-nitrogen efficient cultivars had more grain numbers per ear only under low nitrogen supply. Therefore, no matter the nitrogen supply level, the number of grains per ear is the dominant factor affecting maize yield.

      • 1
    • Jia Liangliang

      Abstract:

      Understanding the impacts of climate change on crop yield is important for taking effective adaptations for national food security. In this research, Hybrid-Maize model was used to evaluate the yield potential changes in 1984-2017 on the Piedmont plain of Hebei Province. The model simulated results showed the averaged yield potential for variety of 1980s was 10.89 t/hm2, while the current used variety was 16.22 t/hm2, increased about 48.9%. A warming trend in the maize growth period was found, the average temperature increasing by 0.22 ℃/10a for variety in 1980s, and 0.69 ℃/10a for current used variety. When the temperature increase 1℃, the yield potential for varieties of 1980s and current used will decrease 0.638 t/hm2 and 0.591 t/hm2, respectively. The total solar radiation for the two maize varieties’ growth period have the trend of decreasing from 1984 to 1994, and then have the trend of up and down fluctuations and keeping as a plateau in1994-2017. When the total solar radiation decreased 100 MJ/m2, the yield for variety 1980s and current used will dreased 0.33 t/hm2 and 0.48 t/hm2, respectively. The maize growth period precipitation has the trend of increasing, but there was no significant correlations between yield potential with rainfall. The climate change effects on maize yield potential could be improved by changing varieties with longer growth periods and high temperature resistance. In general, the climate change in 1984-2017 significantly decreased the yield potential for both varieties of 1980s and current used, the yield decreasing rate was about 16.81% and 25.90%, respectively. The yield potential of current used maize variety was more sensitive to the climate change.

      • 1
    • lixiang

      Abstract:

      Corn stalk rot caused by Fusarium graminearum can lead to serious yield reduction of maize. Screening efficient antagonistic strains is particularly important for controlling corn stalk rot. 810 strains of bacteria were isolated from soil by dilution culture method. Antagonistic bacteria were screened by plate confrontation method, and their molecular identification was conducted through 16S rDNA sequence analysis. A total of 23 antagonistic bacteria were isolated, which accounted for 2.84% of the total bacteria isolated. The inhibition zone diameter was 10.12-27.56 mm. These bacteria were mainly distributed in three phyla: Firmicutes, Proteobacteria and Actinobacteria and five genera: Bacillus, Pseudomonas, Streptomyces, Acinetobacter and Arthrobacter. Among the five genera, Bacillus was the most abundant genus and had relatively strong antagonistic ability. Furthermore, Bacillus siamensis had the strongest antagonistic activity, which indicated that it had great potential for biocontrol and was worth further exploration. The 23 strains isolated from the experiment had good antagonistic activity against Fusarium graminearum and had potential application value in the prevention and control of corn stalk rot.

      • 1
    • zhangdongmin, Zhuhui, Zhou Yujie, Han Jienan, Li Mingshun

      Abstract:

      The endosperm phenotype and the content of protein and starch were changed in the maize of opaque2(o2) mutant, its nutritional quality was greatly improved. We produced a pair of near-isogenic lines of o2 mutation which were constructed by backcrossing. Scanning electron microscopy and transmission electron microscopy were used to analysis the mature and developing endosperm. It was found that starch granules were arranged more random and loosely, and the protein bodies are smaller in CAL58/o2 compared with wild genotype. After analysis of nutrients between the two lines, we found that because of o2 mutation the content of lysine significantly increased 55.88%, total amino acid decreased 9.79%, total protein decreased 8.86%, and the content of fatty and starch increased 30.96% and 5.87% respectively. We also compared the differences of zein between the two lines and found that α、β-zein were decreased, γ-zein was increased in CAL58/o2.

      • 1
    • wuxian, lihongxin, luzongzhi, fulifan

      Abstract:

      In this study, we investigated the effects on activity of GSTs in maize seedling at low temperature and precipitation, and also investigated the number of herbicide damage in maize seedling. The?result?indicated?that, GSTs activity took remarkable difference between the root, stem and leaf in maize seeding, the root was the highest, the stem was second, the lowest was the leaf. The activity of GSTs in maize seeding decreased at low temperature. Under the conditions of low temperature and precipitation, the GSTs activity in maize seedling decreased further. After 72 hours, the activity of GSTs in different parts of maize seedling increased gradually .

      • 1
    • Jianjun Sun, Yuxi Guo, Menghui Lv, Yiping Jiang, Rui Wang, Dexin Wang, Qi Tie, 鲁晓民

      Abstract:

      Auxin plays an important role in all stages of plant development, and auxin-responsive binding in the promoter of the auxin-responsive gene regulates gene expression, which is essential in plant growth and development. In order to further study the spatiotemporal expression and drought response pattern, drought response and interaction network of ZmARF1.In this study, drought-resistant Zheng 36 and weak drought-resistant B73 were used as experimental materials. Cloning and sequencing analysis indicated that the gene contained a 2034 bp open reading frame and translated 677 amino acids.Protein analysis showed that the protein has no transmembrane domain and belongs to a highly hydrophilic protein. The subcellular localization is located in the nucleus.Analysis of potential phosphorylation sites revealed that the ZmARF1 protein contains 39, 16, and 6 potential serine, threonine, and tyrosine phosphorylation sites, respectively.The composite phylogenetic tree, functional domain and conserved motif analysis indicated that the homologous gene was highly homologous to other species, indicating that the gene is functionally conserved in different species.ZmARF1 is a constitutively expressed gene, which is positively induced by drought stress, and the expression level of Zheng 36 gene is increased more than B73. The predicted interaction function proteins mainly regulate the stress response and growth and development of plants under stress by regulating hormone response gene expression and participating in hormone-mediated signaling. The above results provide a reference for further study of the role of ARF genes in maize stress and growth and development, and lay the foundation for excavating drought-related molecular resources and breeding drought-tolerant varieties.

      • 1
    • duanminxiao

      Abstract:

      The induction rates of 80 new haploid induction lines were studied with three hybrids Jingke 968, Xianyu335, Jingke528 and four inbred lines Jing724, Jing92, Jing X005 and Jing17 as test species. The results showed that there were errors in the identification of haploid kernel by means of grain color markers, which affected the identification accuracy, and the actual induction rate was obtained by further correction in field planting. The haploid induction rates of different plants in the same inducer line and among different test species were different. 282 test cross combinations of 140 individual plant from 78 induced lines were analyzed. Among them, the actual induction rate of 25 test cross combinations from 21 induced lines was more than 15.0%, and the highest induction rate was 25.3%. Twelve haploid induction lines were screened for further study. Some related problems such as the evaluation of induction rate and the influencing factors were also discussed.

      • 1
    • MA Zheng-bo, TANG Hui-hui, WANG Qing-yan, LI Rui-jie, DONG Xue-rui, ZHANG Rui-dong, DONG Zhi-qiang

      Abstract:

      Randomized block field experiments were conducted using maize variety of Jingnongke728 in Xinxiang Experimental Station in Henan province in 2018. The experiment include four chlormequat chloride(CCC) treatments,that’s C1 (225 g/hm2), C2 (450 g/hm2), C3 (675 g/hm2 and C4 (900 g/hm2) ,and maize cultivar of ‘Jingnongke728’. Aiming to explore the effects of CCC mixed with nitrogen fertilizer on summer maize yield, nitrogen metabolism and nitrogen use efficiency of North China Plain.The results showed that compared with conventional nitrogen fertilizer treatment,CCC treatment increased maize grain yield, 1000-kernel weight and kernel number, post-silking aboveground dry matter accumulation significantly, and the leaf area index as well, enhances the leaf nitrogen-metabolizing enzyme activities such as nitrate reductase (NR), glutamine synthetase (GS), increase the total chlorophyll content and soluble protein content. Nitrogen utilization rate was improved. The optimum application rate was 675g/hm2. Under the optimal application amount, partial productivity of nitrogen fertilizer, agronomic efficiency of nitrogen fertilizer and physiological utilization rate of nitrogen fertilizer have increased by 5.4%, 45.8% and 22.7% respectively,compared to CK. This study showed that CCC mixed with nitrogen fertilizer could mobilize the key enzyme activity of nitrogen metabolism ,thus enhance the metabolism of nitrogen, thus improving the utilization rate of nitrogen and achieving high yield.

      • 1
    • LUO Shang-ke, LIU Jie, yekaimei, FENG Yun-gui, ZHU De-kun, SONG Bi, ZHANG Jun

      Abstract:

      Abstract: To explore the optimized plastic film mulching mode and nitrogen (N) application rate of spring maize production in Guizhou province, field experiments were conducted at Weining county in 2017 and 2018. The experimental design was a split-plot arrangement with three replications, the main plot had different plastic film mulching modes (wide film mulching mode and narrow film mulching mode), the subplot had different N application rates (0 kg/hm2, 80 kg/hm2, 160 kg/hm2, 240 kg/hm2 and 320 kg/hm2). The yield and dry matter and N accumulation and translocation of spring maize were determined. The results showed that both the film mulching modes and the N application rates affected the yield significantly. The wide film mulching mode achieved 15.61% higher yield than narrow film mulching mode due to the former mode increased aboveground dry matter accumulation, dry matter translocation amount, dry matter translocation percentage, contribution percentage of dry matter translocation to grain yield and N accumulation significantly. The highest yield was achieved at an N application rate of 240 kg/hm2 under wide plastic film mulching mode due to both the highest dry matter translocation amount and the highest N translocation amount.

      • 1
    • XUE Yan-fang, HAN Xiao-wei, ZHANG Hui, GAO Ying-bo, QIAN Xi, LIN Shao-wen, JIANG Li-ping, QI Shi-jun, CUI Zhen-ling, WEN Li-yu, LI Zong-xin, LIU Kai-chang

      Abstract:

      Two-year filed experiment was conducted to investigate the effects of different N forms on the grain yield, shoot N accumulation and N utilization efficiency of maize cultivar Denghai605 (DH) and Ludeng981 (LD) with contrasting N efficiencies and the related physiological mechanisms. Results showed that in 2015 and 2016, compared with LD, the average yield of DH was increased by 17.2% and 20.3%, the shoot N accumulation at maturity increased by 8.5% and 10.3, N use efficiency increased by 6.7% and 8.5%, and the yield per unit fertilizer N increased by 17.2% and 20.3%, respectively. The years, N forms and their interactions had no significant effects on the above parameters with an exception of a significant effect of the year on the shoot N accumulation at maturity. The grain N concentration was not significantly different between the two cultivars in the first year, but the grain N concentration of LD was significantly higher than that of DH in the second year, which was not affected by different N forms. From 35 days after silking to maturity, relative green leaf area of DH reduced slowly with being 73% of stay-green degree while that of LD decreased quickly with being only 48% of stay-green degree. During the grain-filling period, DH had higher key antioxidant enzymes such as SOD, especially the CAT activities while with lower MDA content at 40 DAS. Meanwhile, compared with LD, DH had slightly higher NR activity and significantly higher soluble protein content in ear leaves, showing a higher ability for N uptake and assimilation. From anthesis to maturity, the amounts of post-silking N uptake of DH in two years were 38.8 kg/hm2 and 30.8 kg/hm2 higher than LD, respectively. On the contrary, the amounts of vegetative N remobilization and N remobilization efficiency of LD were 25.8 kg/hm2 and 21.8 kg/hm2 and 10.1~12.1 percentage points higher than DH, respectively. These results suggested that at normal N application rate (220 kg N/hm2), LD with both lower yield and N efficiency, DH with both higher yield and N efficiency, showed higher antioxidative ability to delay senescence, to maintain higher activities of key enzymes related with N metabolism, to improve N uptake and assimilation, and finally to gain higher yield but to decrease grain N concentration.

      • 1
    • YAO Fan-yun, CAO Yu-jun, LV Yan-jie, LIU Zhi-ming, WEI Wen-wen, WANG Yong-jun

      Abstract:

      Under the background of maize ‖ peanut strip rotation system in semiarid region of Jilin Province, the effects of and different amount of maize straw returning (30%, 60% and 100%) on hydro-thermal condition, yield and land equivalent ratio (LER) were studied. The experiment was carried out in 2016-2018. Five treatments were set up, including sole peanut, sole maize and different straw returning treatments in maize-peanut strip rotation system. The results showed that compared with the traditional monoculture, the average soil water content of 0-40 cm of straw returning region in peanut treatment increased by 11.0%-13.9% before sowing, and the maize region increased by 1.9%-3.9%. At the maturity stage, the average soil temperature of the straw returning area from 0:00-8:00 was 0.2-1.1 °C higher than that of the traditional peanut monoculture, but 0.5-1.0 °C lower than that of the traditional peanut monoculture at 10:00-22:00. Straw returning promoted the development of maize ear and grain, and increased the productivity of individual plants, but straw returning was not conducive to the improvement of single plant productivity of peanut. In 2018, with the increase of straw mulching amount, the number of pod per plant and the weight of 100 kernel of peanut decreased significantly. In 2016 and 2017, LER of the maize ‖ peanut rotation system was 1.05-1.16, and the LER of each treatment was less than 1 in 2018. Maize intercropping peanut conservation tillage in the semi-arid area of Jilin improved the soil moisture status before crop sowing, but the impact on crop yield varied in different years.

      • 1
    • Zhang Panpan

      Abstract:

      Six major summer maize cultivars, including ZD958, XY335, ZD309, AY3111, XD20 and DK653, were selected as experimental materials, and five N application of 0, 120(reducing 1/2 of normal N rate), 160(reducing 1/3), 200(reducing 1/6) and 240(normal N rate) kg N/hm2 were setup. We compared the grain yield, transformation of N after anthesis, chlorophyll fluorescence characteristics and NR and GS activity of leaf in the grain filling stage. Compared with no nitrogen application, the grain yield with adding N fertilization was increased by 20.0%, but no significant differences were obtained in grain yield, N concentration, HI and NHI among normal N rate, reducing N 1/3 and 1/6. ZD309 and XY335 showed higher yield and NHI than other genotypes. The transformation amount of leaf in ZD958, XY335 and ZD309 were increased with the increase of N application level, but N remobilization efficiency of stem under the adding N treatments had no significant difference among the six cultivars. Higher chlorophyll Fm, PI and NR activity, and similar SPAD of leaf in the grain filling stage were found under the reducing 1/3 and 1/6 normal N, compared with normal N rate treatment. The maximum and minimize SPAD and PI of leaf after anthesis were AY311 and XD20, respectively. NR and GS activity of leaf in ZD958, XY335 and ZD309 were significantly higher than other three genotypes. We initially consider that reducing normal N rate of 1/6-1/3 could supply adequate N and maintain the chlorophyll content, photosynthetic rate and enzymatic activity of N metabolism of leaf, harmonize the absorption and distribution of N in different organs in the later growth stage of summer maize, therefore resulting in higher-yielding and N utilization efficiency in the maize productions.

      • 1
    • YAO CHENTAO

      Abstract:

      Under drought stress, the effects of different concentrations of S-ABA seed dressing on the germination, physiological and biochemical characteristics of maize seeds were studied. After comprehensive evaluation, the optimal concentration of S-ABA was screened to alleviate drought stress on maize. The results showed that different concentrations of S-ABA seed dressing could increase the germination rate and germination energy of maize and improve the drought resistance of seeds. S-ABA seed dressing can significantly increase the activity of antioxidant enzymes in maize, reduce the content of MDA, slow down the degradation of chlorophyll, and increase the activity of PEPase and RuBPase, thereby improving the photosynthetic capacity of maize and improving the drought resistance of maize. Low concentration of S-ABA can alleviate the damage of drought to maize. However, the high concentration of S-ABA has inhibitory on maize seed germination. Among them, 0.01 g a.i./100 kg seed S-ABA seed dressing can effectively improve the drought resistance of maize.

      • 1
    • Sun-chengtao

      Abstract:

      Using different generations of genetic breeding materials with different genetic background as female parent and high frequency parthenogenetic induction line G5 as haploid induced by male parent hybridization as experimental materials, the spraying doubling equipment was used to spray the experimental materials for 8 hours under the condition of colchicine concentration of 0.625 mg/ml. The results showed that the material doubling rate of Zhengdan 958 in S2 generation was the highest, at 33.75%. The second place was L3258×H71 which was added to NSS germplasm such as Ludahonggu and then to yellow-modified S0 generation. The doubling rate was 13.02%. The third place was that NSS germplasm added to tropical germplasm S1 generation. The doubling rate was 10.34%. The lowest was Liaohuang population, the doubling rate was only 0.33%. Secondly, S121/PH4CV was the S1 generation of NSS germplasm added to Luda Honggu germplasm. The doubling rate was 0.57%. Secondly, L106×PH4CV was the S1 generation of NSS germplasm added to tropical germplasm, and the doubling rate was 0.72%. However, statistical analysis showed that the doubling rate and material was 0.72%. The method of doubling haploid grains with the spraying equipment is simple and easy, but the doubling equipment should be improved and the process standardized, so as to obtain stable doubling effect.

      • 1
    • 苏光秋, 张回灿, 郑利剑

      Abstract:

      In order to provide evidences for breeding resistant varieties and applying diversity of corn varieties on prevention of southern corn leaf blight(SCLB). The resistance of 11 fresh corn varieties in Fujian was determined by using the methods of spraying inoculation and natural infection in the field at the stage of corn seedling and adult-plant, respectively. And field experiments were carried out to evaluate the effect of resistant and susceptible corn varieties intercropping on the prevention of the disease. The results showed that the tested corn varieties had different resistance to the population of 301 Cochliobolus heterostrophus isolates. The resistance frequency of corn varieties ranged from 32.23 to 72.76%, with the “Rongtian NO. 1” and “Yongzhen NO. 7” were higher among them. And 11 corn varieties also had different resistance to SCLB in the adult-plant stage, which “Rongtian NO. 1”、 “Yongzhen NO. 7” and “Mingtian NO. 4” were middle resistance. In addition, the inhibition rates to SCLB by “Yuetian NO. 22” (susceptible corn variety) under intercropping with “Rongtian NO. 1” and “Yongzhen NO. 7” (resistant corn varieties) were 33.78% and 25.41%, respectively in Fuzhou. While the disease index decreased by 58.35%, 21.05% and 52.56%, 46.42% in Pingnan with the same treatments during two consecutive years. According to the results, there was significant resistance differentiation among different corn varieties to SCLB, and intercropping between resistant and susceptible corn varieties could reduce significantly the disease severity in susceptible corn varieties.

      • 1
    • xuelu, majunjie, majingfeng

      Abstract:

      CCS(CO2 capture and storage)is considered as the most promising and potential technology for global CO2 emission reduction.However,its related projects will involve the risk of CO2 leakage,which will have an important impact on the surroundings,especially for the surrounding farmland ecosystem.So deep researching of the response of plants to high CO2 concentrations and selecting resistant plants are very urgent.It provides the reference data for agricultural production decisions in CCS project areas.In this paper, the plant height, wet biomass, dry biomass, net photosynthetic rate, transpiration rate, stomatal conductance and intercellular CO2 concentration are selected as indicators of maize resistant index for different CO2 concentrations.The results indicated that when the CO2 concentration is 10000 and 20000 μmol.mol-1, the growth of maize is promoted, resulting inSplant height increased 7%-12%, biomass increased 10%-15% and net photosynthetic rate increased about 60%;while the CO2 concentration is increased to 40000 and 80000 μmol.mol-1, the growth of maize is inhibited,leading to a reduction of 9%-12% plant height, 10%-17% biomass and 35%-45% net photosynthetic rate.The increase of CO2 concentration within a certain range has a "fertilization" effect on the growth of maize, but at a higher CO2 concentration, the growth of maize will be inhibited.However, no death phenomenon has been observed in maize.Furthermore,through CO2 tolerance index method (LCTI), it is concluded that maize can be used as a CO2 tolerant plant for CO2 leakage from geological storage and can be popularized and planted in farmland in CCS project area.

      • 1
    • JIANG Chun-yu, Li Yinchang, YANG Jin-zhong, ZHU Ru-hua, 丁山, 宋朝玉, 王圣健

      Abstract:

      High broken rates of kernels in maize combine harvesting are one of the most important factors limiting technology transfer, extension and application of mechanical harvesting for maize in China. Broken rates are dependent on both of maize properties itself and shelling machine. This paper aimed at evaluating biophysical factors influencing the broken rates of kernels under mechanical shelling and building single factor models for prediction of broken rates. Ears with an assign set of different moisture levels, from 7 maize cultivars grown at 3 plant densities, were subject to shelling tests using the same machine in order to explore influences on broken rates of such factors as maize cultivars, plant densities, kernel moisture and mechanical strength, as well as to screening optimum predictors and models for prediction of broken rates. Plant densities from 6 to 9 p/m2 didn’t influence broken rates, but all of maize cultivars, kernel moisture, kernel side crushing forces and kernel puncture strength did at statistically significant level. In respect of effect sizes of different factors for broken rates, total contribution, in terms of squared omega, of maize cultivars was smaller than that of kernel moisture to variations in kernel broken rates. Kernel moisture contributed less than both of side crushing forces and puncture strength to broken rate variation, and side crushing forces did less then puncture strength. The contribution of plant densities to broken rate variation was close to zero. Kernel puncture strength was the optimum predictor to estimate broken rates, which are an exponential decreasing function of puncture strength, and read as: kernel broken rate = 10.25×0.990^kernel puncture strength. Value 60 MPa of puncture strength is a lower limit to reach a broken rate no more than 5%. To sum up, the factors ranked as kernel strength and cultivars in descending order by their influence on kernel broken rates, with plant densities negligible. In addition, kernel moisture directly acted on kernel mechanical strength but indirectly act on kernel broken rates. Our findings provide useful information and an approach for broken rate estimation, screening of new maize cultivar suitable to mechanical kernel harvesting, shelling machine design and manufacture.

      • 1
    • lvsiqi, Zhangdi

      Abstract:

      Taking five kinds of maize genotypes by regulating manganese concentration and manganese salt type as research object, analyzed effects of manganese stress on different varieties of nitrogen transformation. In this experiment, five kinds of maize varieties were cultivated with Kenji 1 (KN1), Shuangyu 201 (SY201), Dongqing 1 (DQ1), Ji Nongda 516 (JN516) and Xianyu 335 (XY335). Set five manganese concentration gradient respectively: (Mn1), 0.005mmol/L (CK), 5mmol/L (Mn2), 10mmol/L (Mn3), 20mmol/L (Mn4).Two kinds of form: MnCl2.4H2O and EDTA-Mn. The main results are as follows: With the increasing of manganese concentration, the content of nitrate nitrogen in root decreased, except for J, but the difference was not significant. DQ1 decreased the smallest. The content of ammonium nitrogen in KN1 and SY201 increased first and then decreased with the increasing of manganese concentration. The contents of ammonium nitrogen in JN516 and DQ1 decreased with the increasing of Mn stress. MnCl2·4H2O treatment of maize seedling root ammonium accumulation was greater than EDTA-Mn treatment. Manganese stress significantly inhibited the synthesis of soluble protein. With the increasing of manganese concentration, the content of soluble protein in roots decreased gradually. MnCl2·4H2O treatment of root soluble protein decreased more than EDTA-Mn treatment. The soluble protein content of root in JN516 was the highest among the five cultivars. Manganese stress affects the efficient distribution of nitrogen nutrients in the roots, hindering the transport of phloem and the accumulation of some nitrogen roots. Under the conditions of manganese stress, DQ 1 was a tolerant strain, and SY 201 was a sensitive strain; The inhibiting degree of free manganese ion on nitrogen transformation of maize seedling is greater than that of complexate manganese ion.

      • 1
    • yeyuxiu, ludalei

      Abstract:

      The effects of exogenous trehalose on antioxidant system and osmotic adjustment substances in root and leaf of waxy maize seedlings under drought stress were clarified using Suyunuo 5 as material. The results showed that drought stress significantly decreased the leaf chlorophyll content and root activity, while application of exogenous trehalose increased those contents. Application of exogenous trehalose under drought conditions could up-regulating the activities of antioxidant enzymes such as superoxide dismutase (SOD), ascorbic acid peroxidase (APX), peroxidase (POD) and catalase (CAT) in root and leaf of waxy maize seedlings. Spraying of exogenous trehalose could reduce the production rate of superoxide anion (O2-) and contents of malondialdehyde (MDA) and proline (PRO), whereas the contents of soluble protein and sugar, ascorbic acid (AsA) and glutathione (GSH) were increased significantly. The increase of soluble sugar and protein, AsA and GSH contents in leaves were more pronounced than those in roots, and the malondialdehyde content in leaves decreased greater than that in roots, indicated that alleviation of exogenous trehalose spraying were more pronounced in leaf than in root under water deficit conditions. In conclusion, when waxy maize seedlings suffer drought stress, application of exogenous trehalose could upregulate the antioxidant enzymes activities, adjust osmotic substances, enhance the drought resistance and alleviate the drought damage.

      • 1
    • dongpengfei

      Abstract:

      Maize mechanical harvest is the inevitable trend of maize harvest and industry development in China. Screening maize varieties with high yield and low moisture content is the key to realize mechanized harvest. To popularize the technology of maize mechanical kernel harvest in Henan province, harvest experiments were conducted in Henan Zhengzhou, Zhumadian, Hebi, Xinxiang, Luoyang and Luohe from 2014 to 2018. The results showed that the high grain broken rate is the main problems of maize mechanical kernel harvest in this area, and the high grain moisture content at harvest is the main reason of high grain broken rate, which can be effectively solved planting suitable varieties for mechanical kernel harvest. In this study. According to the two-way average mapping method, we selected many maize cultivars suitable for mechanical grain harvest, including Xianyu335, Huanong138, Lianchuang808, Xindan80, Xindan68, Fengdecunyu10, and so on.

      • 1
    • huyu, 具红光, 曹铁华

      Abstract:

      To investigate the effects of different cultivation methods on grain filling rate and yield of maize, the logistic equation was used to compare the grain filling process of film covered and non- film covered maize kernels in the low temperature cold zone of eastern Jilin Province. The results showed that film covered planting technology effectively improved the temperature of grain filling stages, promoted the growth process of maize and increased the grain filling rate. Additionally, the duration of grain filling were prolonged and the hundred-grain weight and yield were significantly increased, reaching the highest yield of 12483.52 kg/hm2, which is 50% higher than non-film covered. Under maximum grain filling rate, hundred grain weight and maize yield positively correlated with Wmax and Rmean.

      • 1
    • ZHAO Xiao-dong, WU Yi-rong, MAO Rui-lin, ZHENG Teng-fei, zhaoxinxin

      Abstract:

      Coating and non-coating seeds of two maize varieties, NK618 and Jidan 7 were selected as experimental materials, When stored after 16, 28 and 40 months under low temperature and low humidity environment, the germination and vigor of seeds were tested, at the same time, the contents of SOD, POD, CAT, MDA, proline, etc. were tested after seeds were germinated. The purpose is to study the tolerance time used as sowing seeds under low temperature and low humidity conditions of storing and the difference between the coating and non-coating seeds of storage and physiology change. The results showed that maize seeds stored after 16 months under low temperature and low humidity condition, the germination and vigor index of the coating seeds decreased significantly than the contrast seeds, but the showed no significant difference; when stored after 28 months , the germination rate of non-coating seeds of NK618andJidan7 were 91% and 87% respectively,and could be used for sowing, but the coating seeds had no sowing value; All seeds stored after 40 months had no seed value. Coating seeds were easily aged than non-coated seeds. The contents of SOD, POD, and CAT in germinating seedlings all decreased along with extend of storage time. At 28 months, the contents of three protective enzyme were lower than the contrast new seeds, but the difference significance were difference. The contents of MDA and proline increased along with extend of storage time. Germination and vitality index are more sensitive to aging than physiological index. At 40 months the contents of MDA of the seedlings from the coating and non-coating seeds of two maize varieties were the maximum.

      • 1
    • songxiulli

      Abstract:

      In the semi-arid region of western heilongjiang province, the soil quality has deteriorated due to perennial sand erosion. Crop rotation and deep tillage have become the main planting modes to improve the quality of local cultivated land and protect soil ecology. In this study, soybean and corn rotation and corn deep-turning straw mulching were compared with corn continuous cropping to study and analyze soil physical and chemical properties, growth and development indexes and yield of corn, and evaluate the effect of tillage technology. The results showed that rotation could significantly increase the contents of available nitrogen, available potassium and available organic matter in soil, significantly reduce the bulk density of soil by 10% and increase the porosity by 8%, which had a good effect on the improvement of soil physical structure. Deep straw mulching can significantly increase soil organic matter by 26~32%, increase soil available potassium content, and significantly reduce soil PH value by 0.4~1.2 units, which can improve soil fertility and salinization in western semi-arid areas. Deep turning straw mulching was more beneficial to the root growth at jointing and silking stage, the formation of stem diameter and ear dry weight, and the yield of maize increased significantly.

      • 1
    • Konglili, Houyunpeng, Liqian, Yincaixia, Qinyubo, Wangmeng, Yulei, Liuzhiquan

      Abstract:

      To perform the problem of lower fertilizer utilization efficiency and waste resources caused by unreasonable potassium fertilizer application in maize production and provide scientific basis on potassium fertilizer management under mulched drip irrigation in semi-arid region of Jilin province., two-year (2014—2015) field experiment was conducted to study the effects of different potassium application amounts (0, 30, 60, 90, 120, 150 kg/hm2) on maize yield, potassium absorption and utilization under mulched drip irrigation. The results indicated that, (1) potassium application increased maize yield significantly through increased the grains of per spike and 100-kernel weight. Maize yield increased firstly and then decreased with the increment of potassium application. The optimum amount of potassium fertilizer application was at the range of 92.8—102.6 kg/hm2?? (2014) and 95.0-105.0 kg/hm2 (2015), respectively, according to maize yield (y) and potassium fertilizer application (x) fitting, (2) Compared with no potassium application treatment, potassium accumulation amount was increased significantly from jointing stage to maturing stage by applying potassium fertilizer, and it arrived at the highest value under K90 treatment from filling stage to maturing stage. Meantime, the potassium distribution proportion was increased by 12.4%—28.4% (2014) and 2.7%—26.8% (2015) from silking stage to maturing stage by applying potassium fertilizer. (3) Compared with different potassium application treatments, potassium translocation amount, translocation rate and potassium uptake amount of grains were increased significantly by applying potassium fertilizer, and increased firstly and then decreased with the increment of potassium application. The highest values of them were all under K90 treatment. (4) The potassium recovery efficiency and partial productivity decreased and potassium agronomic efficiency increased firstly and then decreased with the increment of potassium application, and the highest values of them were all under K60 treatment. Therefore, the optimum amount of potassium fertilizer application should be controlled at 90-105kg/hm2 under mulched drip irrigation in semi-arid region of Jilin province, according to maize yield, potassium absorption and utilization and other factors under different potassium application amount.

      • 1
    • ZHAO Xun-chao, GE Sheng-nan, WEI Yu-lei, XU Xiao-xuan, DING Dong, LIU Meng, ZHANG Jin-jie, SHAO Wen-jing, Li Jia-Xin, XU Jing-yu

      Abstract:

      Growth regulating factor (GRF) plays an important role in regulating plant growth development and responding to abiotic stress. In this study, Arabidopsis was used as seed sequence for Blastp sequence alignment. A total of 15 ZmGRF genes were identified and their physical and chemical properties, phylogenetic relationships, gene structure, conservative motifs, chromosome localization, protein secondary structure, prediction of phosphorylation sites, the expression profiles of different tissues and under abiotic stress expression were analyzed. The results show that according to phylogenetic tree analysis the relationship between GRF gene of maize and rice of monocotyledon plant was close; 15 ZmGRF genes were located on chromosomes 1, 2, 4, 5, 6, 7, 9 and 10 respectively, which there are highly homologous; gene structure and conserved motif function of each subgroup are relatively conservative; secondary structure of ZmGRF protein was mainly alpha-helix and random curl in maize; according to the prediction analysis of phosphorylation sites, except ZmGRF6 and ZmGRF9 not contain tyrosine, other ZmGRF proteins contain potential serine, threonine and tyrosine sites, and the number of potential phosphorylation sites varied greatly among proteins; transcriptome data analyzed the up-regulated expression of ZmGRF4 and ZmGRF13 genes under NaHCO3 stress, meantime, ZmGRF4 and ZmGRF13 genes were found to have high expression levels under heat, salt and drought stress; ZmGRF1/3/4/15 gene expression was higher under cold stress; the expression profiles of different tissues were analyzed showed that ZmGRF4 and ZmGRF13 were highly expressed in various parts of maize, further clarification of the involvement of GRF gene in plant growth development and abiotic stress response provides a potential theoretical basis.

      • 1
    • chenriyuan

      Abstract:

      Field experiment was conducted to evaluate the effects of applied N post-anthesis on dry matter accumulation, leaf area index (LAI), functional leaves SPAD, Photosynthetic rate (Pn) and root growth for high-yielding spring maize production. On the basis of optimizing nitrogen application in the early stage, the target values of nitrogen supply were set at silking stage (R1) and milking stage (R2), respectively 170, 140 kg N ha-1 (N2 treatment) and 260, 220 kg N ha-1 (N3 treatment), and the actual value of nitrogen supply was determined according to the soil Nmin of R1 and R2 stages. Compared with the non-topdressing nitrogen fertilizer (N1) treatment after silking stage, the average yield of N1,N2 increased by 13.2% and 22.0%. Added N application post-anthesis can increase functional leaves SPAD value, leaf area index (LAI) ,which can slowing the aging of maize and increased intensity of photosynthesis of maize. Added N application post-anthesis did not significantly increase the total of root length, root surface area and root weight; However, root length and root surface area in the 10-20 cm and 50-60 cm soil layers were significantly increased by nitrogen application post-anthises.

      • 1
    • Wu Qiuping, Jiang Fei, Zeng Su-ming, Han Cheng-wei, Song Chun-lin, Liu Bao-Shen, Xu Li-hua, Kong Xiao-min

      Abstract:

      In order to explore the effects of different types of chemical regulators on plant growth and yield of silage corn under different planting densities, a filed experiment was conducted using Sicao No. 2 of silage corn with 3 types of chemical regulators under planting densities of 60000, 67500 and 75000 plants/hm2. The results showed that the increased planting density significantly increased fresh matter yield and dry matter production, plant height and leaf area index at silking stage, while the ear height of plant and leaf SPAD value was not effected. The three chemical control agent improved leaf SPAD value at both the bell stage and the silking stage, with an increase by.5~3.5% and 1.8~3.0% than that of the CK(water-treatment) respectively. The plant height and ear height with sparing chemical regulator“Duoxiaozuo”increased, while the ear height decreased under the chemical regulator of“Baoyu”and”Aiduoduo”. The leaf index at silking stage of “Duoxiaozuo”chemical regulator treatment increased by 3.0% s than that of the CK, while decreased by 4.9% and 8.5% for “Baoyu”and”Aiduoduo”. The fresh matter weight and dry matter production of silage corn with spraying“Duoxiaozuo”chemical regulator treatment increased by 2.2% and 3.1% that that of the CK, but decreased by 3.7% and 3.8%, 6.0% and 5.7% with spraying“Baoyu”and“Aiduoduo”treatments respectively. Under the planting density of 75000 plant/ /hm2, the treatment of chemical regulation of “Duoxiaozuo”could make the fresh matter weight and dry matter production of silage corn reach 82 877kg /hm2 and 26 1892 877kg /hm2 respectively.

      • 1
    • gao tingting

      Abstract:

      Germplasm amplification, improvement and innovation are the basis of commercial breeding of corn. The application of recycling breeding strategy to carry out maize germplasm improvement and innovation is an important means to establish commercial breeding.The results showed that a total of 162, 83, and 140 allelic variations were detected in 39 SSR markers in 62 materials,Tie7922 modified lines, and Ji13S228 modified lines, with an average of 4.05, 2.13, and 3.51. The point polymorphism information index (PIC) averaged 0.45, 0.26, and 0.37, respectively; the gene diversity index averaged 0.51, 0.31, and 0.42; the genetic diversity of the improved 13S228 improved line was higher than that of the iron 7922 improved line.The genetic distance ranged from 0.11-1.87, with an average of 0.76; the genetic distance between the 13S228 modified line group and Ji 13S228 was the smallest (0.09), and the genetic distance between the iron 7922 modified line group and the iron 7922 was also close (0.16).According to the UPGMA method, principal component analysis and model clustering, 62 inbred lines were divided into two major groups:SS group (Tie7922and its cyclic selection material、B73、PH6WC andYe478), NSSgroup(Ji13S228 and Ji13S228 improved line、MO17、Dan340、Huang zaosi and PHB1M).NSS group (Ji 13S228 and its cycle selection materials and standard test species MO17, Dan 340, Huang Zao4, PHB1M).In line with the idea of two heterotic groups of commercial breeding of corn. In the future, we must adhere to the cycle breeding strategy to consistently carry out genetic improvement of maize germplasm.

      • 1
    • zhangxin, caoliru, luxiaomin, zhangqianjin, weixin, weiliangming, wangzhenhua

      Abstract:

      17 parts of Huanghuaihai commonly used backbone and self-selected lines were used as materials, and drought stress was carried out at different growth stages. A series of drought-tolerant maize planting resources were selected to explore the physiological mechanism of drought resistance.Analysis of variance showed that the male-dispersion interval after stress did not reach a significant level compared with normal water, but the ASI interval reached a significant level.The chlorophyll content, Fv/Fm and Fv/Fo of inbred lines in different growth stages decreased, SOD and POD activities increased, but the amplitudes of different inbred lines decreased or increased, and different inbred lines, stress and control in indicators and interactions between the two factors reached extremely significant levels.The grey correlation degree indicates that the POD activity is highly correlated with ASI in both jointing and tasseling stages, and can be used as an important indicator for screening drought-resistant materials.Fuzzy membership function method to identify Chao 4F, Zheng 36, CIMBL12, Zheng 63, HCL645, Zheng 6611 and PH6WC are drought-resistant inbred lines in both growth stages.Among them, the ASI increased slightly after the inbred lines of Chao 4F, Zheng 36 and Zheng 63 jointing and tasseling stress, and the chlorophyll content, chlorophyll fluorescence parameters Fv/Fm and Fv/Fo drought indexs were higher, indicating that these three When the inbred lines are subjected to drought stress, the mechanism of photosynthetic system is mainly adjusted to improve drought resistance.The results of this study can accelerate the cultivation of drought-resistant varieties and lay the foundation for the establishment of drought resistance identification system for maize.

      • 1
    • Qiao Yunfa, Miao Shujie, Lu Xinchun, Wang Tiecheng

      Abstract:

      The Aeolian sand soil of northeast China is a kind of obstructive soil. It is the key point to clear the barrier factor for improving maize yield in the Aeolian sand soil zone. Six pairs of high- and low-productivity Aeolian sand soils were studied, which located in Dulbert Mongolian Autonomous County, Heilongjiang Province, Daqing. Ten physical (layer depth, bulk density, porosity, hardness and three-phase Ratio Structure Distance, field capacity, mean weight diameter, sandy, silt and clay) and ten chemical (pH, organic matter, available nitrogen, phosphorus and potassium, total nitrogen, phosphorus and potassium, exchanged cation and C/N) parameters were determined from four soil profiles (surface, stable, plough pan and core soil layers). Results showed that the difference in high- and low-productivity field might be attributed to four reasons. First, the differ in bulk density, mean weight diameter, sand, silt, clay, organic matter, available nitrogen and phosphorus, total nitrogen and phosphorus, exchange cation in surface soil. Second, there are significant variation in three-phase Ratio Structure Distance, mean weight diameter, silt, clay, organic matter, available nitrogen, phosphorus and potassium, total nitrogen and phosphorus, exchange cation. Third, significant difference was observed in mean weight diameter, clay, organic matter and total nitrogen in plough pan layer. Fourth, higher three-phase ratio structure distance, and lower field capacity, mean weight diameter and clay in low- than high-productivity field at core soil layer. The result of principal analysis showed that the major obstructive layer was surface and plough pan layers, where organic matter, total nitrogen and phosphorus, available potassium and clay were the main obstacle factors.

      • 1
    • DENG Jie

      Abstract:

      Abstract: 89 maize inbred lines were used as experimental materials. During the germination period, MNaHCO3:M Na2CO3=5:1, 170mmol·L-1 saline-alkali stress treatment was used, and 8 traits such as germination potential and germination rate were used as identification indicators. The functional evaluation, correlation analysis, principal component analysis and cluster analysis method were used to comprehensively evaluate the results. The results showed that the varieties showed significant differences under salt-alkali stress, and 89 maize inbred lines were divided into four categories. 6 parts of high saline-alkaline-resistant inbred lines, 13 parts of moderate saline-alkaline -resistant inbred lines, 27 parts of general salt-alkali-sensitive inbred lines, 42 parts of saline-alkali-sensitive inbred lines, 19 parts of salt-alkali-resistant materials can be used for seedling stage or field resistance Salt alkaline research.

      • 1
    • LI Wenlan, MENG Zhaodong

      Abstract:

      The yield and quality of maize were influenced by maize prolificacy, which is regulated by many factors such as environment and genotype. As an important plant growth regulator, auxin plays an important role in organ formation and differentiation. In this study, the transgenic plants with DR5rev::mRFPer and pZmPIN1a::ZmPIN1a::YFP were used to analyze the distribution pattern of the auxin response signal labeled by red fluorescent protein and the auxin transport protein PIN1a labeled by yellow fluorescent protein, respectively. It was found that axillary bud of different nodes were at the same stage of development in the early stage of plant development. Auxin response signal and auxin transport protein are evenly distributed throughout the axillary bud of primordia. With the growth of the plant, the development of axillary buds at different nodes began to be out of sync. The patterns of auxin distribution and poplar auxin transport were significantly different between axillary buds at different nodes, the upper axillary bud showed stronger auxin-responsive signals and polar auxin transport signals. These results suggest that auxin local synthesis and polar transport play a role in the development of axillary buds of maize. The results of this paper will provide useful information for the comprehensive analysis of the mechanism of auxin in the process of maize multi-ear formation.

      • 1
    • CAO Yu-jun, LU Ming, LÜ Yan-jie, YAO Fan-yun, WEI Wen-wen, LIU Zhi-ming, WANG Yong-jun

      Abstract:

      In this paper, maize varieties which had been widely popularized since 1970s in Jilin Province released in three different eras (1970s, 1990s and contemporary era) were used as materials. The effects of long term water deficit on photosynthetic characteristics and dry matter remobilization of maize varieties in different eras were studied by tubular column cultivation experiment with rain shelter. Compared with the control, water deficit reduced the net photosynthetic rate (Pn) and maximum photochemical efficiency (Fv/Fm) of ear leaves of old varieties (1970s and 1990s) more than that of contemporary varieties (2010s). The water deficit treatments of Pn, Fv/Fm in ear leaves of maize in 1970s, 1990s and 2010 decreased by 29.4%, 21.8%, 16.1% and 19.4%, 13.2% and 11.1% respectively from flowering stage to 40 days after flowering. Under long-term water deficit, the dry matter remobilization rate of leave and stem-sheath of contemporary maize varieties was higher than that of the old ones. Relative to the control, the average translocation rate of leaf and stem-sheaths dry matter in 2010s, 1990s and 1970s increased by 48.9%, 47.7% and 33.8%, respectively. In addition, under water deficit, the contribution rate of storage assimilates before anthesis to grain yield decreased with the advancement of the era, while the contribution rate of dry matter accumulation to grain after anthesis increased with the development of the era. So, under long-term water deficit, the post-anthesis photochemistry efficiency of contemporary maize varieties is stronger than that of the old ones, which can drive more stored assimilates of vegetative organs before anthesis to transfer to grains. Meanwhile, under water deficit the contribution of post-anthesis dry matter accumulation of contemporary maize varieties to yield is more advantageous than that of the old varieties.

      • 1
    • Dong Chunlin, Zhai Guangqian, Yang Rui, Zhang Ming-yi, 蒋丹, Chang Jianzhong

      Abstract:

      With compact plant type, high plant population and great potentialities for yield increase, drawf is one of the most important determinant of maize ideal plant type, A2 was identified by EMS treatment. Phynotyping, genetic analysis, exogenous GA3 sensitivity and transcriptome analysis were performed in this study. The results shows that the plant height of A2 decreased significantly by 10.13% due to less internodes number and shorter internodes. The dwarf trait was controlled by a single recessive gene. A2 was sensitive to exogenous GA3 which could recover plant height phenotype of A2 mutant. A total of 74 differentially expressed genes(DEGs) were identified by transcriptome sequecing. KEGG analysis shows that 74 DEGs classified into 4 pathways, including carotenoid biosynthesis, pentose and glucuronate interconversions and glycerophospholipid metabolism, etc. This study laid a foundation for further research and candidate gene cloning of A2 mutant.

      • 1
    • Yin Xue-wei, Zhang Yi-fei, Yang Ke-jun, Wang Yu-feng, Chen Tian-yu, Zhang Peng-fei, Wang Huai-peng, Yang Li, Wu Peng, Zhang Wen-chao, Jian Li-qun, Zhang Ji-wei

      Abstract:

      In this study, maize variety ‘Xianyu 335’ was used as experimental material. 0 kg/ha (CK), 50 kg/ha (C1), 100 kg/ha (C2), 150 kg/ha (C3) and 200 (C4) kg/ha of calcium fertilizer (calculated as Ca) application levels were set under field conditions, and the effects of different calcium fertilizer application levels on dry matter accumulation and translocation, grain yield, product quality, and mineral element content of maize were investigated. The results showed that dry matter accumulation for whole plants, dry matter translocation and post-anthesis dry matter accumulation were significantly increased under C2-C3 treatments. Compared with CK treatment, grain yield under calcium fertilizer treatments in 2016 and 2017 were obviously increased by 12.48%-17.15% and 8.76%-11.58%, the increase of yield was mainly due to a dramatic improvement of the number of productive ears in per unit area and the 100-grains weight. Meanwhile, grain crude starch contents under C2-C4 treatments were increased by 11.6-13.5 g/kg in 2016 and 7.0-12.5 g/kg in 2017, grain test weight under C2-C3 treatments were raised by 7.7-19.0 g/L in 2016 and 28.4-35.7 g/L in 2017, respectively, compared with CK treatment, and all the differences were significant. Furthermore, grain potassium contents under C2-C3 treatments were significantly increased, the increased amount of which in 2016 and 2017 were 0.43-0.63 g/kg and 0.32-0.83 g/kg, and only with C3 treatment, grain zinc contents was significantly higher than CK treatment. In summary, grain yield and quality of maize under calcareous soil conditions in the western Songnen Plain could be effectively improved when the calcium application levels are 100-150 kg/ha.

      • 1
    • WU Xiaochun, MA Xiangfeng, YANG Xiaojun, ZHANG Jixuan, ZHANG Jie, LI Xia

      Abstract:

      Through the measurement and analysis of soil bulk density,soil compaction,soil field water holding capacity, soil water content and corn yield, the effects of three tillage methods, namely deep pine cultivation, deep belt rotation tillage and conventional surface rotation tillage, on soil physical properties and maize yield of spring maize in northwest China were investigated. The results showed that in the spring, the deep pine and spring strip rotation had significant effects on the soil bulk density of 15-25 cm and 25-35 cm in each growth period. The spring deep pine and spring strip rotation significantly reduced the soil compaction of 15-25 cm,and significantly increased soil water holding capacity of 15 ~ 25cm, 25 ~ 35cm.By increasing the length of spikes, the number of grains per panicle and 1000-grain weight, spring deep pine increased economic yield compared with conventional rotary tillage.

      • 1
    • SHAO Rui-xin

      Abstract:

      Climate change could cause high intensity and frequency of extreme weather such as drought, and the sensitivity of maize growth and development, especially, the tassel and ear differentiation and development, to drought stress would increase constantly. Based on our investigations and previous studies, this paper discussed the different degrees of drought stress on the development process of maize ear and tassel from three stages, namely, the differentiation of tassels and ears, the pollination characteristics of tasseling and silking, and the development of grains. The purpose aims to provide an adaptive theoretical guidance for high and stable yield of maize, and also to lay an academic foundation for research on drought resistance of maize.

      • 1
    • hanhuimin, zhanglei, sunmiao, lijian, changxiao, guozhijun, wangxiaobo, yangzhaosheng, laingwenke

      Abstract:

      To explore the response of growth, development and yield of summer maize to sowing date in Huang-Huai-Hai Plain (HHH), three sowing date treatments (June 3, 13 June, 23 June) were conducted with 18 main cultivars in HHH. The results showed that the growth period of maize varieties was shortened, plant height, ear position, leaf area and dry weight per plant decreased significantly with the delay of sowing date. The 100-grain weight, the number of grains per ear and the yield decreased with the delay of sowing date. Under different sowing date conditions, varieties with small changes in various indexes have strong adaptability and long suitable sowing time. And those varieties maintained a relatively stable growth period and larger leaf area to ensure higher dry matter accumulation and stable yield. Therefore, early sowing is beneficial to improve the maize yield, but when early sowing can not be satisfied, the varieties with long suitable sowing period such as Lianchuang 825 or strong yield advantage such as Dika 653 can be selected to prevent the yield reduction caused by high temperature or late sowing.

      • 1
    • luming

      Abstract:

      The maize inbred Si-287 was bred from two inbred lines Si-444 × 255 by 6 generations of continuous inbreeding in North and Hainan province of China. It had the advantages of early maturity, high combining ability, great disease resistance, good firmness, wide adaptability and so on. Compared with the Si-444, it had achieved improvement and innovation in maturity, disease resistance, stress resistance and agronomic traits, which was a successful example of the germplasm improvement of “Tangsipingtou” in Northeast China since 2000. With its use as a parent and derivative system, it had selected new maize varieties such as Jidan 27 promoted and applied in large areas, which promoted the large-scale application of the “Tangsipingtou” germplasm in early maturity areas of spring maize.

      • 1
    • YU Xue-jie, WANG Jun, SHI Hai-chun, YUAN Ji-chao, ZHAO Chang-yun, KE Yong-pei

      Abstract:

      Maize inbred line 698-3 and its improved lines were selected as research materials, the character differences between inbred 698-3 and its improved lines were comparatively studied through morphological data; in order to understand genetic improvement effect and breeding potential, heterosis and combining ability of yield were analyzed by 4×10 incomplete diallel cross. The main achievements were as follows: The analytical results of phenotypic characters showed that, improved lines have various degrees of variation in silking stage, plant height, main economic traits and yield compared with the original maize inbred line 698-3. The improved line K336 have the most difference of phenotypic characters, and its 13 characters reach significant difference in comparison with the 698-3. In contrast, improved lines SP698-3-17, SP698-3-11 are all the least difference of phenotypic characters, they only have 5 characters reach at the 1% or 5% significant level. Positive GCA effect value of yield were in sequence of K336, K389 and 698-3GT42, most of improved line combinations in SCA of yield had not significant difference in comparison with the CK, and only combinations 205-11×698-3GT1109, 205-11×K336 and 205-11×698-3R reach at 1% or 5% positive significant level. Most of combinations’ unification heterosis reach at 5% negative significant level in comparison with Chuandan418, and only the 205-11×K336 reach at 5% positive significant level, with the value of 12.27%,the corresponding heterosis of most of 36 improved line’s combinations are positive value in comparison with corresponding 698-3 combination, among them, 7 combinations reach at 1% or 5% positive significant level. In summary, the main economic characters and yield and their yield GCA of improved lines K336 and K389 have a better improvement, some of their combinations’ yield SCA, and yield heterosis all have a better performance, they could be used as ideal parents in high yield breeding. Maize-breeding practice has also proved that, the improved lines K389 is male parent of the hybrid zhenghong505 which is more appropriate full mechanized planting variety in the two cropping system in hilly rainfed

      • 1
    • xiu weiming

      Abstract:

      In order to better understand the influence of different fertilization regimes on soil meso-and micro-arthropods in fluvo-aquic soil, this study was conducted in the Wuqing experimental station, Agro-Environmental Protection Institute, Ministry of Agriculture. The field experiment included six treatments, i.e., contrast (A0), organic fertilizer (A1), reduce 50% chemical fertilizer plus organic fertilizer (A2), normal chemical fertilizer plus organic fertilizer treatment (A3), increase 50% chemical fertilizer plus organic fertilizer (A4), chemical fertilizer (A5). Indicate :A total of 1570 soil meso-and micro- arthropods were obtained in this survey, belonging to 5 classes, 9 orders and 35 families. On the whole, fertilization increased the total numbers and species of soil arthropods, significantly increased the diversity of soil animal in surface soil. It was beneficial to the stability of animal communities. However, A large number of chemical fertilizers were used to inhibit some soil arthropods and reduce the species of soil arthropods . In addition, higher content of chemical fertilizer could significantly reduce the evenness of soil arthropods. It suggested organic manure plus synthetic fertilizer was good for the amount of soil meso-and micro- arthropods, but the more of chemical fertilizer was bad to the stable of soil arthropods.

      • 1
    • XIA Zhen-qing, LU Hai-dong

      Abstract:

      Soil temperature has a strong effect on the growth and development of crops. In the face of the drastic changes of global temperature, the problem of soil temperature in the root zone of maize growth has become a focus of current research. According to the present situation of soil low temperature and high temperature damage to maize in agricultural production, the effects of soil temperature on soil environment, root system, canopy and yield of maize were discussed in this paper. Several measures to change soil temperature and prospects for the development of maize soil temperature research were introduced in order to provide help for future research.

      • 1
    • 徐淑兔, 郝引川, 薛吉全

      Abstract:

      In this study, 12 declassified American maize inbred lines introduced by the National Maize Industry Technology System in 2012 were used as test materials, and 4 research group core maize inbred lines (KA105, KA064, KB043 and KB204) were used as test species, using NC-II Genetic mating design for combining ability test and analysis. The results showed that the general combining ability (GCA) of KA105 and KA064 were excellent, and the yield GCA effect of PHPR5, MBST, LH213, 2FACC, LH212Ht, LH209 and PHR47 in the US maize inbred lines were excellent. The hybrid combinations PHPR5×KA105, LH213×KA105, PHH93×KA105, 2FACC×KA064, LH212Ht×KA105, and PHPR5×KB204 have strong over-stand heterosis and can be further tested.

      • 1
    • GUO Shu-lei, WEI Xin, WEI Liang-ming, ZHU Wei-hong, ZHANG Qian-jin, GUO Jin-sheng, ZHOU Bo, WANG Yan-zhao, HAN Xiao-hau, ZHANG Xin, WANG Zhen-hua, LU Xiao-min

      Abstract:

      DH breeding based on biological induction has developed into a key technology of maize breeding, application of DH technology can significantly shorten breeding cycle, improve the breeding efficiency and accelerate the breeding process. In recent years, the large-scale induction technique of haploid is quite mature, but batch doubling is an urgent technical problem. Here, we reviewed the new research progress of haploid obtained approaches、doubling technical measures、genes or QTLs of induction rate and doubling rate. In addition, we analyzed the effectiveness of different doubling methods and different doubling reagents, furthermore, the genetic architecture of induction locus were dissected by Meta-QTL analysis, which would provide the reference to further research on haploid breeding technology, broad our further understanding of DH breeding.

      • 1
    • Zhang Meiwei, Liu Jingbao, Li Chuan, Huang Lu, Zhang Panpan, Li Ping, Niu Jun, Guo Guojun, Chen Jinglun, Yu Ting, Qiao Jiangfang

      Abstract:

      In order to study the effect of different irrigation and nitrogen (N) fertilizer on yield characteristics and nitrogen utilization for summer maize cultivars with different genotypes in Huang-Huai-Hai region, a field experiment with two irrigations (no irrigation W0, irrigated twice at flare opening and spinning stages with 75mm precipitation W1) and three N fertilizer levels (0 kg N /hm2 N0, 150 kg N /hm2 N1, 225 kg N /hm2 N2) were conducted on 20 summer maize cultivars. The results showed there were significant influence of cultivar, irrigation and N fertilizer on yield and its components, dry matter accumulation, harvest index and agronomic efficiency of applied N. Additionally, the effect of irrigation on yield and its components, dry matter accumulation, harvest index was greater than cultivar and N fertilizer, while N fertilizer had the greatest influence on agronomic efficiency of applied N. Among all indexes, the highest variable coefficient was found in agronomic efficiency of applied N. Irrigation of W1 treatment increased yield, dry matter accumulation, harvest index and agronomic efficiency of applied N. And N applied also improved yield and dry matter accumulation, while decreased agronomic efficiency of applied N. There was no significant influence between N1 and N2 treatment. Considering both yield and agronomic efficiency of applied N, the treatment of W1N1 with 150 kg N /hm2 and irrigated twice at flare opening and spinning stages with 75mm precipitation was appropriate in Huang-Huai-Hai summer maize area.

      • 1
    • WANG Bin, WANG Yu-bo, TONG Tong, LIU Xiao-ming, ZHAO Meng, LI Cai-feng

      Abstract:

      For study of the effects of nitrogen fertilizer, nitrogen fertilizer synergist and biological fertilizer on the photosynthetic characteristics and key enzymes of nitrogen metabolism in maize, Pingan 18 and Jinyu No. 1 were used as test materials, and Set seven nitrogen application modes (0kg/hm2, 175kg/hm2, 175kg/hm2+ synergist, 175kg/hm2+ biological fertilizer, 175kg/hm2+ synergist + biological fertilizer, 225kg/hm2, 225kg/hm2+ synergist, 275kg /hm2), The photosynthesis rate, chlorophyll content, nitrate reductase (NR) and glutamine synthetase (GS) activities of maize leaves were determined. The results showed that the application of nitrogen fertilizer could increase the chlorophyll content and increase the photosynthetic rate of maize leaves, and the excessive nitrogen fertilizer would inhibit it. Nitrogen application rate of 225kg/hm2+ synergist had higher chlorophyll content and photosynthetic rate during the whole growth period, and NR and GS activities were also higher than other treatments. The nitrogen application mode better coordinated the relationship between photosynthesis and nitrogen metabolism. Fully play the role of nitrogen fertilizer, which can increase the weight of 100 grains. The production of Pingan 18 and Jinyu 1 reached 13116.94kg/hm2 and 13585kg/hm2 respectively.

      • 1
    • DONG fei, YAN Qiu-yan, LI Feng, LU Jin-xiu, YANG Feng, JIA Ya-qin, WANG Miao

      Abstract:

      To exploit potential production and appropriate cultivation techniques for dryland maize in shanxi province, field experiment was conducted to study sowing date (4/17, 4/27 and 5/7) and planting density (5.25, 6.00, 6.75, and 7.50×104 plants/hm2) effects on maize varieties (Xianyu335 and Qiangsheng388) growth and yield using split plot experiment design. The results showed that plant height and ear height increased, stem diameter and plant dry matter weight decreased with the increase of planting density, and the sowing date promoted this increase and decrease effect further. Area yield change in density varied according to different maize varieties, but area yield was lowest under late sowing and highest under middle sowing. As the sowing date in advance, maize growth period is extended accordingly, especially on the growth period of sowing to jointing stage. The suitable density of Xianyu335 was 6.75×104 plants/hm-2 in early sowing and middle sowing date, while lower planting density was suitable for yield increase under late sowing conditions. Low density cultivation were suitable for Qiangsheng388 under the three sowing date. In general, the region's suitable sowing date was April 27 with a suitable planting density of 6.75×104 plants/hm2 for dryland maize, which had a better corn stem traits and yield index.

      • 1
    • Zeng Zhi Tan Lu

      Abstract:

      This paper uses the panel data of the provinces of 17 major maize producing regions in China from 2005 to 2017 to empirically analyze the impact of policy support on corn farmers" income. The study found that policy corn price has a positive effect on farmers" income. At the current stage of the "market price premium" new policy, corn price has no obvious impact on farmers" income, and corn productivity has a greater effect on farmers" income. The influence of peasants" income is not obvious. The urbanization rate has a greater and greater effect on the peasants" income. The urban-rural income ratio is less and less inhibiting the peasants" income. The consumer price level has gradually increased the peasant income. Finally, it proposes to guide farmers to increase grain enthusiasm, increase farmers" transfer income, adjust planting structure, moderately carry out scale operation, establish effective price adjustment mechanism, strengthen market dynamic regulation and control, and establish policy recommendations for symmetric information service system.

      • 1
    • wuhaiyan, FAN Zuo-wei, LI Yang-yang, SHA Hong-lin, CHI Chang, MA Wei, ZHU Ping, pengchang

      Abstract:

      Selection of different fertility black soils in Jilin Province,the soil microbial flora, soil microbial biomass carbon, soil microbial biomass nitrogen and soil enzyme activity were measured in high, medium and low fertility soils.The differences of microbial indicators in different fertility soils were systematically analyzed, and the correlations between different fertility soils and microbial indicators were fitted, and the reference standard values of soil microbial indicators for different fertility soils were determined. The results showed that the soil microbial fertility index varied greatly with different fertility soils. High fertility soil had higher bacteria, actinomycetes, microbial biomass carbon, microbial nitrogen and soil enzyme activity, but the number of fungi was lower, which was healthy soil; The number of bacteria, actinomycetes, microbial biomass carbon, microbial nitrogen and soil enzyme activity in low fertility soil were lower, and the number of fungi was higher. The critical thresholds of soil-related microbial indexes for different fertility soils in Jilin Province were proposed, and the evaluation criteria of microbial fertility indexes for different fertility soils were established.

      • 1
    • renhonglei, huguanghui

      Abstract:

      Abstract: The agronomic characteristics is the main factors of maize yield components,to study the relationship between the agronomic characteristics factors and maize yield could help to enhance the maize yield. The effects of agronomic characteristics factors such as growth period, plant height, ear height, ear length, ear diameter, bald length, rows per ear, grains per row, 100-grain weight, produced grain rate. Studied using stepwise regression analysis and path analysis, decision factors between the agronomic characteristics and maize hybrids yield, The maize hybrids yield was test using normal distribution before path analysis. The analysis results are examined using significance test until each variables in regression equations reached significant level. The results indicated that in the second eco-regions particular attention should be paid to the selection of ear length, ear diameter, rows per ear and produced grain rate in the maize breeding;In the fourth eco-regions particular attention should be paid to the selection of growth period, plant height and ear height in the maize breeding;In the fifth eco-regions particular attention should be paid to the selection of ear length, ear diameter,bald length and produced grain rate in the maize breeding;In the sixth eco-regions particular attention should be paid to the selection of ear length, ear diameter and bald length in the maize breeding.

      • 1
    • wangjingze, 于洋

      Abstract:

      cDNA-AFLP approach with 224 primer pairs was employed to analyze genes differentially expressed in normal and four stress maize inbred lines offspring induced by introducing suaeda salsa DNA into the ‘M-2 maize’. TDFs were successfully sequenced.According to the NCBI BlastX the comparative analysis of the sequencing results, 49 TDFs were homologous to genes involved in photosynthesis, cell signal transduction, stress response, cell metabolism and so on. The remaining 2 TDFs had no signal, 20 TDFs highly homology genes were unknown protein. Two TDFs (TDF3, TDF98) were selected for further study by real-time polymerase chain reaction (RT-PCR) that the expression of the defense genes responsive to play varying degrees of regulation roles in adapting to salt stress environment for maize. Genes involved in salt stress response were identified and their expression patterns successfully determined. This study laid the theoretical basis for the analysis of molecular mechanism and cloning of genes related with salt stress in maize.

      • 1
    • ZHOU Xu-mei, GAO Xu-dong, GAO Hong-min, QIU Zhen, XU E, LI Fang-ming

      Abstract:

      Used Gaoyou5 as haploid inducer, 8 elite double haploid inbred (DH) lines was selected from the foundation material of the hybrid generation F1 of M54×USA maize hybrid through haploid induction, natural doubling in field, cultivation identification and character selection. The combining ability and the application potential of the DH lines were analyzed by NCⅡ design. The results showed that the GCA was different from DH lines with the same genetic foundation. The DH lines of MDH4 and MDH8 had higher yield per plant GCA value, and it was easier to breeding high-yield hybrid with MDH4 or MDH8 as a parent. Comprehensive analysis of the performance of the main agronomic traits showed that the DH line of MDH4 was an ideal parent to breed high yield and high quality excellent maize hybrids, and the DH lines of MDH8 and MDH5 also had great application potential. MDH4×H451, MDH4×S121 and MDH8×H451 had high TCA and high yield per plant, which could be confirmed as good combinations and should be tested in multiple locations for many years in order to exploit their application potential. According to the estimate of genetic parameters, plant height, ear height, ear length and ear rows should be selected in early generation. When breeding maize hybrids, plant height, ear height, ear length and ear diameter should be focus on using the DH or inbred lines with outstanding performance of GCA as parents, ear rows, 1000-kernel weight and yield per plant should be given consideration to GCA of parents and SCA of hybrids, and the selection of SCA should be emphasized in improving kernel number. This research provides a reference for screening, identifying and utilizing DH lines and hybrids with application potential.

      • 1
    • LI Meng, ZHANG Ya-ru, GAO Meng-ya, LI Shu-na, WANG Shu-xiang, LI Ming, LI Hong-ya

      Abstract:

      The structures of milled wood lignin (MWL) and lignin carbohydrate complex (LCC) in corn stalk ear husk and stem bark were characterized by FT-IR spectroscopy in order to clarify the difference of lignocellulosic structure in different sections of corn stalks. MWL and LCC were first extracted and separated from the corn stalk ear husk and stem bark by the improved method of Bj?rkman, and then were identified and analyzed by FT-IR. The results showed that the structure of MWL in the two sections was distinctly different. The concentration of branched chain structure and benzene ring structure of phenylpropane side chains in stem bark lignin were higher than those in ear husk, while the concentration of hydroxyl, methyl and conjugated carbonyl groups were lower than those of stem bark. The lignin in the stem bark was mainly composed by the syringyl structure units and the lignin in the ear husk was mainly composed by guaiacyl structure units. There are also differences between the LCC structure of two sections: the hydroxyl content of LCC in ear husk was higher and the methyl and methylene content was lower than those of LCC in the stem bark. In addition, the strength of the bond connecting the lignin and hemicellulose in stem bark LCC was significantly higher than that of ear husk LCC, which indicates that it is more difficult to separate lignin from the lignocellulose in stem bark than in the ear husk. The results have laid a foundation for the efficient degradation and effective utilization of corn stalk lignocellulose. The results laid the basis for the development of efficient lignocellulose degradation technology and the improvement of utilization rate of corn stalk.

      • 1
    • Wang Huai-peng, Zhang Yi-fei, Yang Ke-jun, Wang Yu-feng, Chen Tian-yu, Wu Qiong, Yin Xue-wei, Wu Peng, Yang Li, Pang Chen, Jian Li-qun, Zhang Ji-wei

      Abstract:

      In order to explore the effect of different silicon fertilizer concentrations for foliar application on the lodging resistance and grain yield of maize, ‘Xianyu 335’ was used as the tested variety, four concentrations (measured by SiO2) of foliar silicon fertilizer at maize jointing stage (30% leaf age index period) were set up, that is, 4 (S1),8 (S2), 12 (S3), 16 (S4) g/L, and control treatment (CK) was sprayed the same volume of water. In this study, the morphological characteristics, inter-node mechanical properties of stalk at filling stage and yield components at maturation period under different treatments were comparative analyzed. The results showed that the effects of foliar application of silicon fertilizer on plant height and ear height was not obvious, but the height for plant's center of gravity were significantly reduced. Compared with CK treatment, height for plant's center of gravity of S3 treatment was reduced by 6.02% which was the most significant one among four concentrations of foliar silicon fertilizer. The diameter, stem wall thickness, cross-sectional area, fresh density, dry matter weight per unit stem length, breaking-resistant force (bending resistance) and puncture strength of third internodes showed a trend of increasing first and then decreasing with the increase of silicon fertilizer spraying concentration, all their values under foliar silicon fertilizer application were higher than that under CK treatment, and the degree of increase varied with spraying concentration. Length and oblateness of third internodes was gradually declined with the increase of spraying concentration of silicon fertilizer. Spraying the appropriate concentration of silicon fertilizer promoted the improvement of the mechanical strength of the stalk and reduced the risk of maize lodging. Furthermore, appropriate concentration of foliar silicon fertilizer also significantly promoted the maize grain yield and yield components, of which S2-S4 treatments had significantly higher grain yield than CK treatment, and S3 treatment had the highest grain yield of 11485.68 kg/ha. Comprehensive analyzed stalk lodging resistance characteristic and grain yield levels of maize, in this experiment, 8-12 g/L was the optimum spraying concentration of foliar silicon fertilizer at maize jointing stage, which is benefit to regulate maize lodging resistance and promot higher yield.

      • 1
    • GAO Ying-bo, ZHANG Hui, XUE Yan-fang, KUANG Pu, QIAN Xin, DAI Hong-cui, LI Yuan-fang, WANG Zhu, HAN Xiao-wei, LI Zong-xin

      Abstract:

      Salt tolerant ability of 30 popularized maize varieties were evaluated by conducting field experiment, combined with germination test using solution culture. Comprehensive evaluation was based on germination rate (GR), germination potential (GP), shoot length (SL), shoot weight (SW), and its grain yield (GY) in field condition. Results showed that the germination of the maize was inhibited when the concentration of NaCl was over 160 mmol?L-1. The sensitive degree of these indicators for evaluating salt tolerant ability were in the order of RGP> RSL> RSW> RGR. Grain yield, germination percentage, plants per unit, and shoot weight was closely related to salt tolerant ability of the varieties. With the weight membership function method and cluster analysis, These 30 maize varieties can be divided into 4 groups: high salt-tolerant maize, salt tolerant varieties, salt-sensitive varieties, high sale-sensitive varieties. Thus, 160 mmol·L-1 can be regarded as the suitable concentration for salt tolerant evaluation, and grain yield, germination percentage, plant per unit and shoot weight can be as the indicator for salt tolerant detection. Bangyu339, Ludan818, Denghai605 and Qingnong105 were four salt tolerant varieties, which could be used for the saline-alkali soil.

      • 1
    • Gong xiujie

      Abstract:

      [Objective] In the continuous cropping area of maize in heilongjiang province, two treatments of no-nitrogen application and 300kg· hm-2 nitrogen application were set up to study the effect of nitrogen fertilizer on the decomposition rate of returned corn straw during the growth period of maize and the effect on soil nutrients and soil enzyme activity. [Results] The activities of soil urease, soil catalase and soil sucrase were increased by straw combined with nitrogen fertilizer. From seedling stage to maturity stage of maize, urease activity ranges of soil without and under nitrogen treatment were 13.53U/ml~14.21U/ml and 11.80U/ml~15.67U/ml, respectively. The activity range of soil catalase was 48.57U/ml~55.92U/ml and 50.69U/ml~59.34U/ml, respectively. The range of sucrase activity was 36.90 U/ml~51.85 U/ml and 46.40 U/ml~58.22 U/ml, with significant differences in all three stages. The effects of straw mulching and the application of appropriate nitrogen fertilizer on the mass fraction of ammonium nitrogen were not significant, but the mass fraction of nitrate nitrogen and rapidly available nitrogen could be increased. The average mass fraction of nitrate nitrogen and rapidly available nitrogen under no nitrogen treatment and nitrogen treatment were 10.39ug/kg, 18.45ug/kg, 126.43mg/kg and 145.39mg/kg, respectively. During the whole growth period of corn, the decomposition rate of corn straw under nitrogen treatment was higher than that without nitrogen treatment. After 150d, the difference in the decomposition rate of corn straw reached a significant level. The decomposition rate of corn straw without nitrogen treatment and under nitrogen treatment was 65.29% and 67.81%, respectively.

      • 1
    • hezeng, 刘志, 贾彪

      Abstract:

      The main objective of the study was to explore the photosynthesis response mechanism of drip irrigation water and fertilizer integrated maize in Ningxia Yellow River Irrigation District. The portable gas exchange measurement system (Li-6400XT) was used to measure the light response curves of two years maize at the big flare stage under six different nitrogen rates. The most frequently used four models were used to analyze, compare and fit light response curves of maize to screen the best of them all under different nitrogen application rates, which was used to calculate the photosynthetic physiological characteristics parameters. It showed that the photosynthetic capacity of functional leaves increased with nitrogen application rates increasing in drip irrigation maize. Model error analysis showed that there were differences in fitting accuracy of four light response curve models. And the fitting accuracy of high nitrogen treatments was better than these of low about rectangular hyperbolae model, non-rectangular hyperbolae model and exponential model. However, compared with the three models, the fitting accuracy of modified rectangular hyperbola model was the best highest in four models, which could be the best one to fit light-response curves of maize in integration of water and fertilizer in irrigation Area of Yellow River Diversion. Using Optimum model was used to calculate and analyze the photosynthetic physiological parameters. It showed that apparent quantum efficiency (α), dark respiration rate (Rd), light compensation point (LCP), light saturation point (LSP) and maximum net photosynthesis rate (Pnmax) of N4 (360 kg/hm2) were higher than those of others. Reasonable nitrogen application can improve the adaptation range to strong-light, light use efficiency and photosynthesis of maize.

      • 1
    • LI Congcong#, WANG Yajiao#, LI Qiusheng, JI Lijing, WANG Liansheng, KONG Lingxiao

      Abstract:

      The physiological races of 356 strains of Bipolaris maydis were identified, which were collected from Hebei province from 2007 to 2016. Results showed that isolation frequencie of Race T, Race C, Type S and Race O is different from year to year. Race O is the dominant race of of B.maydis in Hebei province with 94.94% everage isolation frequence. Meanwhile, the pathogenicity of race O to hybrid Zhengdan 958 and inbred line C103 was declining. However, the pathogenicity of Bipolaris maydis to C103 decreased less than that to zhengdan 958. ITS sequence of 43 strains collected from Shijiazhuang, Baoding, Hengshui, Cangzhou Hebei Province, Shenyang Liaoning Province and Jinan Shangdong Province were analyzed and UPGMA evolutionary Tree was construction .The result indicated that the genetic evolution of Bipolaris maydis was weakly geographically related.

      • 1
    • sunhua, lipo, guoning, shijie, zhangjiaqi, zhanghaijian

      Abstract:

      In order to confirm an uncommon Fusarium sp. causing maize ear rot and its biological characteristics, the isolate ZBSF002 was isolated and purified from Fusarium species corn ear rot, and the pathogenicity was identified based on the the Koch’s rule, morphological characteristics, molecular biological technology. The results showed that ZBSF002 was Fusarium temperatum that causing maize ear rot. Biological characteristics showed that the optimum carbon and nitrogen sources of the isolate ZBSF002 were soluble starch and yeast extract, respectively. The temperature range of mycelial growth and sporulation was 10-35℃, and the optimum temperature was 30℃.The isolate could grow and produce conidia at pH 4-11, but the optimum pH for hyphae growth and sporulation was 7-10. The isolate could grow and produce conidia in continuous illumination, darkness and alternate darkness (12h) and illumination (12h), but hyphae grow fastest and spore produce largest in continuous illumination. The lethal temperature for the mycelia and conidia was 65℃ for 10 minutes.

      • 1
    • LIN Shan, ZHAO Xue, CHEN Xian-Min, WU Gong, GAO Zhen, SHEN Si, LIANG Xiao-Gui, ZHOU Shun-Li

      Abstract:

      In maize, kernel abortion was always occurred in the apical region of the ear. The apical kernel was not only showed the disadvantages in position but related to the late events of differentiation and pollination. In recent, many researchers suggested that delayed pollination was the cause of kernel abortion. However, whether delayed pollination was causal link to kernel abortion is still unclear. Experiment was carried out by delayed pollination on late emergence silks under normal growth conditions. We found that delayed pollination had little effect on growth and development of the early pollinated kernel. However, delayed pollination significantly reduced the weight of late pollinated kernel, Xianyu335 and Denghai605 hybrids both showed the same trend. Our results also showed that there was no significantly difference in dry matter accumulation between late pollinated kernel and normal kernel with same time after pollination, Xianyu335, Denghai605, Zhengdan958 and Dacheng168 hybrids all showed the same trend. In general, delayed pollination only delayed and shortened the development of late pollination kernel development, thus affected kernel weight under no stress conditions. It was mentioning that factors other than delayed pollination likely play key role in controlling kernel development under stress condition.

      • 1
    • LIU WEI, Zhu Xin-yan, Li Shu-chao, 孙兆明

      Abstract:

      Based on the two-stage double bootstrap DEA method, this paper uses the micro-survey data of Maize growers in the typical agricultural industrialization area to estimate the bias-corrected robust DEA efficiency scores of farmer's Maize production and analyze the specific factors affecting its technical efficiency. It is found that the farmer's investment scale has a negative impact on the efficiency of Maize production technical efficiency, and the effect of government subsidies to Maize planting to improve the technical efficiency of Maize production is not significant.

      • 1
    • wangxiaobo

      Abstract:

      In order to make sure evaluation indexes and screening methods of shade-tolerance species maize inbred line, for screening shade-tolerance maize inbred line. This study use filed experimental method, through 41maize inbred lines as test materials under shade (15% of ambient sunlight) and control (no shade) in plant morphogenesis stage. Systematic research plant morphology, material production and yield etc 11 plant morphology and physical indexes of shade-tolerance index change rule, cluster analysis in maize silk stage and shade tolerance of inbred lines was evaluated by change rule. The results showed that shading treatment increased plant height, ear height, delay the growth period and decreased leaf area index (LAI), SPAD value, ultimately affect the material accumulation and yield of maize inbred line, The shade tolerance of each index was further analyzed by mathematical statistics, the results showed that stem dry matter, leaf area index and yield could be used as indexes to evaluate shade tolerance of Maize Inbred lines; Screen out highly shade tolerance M173, Yu82, DH382, 618B, P6874, Chang7-2, 8612A, M753, ZY608, Yu1122, PH6WC, M109 and shade sensitive ZY602, ZY606, 658, HT60, ZY601, C70, Waiyin-2, Si-144, KW7M14, NS501, PH4CV maize inbred lines, This will provide a basis for further revealing the shade tolerance mechanism of maize and breeding of shade tolerant maize varieties.

      • 1
    • wangxiaoxu, zhengxuefeng, caoying, yuhuijia, Wu Tong

      Abstract:

      The experiments were conducted in May 24, 2017, using Substrate nursery, with maize variety Liaodan 566 as material, cutting leaf and root of source-sink regulation treatments, when the maize grow in 6 blades. The leaf cutting treatments were set at 0%, 15% and 30% 3 levels, and the root cutting treatments were set at 2 levels, cutting roots and not cutting roots, transplanted to farmland on July 1st. The main results were as follows: Under the treatment of 15% leaf cutting, the translocation rate of stem-sheath and leaf and the grain contribution rate increased significantly, meanwhile, ear diameter, grain weight per ear and thousand-kernel weights also increased significantly, resulting in a more increasing in yield. The treatment of cutting leaves and roots significantly reduced the dry matter transport rate and the contribution rate of grains in the leaves and stem-sheath during the silking stage to the mature stage, and the accumulation of dry matter decreased, leading to a significant decrease in yield. However, with the increase of leaf area, the adverse effects of root cutting can be alleviated to a certain extent. Different effects of source alteration on grain starch, protein,total amino acids and oil concentration could be found. After reducing the source of transplanted maize, it was found that the grain oil content was not affected by the change of source-sink relationship, and there was no significant change. In addition to oil content, protein content and total amino acid content reached the maximum when the leaf source was reduced by 15% after transplanting at seedling stage. Removal of leaf and root causes significantly reduced the percentage of protein and total amino acids in grains. The percentage of starch showed the opposite trend with the percentage of protein and total amino acid, and reached the maximum when the leaf and root sources were reduced by 15% after transplanting at seedling stage.

      • 1
    • CUI Shuai, ZHANG Di-di, LIU Shuo-ran, ZHU Xi-ru, YING Fei-yu, GAO Qiang

      Abstract:

      Potassium is an essential nutrient for maize growth, and the application of potash fertilizer is a necessary means to ensure high and stable yield of maize. In this research, the effect of potash fertilizers (potassium chloride, potassium sulfate, crystal potassium chloride and potassium magnesium sulfate) on soil potassium dynamic change and maize growth in Aeolian sandy soil were investigated by pot experiments. The results showed that the contents of soil water-soluble potassium, exchangeable potassium, available potassium, slow-available potassium and azeonitric potassium were significantly increased by applying four potash fertilizers. All of them reached their peak values at 12th days after fertilization except the contents of slow-available potassium, which reached the peak values at 15th days after fertilization. With the rapid growth of maize at jointing stage and the absorption and consumption of potassium in soil, the content of available potassium in soil decreased rapidly at 40th~60th days after fertilization, and then the slow-acting potassium in soil was released into available potassium (mainly exchangeable potassium), which increased significantly at 60th-70th days. There were significant differences in plant growth among the four potash fertilizers at the six-leaf stage, and the stem diameter of potassium sulfate and potassium magnesium sulfate were higher than the other two potash fertilizers. But, the agronomic traits and yield of maize among different potash fertilizers at the mature stage had no significant effect. Compared with other potash fertilizers, potassium uptake of plants and the recovery rate of potassium fertilizer (reaching 35.3%) treated with potassium sulfate were the highest. In summary, four potash fertilizers have rapidly increased the content of different forms of potassium in Aeolian sandy soil and maintained the potassium demand during the growth period of maize. The effects of different potash fertilizers on maize growth and yield are slightly different. Considering the situation of plant potassium absorption and utilization, the effect of potassium sulfate is slightly better than the other three potash fertilizers.

      • 1
    • zhoushuxiang, luxin, lilijuan, zhangguohong, dingyan, changxue

      Abstract:

      The dynamic relationship between the oviposition of corn borer and the parasitism of Trichogramma was clarified through 11 years field investigation. During the first generation corn borer egg stage, most of the eggs hatched, and the hatching rate reached more than 80%, only a small number of eggs were parasitized by Trichogramma. The parasitic rate of the second generation was higher, the parasitic rate of egg masses was more than 70%, and the parasitic rate of eggs was more than 60%. Trichogramma parasitism usually occurred in the middle and late stages of corn borer oviposition, and few egg masses were completely parasitized. The parasitic rate of Trichogramma were varied in different years. The results play an important significance in revealing the relationship between pests and natural enemies. Moreover, our studies have great practical implications for carrying out corn borer biological control.

      • 1
    • YAO Yu-bo, YU Ying, ZHOU Fei, ZHAO Dong-sheng, GUO Yong-li, ZHANG Shu-quan

      Abstract:

      35 maize inbred lines were used as the material, germination energy, germination rate, germination drought resistance index, storage material transfer rate, number of radicles,radicle length and germ length were studied under 0.4 MPa PEG-6000 at germination stage. Comprehensive evaluation and classification of drought resistance of maize inbred lines using drought resistance coefficient (DC), principal component analysis and cluster analysis. Results showed that drought stress influence all indicators, four drought tolerant materials (1153、1245、1246and PHT11 ), three drought sensitive materials (PHJR5、LH284 and A14242), twenty-eight relatively drought tolerant and relatively drought sensitive materials were identified out.

      • 1
    • TENG Yuan-xu, BAI Jing, LI Ming-dong, ZHI Meng-ting, ZHANG Zhi-lin, ZHANG Li, YANG Xin-jun, LIANG Xiao-ling, LI Zhao-feng

      Abstract:

      The objective of this study was to evaluate the heat resistance of 21 inbred lines of maize, which was based on heat treatment 21d to 26d after sowing. The heat comprehensive evaluation of heat tolerance coefficient of the plant height, stem diameter, leaf area, shoot fresh weight, shoot dry weight, total dry weight, root length, root dry weight, root shoot ratio, SPAD value of each inbred line was evaluated principal components analysis, membership function method, hierarchical cluster and gray relational grade analysis. The result showed that 3 independent comprehensive components ware obtained from 10 single indexes by principal component analysis, which reflected 83.160% information of all traits information. The comprehensive heat tolerance values(D) were calculated from the membership function methods, and 21 inbred lines of maize were divided into four heat tolerance types by cluster analysis,2 materials were high heat tolerance type(class Ⅰ, KW4M029 and DM08), 8 materials were medium heat tolerance type(class Ⅱ), 6 materials were weak heat tolerance type(class Ⅲ), 5 materials were heat sensitive type(class Ⅳ). Total dry weight can be used as simple and intuitive indices of heat resistance of inbred lines of maize at seedling stage.

      • 1
    • Chenchen, Yuguang Zhu, Jun Zong, Dongling Zhang, Yahui Dong, Haixia Zeng, Shengbo Han, Yun Han, Huihui Su, Lixia Ku, Yanhui Chen

      Abstract:

      A maizelight-sensitive tropical maize inbred line CML288 was used as experimental material to construct yeast one-hybrid library. The core promoter of ZmDPS10-2 (1148bp)was used as a bait, and use yeast one-hybrid technology, we got 33 genes interacting with ZmDPS10-2’s promoter. According to gene annotation, we selected 4 genes related to photoperiod and stimulus response,including PAO4、RPL23A、bZIP60 and BAG. These four genes were constructed into pGADT7 to confirm their interaction. Their interaction with ZmDPS10-2’s promoter was preliminarily confirmed. By bioinformatics analysis, it is speculated that ZmDPS10-2 may play a certain role in regulating plant flowering, ER stress and heat stress response. These results of this study laid the foundation for further analysis of the molecular mechanism of ZmDPS10-2 and the genetic mechanism of photoperiod sensitivity in maize. It provided a theoretical basis for the photoperiod sensitivity of passivated maize and the cultivation of new maize varieties with early maturity, lodging resistance and disease resistance.

      • 1
    • Zhao Fang, Wang Rui, Zhao Huiying, Li Xiufen, Lin Weinan, Tian Baoxing

      Abstract:

      To understand the potential utilization efficiency of accumulated temperature(≥10℃) can reflect the contribution of heat and its effects on maize yield in Heilongjiang over 56 years. It has great significance for local crop layout. Based on the daily meteorological data, maize growth period and yield data of 80 meteorological stations in Heilongjiang from 1961 to 2017, used the methods of Morlet wavelet, the spatial-temporal variation characteristics of potential utilization efficiency of accumulated temperature(≥10℃) of maize in cold regions and its difference from actual heat utilization efficiency were analyzed. The results showed that the potential utilization efficiency of accumulated temperature(≥10℃) in maize growth season from 1961 to 2017 showed a slight downtrend with the amplitude of 5.87~7.65 kg.hm-2.℃-1. There were 3 periodic changes scales in the utilization efficiency potential of accumulated temperature(≥10℃) in maize, which were 29 years, 10 years and 6 years, the time of 1961-1986 was the rising stage, and the time of 1987-2017 was the opposite. The spatial distribution of

      • 1
    • HUO Shi-ping, FENG Yun-chao, YAN Qingjiou, YANG Lian, XIANG Zhen-fan, ZHANG Fang-kui

      Abstract:

      Based on the germplasm of American corn belt,XZ966-14 inbred line was created, and then bred into 5 derivative lines WZ049、WZ0714、WZ126、WZ1422 and WZ1423 after being improved. Combining ability of them was determined by mating design using NCII,and inheritance potential of them was tested in applicating whole genome SNP chip technology.The results showed that XZ966-14 had high yield combining ability,and had strong heterosis with the derivative lines of Reid and Luda Red Bone germplasm. Combining ability of the derivatives lines of XZ966-14 was higher,and had strong heterosis with the derivative lines of Luda Red Bone and PN(PA and PB) germplasm derivative lines.XZ966-14 and its derivative lines had been used to breed 2 varieties passed the national examination and approval, 2 varieties passed the examination

      • 1
    • zhengling

      Abstract:

      WOX is a family of specific transcription factor family in plants, which is involved in the life activities of plants at various stages and has the functions of regulating the division and differentiation balance of plant stem cells. In this study, the maize (Zea mays) genome data was used to search and identify the three databases (Phytozome, PlantTFDB and NCBI). The 31 families of WOX family genes were identified . Multiple sequence comparisons revealed that the WOX family members of maize had a highly conserved HOX domain. The phylogenetic tree was constructed using the WOX family members of Arabidopsis thaliana as a reference, which were divided into 3 groups. Intron and motif analysis showed that the introns and motifs within each subfamily had extremely high similarities, and there were great differences among different subfamily. Finally, the expression patterns and functions of the WOX family genes in maize were analyzed. Made a preliminary summary.

      • 1
    • guozifeng

      Abstract:

      Genome-wide association were conducted using phenotypic data from three environments (Sanya, Hainan; Xinxiang, Henan; Shunyi, Beijing) on a panel of 365 inbred lines and a set of 55K single-nucleotide polymorphism (SNPs) generated by Chip. The results showed that plant height varies very abundantly in three environments, and tends to increase gradually from low latitude to high latitude. Plant height has extremely significant correlation in all three environments. Variance analysis showed that plant height has extremely significant differences in genotype, environment, genotype and environment interaction. Genome-wide association study showed that significant association sites with plant height were detected in different environments. Significant association SNPs were found on chromosomes 1, 3, 5, 6, 7 and 8. In Xinxiang and Shunyi environments, Significant association SNPs were found in the bin5.05 region. In Hainan and Shunyi environments, significant association SNPs were found in the bin6.05 region. By comparing the significant SNP loci in association analysis with the reference genome, 22 most likely candidate genes were obtained in the MaizeGDB database . Once these SNPs are validated, they will be useful for marker-assisted selection and for a better understanding of maize plant height.

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    • yuxiaofang, 王玥, gaojulin, hushuping, sunjiying, wangzhigang, lixiaolong

      Abstract:

      In 1970s-2010s, ten maize cultivars were used as experimental materials, a field experiment was established to study the root traits and yield changes during maize cultivars succession under subsoiling and densification. The result showed that: the root traits (roots dry weight, root length, root surface area and root mean diameter) showed a unimodal curve change, which increased with the time and reached to the highest in 1980s, then decreased thereafter. The proportion of these root traits increased with the maize cultivars succession in 20 – 50 cm soil depth, and the roots gradually extended into the deeper soil layer. The subsoiling and densification system favored to the establishment of new maize cultivars, and it not only achieved a "structural" yield increase, but also obtained the yield increased by the improvement of root zone environment. Therefore, in future maize high-yield breeding, we should select proper root traits and focus on the combination of cultivation practice to reach the goal o