[关键词]
[摘要]
辽热群体是北方春玉米区的优良热带种质基因库,开展辽热群体轮回改良对提升北方玉米育种和保持杂优模式具有重要意义。本试验以辽热群体4个改良世代为试验材料,利用田间表型和SNP基因型分析群体改良效果及染色体区段遗传特征。结果表明,经过3轮S1家系密植鉴定轮回改良,辽热群体的产量由7575.65kg/hm2显著增长到8247.50kg/hm2,百粒重由31.22g显著提高到36.03g,株高由242.62cm显著提高到271.83cm,达到了比较理想的改良效果。染色体结构分析发现,初始世代中超过96%的遗传背景在后续轮回改良群体中获得稳定遗传,这是辽热群体保持优良种群特征的基础;随着改良轮次的增加,辽热群体染色体差异片段大小由13.14Mb增加倒70.29Mb,且存在控制水分、穗行数和其他性状的分子标记和QTL,这可能是引起辽热群体产量和农艺性状发生显著变化的原因。研究结果表明,辽热群体经S1家系密植鉴定改良法进行多轮改良,有效提升了产量相关性状的同时还保持了优良农艺性状,为辽热群体后续育种应用、玉米群体改良和种质资源创新提供理论依据。
[Key word]
[Abstract]
Liaore population is an excellent tropical germplasm gene bank in northern spring maize region. It is of great significance to carry out the cyclic improvement of Liaore population for improving maize breeding and maintaining hybrid optimal pattern in northern area maize breeding. In this study, four improved generations of Liaore population were used as experimental materials,phenotype and SNP genotype were tested to analyze the improvement effect and the genetic characteristics of chromosomal segments. With the increase of three cycles, the yield of Liaore population significantly increased from 7575.65kg/hm2 to 8247.50kg/hm2, the 100-grain weight was significantly increased from 31.22g to 36.03g, the plant height was significantly increased from 242.62cm to 271.83cm. The cyclic improvement had achieved an ideal result. The results of genome character showed that more than 96% of the C0 genetic background was stable inherited in the subsequent generations. The stable inheritance segments may maintain the excellent characteristics of Liaore population. With the increase of improvement cycles, the size of the chromosome differential fragments increased from 13.14Mb to 70.29Mb, and some of the molecular markers and QTLs such as controlling water content, ear row number and other traits existed in these fragments. This may be the reason for the remarkable change of yield and agronomic traits in Liaore population. Liaore population had significant improved yield related traits meanwhile maintained the excellent agronomic traits by high density S1 family improved method. This experiment provided a theoretical basis for future breeding application of Liaore population, maize population cyclic improvement and germplasm innovation.
[中图分类号]
[基金项目]
国家重点研发计划(2016YFD0101203-1);辽宁省农业科学院农业种质资源发掘创新与利用项目(2021GR2924)。