本文选用生育期相近的宏硕899、粒收1号、郑单958共3个品种，在3个种植密度下进行生理成熟期与收获期籽粒含水率与植株叶片、茎秆、穗部、籽粒脱水特性分析，结果显示：植株各部位含水率生理成熟期前后变化差异较大，生理成熟前2周，穗位茎、茎秆、穗柄、穗轴含水率几乎不变，穗位叶、苞叶、籽粒含水率呈降低趋势，籽粒含水率在30% ~ 35%时苞叶与叶片进入迅速脱水期；生理成熟后穗位茎含水率下降快于其他茎秆，茎秆与穗柄含水率下降速率相近，穗轴与籽粒含水率下降幅度相近。品种间生理成熟时籽粒含水率无显著差异，郑单958生理成熟后籽粒脱水速率低于宏硕899与粒收1号，因此2019年收获时籽粒含水率最高。随密度增加，生理成熟期植株叶片、茎秆含水率呈降低趋势。密度对穗轴、穗柄及籽粒含水率影响较小，不同密度处理间含水率无显著差异。由此可见，辽东地区增加密度能够提高植株生理成熟后叶片、茎秆脱水速率，但对籽粒含水率及脱水速率无显著影响，品种持绿性与籽粒后期脱水相关性不大。受降雨影响辽东地区玉米生理成熟后空气相对湿度大，籽粒脱水速率慢，降低收获时籽粒含水量应从立秆延迟收获入手。

To understand the correlation between maize plant and kernel dehydration in eastern Liaoning, a 2-year (2017 and 2019) field experiment was conducted at Dandong experimental station including 3 hybrids and 3 plant densities. Kernel and plant moisture during the maturity period was measured. The results showed that, 2 weeks before maturity, stem at the ear, other stem, ear-pedicel and cob moisture content were constant, while ear leaf, bract and kernel moisture content decreased. Moisture content of bract and leaf decreased rapidly when the kernel moisture content ranging from 30% to 35%. After maturity, stem at the ear dehydrated rate faster than the other stem. Ear-pedicel moisture content was similar with stem. Dehydration rate of cob and kernel was the same. Kernel moisture content at maturity was the same between hybrids. ZD958 kernel dehydration rate was slower than that of HS899 and LS1 after maturity. With the plant density increasing, leaf and stem moisture content decreased around the maturity. No significant difference in ear-pedicel and cob and kernel moisture content was found between the different plant density. Increasing plant density improved leaf and stem hydration rate after maturity, while had no impact on that of kernel. Plant Hydration at late of growing stage was irrelative to the plant stay-green trait. Causing of large amount participation after maturity, relative humidity in eastern of Liaoning was very high, which slow down the kernel hydration rate. Delaying harvest date was benefit for the decreasing kernel moisture content.

粮食丰产增效科技创新(2016YFD0300304-4,2017YFD0300705-A04)