不同年代玉米品种穗部性状差异及其对子粒脱水速率的影响

Differences in Ear Traits of Maize Varieties from Different Eras and Their Effects on Grain Dehydration Rate

以我国1970-2010年代的5个主推品种为试验材料,分析随品种更替穗部性状的变化,明确其对子粒脱水速率的影响。结果表明,随品种更替玉米苞叶面积、厚度、层数均减小,苞叶蓬松度增加,粒长显著增加,穗长和行粒数减小,穗轴直径、穗柄长度、穗行数和穗粗无明显变化;生理成熟前、后子粒脱水速率呈增加趋势。通过逐步回归分析筛选出苞叶面积、穗柄长度、粒长、穗粗、行粒数4个性状和苞叶面积、苞叶厚度、穗柄长度、粒长、穗长、穗粗5个性状分别为生理成熟前、后子粒脱水速率的主要影响因子。相关分析表明,苞叶面积、穗轴直径、穗柄长度、穗长与生理成熟前、后子粒脱水速率均达到极显著负相关,说明苞叶较小较薄且层数少、穗轴细、穗柄短、较短较细的果穗有利于子粒脱水。

Five main maize hybrids from the 1970s to the 2010s in China were used as experimental materials to analyze the changes of ear traits,and determine the effects of these ear traits on the rate of grain dehydration.The results showed that with hybrids replacement,the area,thickness and number of layers of bracts decreased,the fluffy degree of bract increased,grain length increased significantly,grain thickness decreased slightly,ear-pedicel length and row number decreased,but the cob thickness,ear-pedicel length,rows per ear and ear diameter did not change significantly.The rate of grain dehydration increased before and after physiological maturation.Bract area,ear-pedicel length,grain length,ear thickness,rows per ear were the main factors influencing the rate of grain dehy⁃dration before physiological maturation,and bract area,bract thickness,ear-pedicel length,grain length,ear length and ear thickness were the main factors influencing the rate of grain dehydration after physiological maturation.The results of correlation analysis showed that bract area,cob thickness,ear-pedicel length and ear length were signifi⁃cantly negatively correlated with the rate of grain dehydration before and after physiological maturity,the results in⁃dicated that smaller and thinner bracts with fewer layers,thin cob,short ear-pedicel and shorter and thinner ear were beneficial to grain dehydration.