玉米种质资源苞叶相关性状鉴定及综合评价

Identification and Comprehensive Evaluation of Bract Related Traits of Maize Germplasm Resources

以220份玉米自交系为材料,通过两年两点田间试验对6个苞叶相关性状进行鉴定,利用遗传多样性分析、主成分分析、聚类分析和逐步回归分析进行苞叶性状的综合评价与评价指标筛选。结果表明:供试自交系苞叶相关性状的变异系数为13.41%~51.79%,遗传多样性指数为1.71~2.08,遗传变异丰富。主成分分析将6个性状转化为3个主成分,其累积贡献率为86.674%,第1主成分主要和苞叶干重、苞叶长度有关;第2主成分和第3主成分主要与苞叶包裹度和苞叶层数有关。220份自交系综合评价D值范围为0.161~0.728,其中101314的D值最高,7026B的D值最低。聚类分析将220份自交系划分为3类,其中第I类有62份自交系,其苞叶层数少、苞叶短且窄、干重和包裹度低。逐步回归分析表明苞叶长度、宽度和包裹度3个性状可作为玉米种质苞叶性状综合评价的关键指标。以上结果为适宜籽粒机收玉米种质资源的精准鉴定提供了理论参考。

Based on 220 maize inbred lines,6 bract related traits were evaluated in field experiments at two locations in two years.The genetic diversity analysis,principal component analysis,clustering analysis and stepwise regression analysis were applied for statistical analysis and identifying the evaluation indicators.The results showed that the genetic variations at bract related traits were abundant,with the coefficient of variation ranged from 13.41%to 51.79%as well as the genetic diversity index ranged from 1.71 to 2.08.Principal component analysis simplified the six traits into three principal components,showing the cumulative contribution rate of 86.674%.The first principal component was mainly related to the bract mass and the bract length.The second principal component and the third principal component were mainly related to the bract wrapping degree and the bract number,respectively.The comprehensive evaluation D value ranged from 0.161 to 0.728,of which 101314 and 7026B showed the highest and lowest D value,respectively.220 inbred lines were divided into three groups by cluster analysis,among which 62 inbred lines were in group I,with few bract numbers,shorter and narrower bracts,lower bract mass and wrapping degree.Stepwise regression analysis showed that bract length,bract width and wrapping degree could be used as the important indicators for the comprehensive evaluation of bract traits in maize.Collectively,these results provided a theoretical reference for the accurate identification of bract traits in maize germplasm resources suitable for mechanical harvest.