基于苞叶表型性状的玉米自交系遗传多样性及遗传距离分析

Analysis of Genetic Diversity and Genetic Distance of Maize Inbred Lines Based on Phenotypic Traits of Husks

为精准鉴定玉米自交系种质资源的遗传基础,探明种质资源之间的亲缘关系,以42份玉米骨干自交系为试验材料,基于8个苞叶表型性状,通过遗传变异、主成分分析和遗传距离聚类分析,研究了玉米自交系种质资源的遗传多样性及遗传距离。结果表明,42份玉米自交系苞叶表型性状变异幅度为3.23%~26.15%,变异系数平均17.03%,苞叶干重和最长苞叶宽变异丰富,苞叶松紧度变异最小。遗传多样性指数(H′)为1.53~1.99,其中苞叶干重最高,苞叶层数最低,H′越高变异系数越大。相关性分析表明,自交系苞叶表型性状间存在复杂的相关性,苞叶干重与苞叶层数、长度、宽度、厚度呈正相关,苞叶层数与苞叶长度、宽度呈极显著负相关。主成分分析表明,前3个主成分累计贡献率达74.21%,以前3个主成分得分值为指标进行主成分二维排序,分析42份玉米骨干自交系在特定因子性状上的差异。欧式距离聚类分析发现,42份玉米自交系可分为5个类群,类群间平均遗传距离为10.64。

In order to accurately identify the genetic basis of maize inbred line germplasm resources and explore the distance of genetic relationships between germplasm resources,42 maize backbone inbred lines were used as experimental materials,and genetic diversity and genetic distance of maize inbred line germplasm resources were studied through genetic variation,principal component analysis,and genetic distance clustering analysis based on eight husk phenotypic traits.The results showed that the variation range of husk phenotypic traits of 42 maize inbred line germplasm resources was 3.23%-26.15%,and the average coefficient of variation was 17.03%.The variation of husk dry weight and the longest husk width were abundant,but the variation of husk tightness was the least.The genetic diversity index(H')ranged from 1.53 to 1.99,the genetic diversity index for husk dry weight was the highest,while the husk layer was the lowest.Correlation analysis showed that there were complex correlations among the husk phenotypic traits of inbred lines.There was a positive correlation between husk dry weight and husk layer,husk length,husk width,and husk thickness,while husk layer was significantly negatively correlated with husk length and width.The differences in particular factor qualities of 42 maize backbone inbred lines were examined,and the first three principal component scores served as markers for the two-dimensional sorting of principal components.The principal component analysis results showed that the cumulative contribution rate of the first three principal components reached 74.21%.Euclidean distance clustering analysis showed that 42 maize inbred lines were divided into five groups,and the average genetic distance between groups was 10.64.