基于生殖性状的玉米自交系遗传多样性与遗传距离分析OACSTPCD

In order to improve the utilization efficiency of maize inbred lines,know about their genetic bases,and explore their relationships,18 reproductive traits of 30 maize backbone inbred lines planted in field were analyzed by genetic variation analysis,principal component analysis and cluster analysis to study the ge-netic diversity and genetic distances of the inbred lines.The results showed that the variation coefficients of tassel branch number,husk weight,tassel length,cob diameter and bald tip length were greater than 10% with higher variation richness.The variation coefficients of grain length,ear row number,the longest husk length,ear length and ear diameter were all less than 2% indicating relatively higher stability.The average ge-netic diversity index(H′)was 1.51 with a range from 0.68 to 2.09.The genetic diversity index of 100-grain weight was the highest,while that of husk layer number was the lowest.The larger the coefficient of variation was,the higher the genetic diversity index was.Principal component analysis results showed that the cumula-tive contribution rate of the first seven principal components was 77.39% ;the two-dimensional sorting chart obtained based on principal component scores showed that the inbred lines 7922,Zhu136,ZM7211,H1613,Zhu85,21H86,Xun92-8 and Mo17 had rich genetic diversity.The Euclidean distance of these inbred lines ranged from 0.002 to 0.161 with the average of 0.031;at the Euclidean distance of 0.03,the 30 inbred lines could be divided into 5 groups,and at the Euclidean distance of 0.01,they could be further divided into 13 subgroups with the average genetic distance between subgroups as 23.10.In conclusion,selecting heterosis models for different breeding objectives could improve the utilization efficiency of inbred lines,thus accelerate the breeding process of maize varieties.