Study On The Genetic Diversity And Heterosis Of Popcorn

The genetic diversity and heterotic group classification of 56 popcorn inbred lines and 12 representative lines were studied using SSR markers. The combining ability and heterosis of 66 crosses made form 12 inbreds was analyzed for grain yield per plot at two locations. Considering popping characters simultaneously, the utilization of over-check crosses in production were evaluated. The correlation among SCA, heterosis, GD ,GH and SH , and their correlation with F1 grain yield, and their ability to predict heterosis were analyzed. The results showed that: 1.There were rather plenty SSR polymorphism among the 56 popcorn inbred lines, and a cluster analysis using the SSR genetic distance placed the 56 inbred lines into 6 clusters , which corresponded with breeding practice and most of their pedigree. Therefore, SSRs might be a valuable complementary tool to traditional field trails for identifying heterotic groups and can be used to study the genetic diversity of popcorn inbred lines. Considering the results at two locations, using N14-421 and M1 could produce much more high yield crosses than others, and the yield of 3 crosses were significantly higher than CK , but their utilization in production should be tested deeply.3.According to SSR genetic distance, 12 inbred lines were divided into 5 groups, and the average GD, GH, SH between group I and the others were different greatly, which were 0.317~0.451, 0.481~0.585 and 0.500~0.725 respectively. The average GD, GH between N16-9 of group V and lines from other groups were rather high, 0.427~0.456 and 0.585~0.626 respectively, and the smallest (0.317 and 0.481) between lines from I and II group. The average SH between N16-9 and lines from group I was the biggest, the smallest (0.500 and 0.503) between lines from group I and IV, II and III, which were not completely consistent with the result of GD and GH.4.The correlations among over- check heterosis, over- average heterosis, SCA, GD, GH and SH, and their correlation with grain yield per plot were not completely consistent at the two locations. The correlation among over- check heterosis, over- average heterosis, SCA and yield per plot were all significantly positive, so these 3 parameters could reflect hybrid yield well and be replaced each other. The correlations among GD, GH and SH were significantly positive, but only at Zhengzhou the correlations of GD, GH wth yield per plot, and SH with SCA were positive significantly.