Analysis Of Genetic Diversity Of Maize Populations By SSR Marker And Heterotic Grouping

In order to broaden the germplasm resource of maize, many maize breeding researchers have done much work to collect local germplasm and introduce excellent exotic germplasm to China. Maize germplasm gets more and more mixed. To make full use of heterosis, it is very important for maize breeders to distinguish heterotic groups and to design heterotic patterns. In this experiment, firstly, the use of 90 individuals DNA from Gold Queen maize population, 6 inbred lines DNA representing Chinese different types of resources, and 15 pairs of SSR primers, the effect of 4 kinds of DNA sample treats of the individual DNA sample, the mixed DNA sample with 3 individuals, with 10 individuals, and with 15 individuals for the genetic diversity in the same population were compared and analyzed. And then the use of Huang Zong Qun, BSSS, Liao Lü Zong, Pob21, Goldqueen Landrace, Yu Zong 5 Hao, six maize populations and former 6 inbred lines. To adopt the mixed DNA sample with 10 individuals, analyzed the genetic diversity of six maize populations and clustered. The result indicated: (1) Individual DNA sample could provide comparatively complete genetic information including allele numbers, gene frequency, proportion of heterozygosity etc. It could be applied to the analysis of genetic structure of a single or a few maize populations. But this method will need much more work than that of bulk sample. (2) The use of bulk DNA sample will reduce the genetic information. Comparison of the result of 4 methods of DNA sample treatment suggested that the result of the mixed DNA sample with 15 individuals had a bigger error rate, but the mixed DNA sampling method with 3-10 individuals could reflect allele numbers and SSR difference of a maize population, because of much reduced experiment workload, it can be applied in comparison for genetic difference in more maize populations. (3) Clustering was based on SSR markers. Six maize populations were divided into 4 heterotic groups. Of the 6 population, Yu Zong 5 Hao and BSSS are one group, Goldqueen Landrace and Huang Zong Qun are another group. Pob21 and Liao Lü Zong are separate heterotic groups. (4) The six groups classified by cluster analysis of SSR markers is consistent with the available pedigree and the result of combining ability. So it is feasible to analyze the genetic diversity of maize population by SSR markers and to distinguish heterotic group by method of mixed sampling.