Diversity Of Southern Summer Soybean And Establishment Of Its Core Collection In The Coastal Areas

There were the most species of soybean cultivars in the region of southern summer soybean in China. So southern summer soybean was precious genetic resource. Core collection represents a maximum of the genetic diversity of the entire collection with a minimum of accessions and a minimum of redundancy. core collection was beneficial to collection, preservation, research and utilization of the soybean germplasm resources. This research analyzed genetic diversity of the Southern summer soybean of littoral based on agronomic characters and SSR molecular data. Core collection Southern summer soybean in coastal areas was primarily established by the stratified cluster the main. The results were summarized as follows:1. In this research, the entire collection and primary core collection of southern summer soybean coastal areas were used as the materials. And their discrepancies were estimated by comparisons of agronomic characters. The eigenvalue and frequency distribution of quantitative characters were statistically similar in both the primary core and the entire collection. The X2 test for the nine of qualitative characters did not reach significant level between the primary core collection and the entire collection. The results revealed that the primary core collection held most genetic diversity of entire collection at morphological level.2. 191 southern summer soybean cultivars in coastal areas with were analyzed with 60 SSR primers.663 different alleles were detected with averaged 11.05 alleles per locus. The range of Shannon-weaver diversity index was form 0.288 to 2.638 with averaged 1.664 per locus. The averaged Simpson diversity index is 0.7133. the genetic diversity is less.4. The range Nei-Li similarity coefficient of between two cultivars was form 0.19-0.95 with averaged 0.29. It was indicated that the similarity between of the southern summer soybean in coastal areas relatively upper, which is the same as agronomic traits.5. Genetic diversity was analyzed for southern summer soybean in Chinese coastal areas. Based on Nei-Li similarity coefficient matrix, the cultivars were divided into for groups by the standard of similarity coefficient 0.26. But only the cultivars in other provinces were clustered in the different groups. Then the cultivars were clustered again based on valley and latitude. It was found that the most majority of the cultivars of the Changjiang river and Zhujiang river were clustered together in dividually. It was indicated that the cultivars were specific to the same valley of the same latitude.Sampling was done by stratified cluster with Nei-Li similarity coefficient of between two cultivars of 0.45, 0.43, 0.41, 0.39, 0.37, 0.35, 0.33, 0.29,0.21. The "turn point" that was the best method of sampling was determined by the plot according to the proportion of sampling. It was indicated that the proportion of sampling 35.6% of primary core collection, namely sampling 2.74% of whole collection optimal one. 68 cultivars were selected as core collection of southern summer soybean in coastal areas According to t-test of quantitative traits, x2 test of quality traits, the established collection could represented the original collection in view of genetic diversity.Postgraduate: Rihua Piao Major: BotanySupervisor: prof. Zaibin Hao...