Genetic diversity analysis using simple sequence repeat markers in soybean

To evaluate the genetic diversity (GD) of wild and cultivated soybeans and determine the genetic relationships between them, in this study, 127 wild soybean accessions and 219 cultivated soybean accessions were genotyped using 74 simple sequence repeat (SSR) markers. The results of the study revealed that the GD of the wild soybeans exceeded that of the cultivated soybeans. In all, 924 alleles were detected in the 346 soybean accessions using 74 SSRs, with an average of 12.49 alleles per locus. In the 219 cultivated soybean accessions, 687 alleles were detected, with an average of 9.28 alleles per locus; in the 127 wild soybean accessions, 835 alleles were detected, with an average of 11.28 alleles per locus. We identified 237 wild-soybean-specific alleles and 89 cultivated-soybean-specific alleles in the 346 soybean accessions, and these alleles accounted for 35.28% of all the alleles in the sample. Principal coordinates analysis and phylogenetic analysis based on Nei's genetic distance indicated that all the accessions could be classified into two major clusters, corresponding to wild and cultivated soybeans. These results will increase our understanding of the genetic differences and relationships between wild and cultivated soybeans and provide information to develop future breeding strategies to improve soybean yield.