Variability among Chinese Glycine soja and Chinese and North American soybean genotypes

The narrow genetic base of elite soybean, Glycine max (L.) Merr., germplasm may impede further attempts to improve grain yield and other important agronomic characters. Germplasm collections of wild soybean, Glycine soja Siebold & Zucc., are a source of genetic variability for soybean breeding programs. The objectives of this research were to use genetic markers to characterize diversity among 60 G. soja accessions collected in China and to compare this diversity with 18 U.S. ancestral soybean genotypes, 12 Chinese G. max plant introductions (Pis), and 47 elite soybean lines from the northern USA. These accessions were genotyped with a set of 72 simple sequence repeat markers. The G. soja accessions were found to contain more alleles per locus (17) than the U.S. ancestral genotypes (5.8), the Chinese Pls (5.5), or the elite lines (4.5). Multivariate analyses were able to separate the G. max lines from the G. soja accessions and identify the most diverse subset of G. soja accessions. Multidimensional scaling separated G. soja accessions from high and low latitudes, while Ward's clustering method separated the G. soja accessions into distinct clusters that tended to include accessions from similar geographical regions. These data will be useful to breeders selecting G. soja accessions as parents in a breeding program and for establishing a core collection of G. soja to be used in future research.