Evaluation of Genetic Diversity in Thai Indigenous and Recommended Soybean Varieties by SSR Markers

Abstract Information on genetic diversity and relationship among breeding materials is essential to a plant breeder for an efficient crop improvement. The objective of this study is to evaluate the genetic diversity and to group 160 Thai indigenous and recommended soybean varieties using 18 SSR markers. The SSR loci produced the total of 213 alleles with the average of 11.8 alleles and a mean gene diversity ( H ) of 0.831. Cluster analysis with the UPGMA method and principal component analysis (PCA) separated this population into 2 major groups. This indicates that the indigenous and recommended soybean varieties in Thailand have a small genetic differentiation based on SSR markers. However, they can still serve as a good source of genetic materials for cultivar improvement in Thailand and other tropical countries where soybean genetic resources are limited. Keywords: Glycine max , soybean, SSR marker, genetic diversity, UPGMA, PCA Introduction Soybean ( Glycine max (L.) Merr.) is the world’s most important grain legume as a source of protein and oil. It belongs to family Leguminosae, genus