Population Structure and Association Analysis of Traits in Summer Soybeans

ABSTRACTThe summer soybeans (Glycine max (L.) Merr.) in Hebei Province, China, which have adapted to different environments, show extraordinarily rich genetic diversity and extensive species variation. The objectives of this study were to analyze the population structure of summer soybean using simple sequence repeat (SSR) markers and to identify the SSR markers associated with specific traits. A set of 135 SSR markers was used to analyze 50 soybean cultivars, of which 47 cultivars were from 10 breeding institutions in Hebei Province and three cultivars were introductions from the United States. Software tools, the TASSEL, DARwin, and STRUCTURE, were used to analyze linkage disequilibrium (LD) and genetic structure. In addition, an association analysis between the molecular markers and the phenotypic values of 15 agronomic and quality traits was performed. The yield-related agronomic traits included plant height, bottom pod height, effective branch number, number of nodes on main stem, pod number per plan...