Identification of QTLs for Glycinin (11S) and β-Conglycinin (7S) Fractions of Seed Storage Protein in Soybean by Association Mapping Association Analysis of Agronomic and Quality Traits with SSR Markers in Glycine max and Glycine soja in China: II. Exploration of Elite Alleles Association Analysis of Agronomic and Quality Traits with SSR Markers in Glycine max and Glycine soja in China: I. Population Structure and Associated Markers