Effect of Origin, Seed Coat Color, and Maturity Group on Seed Isoflavones in Diverse Soybean Germplasm

Soybeans are grown worldwide owing to their protein, oil, and beneficial bioactive compounds. Genetic and environmental factors influence soybean seed isoflavones. In the present study, we profiled the seed isoflavones in world diverse soybean germplasm grown in two locations over two years in China. Significant differences (p < 0.001) were observed between the accessions, accession origins, seed coat colors, and maturity groups for individual and total isoflavone (TIF) content. TIF content of the soybean accessions ranged from 677.25 μg g^-1 to 5823.29 μg g^-1, representing an 8-fold difference. USA soybean accessions showed the highest mean TIF content (3263.07 μg g^-1), followed by Japan (2521.26 μg g^-1). Soybean with black seed coat showed the highest (3236.08 μg g^-1) TIF concentration. Furthermore, isoflavone levels were significantly higher in late-maturity groups. Correlation analysis revealed significant positive associations between individual and TIF content. Malonyldaidzin and malonylgenistin showed higher correlations with TIF content (r = 0.92 and r = 0.94, respectively). The soybean accessions identified as having high and stable TIF content can be utilized in the food and pharmaceutical industries and breeding programs to develop soybean varieties with enhanced isoflavone content.