Biochemical profiling and diversity studies in soybean for nutritional improvement

Abstract

Soybean seed quality, defined by its biochemical constituents, is paramount for nutritional security and industry utility. This study was aimed to characterize the genetic variability for four key seed quality traits viz., oil (%), crude protein (%), potassium (%) and phosphorus (%) along with four micronutrients (ppm) viz., iron, manganese, zinc and copper across 64 genotypes, including 17 parents, their single crosses with PS 1556 and Himso 1685, backcrosses involving PS 1556 × Himso 1685 hybrid. The results reported significant genetic variability for all the traits under study. Descriptive statistics revealed wide variation among all the traits. Pearson correlations showed significant positive associations among oil, protein, iron, manganese and zinc, while phosphorus and potassium loaded onto an orthogonal axis. Principal component analysis retained three PCs (eigenvalue>1) accounting for 62.39% variance, PC1 primarily driven by oil, protein, iron, manganese and zinc, and PC2 by phosphorus and potassium. Hierarchical clustering partitioned genotypes into four clusters (I:11, II:30, III:15 & IV:8) with clusters I+II more similar to each other than to III+IV. Strategic crossing recommendations between divergent clusters are proposed to maximize transgressive segregation and heterosis for nutritional quality enhancement. Elite genotypes like JSM 245 × Himso 1685 (42.52% crude protein, 116.05 ppm Fe, 19.86 ppm Cu), JSM 302 (28.41% oil, 36.75% crude protein), M 1085 × PS 1556 (75.45 ppm Zn, 68.80 ppm Mn) and EC 241756 × Himso 1685 (0.714% P) were identified for high protein/oil/micronutrient content. This integrated biochemical and genetic profiling provides a robust foundation for developing biofortified soybean varieties with improved nutritional quality.