Phenotypic characterization and germplasm screening for sprout agronomic performance in Huang-Huai soybean accessions

Soybean sprouts are a nutritionally enriched vegetable commodity of considerable commercial importance in Asian markets. This study evaluated 188 soybean accessions from the Huang-Huai ecological region to identify elite germplasm for sprout production through multi-trait phenotypic assessment. Four agronomically important traits were quantified under controlled germination conditions: germination rate (GR), fresh weight (FW), soluble sugar (SS) content, and isoflavone (IF) content. Considerable genetic variation was detected across all four traits. Correlation analysis revealed a strong positive association between GR and FW (r = 0.86, P < 0.001), while SS and IF contents showed trait independence, suggesting distinct genetic control mechanisms. Comprehensive evaluation using multi-trait selection indices identified seven superior accessions with exceptional sprout performance: Pudou 955, Shengdou 29, Shengdou 2, Zhoudou 25, Zhoudou 26, Zhudou 19, and Xudou 14. Zhoudou 26 exhibited outstanding GR (97%) and IF accumulation (3508.09 µg/g), while Shengdou 2 demonstrated superior FW (61.74 g) and SS content (2.09%). These accessions may serve as genetic resources for marker-assisted breeding and functional genomics approaches targeting sprout-specific traits. The identified germplasm offers a basis for developing soybean cultivars better suited to sprout production.