Phenotypic Diversity and Nutritional Profiling of a Mung Bean (Vigna radiata L.) Germplasm Collection for Functional Food Breeding

Abstract

Mung bean (Vigna radiata L.) is a nutritionally valuable legume; however, the lack of a comprehensive evaluation of quality traits across diverse germplasm hinders targeted breeding efforts. To identify superior genetic resources, this study assessed key nutritional quality traits, including crude protein, starch, fat, total polyphenols, total flavonoids, caffeic acid, vitexin, and isovitexin, across 370 diverse mung bean accessions. Phenotypic data were evaluated utilizing correlation analysis, principal component analysis (PCA), and cluster analysis. Significant phenotypic variation was observed, with coefficients of variation ranging from 5.05% to 37.41% and Shannon's diversity indices between 0.10 and 0.59. Key correlations revealed a negative relationship between protein and starch, alongside strong positive associations among total polyphenols, flavonoids, caffeic acid, vitexin, and isovitexin. Furthermore, cluster analysis stratified the germplasm into five distinct groups exhibiting significant differences in quality traits. A comprehensive evaluation successfully identified elite accessions characterized by high overall nutritional profiles. These findings provide a strategic roadmap for targeted mung bean improvement, offering pre-selected elite germplasm and clear trait–association insights to accelerate the development of nutritionally superior and functionally specialized cultivars.