Genetic diversity assessment and morpho-agronomic characterization of mungbean (Vigna radiata (L.) Walp.) germplasm using multivariate analysis

The present study assessed the phenotypic and genetic diversity of 115 mungbean (Vigna radiata L.) genotypes using a combination of qualitative, quantitative, and multivariate analyses. Frequency distribution of qualitative traits revealed substantial morphological variation, with most genotypes exhibiting good early plant vigor, semi-erect plant type, indeterminate growth habit, and green reniform leaves. Traits such as curved pods, pod pubescence, above-canopy pod position, and lustrous seed surfaces were prevalent, while seed coat color was predominantly green or olive, and seed shape was nearly equally distributed between oblong and oval. Quantitative traits showed wide variability, with early flowering and maturity observed in several genotypes. Best Linear Unbiased Predictions (BLUPs) across 12 environments revealed significant variability in days to flowering, maturity, pod length, seed number, and seed weight, with moderate to high heritability for most traits, particularly seed diameter and hundred-seed weight. Mineral nutrient content also varied broadly, though heritability was generally low for micronutrients like iron, zinc, and manganese. Correlation analysis highlighted strong positive associations among key agronomic traits such as pod length, pods per plant, seed size, and plant height, whereas seed diameter showed negative correlations with multiple yield components, indicating potential trade-offs. Principal Component Analysis (PCA) identified seed diameter, seed size, hundred-seed weight, and days to flowering and maturity as the major contributors to phenotypic variation. The PCA biplots and scatter plots revealed distinct genotype groupings and identified outliers such as genotypes 57, 83, and 110 with unique trait profiles, offering opportunities for trait-specific selection. A circular phylogenetic tree further confirmed substantial intra-specific diversity and identified genetically distinct genotypes (e.g., 14, 27, 78), reinforcing their potential utility in breeding programs. These findings provide a comprehensive understanding of mungbean diversity and support the selection of promising genotypes for future genetic improvement.