Phenotypic Diversity and Selection Potential in Mung Bean (Vigna radiata L.) Based on Agro Morphological Traits

Abstract

Background and Aim: Mung bean (Vigna radiata L.) is an important short-duration grain legume valued for its protein content and contribution to sustainable agriculture via biological nitrogen fixation. However, its productivity is constrained by narrow genetic variability. This study aimed to assess phenotypic diversity among selected mung bean genotypes through agro-morphological characterisation under field conditions. Methodology: The experiment was conducted at the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria, during March–June 2025 (season I) and July–October 2025 (season II). Fifteen mung bean genotypes sourced from the Genetic Resources Centre (GRC), IITA, were evaluated using a Randomized Complete Block Design with three replications. Each plot measured 5 m × 5 m, with planting at a spacing of 1.0 m × 0.75 m under uniform agronomic management, including weeding, staking, and pest control. Data were recorded on key traits including days to flowering, plant height, pods per plant, pod length, seeds per pod, and 100-seed weight. Data were analysed separately for both seasons using analysis of variance (ANOVA), with mean separation performed using the Least Significant Difference (LSD) test at 5% probability. Coefficient of variation, heritability estimates, and genetic advance were also computed. Results: Significant (P < 0.05) differences were observed among genotypes for all traits across both seasons, indicating substantial phenotypic variability within the germplasm. Yield-related traits, particularly pods per plant, pod length, seeds per pod, plant height, and 100-seed weight, contributed markedly to genotypic differentiation. Genotype G5 consistently exhibited superior performance across most yield traits in both seasons, followed by G3, indicating strong genetic potential, stability, and adaptability across environments. Moderate to high coefficients of variation recorded for pods per plant and seed weight highlighted considerable genetic diversity and selection potential. Overall, trait expression remained relatively stable across seasons, suggesting limited environmental influence and consistent genotype ranking. Conclusion: The study reveals substantial exploitable phenotypic diversity among mung bean genotypes. High heritability coupled with substantial genetic advance for key yield components, particularly pods per plant and 100-seed weight, indicates strong prospects for effective selection. The superior genotypes identified provide valuable genetic resources for breeding programmes aimed at improving yield and adaptability.