Uncovering superior alleles and genetic loci for yield-related traits in mungbean (Vigna radiata L. Wilczek) through a genome-wide association study

Background Mungbean is a key warm-season legume crop in South and Southeast Asia, but its low productivity, driven by limited genetic diversity, necessitates dissecting yield-related traits to develop stable, high-yielding varieties. However, its potential for phenological and yield contributing traits in mungbean breeding remains largely unexplored. Results In this study, 296 mungbean germplasm from the World Vegetable Center mini-core collection were evaluated in Bangladesh. Of these, 206 flowered, yielded, and were further evaluated over three years. These genotypes exhibited significant variation in phenological and yield-related traits: flowering time, maturity, plant height, pods per plant,100 seed weight and seed yield. Moderate to high broad − sense heritability was found for all phenotypic traits. The significant environmental (year) effects and genotype × year interaction, and comparatively lower heritability for the combined multi-year (MET) analysis compared to single-year analysis for most of the traits highlighted strong environmental influences. Using MET data, a genome-wide association study (GWAS) using 4,307 high quality SNPs obtained from DArT sequencing identified 18 significant SNPs located in 17 genomic regions across the six mungbean chromosomes (1, 2, 5, 6, 7 and 8) associated with the six traits. Further, we identified five genotypes (G91, G106, G107, G125, and G130) with a higher number of favorable alleles and superior yield performance. We also employed genomic prediction models and found moderate prediction accuracies (> 30%) for 100 seed weight and seed yield. Conclusions This study has identified a few promising genotypes and several novel genomic regions and putative candidate genes. These results will assist in incorporating important alleles into elite mungbean germplasm through marker-assisted breeding and/or genomic prediction to improve mungbean yield.