Identification and characterization of candidate R gene controlling resistance to Mungbean yellow mosaic virus disease in mungbean (Vigna radiata (L.) Wilczek).

Mungbean ( Vigna radiata (L.) Wilczek) is a vital legume crop in Asia, but its productivity is severely hampered by Mungbean yellow mosaic virus (MYMV), often leading to yield losses up to 85%. Developing MYMV-resistant cultivars through genetic intervention is a sustainable approach to disease management. In this study, 16 mungbean genotypes, including resistant and susceptible lines, were evaluated for MYMV resistance using both natural and artificial inoculation methods. Genomic DNA was isolated and amplified using two pairs of degenerate Resistance Gene Analog (RGA) primers, CYR1 and VMR1, targeting conserved NBS-LRR domains associated with disease resistance. PCR amplification confirmed the presence of MYMV resistance genes in several genotypes, notably MYB-6, MYB-7, MYB-8, MYB-9, MYB-12, DR-12, DR-3, and KKM-3. Sequencing and BLASTn analysis of the RGA amplicons revealed high similarity with known resistance genes in Vigna species. Phylogenetic analysis further validated the relationship of these candidate R genes with established MYMV resistance genes. The study demonstrates the utility of RGA-based markers for rapid identification and characterization of MYMV resistance in mungbean, providing valuable tools for marker-assisted selection and breeding of resistant cultivars.