Genetic Dissection of Genomic Regions Associated with Resistance to Urdbean Leaf Crinkle Disease and Yield Related Traits in Black Gram (Vigna mungo (L.) Hepper)

The genetic complexity of various quantitative traits like yield, resistance to urdbean leaf crinkle disease (ULCD), and other yield-related traits in black gram is not well understood. To dissect the genetic basis of urdbean leaf crinkle virus resistance and yield components, 50 diverse black gram genotypes originating from 11 states of India with different pedigrees were evaluated by using association mapping. The germplasm was genotyped with 120 SSR markers and 38 SSR markers were polymorphic. STRUCTURE analysis partitioned the population into three genetically distinct subpopulations based on ad hoc, Delta K. Two statistical approaches, the General Linear Model (GLM) and the Mixed Linear Model (MLM) identified 19 significant marker-trait associations for various yield components and resistance to ULCD using the genotypic data from the identified polymorphic markers, Q matrix (from STRUCTURE), and phenotypic data. Marker trait analysis revealed that; two markers, viz., CEDG133 and CEDG044 were associated with resistance to ULCD. Further, the markers CEDG043, CEDG268, CEDG092, and CEDG275 were associated with plant height, pods per plant, days to maturity, and branches per plant, respectively. Similarly, the marker CEDG044 was linked to both days to 50% flowering and days to maturity indicating pleiotropy. One more marker, MB87 also exhibited pleiotropy for both grain yield per plant and plant height. The identified marker-trait associations provide reliable insight for marker-assisted breeding aiming at the development of ULCD-resistant and high-yielding black gram varieties.