QTL mapping using a high-density SNP map and development of KASP markers for MYMIV resistance in mungbean (Vigna radiata L.).

Abstract

Mungbean yellow mosaic India virus (MYMIV) poses a severe threat to mungbean (Vigna radiata L.) cultivation, leading to substantial yield losses across tropical and subtropical regions. The present study was aimed to identify genomic location(s) governing MYMIV resistance in the resistant source of mungbean, ML1808. Inheritance studies from the crossSML 1082 × ML 1808in mungbean indicated the presence of a single dominant gene governing MYMIV trait in both the crosses. Leveraging genotyping-by-sequencing platform, a high-density linkage map was constructed in mungbean using F₂ individuals derived from cross SML 1082 × ML 1808.The map contained 2638 single nucleotide polymorphism (SNP) markers distributed in 11 linkage groups and spanned for 1924.279 cM length with an average marker distance of 0.729 cM. The individual linkage group ranged from 129.3 to 207.6 cM in length, with 102-395 SNP markers per chromosome. The QTL analysis using the genetic map and F₃ and F₄ phenotyping data identified a major QTL, designated as qMYMIV3_3 at 5 cM position on chromosome 3, common in both the populations. This QTL mapped for MYMIV resistance in mungbean variety ML1808 harbor possible candidate genes for controlling MYMIV resistance. Linkage mapping using KASP (Kompetitive Allele-Specific Polymorphism) markers developed from potent candidate genes involved in disease resistance identified the 380 kb genomic region linked with MYMIV. The two KASP markers closely associated with MYMIV, viz. Vrad305 and Vrad308 originated from RPL19 (ribosomal protein L19-1) and WRKY transcription factor genes, respectively. The constructed genetic linkage map and QTL/gene (s) along with the closely linked markers for MYMIV resistance identified in this study will be important for marker-assisted breeding programs.