Identification and confirmation of quantitative trait loci controlling resistance to mungbean yellow mosaic disease in mungbean [Vigna radiata (L.) Wilczek]

Mungbean yellow mosaic India virus (MYMIV) is a major constraint on mungbean production in South and Southeast Asia. The virus belongs to the genus Begomovirus, causing yellow mosaic disease and subsequently yield loss up to 75-100 %. The present study employed F-2 and BC1F1 populations derived from a cross between susceptible (BARImung 1; BM1) and resistant (BARImung 6; BM6) mungbeans to identify quantitative trait loci (QTLs) associated with resistance to MYMIV. Resistance to the virus was evaluated using F-2:3 and BC1F1:2 populations under field conditions in two locations in Bangladesh in 2012. A total of 1,165 simple sequence repeat markers from different legumes were used to detect the polymorphism between BM1 and BM6. Sixty-one polymorphic markers were used to construct a linkage map comprising 11 linkage groups. Composite interval mapping consistently identified two major QTLs, qMYMIV2 on linkage group 2 and qMYMIV7 on linkage group 7, conferring the resistance in both F-2 and BC1F1 populations. qMYMIV2 and qMYMIV7 accounted for 31.42-37.60 and 29.07-47.36 %, respectively, of the disease score variation, depending on populations and locations. At both loci, the resistant alleles were contributed by the parent BM6. qMYMIV2 appeared to be common to a major QTL for MYMIV resistance in mungbean reported previously, while qMYMIV7 is a new QTL for the resistance. The markers linked to the QTLs in this study are useful in marker-assisted breeding for development of mungbean varieties resistant to MYMIV.