T. S. Bains

Detection of quantitative trait loci for mungbean yellow mosaic India virus (MYMIV) resistance in mungbean (Vigna radiata (L.) Wilczek) in India and Pakistan

Yellow mosaic disease (YMD) is one of the major diseases affecting mungbean (Vigna radiata (L.) Wilczek). In this study, we report the mapping of the quantitative trait locus (QTL) for mungbean yellow mosaic India virus (MYMIV) resistance in mungbean. An F8 recombinant inbred line (RIL) mapping population was generated in Thailand from a cross between NM10-12-1 (MYMIV resistance) and KPS2 (MYMIV susceptible). One hundred and twenty-two RILs and their parents were evaluated for MYMIV resistance in infested fields in India and Pakistan. A genetic linkage map was developed for the RIL population using simple sequence repeat (SSR) markers. Composite interval mapping identified five QTLs for MYMIV resistance: three QTLs for India (qYMIV1, qYMIV2 and qYMIV3) and two QTLs for Pakistan (qYMIV4 and qYMIV5). qYMIV1, qYMIV2, qYMIV3, qYMIV4 and qYMIV5 explained 9.33%, 10.61%, 12.55%, 21.93% and 6.24% of variation in disease responses, respectively. qYMIV1 and qYMIV4 appeared to be the same locus and were common to a major QTL for MYMIV resistance in India identified previously using a different resistant mungbean.

Evaluation and molecular characterization of advanced interspecific lines for genetic improvement in mungbean [Vigna radiata (L.) Wilczek]

The present study was undertaken to evaluate advanced interspecific lines of mungbean [Vigna radiata (L.) Wilczek] for yield and its components and to understand genetic diversity among these lines using microsatellite markers (SSRs). The experimental material consisted of 51 advanced interspecific lines developed from mungbean [Vigna radiata (L.) Wilczek] ×urdbean [Vigna mungo L. Hepper] and mungbean [Vigna radiata (L.) Wilczek] ×ricebean [Vigna umbellata Thumb.] crosses and 13 parental lines (mungbean, urdbean and ricebean). A wide range of variability was observed for eleven yield and its component characters and many superior lines were identified. SSR markers synthesised from different Vigna species were used to assess genetic diversity in advanced interspecific lines along with their parents. The interspecific lines were converged into three main clusters while the parental lines were converged into three main and four sub clusters, depicting genetic diversity among them.

Comparative assessment of ssr markers derived from different sources in genetic diversity analysis of Vigna genotypes

Mung bean (Vigna radiata (L.) Wilczek), also known as green gram, is an important food legume crop and provides an inexpensive source of dietary protein. Due to lack of sufficient variability and its importance in Asian countries there is need of broadening its genetic base. Genetic diversity among 21 Vigna genotypes of mung bean, rice bean and urd bean was assessed using SSR markers derived from genomic sequences of azuki bean (Ced) and mung bean (VR) and EST sequences of mung bean (MBM). Of the 67 SSR markers selected, 45 were found polymorphic among different genotypes which yielded 138 alleles of which 16 were mung bean specific, 27 urd bean specific and 17 rice bean specific alleles. Azuki bean derived SSRs (Ced) were more polymorphic. PIC value was similar in three sets of SSRs. Number of observed and effective alleles were more in Ced markers along with high value of various other parameters like EMR (3.6), MI (1.26), RP (2.7), H(0.33), H(0.62), and H(0.6), calculated to identify effectiveness of markers. Dissimilarity analysis divided mung bean and rice bean genotypes into two subclusters while 12 genotypes of urd bean formed two clusters.