Interspecific Hybridization Between Vigna radiata and Vigna mungo Towards the Broadening of Genetic Base for MYMV Disease Resistance and Generating Variability

Abstract

Background: The main cause for low yield in greengram is its susceptibility to Mungbean Yellow Mosaic Virus (MYMV) which is the most prevalent and destructive viral pathogen cause 85% yield lose. Inter specific hybridization between Vigna radiata and Vigna mungo could be an alternate approach to develop MYMV resistant genotypes in greengram which leads to additional source of creating variability for desirable attributes including yield, nutritional quality, biotic and abiotic stresses.Methods: The present investigation was carried out at National Pulses Research Centre (NPRC), Tamil Nadu Agricultural University, Vamban during 2016-2017. Interspecific hybridization has been effected between Vigna radiata var. VBN (Gg)2, VBN (Gg) 3 (as females) and Vigna mungo Var. Mash 114 (as male) during Summer 2016. The interspecific F1 hybrids, F2 and F3 populations were evaluated during Kharif 2016, Rabi 2016-17 and summer 2017 respectively. The F2 and F3 populations were evaluated for days to 1st flowering, days to maturity, plant height (cm), number of branches / plant, number of clusters / plant, number of pods / clusters, pod length (cm), number of seeds / pod, number of pods / plant, single plant yield (g.). The MYMV resistance has been confirmed under infector row method using CO 5 as susceptible check variety. Phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV), Heritability (h2) in broad sense, genetic advance as per cent of mean, Skewness and Kurtosis were estimated for yield and yield components. Result: Four true F1 plants were recovered in Vigna radiata var. VBN (Gg)2 x Vigna mungo Var. Mash 114 cross combination. The fertile F1 had the shallow lobbed leaf of Vigna radiata var. VBN (Gg)2 and black colour seed of Vigna mungo var. Mash 114 with pollen fertility of 42.0 per cent and crossability of 12.50%. Most interestingly all the four interspecific F1 plants were free from MYMV disease. In F2 generation, only one healthy plant was survived which had a pod, stem and branching behaviour of blackgram and greengram characters of lobbed leaf and green seed colour. In F3 generation, number of branches per plant, number of clusters per plant, number of pods per plant, pod length and seed yield per plant had high GCV, high PCV, high heritability coupled with high genetic advance as per cent of mean. Present study suggests that MYMV resistant cultivars of greengram can be explored through interspecific hybridization with Vigna mungo var. Mash 114 as a source of resistance and the hidden transgressive segregants can be recovered in F3 generation.