Development of Genotypes for Foliar Disease Resistance in Mungbean [Vigna radiata (L.) Wilczek] through Recombination and Mutation Breeding

Background: Despite the best efforts for improving the greengram varieties, the yield potential of this crop remains low owing to both biotic and abiotic factors. Yield losses caused due to various diseases were estimated to be 24-67 per cent in anthracnose, 80-100 per cent in mungbean yellow mosaic virus and 40 per cent due to powdery mildew So, the use of resistant cultivars is the most effective and eco-friendly method of managing the disease. Methods: A series of field experiments spanned over seven years (2014-2021) were conducted at Main Agricultural Research Station, University of Agricultural Sciences, Dharwad, Karnataka. In the first set of experiments, the material comprised of eight varieties of greengram which were treated with 20kR gamma radiation. M1was planted in Kharif 2014 and each variety was bulk harvested. M2 was planted in summer 2014 and individual plant selection was carried out. Mutant families were advanced to the further generation in Kharif 2015 and Rabi 2015. The M2 mutants were scored for their reaction to anthracnose, cercospora leaf spot and powdery mildew diseases with respective susceptible and resistant checks. In another set of experiments aimed at developing MYMV tolerant genotypes, an investigation was carried out with 168 F2 individuals derived from crossing Vigna trilobata and DGGV2. One row infector line of DGGV-2 was raised after every three test entries to study the reaction to MYMV. Three rows of susceptible check was planted all around the border to ensure enough inoculum load. Of the 168 F2 individuals, two lines showed resistance to MYMV. They were stabilized through a series of selfing generations. Result: Evaluation of advanced breeding lines for their reaction to various foliar diseases revealed that the advanced breeding lines DGG-203, DGG-206, DGG-208, DGG-21, DGG-80, DGG-273, DGG-274, DGG-275, DGG-262, DGG-263, DGG-264, DGG-82, DGG-200, TARM-1 (C), DGG-215-5, DGG-302, DGG-152, IPM-3-2, DGG-20, DGG-73, IPM-14-10, DGG-121, DGG-250, DGG-109, DGG-96 had seed yields ranging from 9.8 g to 12.4 g and moderately resistant to both anthracnose and CLS. The breeding lines DGG-203, DGG-206, DGG-21, DGG-273, IPM-3-2 (Check), DGG-96 have recorded combined resistance to anthracnose, cercospora leaf spot and powdery mildew diseases.