Evaluation of diverse blackgram (Vigna mungo (L.) Hepper) germplasm accessions for root-knot nematode resistance and genetic diversity study

Blackgram (Vigna mungo (L.) Hepper), a nutritionally and economically important food legume crop grown in different parts of the world is important for food and nutritional security. However its production is severely affected by root-knot nematodes (RKN), Meloidogyne spp. in both tropical and subtropical regions. The identification of source of resistance is an important step to develop RKN control strategies that are expected to facilitate the development of RKN resistant cultivars alleviating yield and economic losses. In the present study, 169 diverse accessions of blackgram from the National Genebank (NGB), India were evaluated under artificial inoculation conditions against RKN, M. incognita during year 2020. The number of root galls and egg masses varied among all the tested accessions. The study led to identification of one resistant accession (IC0485566) and 13 moderately resistant accessions. Based on the number of root galls, a panel of 10 accessions with less than 30 galls per root system and 10 most susceptible accessions with more than 100 galls per root system were further evaluated twice in year 2021. The resistant accession was revalidated in year 2022. Genetic diversity in a panel of accessions was studied using 30 simple sequence repeat (SSR) markers which generated a total of 93 alleles with a mean of 3.1 alleles per locus and mean Shannon’s Information index of 0.86. The identified resistant accession showed better phenotypic growth, comparable resistance and can potentially be used in blackgram breeding program as a donor for RKN resistance and genetic dissection of RKN resistance in blackgram.