Unveiling resistant sources and characterizing germplasm for effective management of yellow mosaic virus (YMV) disease in blackgram [Vigna mungo (L.) Hepper]

Yellow mosaic virus (YMV) disease poses a serious threat to blackgram production, causing substantial reductions in yield. Identification of stable resistant sources is considered as the most economical and eco-friendly option to manage YMV disease incidence. In the present study, we investigated the response of a set of 144 blackgram genotypes to YMV under natural infection using infector row method over the four growing seasons, viz., summer-2020 (S1), Kharif 2020-21 (S2), Summer 2021 (S3), and Kharif 2021-22 (S4) and at the two developmental stages (viz., 30 and 60 days after sowing). Genotypes were evaluated based on percent disease incidence (PI) and percent disease index (PDI). Results showed a differential response of genotypes with respect to disease severity. Based on mean performance over all growing seasons and developmental stages, five genotypes viz., NUK 15 − 01, NUK 17 − 05, VUG 100, VUG 108, and VUG 146 were identified as highly resistant. Additionally, 16 genotypes with differential responses to YMV were selected based on multi-seasonal performance and were evaluated for 13 yield contributing traits to assess the effect of YMV during kharif 2021-22. Maximum yield reduction was noticed in plants which were infected severely in early stage. However, resistant genotypes exhibited high seed yield, pods per plant, clusters per plant, seeds per pod including early flowering and early maturity as compared to highly susceptible genotypes. The highly resistant and resistant genotypes identified in the present study can be used as a potential donor in breeding programs to develop YMV resistant, high-yielding blackgram cultivars.