Vol. 12, Issue 3 (2023)

Author(s):
Jyothirmai Madhavi K and Lal Ahamed M

Abstract:
In the recent years, viruses causing necrosis, transmitted by thrips has assumed epidemic proportion and became a serious production constraint in pulses like blackgram. Leaf curl disease caused by Peanut bud necrosis virus (PBNV)-Tospo group considered being a major threat. Tobacco streak virus (TSV)-Ilar group has also been reported to be a cause of leaf curl symptoms. Controlling thrip vectors by physical, chemical and biological methods can reduce thrips population to economically viable direct damage level, but not enough to prevent the spread of disease. Development of genetic resistance has become the best management strategy for these diseases in both medium and the long term. Fifty of each black gram and green gram genotypes, obtained from All India Coordinated Pulses Improvement Project (AICPIP), RARS, Lam and NBPGR-RS, Hyderabad, were screened for resistance against PBNV and TSV during kharif under field conditions at hot spot locations, Tandur and Anantapur, respectively. None of the entries was recorded with resistant reaction where all the genotypes showed susceptible reaction with a range of chlorotic to necrotic symptoms at both the locations. At Anantapur, hundred per cent disease was recorded in LBG-20 at 45DAS followed by LBG-741, -752 with 90% while OBG-15 (77.55%), 99-U-21 (77.08%) and TAU-1 (77.08%) showed susceptible reaction and all the remaining genotypes showed a range of PDI 80-90. At 30 DAS, PDI ranged between 11.76% (99-U-19) and 50.00% (LBG-611) whereas the green gram genotypes screened under field conditions showed a range of disease incidence 62.50-93.33% at 45 DAS. Susceptible reaction was observed in LGG-505 (62.50%), -527 (63.82%), -526 (66.66%), and LGG-470 (79.59%), while all the remaining genotypes were recorded with >80% indicating highly susceptible reaction. At Tandur, the PDI ranged from 83.30 to 100 where minimum was recorded in LBG-744 at 45DAS in black gram genotypes. Hundred per cent disease was recorded in LBG-709, -735, -752, PANT-U-30, NSM-74 and CN-9027 while the remaining showed highly susceptible reaction with >80% whereas green gram genotypes showed a range of disease incidence 96.15-100% at 45 DAS, while it was 93.75-100% at 30DAS indicating highly susceptible reaction where hundred per cent disease incidence was recorded in majority of the genotypes screened including the susceptible check K-851.