Antiviral Efficacy of Bacillus sp. against Groundnut bud necrosis orthotospovirus in Cowpea

Tomato spotted wilt, a disease caused by Groundnut bud necrosis virus (GBNV), is a major disease affecting tomatoes causing great yield loss to the farming community. In this study, the GBNV-TNAU 1 virus isolate was obtained from infected plants and maintained through mechanical transmission on cowpea cv. CO7, which induced chlorotic and necrotic local lesions by the fourth-day post-inoculation (dpi). The pathogenicity of GBNV on tomato cv. PKM1 was confirmed through sap transmission. In vitro screening of Bacillus sp. viz., B. amyloliquefaciens (Ka1), B. subtilis (Bbv 57), and B. subtilis (BST 8) demonstrated effective reduction of GBNV-induced lesions in cowpea. B. amyloliquefaciens (Ka1) and B. subtilis (BST8) displayed a maximum germination percentage of 100 %, while B. amyloliquefaciens (MM12) exhibited 83.33 %. Futhermore, maximum vigour index of 1743.8, 1699.6 & 1436.5 was noticed in B. amyloliquefaciens (Ka1), B. subtilis (BST8) & B. subtilis (Bbv 57) treated plants. These findings provide valuable insights on sustainable management strategies against the disease, benefiting farmers by enhancing tomato cultivation productivity and profitability.