Screening of the Biocontrol Efficacy of Potent Strains against f.sp. and Causing Wilt and Collar Rot in Chickpea.

Chickpeas contribute to half of the pulses produced in India and are an excellent source of protein, fibers, carbohydrates, minerals, and vitamins. However, the combination of the wilt and root rot diseases drastically lowers its yield. The use of antagonist microbes that restrict the growth of other phytopathogens is an ecofriendly approach to combat the serious threats raised by the plant pathogens. spp. are well known as biocontrol agents, especially against soil- and seed-borne phytopathogens. In this study, 21 isolates that were collected from different rhizospheric soils were evaluated against two notorious soil-borne pathogens, such as f.sp. and . The maximum percentage of inhibition against the tested pathogens was observed in isolate PBT13 (72.97%, 61.1%) followed by PBT3 (72.23%, 59.3%). The mycelial extension rate method, dual culture (antagonism), production of cell-wall degrading enzymes (CWDs), and antifungal metabolites (by GC-MS) were used as selection criteria for potent isolates. Among the 21 isolates, PBT3, PBT4, PBT9, and PBT13 exhibited high antagonistic activity, production of antifungal metabolites, and chitinase and β-1,3-glucanase activity. These four species were subjected to molecular characterization using an internal transcribed spacer (ITS 1 and ITS4). The results of molecular characterization identified the four species as , , and . Moreover, significant chitinase and β-1,3-glucanase activities of all isolates were recorded in the growth medium. (isolate PBT13) was found to exhibit the highest chitinase activity in terms of zone formation (4.40 ± 0.17 cm), whereas (isolate PBT3) exhibited the highest β-1,3-glucanase activity1.511 μmole/min. A GC-MS analysis of ethyl extracts from two isolates of (PBT9, PBT13) revealed the presence of 28 VOCs. Overall, this study suggests that these four strains are promising biological control agents (BCAs) and could be developed as bio-pesticides after stringent field trials for the management of soil-borne diseases of chickpeas.