Exploiting novel rhizosphere Bacillus species to suppress the root rot and wilt pathogens of chickpea

Abstract

Thirty isolates of Bacillus were collected from chickpea rhizosphere and screened for their in vitro inhibition against root rot (Rhizoctonia bataticola) and wilt (Fusarium oxysporum f.sp. ciceri) pathogens and growth promotion of chickpea. Based on the in vitro inhibition and growth promotion tests, the best eight isolates were selected and PCR-based detection of antibiotics genes viz., surfactin, iturin, fengycin and bacillomycin D was carried out. The isolate which produced all these antibiotics and showed maximum in vitro inhibition (CaB 5) was further used for crude antibiotics extraction and inhibition assays. The presence of antibiotics in crude extract was detected through TLC. The inhibitory effect of the crude extract was proved through agar-well diffusion assay and spore germination inhibition test. From this study, it was inferred that the Bacillus subtilis strain CaB5 was promising in inhibiting the root rot and wilt pathogens of chickpea and enhance seedling vigour. Key words: Biological control, plant growth promotion, surfactin, iturin, fengycin.