Biocontrol Activity of Endophytic Isolates Bacillus safensis and Pseudomonas lactis From Azadirachta indica Against the Pathogen Xanthomonas campestris pv. vesicatoria in Tomato Plants

Abstract

Biocontrol plays a pivotal role in mitigating biotic stress and promoting plant growth by utilizing beneficial microorganisms that exhibit antagonistic activity against phytopathogens. Xanthomonas campestris is a bacterial pathogen known to cause diseases such as bacterial black leaf spots in various economically important crops. Therefore, in the current study to identify effective biocontrol agents, over 30 endophytic isolates from various tissues of Azadirachta indica were examined for their antagonistic activity against X. campestris pv. vesicatoria. Among these, two potential isolates, Bacillus safensis (strain LE8) and Pseudomonas lactis (strain LE11), based on their inhibitory effects, were subsequently selected for further analysis to contribute to sustainable agricultural practices. The in vitro as well in vivo treatments to tomato leaves with these potential isolates showed both preventive as well as curative effects. The current investigation confirmed a notable reduction in disease symptoms, showcasing their effectiveness as a biocontrol agent. Our findings highlight the beneficial impact of endophytic bacteria as a biocontrol, providing a sustainable alternative to pesticides.