Evaluation of Antifungal Activity of Bacterial Endophytes Against Fusarium Oxysporum Causing Wilt Disease

Abstract

Fusarium oxysporum is main causative agent behind the most destructive soil-borne plant disease, fusarium wilt, which damages economically significant food crops like bananas, sweet potatoes, tomatoes, legumes and melons. Traditionally, the disease is controlled by physical and chemical methods that affect the environment adversely. One of the ecofriendly approach of plant disease prevention is biological control. Plant growth promoting rhizobacteria and endophytes are now consider as promising agent for disease control. In the present study bulb of Allium sativum plant were used for isolation of endophytes and the endophytes were screened for their bio-control potential. Thirteen bacterial endophytes (ESS01, ESS02, ESS03, ESS06, ESS023, ESS024, ESS025, ESS072, ESS073, ESS074, ESS075, ESS076 and ESS077) exhibited antifungal activity against Fusarium oxysporum f. sp. ciceris. All the isolates inhibited more than 59% mycelial growth on dual-culture assay. However isolate ESS01 and ESS02 exhibited higher antifungal activity (74.81% & 71.48%) against the pathogen Fusarium oxysporum f. sp. ciceris. Only five endophytic isolates (ESS01, ESS02, ESS023, ESS076 & ESS077) out of thirteen endophytes were selected for the pot experiment because of having plant growth promoting attributes and inhibiting more than 70% mycelia growth of Fusarium oxysporum. Biocontrol technique of production of plant against harmful pathogen is now a promising approach for ecofriendly and sustainable agriculture. In this context endophytic isolates were analysed for their antifungal properties especially on Fusarium oxysporum. The endophytic isolates Bacillus aerius ESS02, Bacillus velezensis ESS076, and Bacillus siamensis ESS077 significantly enhanced the plant biomass in chick pea plant even in presence of pathogen and eliminating the harmful effect of Fusarium oxysporum on chick pea plant. Overall, present investigation indicate that Allium sativum harbors various endophytic bacteria that possess excellent antifungal activity and can be used as bio-control agent to control wilt disease of various plants.