Biocontrol potential of endophytic bacteria against Fusarium wilt pathogen (Fusariumoxysporum f. sp. ciceris) in chickpea

Introduction Fusarium wilt of chickpea, caused by Fusarium oxysporum f. sp. ciceris (FOC), is a major soil-borne disease that severely affects chickpea production worldwide. The present study aimed to isolate and characterize endophytic bacteria from different plant species and evaluate their antagonistic potential against FOC. Methods Endophytic bacteria were isolated from leaves, stems, and roots of various plant species. A total of 73 bacterial isolates were obtained from 210 plant samples and screened for antagonistic activity against FOC under in vitro and in vivo conditions. Five promising isolates were selected for detailed studies, including biochemical characterization, stress tolerance assays (salinity, heat, and drought), and molecular identification through 16S rRNA gene sequencing. Results The selected isolates were identified as Ochrobactrum quorumnocens, Bacillus velezensis, Alcaligenes faecalis, Bacillus subtilis , and Acinetobacter schindleri . These isolates exhibited significant inhibition of FOC on potato dextrose agar (PDA), with inhibition percentages of 36.29%, 48.48%, 45.89%, 57.37%, and 55.50%, respectively. Under field conditions, all five isolates significantly reduced disease incidence and enhanced chickpea growth compared to the untreated control. Discussion The findings demonstrate that the selected endophytic bacterial isolates possess strong antagonistic activity against FOC and also exhibit plant growth-promoting traits. These isolates have considerable potential as biocontrol agents and PGPR for sustainable management of chickpea Fusarium wilt under both laboratory and field conditions.