Antagonistic and growth-promoting potential of multifarious bacterial endophytes against Fusarium wilt of chickpea

Background Chickpea is the most important legume crop in India, and its productivity is significantly lowered due to biotic constraints such as wilt caused by Fusarium oxysporum f. sp. ciceris. Endophytes help plants to thrive better under stress conditions by regulating plant hormones and inducing systemic resistance. The aim of the present study was to identify chickpea root bacterial endophytes having antagonistic ability for the management of the Fusarium wilt. Results Twenty endophytic bacterial strains were isolated from the susceptible and resistant chickpea cultivar, amongst which 35% bacterial endophytes gave positive results for siderophore and 15% isolates were HCN producers, whereas 55% showed good growth on ACC-supplemented medium. Based upon 16S rRNA phylogenetic analysis, efficient endophytic bacterial isolates CRBE1, CRBE3 and CRBE7 were identified as Priestia megaterium, Brucella haematophila and Microbacterium paraoxydans, respectively. Bacterial endophyte CRBE7 and CRBE3 showed pronounced antagonistic activity against Fusarium oxysporum f. sp. ciceris under in vitro conditions. Inoculation of chickpea with isolated bacterial endophytes alone and in combination through seed priming resulted in significant biocontrol activity against Fusarium wilt of chickpea under screenhouse conditions. Biopriming of chickpea seeds alone with CRBE3 and as consortium of CRBE3 + CRBE7 upsurged the phenol content in susceptible and resistant chickpea varieties JG 62 and HC 3, which indicated the role of promising endophytes as potential bio-agents under in vivo conditions. Conclusions Chickpea root bacterial endophytes Priestia megaterium (CRBE1), Brucella haematophila (CRBE3) and Microbacterium paraoxydans (CRBE7) exhibiting antagonistic activity could be incorporated in integrated disease management module against Fusarium wilt of chickpea.