Coordination of Mesorhizobium sp. and endophytic bacteria as elicitor of biocontrol against Fusarium wilt in chickpea

Antagonistic Plant growth promoting rhizobacteria can contribute to disease management by induction of host defenses and biological control of pathogens. The present study was thus planned to develop a bio-inoculant with the ability to promote plant growth and reduce disease incidence due to Fusarium oxysporum sp. ciceris in chickpea. Isolates of Mesorhizobium sp. (6) and endophytic bacteria (5) were screened as potential antagonists exhibiting 50–93.7% growth inhibition of Fusarium wilt (in vitro). Selected Mesorhizobium sp. and endophytic bacteria were assessed for their compatibility to develop dual combinations with no mutual inhibition. Dual inoculants significantly enhanced in vitro plant growth promoting traits viz., Indole Acetic Acid, siderophores, phosphate solubilization and 1-aminocyclopropane-1-carboxylate-deaminase enzyme activity. Dual mesorhizobia and endophytic bio-inoculants (able to grow with recommended fungicide captan @ 3 g/kg seed) were further assessed in wilt-sick field conditions for growth, symbiosis, soil health, yield and bio-control parameters in two chickpea varieties (PBG-7 and PBG-1). Seed priming with dual inoculants significantly enhanced growth, symbiosis, soil quality parameters and antioxidant enzymes viz., catalase, peroxidase and total phenols over control. Dual bio-inoculant LGR2 + LCNE8 improved the grain yield by 6.5% over captan as the control. These results suggest that bio-inoculants of Mesorhizobium sp. and endophytic bacteria under a competitive environment can be explored as bio-fertilizers/bio-protectants for improving productivity and suppression of Fusarium wilt in chickpea.