In vitro antagonism of soil and chickpea nodule isolates against Fusarium oxysporum f. sp. ciceris in chickpea

Fusarium oxysporum f. sp ciceris (Foc) causes Fusarium wilt disease of chickpea (Cicer arietinum L.) resulting in severe losses in the irrigated belt of Punjab. The most effective and practical method is the use of fungicides or resistant cultivars to control Fusarium wilt in chickpea. Rhizobia application could be used as an alternative way to control Fusarium wilt of chickpea. Rhizobium spp. are effective biological control agents as they promote plant growth directly by effecting symbiotic N2 fixation, nodulation or nodule occupancy in chickpea. Twenty soil and chickpea nodule isolates along with reference Mesorhizobium spp. (LGR 33) were tested as biocontrol agent in vitro against the causative agent of Fusarium wilt of chickpea via production of cell wall degrading enzymes and volatiles. Out of 20 soil and chickpea nodule isolates including LGR 33, 43 and 33% were able to produce siderophores and HCN respectively, whereas 62 and 57% produced cellulase and protease enzymes respectively. Soil and chickpea nodule isolates revealed maximum inhibition of 45% followed by 35 and 30% for control of F. oxysporum strains 1, 3 and 2, respectively. Three native isolates of soil and chickpea nodule (LGR 46, LGR 50 and LGR 52) including LGR 33 were able to produce volatiles, cell wall degradation enzymes and antagonistic effect. Further extensive research is required to understand the mechanism of potential isolates of soil bacteria and chickpea in controlling Fusarium wilt disease of chickpea. Selection of rhizobia with twin functional traits (N2 fixation and biocontrol agent) can be exploited as future biofertilizer in chickpea.