Synergy between Paenibacillus lentimorbus and Pseudomonas putida mediates ecological benefit to chickpea by decrementing Fusarium oxysporum f. sp. ciceris.

Fusarium wilt is a major problem in agriculture. It significantly affects the growth and development of chickpea and its management mainly relies on heavy use of chemical fertilizers. The negative impacts posed by the excessive use of chemical pesticides necessitate the investigation into microbial antagonism. Currently, root-associated single microorganisms form the basis for microbe-based biological control. Recent studies have highlighted the synergistic interaction among microbes for management of biotic stresses. The present study focussed on the development of an effective microbial consortium for enhanced plant growth and health. The biocontrol agents, Paenibacillus lentimorbus (NBRI-CHM12), Bacillus amyloliquefaciens (NBRI-SN13) and Trichoderma harzianum (NBRI-Fx), were combined with P solubilizer Pseudomonas putida (NBRI-RA) based on their compatibility, plant growth-promoting traits (PGP) and antagonism against Fusarium oxysporum. The best selected consortium of NBRI-CHM12 and RA was inspected for disease management against F. oxysporum f. sp. ciceris on sensitive (JG-62) and resistant (K-850) chickpea cultivars. The NBRI-CHM12+RA consortium led to increased productivity (dry weight) in both JG-62 (81.48%) and K-850 (20.5%) cultivars. Modulation in pectin- and cellulose-degrading enzymes (PCDEs), reactive oxygen species (ROS), antioxidants and phenylpropanoid activity in plant justifies enhanced induced systemic resistance in the presence of consortium. The consortium also showed a reduction in Fusarium population compared to individual treatments, positively correlating with enhanced soil microbial enzymatic activities. The use of microbial consortia is best suited to fulfil the dual purpose of plant growth promotion and disease suppression.