Prospecting catabolic diversity of microbial strains for developing microbial consortia and their synergistic effect on Lentil (Lens esculenta) growth, yield and iron biofortification.

Carbon profiling of heterotrophic microbial inoculants is worthwhile strategy for formulating consortium-based biofertilizers. Consortium-based biofertilizers are better than single strain-based biofertilizers for sustaining agricultural productivity and enhancing micronutrient concentration in grains. Currently, we investigated catabolic diversity among microbes using different carbon sources and certain enzyme activities. A field experiment was also carried to evaluate the synergistic effect of selected lentil Rhizobia and plant growth promoting rhizobacteria strains on lentil growth, yield, nitrogen fixation, and Fe-content in seeds. On the basis of carbon profiling Bacillus sp. RB1 and Pseudomonas sp. RP1 were selected for synergistic study with lentil Rhizobium-Rhizobium leguminosarum subsp. viciae RR1. Co-inoculation of Rhizobium with Bacillus sp. RB1 and Pseudomonas sp. RP1 significantly enhanced the plant height, number of pods per plant, seed yield, number of nodules per plant, nitrogenase activity and Fe biofortification in seed over the single Rhizobium inoculation or dual combination of Rhizobium + RB1 or RP1.The response of single Rhizobium inoculation or co-inoculation of Rhizobium with RB1 and/or RP1 at 50% RDF was almost similar or higher than full dose of recommended N:P:K with respect to lentil yield and Fe biofortification in seed. This deciphered grouping of microbial strains for formulation of microbial consortia-based biofertilizers and revealed the promise of consortium of Rhizobium and plant growth promoting rhizobacteria in improving the biological yield and enhancing the Fe content of lentil seed.