Synergistic effect of plant growth promoting bacterium Pseudomonas fluorescens and phosphate solubilizing fungus Aspergillus awamori for growth enhancement of chickpea

Many rhizosphere microorganisms solubilize the fixed phosphorus present in soil and make it available to the plants and also contribute towards better growth and yield of plants through other direct and indirect plant growth promoting activities. This communication deals with synergistic effect and compatibility of two rhizosphere microorganisms, Pseudomonas fluorescens BAM-4 and Aspergillus awamori S-19 in vitro and in planta in chickpea. BAM-4 and S-19 solubilized 354.41 and 361.12 mg kg-1 of P in vitro, respectively. BAM-4 also showed indole acetic acid (IAA) production and 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. Under pot culture conditions, the overall plant growth in all treatments assayed increased significantly over the untreated soil. The length and fresh and dry weight of plants were significantly higher in co-inoculation treatment by BAM-4 and S-19 as compared to single inoculation of either microorganism, showing the positive synergistic effect. The number of pods and weight of pods per plant were maximum in soil + BAM-4 + S-19 treatment with and/or without TCP. Maximum total chlorophyll content was 4.28 mg g-1 fresh weight in dual inoculation treatment with TCP. The results indicated the potential usefulness of co-inoculation by rhizosphere bacteria and fungi in stimulation of plant growth and yield in chickpea for sustainable environment and agriculture