Characterization of phosphate solubilizing Pseudomonas stutzeri for nodulation in chickpea

Abstract

Phosphorus is a vital but least mobile element in plants and soil as compared to other macronutrients. Native phosphate solubilizing bacterial strains were isolated from the rhizosphere of chickpea. Based on in vitro study, the isolate showed lower pH, remarkable phosphate solubilizing index, and thermotolerant ability selected for further characterization. The 16 s rRNA sequencing confirmed that the isolate showed 99.23% similarity with Pseudomonas stutzeri CW202. Pot trial treatments include Rhizobium ciceri, Pseudomonas stutzeri, and fertilizer alone and in combination with inoculants and control. The results of co-inoculation with R. ciceri + P. stutzeri showed the highest germination rate, increase in nodule number, and fresh nodule weight. This treatment was at par in plant height, number of branches, shoot and root dry weight per plant, number of pods per plant, seeds per pod, 100 seed weight and phosphorus uptake in seed and straw over the best treatment R. ciceri + P. stutzeri + Fertilizer. Co-inoculation of R. ciceri + P. stutzeri shows not only significant enhancement in nodulation, nodule fresh weight but also yield attributes and phosphorous uptake as compared to R. ciceri alone, indicating its role in phosphorus nutrition in chickpea. The results infer that the native P. stutzeri could be considered as a proficient biofertilizer in the organic farming system.