Plant Growth Promoting Traits of Indigenous Phosphate Solubilizing Pseudomonas aeruginosa Isolates from Chilli (Capsicumannuum L.) Rhizosphere

Phosphorus (P) is the second key nutrient for plants and it affects several attributes of plant growth. Identification of a potent phosphate solubilizing microorganism capable of transforming the insoluble P into soluble and plant-accessible forms is considered as the best eco-friendly option for providing inexpensive P to plants. Hence, this study was focused to assess the growth enhancement traits of the phosphate solubilizing bacteria (PSB) isolated from chili rhizosphere. Twelve PSB were isolated by enrichment culture technique and its P solubilization efficiency was checked using Vanadomolybdate phosphoric yellow color method. Among them, two potent strains PS2 and PS3, identified as Pseudomonas aeruginosa KR270346 and KR270347 based on biochemical and molecular characterization, were selected for further study. The Pseudomonas aeruginosa isolates interestingly showed the presence of various potential plant growth-promoting properties including indole acetic acid and siderophore production. The growth enhancement effect of Pseudomonas aeruginosa isolates on chilli showed promising results, and the growth parameters were found to be statistically signi?cant when compared to control. The results demonstrated an eloquent impact on various aspects, namely microbial count and PSB population, phosphatase and dehydrogenase activity, available phosphorous in the soil, plant nutrient uptake, and yield parameters. Inoculation of these two isolates together with the addition of rock phosphate increased comparable amount of available P and these treatments were statistically at par throughout the growth period. The results con?rmed the growth-promoting potential of the isolates to develop as biofertilizers either alone or as components of integrated nutrient management systems.