Isolation and characterization of phosphate solubilizing bacteria from Western Indian Himalayan soils

Previous studies confirmed the existence of diversified microbial flora in the rhizosphere of Himalayan Red Kidney Bean (RKB) (Phaseolus vulgaris L.). Therefore, fifteen different temperate and subtropical regions of Western Indian Himalaya (WIH) were explored for the isolation of RKB rhizosphere-associated Phosphorus (P) solubilizing bacteria. On the basis of qPCR analysis, three soils, i.e., Munsyari, Kandakhal and Nainital soils were selected for the isolation of P solubilizers. Among 133 isolates, three bacteria viz. Lysinibaccilus macroides ST-30, Pseudomonas palleroniana N-26 and Pseudomonas jessenii MP-1 were selected based on their P solubilization potential. Moreover, in vitro seed germination assay was performed to investigate their effectiveness against four native crops viz. (Cicer arietrinum L.), (Vigna radiata L.), (Pisum sativum L.) and (Zea mays L.). Treated seeds showed significant increase in germination efficiency over their respective controls. The results suggest that Lysinibaccilus macroides ST-30, strain is a potential plant growth-promoting bacterium for chickpea (Cicer arietrinum L.) and, therefore, could be implemented as a low-cost bio-inoculant in hill agriculture system.