RESUMO
This study assessed potential of plant growth promoting rhizobacteria (PGPR) found in 34 soil samples collected from Sirmaur, Himachal Pradesh. Out of 238 rhizobacterial isolates, 48 rhizobacterial isolates exhibited multiple PGP (plant growth promoting) traits. Out of the 48 isolates, nine isolates exhibiting most promising PGP traits were evaluated. CSRS12 isolate showed maximum solubilization of phosphate and potassium up to 530.71 and 30.44 mg l-1, respectively. Maximum zinc solubilizing efficiency (ZSE) was also observed in case of isolate CSRS12. The maximum IAA production was observed by isolate PPRS17 with 37.34 mg l-1 followed by PCRS24 with 34.44 mg l-1 after 120 h. Maximum siderophore unit production was observed upto 92.29% by isolate CSRS12 followed by 65.54% with isolate TA1PS. The selected PGPR isolates were identified through 16S rDNA sequencing. The identified PGPRs were Burkholderia arboris (isolate CSRS12), Pseudomonas aeruginosa (isolate PPRS17) and Acinetobacter baumannii (isolate TA1PS). B. arboris CSRS12 isolate showed multiple PGP traits as mineral solubilization of phosphate, potassium and zinc, production of siderophore and ammonia. Among all three PGPR treatment, B. arboris CSRS12 isolate showed significant increment in lateral root number, root and shoot length, fresh and dry weight of root and shoot of mung bean (Vigna radiata) in pot experiments. The results showed that CSRS12 isolate could be used for exploitation as bio-inoculant, which can facilitate better productivity and ecological dynamics for both domesticated crops as well as wild varieties.
