Assessment of potent Phosphate-Solubilizing Bacteria isolated from Rice Fields in Odisha and Unraveling their Growth-Promoting Efficacies

Abstract

Phosphate-solubilizing bacteria play a vital role in enhancing phosphorus availability for plants by solubilizing inorganic phosphate sources, leading to improved phosphorus, enhanced plant growth, and increased productivity. The investigation focused on evaluating the phosphate solubilizing capabilities of selected bacterial isolates on rice under controlled laboratory conditions. A total of 60 soil samples were collected from different districts in Odisha, India, and six phosphate-solubilizing bacteria (PR, PD, PSB19, PSB5, PK, and PSB16) were screened and isolated. PSB5 exhibited the highest P-solubilizing efficiency in NBRIP culture medium. Seed treatments with the bacterial isolate resulted in significant improvements compared to the control group. The treated rice plants exhibited a notable increase in height, ranging from 16.78 ± 0.17 cm to 26.48 ± 0.31 cm, along with a substantial improvement in fresh weight, ranging from 0.82 ± 0.01 gm to 1.82 ± 0.07 gm, an impressive boost in dry weight, ranging from 0.30 ± 0.01 gm to 0.65 ± 0.02 and vigor index from1428.481 to2583.876. Six bacterial isolates were assessed qualitatively for phosphate solubilization and PGP functions, out of which, four highly efficient organisms were identified. The 16S rRNA sequencing identified PR asKlebsiella pneumoniae, PD asBurkholderiaspecies strain EIKU9, PSB19 asBacillus siamensis, and PSB5 asPseudomonas guariconensis, confirming their efficiency.