Vol. 11, Issue 12 (2022)

Author(s):
Rajeshwari M Channappagoudar, NK Biradarpatil, PU Krishnaraj, Ashok Sajjan and MSL Rao

Abstract:
Bacterial endophytes are the microorganisms residing inside the plant tissues and have been known enhance the plant growth. However little is known about the plant growth promoting activities of sorghum endophytes. Therefore, the aim of this study was to elevate the in vitro bacterial mechanisms related to the plant growth promotion and their tolerance for polyethylene glycol (PEG) and sodium chloride (NaCl) in culture media. Total 55 bacterial strains were studied for both stress tolerance under varying concentration of PEG and NaCl. Out of them, five bacterial strains (AUST 3, AUST 20, AUST 29 AUST 44 and AUST55) were found tolerate to stress (25% PEG 8000 and 115 NaCl) and further used for biochemical characterization of IAA, Pi-solubilization and ACC-deaminase activities along with reference isolate P. fluorescens. The strain AUST 3 had highest IAA activity (15.25 μg ml^-1 broth), the highest phosphate solubilization potential was shown by the reference isolate P. fluorescens (14.73 ppm) followed by AUST 3 (14.50 ppm) and all five potent endophytes have shown positive result for ACC deaminase activity.