Indole-3Acetic Acid Production by Plant Growth Promoting Rhizobacteria of Saline Soil, Odisha and its Role in Root Elongation in Rice Plant

Abstract

In the present study five PGPR were isolated from Casuarina rhizosphere, coastal Odisha, India and were identified as B. acidiceler, Sphingomonas paucimobilis, Kocuria kristinae, B. subtilis and B. megaterium by 16SrDNA sequencing. The production of IAA by five PGPR ranges from 1.34 µg/ml to 2.509 µg/ml in absence of tryptophan whereas 3.103 µg/ml to 7.929 µg/ml in presence of tryptophan by using Salkowski’s reagent. The optimum activity of five PGPR was recorded at 2 mg/ml of tryptophan concentration. The optimum temperature and pH for IAA production by five PGPR were recorded at 30oC and 7.0. Partial purification of tryptophan was also done by TLC with Rf value 0.9. It is also found that the five PGPR have potential in the elongation of root length of rice plant grown in saline soil.