Saline tolerant plant growth promoting diazotrophs from rhizosphere of bermuda grass and their effect on rice

Abstract

In this study, beneficial effects of multifaceted growth promoting isolates for rice were investigated under two different salt concentrations in pot culture conditions. Two most salt tolerant isolates (TRY2) Serratia sp. and Bacillus sp. (TRY4) were selected and their growth promoting characters were studied under slight and moderate NaCl concentration. Isolates Serratia sp. and Bacillus sp. were able to fix the nitrogen and solubilise phosphate, synthesise IAA, acc deaminase regardless of NaCl concentration in most cases, under conditions of salinity. In pot experiments, plant growth (plant height, dry weight, and chlorophyll content) was promoted by bacterial inoculation with 2.9 and 5.8 g NaCl/kg soil. In this study, uptake nutrients (N+, P+, and K+) were increased regardless of NaCl concentration with inoculation of Serratia sp. and Bacillus sp. and uptake of Na+ was reduced with treatments receiving 5.8 NaCl/kg soil with Serratia sp. and Bacillus sp. isolates used as inoculants as compared to control. The present observations showed that strains Serratia sp. and Bacillus sp. partially alleviated the saline stress in rice, likely through the integration of several mechanisms that improve the plant response.