Isolation and characterization of PGPR and their effect on growth, yield and nutrient content in wheat (Triticum aestivum L.)

The aims of our study were to enhance growth, yield and micronutrient status of wheat crop by various combinations of microbial strains (Bacillus megaterium,Arthrobacter chlorophenolicus and Enterobacter sp.) under pot and field experiments. Microbial strains were isolated from soils of different cropping systems and characterized by biochemical and molecular methods. Microbial strains (B. megaterium BHU1 and A. chlorophenolicus BHU3) showed positive result for nitrogen fixation and phosphate solubilization, while Enterobacter sp. BHU5 gave positive result in nitrogen fixation only. However, A. chlorophenolicus and Enterobacter sp. showed HCN production while B. megaterium and Enterobacter sp. gave siderophore. Maximum N2-fixation and IAA production were observed with 15.0 mg N g−1 carbon by A. chlorophenolicus and 26.4 µg ml−1 at tryptophan 100 µg ml−1 by Enterobacter sp, respectively. Triple combination of strains B. megaterium,A. chlorophenolicus and Enterobacter significantly increased 17.5%, 79.8%, 78.6% and 26.7% plant height, grain yield, straw yield and test weight under pot condition and also 29.4%, 27.5%, 29.5% and 17.6% under field condition, respectively. Similarly these treatment combinations showed maximum nutrient acquisition and content of micronutrient viz. Fe, Cu, Mn and Zn in grain of wheat under both conditions. The results showed that the combined application of indigenous PGPR, B. megaterium,A. chlorophenolicus and Enterobacter can be used as efficient microbial consortium for wheat production.