Selection and evaluation of Azospirillum brasilense strains growing at a sub-optimum temperature in rhizocoenosis with wheat

Fourteen Azospirillum brasilense strains growing at a sub-optimum temperatu re were selected based on their ability to grow and carry out plant growth promoting activities at 22 degreesC. The strains were tested for their resp onse to inoculation in wheat (two popular cultivars, HD2285 and WH547, unde r sterile conditions) crop using sterile and nonsterile rooting medium, Sig nificant increase in plant growth parameters was observed the overall respo nse to inoculation was better in cultivar HD2285 Based on their performance under sterile conditions, 4 strains were selected and compared under nonst erile conditions with strain sensitive to a sub-optimum temperature in pots using wheat variety HD2285. The strains capable of growing at the sub-opti mum temperature can colonize the wheat endorhizosphere efficiently and impr ove the plant growth and yield as compared to sensitive strain, a 25-27 % i ncrease in grain yield was found on inoculating two selected strains compar ed to NO3 control.