Morphological and biochemical characterization of Azospirillum isolates from rhizoplane of foxtail millet [Setaria italica (L.) Beauv.]

Abstract

Azospirillum represents the best characterized genus of plant growth promoting rhizobacteria. Forty different strains of Azospirillum spp. were isolated from the different rhizoplane samples of foxtail millet grown in forty different locations in Raichur and Koppal districts of Northern Karnataka and were studied for their morphological and biochemical characters. Out of 40 isolates, 17 isolates were positive for biotin requirement, glucose utilization and acid production tests. 21 isolates were negative for denitrification test and all forty isolates were positive for nitrate reduction test. Out of forty isolates, twenty three isolates were identified as A. brasilense and remaining seventeen as A. lipoferum.