Isolation and characterization of local Azospirillum and yeast strains to be used for wheat grains inoculation to improve plant growth and yield under field cultivation

Abstract

Four Azospirillum strains and three yeast isolates were isolated from rhizosphere soil of wheat plants grown on Soil of the Experimental Farm of Soil and Water Department, Assiut University, Egypt. There were studied the characteristic of both Azospirillum and yeast to be used as a biofertilizers in inoculation of wheat grains under field condition to study the response of growth and yield to inoculation. For Azospirillum, the isolation was on Nitrogen free bromothymol (Nfb) semisolid medium, their morphology (light microscope, scanning electron microscope), cultural characteristics to verity their identity to those reported on Bergey's Manual of Determinative Bacteriology (1994), and N2fixing capacities, which were ranged from 13.8:42.5 mg N2-fixed/g malic acid. For yeast, the isolation was on Malt Extract Peptone Glucose (MEPG) medium, their morphology, cultural characteristics and acid production were determined, as well as the promotive stimulating effects of Azospirillum and yeast on grain germination and early seedling growth of wheat.