Enhancement Nitrogen Fixation via Inducing Recombinants in Azospirillum

2 Abstract: This study aimed to induce recombinants between Azospirillum and Azotobacter inoculants. Azotobacter strains used as donors, however, Azospirillum strains were used as recipients, as well as, the reverse mating were done to induce recombinants from each microbe. Three Azospirillum strains and four Azotobactor strains were used in this study. The resulted isolates were evaluated for IAA production. The results revealed that eight transconjugants from four matings between Azotobacter as a donor and Azospirillum as a recipient produced significant values of IAA over the better parent. The mentioned transconjugants were selected to be applied in pots and field experiments at the absence and presence of 2,4-D. Some of transconjugants appeared significantly increase in some parameters over both the better parents and plants fertilized with the recommended dose. On the other hand, many transconjugants significantly increased some parameters over the better parent in response to the interaction between the addition of 2,4-D and biofertilizers. Although some transconjugants resulted from the reverse mating between Azospirillum as a donor and Azotobacter as a recipient produced significant amounts of IAA over the better parent This study indicated that Azospirillum was better recipient than Azotobacter.