Effect of coinoculation with endomycorrhiza, Pseudomonas aeroginosa and Rhizobium meliloti on Medicago sativa under water stress

Abstract Plants are frequently and naturally exposed by different of biotic and abiotic stresses including drought have negative effects on plant growth and yield. Symbiosis with mycorrhizal fungi is the broadest plant strategy for acclimation to environmental stresses. Hence in present study interaction of endomycorrhizal fungus and Pseudomonas aeroginosa, as Mycorrhizal fungi with Rhizobium meliloti in completely randomized blocks under three levels of irrigation and three replications wave examined. Spores of native endomycorrhizal fungus symbiont with medicago from Bagherabad region in Kerman are propagated by Zea mays and then used with mycorrhizal spores, Pseudomonas and Rhizobium separately and together in pots for three months under 3 different levels of irrigation, 70, 50, 20 persentage of field capacity. Results showed reduction of protein content but proline and reducing sugars concentration increased significantly under water stress. Changes in total nitrogen concentration were not significant. Inoculation with endomycorrhiza and bacteria significantly enhanced protein, proline, reducing sugars and nitrogen concentration under stress and without stress in comparison to control. In addition to, endomycorrhiza and bacteria had synergistic effect so that in many cases coinculation were more effective in relation to single inoculation. On the basis of these results, coinoculation with endomycorrhizal fungus, Pseudomonas aeroginosa and Rhizobium meliloti is suggested for increasing medicago tolerant to water stress.