Evaluating synergistic effects of arbuscular mycorrhizal fungi on symbiotic nitrogen fixation in lentil plant under water stress conditions

Biological nitrogen fixation would be affected severely by water stress. In recent years, beneficial microorganisms were evaluated as one of the practical methods to reduce the effects of drought stress and increase agricultural production. To investigate the synergistic effects of mycorrhizal fungi on symbiotic nitrogen fixation in lentil plant under water stress conditions, a completely randomized factorial design was conducted in green house condition. The first factor had four levels of water stress (0/2, 0/4, 0/6 and 0/8 field capacity). The second factor had four microorganism types (Rhizophagus intraradices, Funneliformis mosseae, their combination and negative control). The results showed that in water stress treatments, the number of root nodules, root and shoot dry weight, chlorophyll fluorescence, root colonization percentage, total nitrogen content decreased significantly. When plants inoculated by mycorrhizal fungi, shoot N content and shoot and root dry weight of inoculated were significantly different compared to non-mycorrhizal plants. Nodule number, shoot nitrogen content, shoot and root dry weight, chlorophyll fluorescence, and root colonization percentage were increased by inoculation of mycorrhizal fungi.