Effect of mycorrhiza fungi on morphological, physiological and biochemical characteristics of four cool Season grass genera under drought stress conditions

In order to evaluate three species of mycorrhizal fungi (Glomus clarum, Glomus fasiculatum and Glomus mosseae) and drought stress (80, 55 and 30 percent of field capacity) on characteristics of grass genera, Lolium perenne, Poa pratensis, Festuca aurandiancea and Agropyron elongatum, a factorial experiment based on randomized complete block design was carried out in the greenhouse using a cylindrical pots. According to the results, Lolium showed the highest root colonization with G. mosseae while Poa showed the lowest colonization with G. clarum. Drought stress reduced the root colonization of Festuca and Lolium in all mycorrhizal treatments, but increased the root colonization of Agropyron and Poa with G. clarum and G. fasiculatum. At highest level of stress, G. fasiculatum and G. mosseae increased the chlorophyll and carotenoid contents of grass genera, more than 38 percent. Grasses symbiotic with G. mosseae showed the highest relative water content and lowest electrolyte leakage and malondialdehyde content compared to grasses symbiotic with other species of mycorrhizae. In general, mycorrhizal fungi could reduce the adverse effects of drought stress on grass characteristics, but the tendency to symbiosis and that’s influence on the grass genera under stress, were different.