The Effect of Mycorrhiza and Nutrients on Some Pistachio Seed characters in Interaction with Phytophtora drescleri

Pistachio is one of the most important export crops of Iran. One of the diseases that damages pistachio trees in most pistachio growing areas is Gumosis disease caused by Phytophthora drescleri. Mycorrhizal fungi are the most successful microorganisms in the field of biological control and one of the effective agents to reduce the root rot diseases incidence caused by P. drescleri. Nutrients are also able to increase the level of tolerance or resistance of plants against to some diseases. In this study, mycorrhizal fungi and various nutrients were used to control the root rot disease. In this study, ammonium sulfate, potassium sulfate and triple superphosphate compounds were used against the root rot disease in vitro. The results showed that the highest amount of growth inhibition of pathogen was related to 2500 ppm concentration of ammonium sulfate with 67.16%. In the second section of the study, the effect of different treatments including mycorrhiza and ammonium sulfate alone and their combination in the reducing P. drescleri disease on characters such as fresh and dry root and shoots and shoots. The levels of phosphorus, nitrogen and potassium were evaluated. Finally, the expression levels of the two peroxidase and catalase genes was measured. The results showed that the combination of fungal mycorrhiza and ammonium sulfate always had the highest dry and fresh weight of shoots and roots among the treatments applied in both cultivars in the absence of pathogen.