Inoculations of plant roots with arbuscular mycorrhizae can reduce Verticillium wilt severity. In present research, the effect of inoculation of Verticillium dahliae (Vd) and three species of arbuscular mycorrhizae (AM), Funneliformis mosseae, Rhizophagus irregularis and Claroideoglomus tunicate were studied on the activity of catalase, peroxidase, superoxide dismutase and phenylalanine ammonia-lyase in the root of Ahmad Aghaei and Badami Zarand pistachio rootstocks. The roots of the pistachio seedlings were inoculated with 100 propagules per gram of three species arbuscular mycorrhizae and two months later, Verticillium dahliae was inoculated. Measurement of enzyme activity was done after V. dahliae inoculation at 11 different times. The experiment was conducted as a factorial in a completely randomized design with 5 replications. The results showed that in Vd treatment, the specific activity of enzymes in Ahmad Aghaei decreased after an increasing period in days 8 to 12 after vd inoculation, then decreased less than AM inoculations, but in Badami Zarand, the activity of enzymes increased in a (days 8-16) and after that, despite the decreasing trend, it was still higher than AM treatment. In AM+Vd treatment, enzyme activity increased faster in both pistachio rootstocks compared to other treatments. In Badami Zarand, the time of the enzymes, peak activity was longer than in Ahmad Aghaei rootstocks. In general, the results of the present research indicated that increasing antioxidant enzyme activity can reduce the severity of Verticillium wilt in pistachio seedlings. تفاصيل المقالة