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. پرونده مقاله

Aspergillus flavus and aflatoxin on pistachio are the most important hazards to human health, which start in the orchard and will continue to the storage. This research selected 16 most effective yeast strains through dual culture (DC) assay according to the interaction between 376 yeast strains and A. flavus isolate P1684 in an initial screening. The antifungal ability of the strains was determined to be 94.5%, 72.08 %, and 91.31% in DC, volatile organic compounds (VOCs), and extracellular secretions (ESs) assays, respectively. In DC and VOCs assays, the YE 43-6 yeast strain showed maximum inhibition of growth, whereas powder and liquid formulation of the YE 43-10 yeast strain showed better performance. Ammonia vapor assay revealed that yeast strains significantly reduced aflatoxin production in A. flavus. Under in-situ conditions, trees were sprayed with cell/spore populations of both effective yeasts and A. flavus to determine the ability of yeast strains to compete with the pathogen. After 45 days, the fruits were harvested, and the average number of colonies per pistachio fruit unit (CFU/Nut) was determined. The highest and lowest reduction of populations were observed in YE 43-10 (85.71%) and YE 36-9 (35.18%), respectively. In both YE 43-6 and YE 43-10 strains, powder formulation was slightly more effective than liquid, and VOCs effectively prevented pistachio contamination with A. flavus and aflatoxin. پرونده مقاله