برهمکنش بین قارچ‌‌های میکوریز آربوسکولار و نماتُد ریشه گرهی پسته در شرایط گلخانه

Root-knot nematodes are one of the most important pathogens of pistachio that cause a reduction in yield and the useful life of pistachio trees. On the other hand, the presence of arbuscular mycorrhizal fungi in the roots can improve the absorption of water and nutrients, enhance plant growth and reduce the damage caused by plant diseases. In the present study, the effect of inoculation with Funneliformis mosseae and Rhizophagus irregularis was evaluated on the root-knot nematode Meloidogyne incognita (Mi) and the growth of two pistachio rootstocks (Pistacia atlantica and P. vera cv. Badami Zarand) under greenhouse conditions. Three-month-old seedlings of pistachio were inoculated with a mixture of propagules of two species of arbuscular mycorrhizal fungi (30 propagules per gram of each species) and two months later, 2000 juveniles (J2) of M. incognita per plant were inoculated on the pistachio seedlings roots. The results showed that inoculation of arbuscular mycorrhizal fungi (AMF) on the roots of Badami Zarand and Atlantica rootstocks increased shoot dry weight (18.1 and 26.9%, respectively), root fresh weight (8.7 and 12%), leaf area (4 and 5%), plant height (2.8 and 2.7%), total chlorophyll (19 and 32%) and soluble sugars concentration (16 and 20%), as well as the concentration of mineral elements compared to the control. In contrast, inoculation with M. incognita (Mi) reduced the above criteria which the reduction was higher in Badami Zarand compared to Atlantica. In the combination of arbuscular mycorrhizal fungi and M. incognita treatments (AMF+Mi), all traits increased compared to the nematode treatment (Mi). In the absence of the pathogen, the percentage of AMF-colonized roots in Badami Zarand and Atlantica rootstocks was 67 and 78%, respectively, and after inoculation with M. incognita, it decreased to 54 and 73%, but the difference was not significant. Therefore, nematode inoculation had no effect on the AMF root colonization percentage. In the AMF+Mi treatment, the number of galls (49 and 39) and egg masses (30 and 18) per gram of roots of Badami Zarand and Atlantica were reduced and showed a significant difference compared to the nematode treatment (Mi). In total, the results of this research showed that root colonization of pistachio seedlings with a mixture of arbuscular mycorrhizal fungi can improve the growth and nutritional characteristics of pistachio seedlings and reduce the disease severity of M. incognita.