Role of Mycorrhyzal Symbiosis on Growth and Nutrients Uptake of  Qazvini Pistachio Seedlings under Cadmium Stress

In this research, the interactive effect of cadmium and mycorrhzal symbiosis was studied on growth, nutrients uptake and mycorrhizal colonization percentage in ‘Qazvini’ pistachio seedlings. The experiment was carried out based on completely randomized design as factorial with two factors of mycorrhiza at two levels (with or without mycorrhiza) and cadmium (0, 0.5, 1, 2, 4 and 6 mg l-1). Cadmium caused a reduction in vegetative parameters and increase in leaf abscission percentage. Nutrients uptake was also affected by cadmium where root P, Mg, Fe and Mn reduced. Stem Ca and Zn were increased primarily and then decreased. Leaf Zn, Stem and leaf Mn and root, stem and leaf Cd were increased. Moreover, mycorrhizal colonization of pistachio seedlings improved vegetative parameters under cadmium stress in comparison with non-mycorrhizal seedlings. Cd uptake and translocation was significantly higher in non-mycorrhizal seedlins in comparison with mycorrhizal ones. Mycorrhizal colonization percentage was increased with increasing cadmium levels. In conclusion, mycorrhizal symbiosis with ‘Qazvini’ pistachio seedlings in the presence of Cd, improved nutrients uptake like Mg, Fe and P and reduced Cd uptake and as a result, it reduced the toxicity effects of Cd on plants and maintained their growth.