Evaluation of Leaf Physiomorphological Responses of Three Pistachio Rootstocks inoculated with Arbuscular Mycorrhizae to Salt Stress

An experiment was conducted to study the effect of different salinity levels of irrigation water on leaf morphological changes, electrolytes leakage and pigments content in the presence of arbuscular mycorrhizal fungi. The experiment was a completely randomized design and a factorial combination of two mycorrhizal treatments (with and without mycorrhiza), four salinity levels of irrigation water (0.5, 5, 10 and 15 dS m-1) and three rootstocks (Sarakhs, Abareqi and Bane-Baqi). In this experiment, 150-days-old pistachio seedlings were exposed to different salinity levels for 75 days. Leaf indices in general and leaf area in specific were reduced as the effect of salt stress levels. Leaf abscission was increased with increase in salt stress severity. Chlorophyll concentration and electrolytes leakage were affected by salt stress in all rootstocks as it reduced chlorophyll content and increased electrolytes leakage. The results showed that colonization of pistachio seedling with mycorrhiza improved leaf indices (leaf number, dry weight, area, abscission and leaf area ratio) under salt stress in comparison with non-mycorrhizal seedlings. Chlorophyll contant of mycorrhizal seedlings were also higer than respected control. Mycorrhizal application reduced leaf electrolytes leakage over control. There were significant differences between rootstocks in case of mentioned parameters and Bane-Baqi and Sarakhs were superior over Abareqi (in case of leaf area, leaf area ratio, leaf abscission, specific leaf area and specific leaf weight) in response to salt stress.