Influence of arbuscular mycorrhizal fungi symbiosis with different pistachio rootstocks in salinity stress condition

This study was designed to investigate the effect of Mycorrhiza symbiosis on some orphophysiological characteristics of four different pistachio rootstocks under salinity stress. This research was conducted in a completely randomized design with factorial arrangement with three factors. The factors were included rootstocks at four levels (Badami-e Riz Zarand, Qazvini, Sarakhs, and UCB1), mycorrhiza at two levels (inoculated and non-inoculated plants) and irrigation water salinity at four levels (0.91, 7.57, 16.12 and 24.63 dS/m). Sampling done of 6-month-old plants that they were under salinity stress conditions for 60 days. Then morphophysiological indices such as leaf number, height, relative water content (RWC), water use efficiency (WUE), chlorophyll and carotenoid, hydrogen peroxide (H2O2), malondialdehyde (MAD), sucrose and protein content were measured. The results showed that the leaves number of all rootstocks and height of all rootstocks except Sarakhs decreased and leaf abscission percentage increased. The RWC, WUE, a, b and total chlorophyll and leaf and root protein content in mycorrhizal plants were higher than non-mycorrhizal plants. As well as, leaf H2O2 and root MAD concentration on inoculated plants were lower than non-inoculated plants. The lowest content of a, b and total chlorophyll, RWC and WUE and the highest content of leaf and root H2O2 and leaf MAD were founded in Sarakhs rootstock, and there was no significant difference between Badami-e Riz zarand and UCB1 rootstocks in terms of total chlorophyll, leaf and root H2O2 and leaf MAD. Salinity stress decreased total chlorophyll, RWC and leaf and root protein and increased H2O2, MAD and sucrose in leaves and roots. Generally, in the present study, mycorrhiza improved rootstocks tolerance under salinity stress. The Sarakhs rootstock was more salinity-sensitive than other rootstocks and the Badami-e Riz zarand and UCB1 rootstock had almost the same response to salinity stress.