Screening Salt Tolerance in Pistachio Seedlings by Evaluating Growth, Oxidative Damages and Mineral Composition

Salinization of the central lands of Iran has had limited pistachio cultivation and production during the recent decade. In this study, seedlings of Pistacia vera ‘Akbari’ and ‘Ghazvini’, and an interspecific hybrid of P. vera ‘Ghazvini’ × P. atlantica (G × A)were subjected to different NaCl concentrations (0, 50, 100 and 150 mM) in half strength Hoagland’s solution for 90 days. Salt stress significantly reduced growth of the plants. The highest and the lowest root volumes were observed in ‘Akbari’ and G×A respectively. The leaf area of ‘Akbari’ seedlings was significantly higher than the other genotypes under salt stress. Moreover, salt stress significantly reduced total chlorophylls, membrane stability index, the ratio of chlorophyll: carotenoid and greenness of the leaves. In comparison to the control, the lowest values of the mentioned parameters were observed under 150 mM NaCl stress. By increasing NaCl concentration in the growing medium, concentration of Na+ significantly increased in shoot and root and significant decrease in K+ and Ca2+ concentration was observed in the shoot and root. Accordingly, Na+: K+ and Na+:Ca2+ ratios in the root and shoot were increased. The lowest Na+: K+ and Na+:Ca2+ ratioswere found in G×A. According to the capability of preserving vigor, and the lowest leaf abscission and oxidative damages under salt stress, pistachio ‘Akbari’ was introduced as the most salt tolerant genotype among the studied genotypes.