Evaluation of Salinity Tolerance in Three Olea europaea L. Cultivars

A greenhouse experiment was conducted with a factorial arrangement based on a randomized complete block design with five replications to investigate salinity tolerance in three olive cultivars (Zard, Arbequina I-18, and Koroneiki I-38). In this study, two years old rooted cuttings of these cultivars were treated with four levels of salinity (0, 50, 100, and 150 mM NaCl). Olive cultivars showed different responses in terms of morphological and physiological salinity levels. Visually, Zard and Koroneiki I-38 were sustainable and tolerant cultivars of salinity, respectively. In proportion to increases in salinity levels, in all studied cultivars increased accumulation of Na, Na/K, and Zn, decreased N, P, K, Ca, Mg, Fe, chlorophyll, carotenoid, total soluble proteins, increased activity of superoxide dismutase and peroxidase and thereby decreased plant growth parameters such as tolerance index of leaf number and tolerance index of stem length. Among the studied cultivars, Koroneiki I-38 could tolerate salinity stress better than Arbequina I-18 and Zard, by a decrease in Na transfer to leaves, accumulation of N, P, and K in leaves, increase in photosynthetic pigments, activity of enzymatic antioxidants, total soluble proteins and the growth parameters and Zard cultivar had the least salinity tolerant vice versa.