Comparison of salinity tolerance of three olive cultivars based on growth characteristics and leaf sodium and potassium concentrations
Salt stress is one of the main limiting factors for developing olive growing in many parts of Iran. Therefore, selection of salt tolerant cultivars could be the main strategy to overcome this problem. In this study, salt tolerance of the main Iranian olive cultivar 'Zard' was examined in comparison with the two commercial cultivars 'Koroneiki I18' and 'Arbequina I38', under greenhouse conditions and in nutrient solution pot experiment. Two-year-old plants were transplanted to sand-perlite culture and irrigated with half-strength Hoagland nutrient solution containing NaCl at various concentrations (0.0, 0.5, 50, 100 and 150 mM). Salinity effect was examined for different growth parameters in addition to leaf chlorophyll, Na and K content. Globally, plant growth was significantly affected by the increased concentrations of NaCl and the maximum suppressing effect was found at 150 mM NaCl. The high salt stress was associated to change in stem height, leaf number, stem diameter, chlorophyll value, shoot and root dry weight. The highest level of leaf abscission (60%) was observed in cultivar 'Zard' especially when treated with 150 mM NaCl as compared to controls. Shoot and root dry weights were significantly reduced at 100 mM NaCl in 'Zard' while this effect was obtained at 150 mM NaCl in 'Koroneiki' and 'Arbequina'. With increasing salt stress, leaf cells content of K+ as well as Na+/K+ ratio significantly increased in the three studied cultivars reaching the highest value in 'Zard'. Overall, the Iranian olive cultivar 'Zard' appeared to be less tolerant to salt than the European ones.
Khademi, F., Ghasemnezhad, M. and Salehi, M.M. (2018). Comparison of salinity tolerance of three olive cultivars based on growth characteristics and leaf sodium and potassium concentrations. Acta Hortic. 1190, 151-156
chlorophyll, Olea europaea L., cultivar, sodium chloride, salt tolerance