Evaluation of growth responses of two olive cultivars under salinity stress

A greengouse experiment was conducted to evaluation of salinity stress on growth parameters of two olive cultivars during 2013-2014 at Agricultural and Natural Resources Research Center of Tehran. In the experiment, effects of five levels of irrigation water salinity including 0, 4, 8, 12 and 16 dS.m-1 were evaluated on ʻZardʼ and ʻMissionʼ olive cultivars under soilless culture. Data showed that salinity had significant effects on all growth parameters in both olive cultivars. Leaf dry weight, shoot and root dry weight, leaf chlorophyll index, shoot and root tolerance index, shoot and internodes length, leaf area, leaf number and leaf relative water content were affected by salinity and significantly decreased. These reductions were more in ʻZardʼ comparing to ʻMissionʼ. Shoot dry weight, leaf dry weight and root dry weight were decreased 80, 80 and 69 percent, respectively at 16 dS.m-1 salinity treatments with compare to control. Leaf sodium (Na) concentration and rate of sodium to potassium (K) in leaf were increased and leaf potassium concentration was decreased by salinity. Increase of Na and decrease of K were more in ʻZardʼ comparing to ʻMissionʼ. Also, leaf and shoot dry weight were affected by concentration of Na, K and Na: K in leaf and there were a significant correlation among these parameters with leaf and shoot dry weight. Results indicated that ʻMissionʼ variety were more salt tolerance than ʻZardʼ.