Mohsen Seilsepour; Ahmad Golchin; Mahmoud Reza Roozban
Abstract
A greenhouse experiment was carried out to evaluate the effects of salinity stress on growth and macroelements contents of two olive varieties in soilless culture medium. In the research, one-year old saplings of two olive varieties, ‘Zard’ and ‘Mission’, were subjected to different ...
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A greenhouse experiment was carried out to evaluate the effects of salinity stress on growth and macroelements contents of two olive varieties in soilless culture medium. In the research, one-year old saplings of two olive varieties, ‘Zard’ and ‘Mission’, were subjected to different salinity levels induced by NaCl including 0, 4, 8, 12 and 16 dS/m-1 for 5 months. Based on the results, total dry weights of the varieties were decreased at 16 dSm-1 compared to control up to 63 and 85% at ‘Mission’ and ‘Zard’, respectively. Also, a 25% reduction in total dry weight was observed under salinities of 7 and 3.6 dSm-1 for ‘Mission’ and ‘Zard’, respectively. Salinity was decreased the concentrations of macronutrients and increased the concentrations of Na and Cl in roots and leveas of the both varieties. Compared to control, Na and Cl concentrations in leaves and roots was increased under salinity of 16 dS/m-1 at 1660 and 679% for Na and 1069 and 506% for Cl. In all salinity levels, Na and Cl concentrations in the leaves and roots of 'Zard' variety were more than that of 'Mission'. Thesa data demonstrated that ‘Mission’ has a more salinity tolerance than ‘Zard’, and could be used as a salt-tolerant variety for cultivation under salinity conditions. The defence mechanisms of ‘Mission’ are restricting in absorbtion and translocation of Na to aerial parts and accumulate a proper concentration of K in Leaves.
Mohsen Seilsepour; Ahmad Golchin; Mohammad Reza Rouzban
Abstract
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 ...
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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.
Mehdi Rezaei; Abass Rohani
Abstract
Stomatal resistance has an important role in plant water exchange and photosynthesis under stress condition hence it is a key parameter in ecological and biological models. In the present research, optimum values of effective parameters on stomatal resistance of olive to achieve maximum stomatal resistance ...
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Stomatal resistance has an important role in plant water exchange and photosynthesis under stress condition hence it is a key parameter in ecological and biological models. In the present research, optimum values of effective parameters on stomatal resistance of olive to achieve maximum stomatal resistance were determined. Salinity levels (0, 25, 50 and 100 mg/l NaCl), percentage of leaf ions (chlorine, sodium, potassium, calcium, phosphor, magnesium), K/Na ratio, wet weight of leaf (mg), leaf area (cm2), relative water content (%) and leaf area ratio (cm2/g) were considered as effective parameters in stomatal resistance of olive. The stomatal resistance was modeled as a function of the variables using a radial basis function (RBF) neural-network model. The predicted results demonstrated that the neural network could provide a good performance since prediction results were in rather good agreement with measured results. The maximum percentage error between predicted and experimental data was less than 2.57% and the correlation coefficient between them was 0.994. Also, the statistical comparison between the predicted and experimental data indicates the reliability of the predictions using a RBF neural-network model. The trained neural network is used as objective function to get optimal parameters using the genetic algorithm. The optimum values of the parameters obtained at a 100, 0.15, 0.57, 0.78, 0.32, 0.06, 0.17, 1.29, 26.63, 5.03, 0.76 and 72.89 for the first parameter through the last parameter, respectively.