Responses of lettuce (Lactuca sativa L. var. longifolia) grown in a closed hydroponic system to NaCl- or CaCl2-salinity

摘要: Lettuce plants (Lactuca saliva L. var. longifolia) grown in a closed hydroponic system using perlite as substrate were exposed to similar levels of NaCI- and CaCl 2 -salinity an attempt distinguish between osmotic salt-specific effects on plant growth quality. A standard nutrient solution for lettuce (control) was compared with two salinity each level imposed by adding either NaCI or the solution. The mean electrical conductivity root zone, indicated values measured drainage solution, 2.5, 3.7, 3.5, 5.6 5.4 dS m - 1 control, low NaCl-, -, high treatment, respectively. increase NaCl-salinity zone restricted shoot lettuce. In contrast, had no significant effect above-ground plants. not affected any treatment. leaf.Cl concentration increased all treatments but resulted significantly higher Cl leaf at concentrations zone. Mg decreased most marked suppression observed highest level. K without differences source. chlorophyll ascorbic acid treatments. It concluded that are primarily Na-specific.