Ameliorative effect of CaCl2 on growth, membrane permeability and nutrient uptake in Atriplex halimus subsp. schweinfurthii grown at high (NaCl) salinity

A hydoponic culture was carried out with Atriplex halimus subsp. schweinfurthii to investigate the effects of supplementary calcium chloride on plants grown at high NaCl concentration (400 mM). Treatments were: (1) Control: nutrient solution alone (C); (2) nutrient solution plus 400 mM sodium chloride (NaCl); (3) nutrient solution plus 20 mM calcium chloride (CaCl2⁎); (4) nutrient solution plus 40 mM calcium chloride (CaCl2⁎⁎); (5) nutrient solution and 400 mM NaCl plus supplementary 20 mM CaCl2 (NaCl +CaCl2⁎); and (6) 400 mM NaCl plus additional mixture of 40 mM CaCl2 in nutrient solution (NaCl + CaCl2⁎⁎). The plants grown under salt stress produced low dry weight and relative water content than those grown in standard nutrient solution and in CaCl2 alone. Supplemental calcium chloride added to nutrient solution containing salt significantly improved growth and relative water content. Membrane permeability increased with high NaCl application and these increases in root membrane permeability were decreased with supplementary Ca. The concentration of chloride (Cl) increased highly for all treatments. Sodium (Na) concentration in plant tissues increased in both shoots and roots at high NaCl treatment. Application of supplementary Ca lowered Na concentration. Concentrations of Ca, K and N were at deficient ranges in the plants grown at high NaCl levels and these deficiencies were corrected by supplementary Ca. The ameliorating effect of Ca on growth and physiological variables could reduce the negative effect of salinity on A. halimus plants.