Effect of NaCl Concentrations on some Morphological and Physiological Characteristics of Three Salicornia Species under Hydroponic Condition

To compare morphological and physiological responses of three salicornia species to NaCl concentrations, a greenhouse experiment was carried out. The factors consisted of five levels of NaCl concentrations (5, 100, 200, 400 and 600 mML-1) and three Salicornia species (Salicornia persica ، Salicornia perspolitana and Salicornia bigelovii). The results showed that, simple effects of salinity and species on proline, glycinebethein, carbohydrates, chlorophyll a, chlorophyll b, relative water content, osmotic potential in shoots, dry and fresh weights were significant. Interaction effects between salinity and species on proline, glycine betaine, carbohydrates, chlorophyll a, chlorophyll b, osmotic potential in shoots, dry and fresh weight were also significant. Carbohydrates concentration increased by 70-80% at 400 mM and then decreased from 5% to 13% at 600 mM concentration. Increasing salt concentration up to 600 mM, increased proline and glycine betaine contents. Osmotic potential was also increased by 3 to 4 times with increasing salinity levels. The chlorophyll a and chlorophyll b contents decreased at 600 mM. At 200 mM NaCl concentration, wet and dry weights were significantly increased 2 to 3 times as compared control in all of three species while at 600 mM, it was decreased by 60% to 65%. It can be concluded that with increasing salt concentration all three species tolerated higher salt concentrations throught proline and glycine-betaine accumulation and reduction of osmotic potential. S.bigelovii had the highest Na+ accumulation at 600 mM of NaCl and least accumulation of K+, Ca2+ and Mg2+. On the other hand, S.perspolitana at 600 mM NaCl concentration, had the highest accumulation of potassium, calcium and magnesium, and was superior to other species in terms of dry weight yield under salinity.