Effect of Salinity on the physiological responses of selected lines/variety of wheat

Abstract

The effect of different concentrations of salinity (NaCl up to 250 mM) was studied on the germination, dry matter production and some relevant metabolic parameters of two lines (Sakha 69 and Sakha 164) and one variety (Stork) of wheat (Triticum aestivumL.). During the germination and seedling stages the experimental lines tolerated lower and moderate doses of salinity, while the variety was significantly retarded at the lower and moderate levels and completely inhibited at higher doses of salinity. The water content remained more or less unchanged in the two lines under saline conditions, whereas in Stork increasing salinity resulted in a significant decrease in water content. A stimulation of the net photosynthetic rate in both lines, Sakha 69 and Sakha 164, was observed at moderate salinity, but the highest levels proved to be inhibitory. In the Stork variety all salinization levels inhibited photosynthetic activity. The respiration rate in the two tested lines was influenced from salinity levels of 150 mM upwards and increased progressively with the salinity level. In Stork plants increasing salinity levels increased the respiration rate. The soluble sugar and soluble protein contents of the lines increased with increasing salinity. The opposite pattern was revealed in the case of Stork. The amino acid content, including proline, increased significantly with an increase in salinity in all tested plants. the potassium/sodium ratio decreased significantly with a rise in salinization.