Physiological response of Lycium ruthenicum seedling to exogenous betaine under salt stress

Lycium ruthenicum seedlings were treated with 0.5, 1.0 and 2.0 mmolL-1 betaine by root irrigation under 300 mmolL-1 NaCl stress to study physiological responses of L.ruthenicum to exogenous betaine under salt stress. Changes of main physiological indices of the seedlings were analyzed after 7 and 14 days of the treatments. The results showed that total chlorophyll, membrane permeability, malondialdehyde (MDA), proline and soluble sugar contents of L.ruthenicum leaves markedly increased in comparison with the control under salt stress condition. In the case of equal salt stress, MDA content and the damage rate of membrane permeability of the seedlings treated with betaine reduced markedly; while contents of chlorophyll, proline and soluble sugar increased significantly. Betaine had effective effects on inhibition of MDA generation and on alleviating damage of cell membrane, and also increased contents of total chlorophyll, proline and soluble sugar after root irrigation on L. ruthenicum seedlings. Applying the optimum concentration of betaine under salt stress can improve salt resistance of L.ruthencium seedlings and increase adaptabilities of salt stress condition.