Growth and Physio-biochemical Responses of Syzygium hancei Seedlings to Varying Drought and Salt Conditions

The experiments were conducted by using potted one-year-old Syzygium Hancei seedlings. Different salt stress concentrations and drought degrees were set up to study the effects of salt-drought interaction on the growth of height and ground diameter, and several important physiological traits of S. hancei seedlings.The results showed that: the growth of seedlings were inhibited by drought and salt stress, and the impacts of salt stress more than drought stress. Height growths were more limited than that of ground diameter. The ground diameter was facilitated in the treatment of 2 g/kg salt concentration under sufficient water supply. The relative conductivity and content of malondialdehyde were increased along with the intensification of drought and salt stress. The relative conductivity was same variation tendency under drought stress, while no significant differences under different salt stresses. The content of malondialdehyde in high salt concentration was remarkable higher than that in lower salt concentration, it means that S. hancei seedlings were injured severely under salt stress. The contents of free proline were no obviously differences between salt stresses when the water supply was sufficient. As the stresses intensifying, the osmotic adjustment adaptability was significantly increased. Under lower salt concentration, the antioxidant enzymes activities were no significantly affected in sufficient water supply. Nevertheless, the activity of antioxidant enzymes sharply increased with the drought stress strengthening upon the higher salt concentration.