红鳞蒲桃苗木生长和生理生化特征对不同盐分和干旱胁迫的响应

以1年生红鳞蒲桃盆栽苗木为研究对象，设置不同盐胁迫浓度及干旱程度，研究盐旱交互作用对红鳞蒲桃苗木的高、地径生长和各项生理指标的影响。结果表明：干旱和盐胁迫都抑制了红鳞蒲桃的生长，盐胁迫的影响要大于干旱胁迫，高生长受到的限制大于地径生长，2 g/kg盐分浓度在水分充足条件下促进了地径生长。相对电导率和丙二醛含量均随着干旱和盐胁迫的增强而增大。不同盐分浓度下，干旱胁迫对相对电导率的影响趋势一致，不同盐分胁迫的影响差异不显著。高盐浓度下丙二醛含量的增加显著大于低盐浓度，表明盐胁迫对红鳞蒲桃的伤害更大；红鳞蒲桃的渗透调节物质在干旱和盐交互胁迫下有一定程度的提高。水分充足时，盐分浓度的变化没有对红鳞蒲桃的游离脯氨酸含量产生影响。随着胁迫的增加，渗透调节能力显著提高。低盐浓度下，抗氧化酶活性在水分充足时没有受到显著影响，高盐浓度下，随着干旱胁迫的加剧则显著提高。

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.