NaCl与干旱双重胁迫下黑果枸杞幼苗对外源水杨酸的生理响应

干旱、盐分已成为限制植物生长发育的主要因子，在干旱与NaCl双重胁迫下植物的生长发育受到一定影响。为了探究黑果枸杞（Lycium ruthenicum）对盐旱逆境的适应性，该文采用盆栽试验，研究NaCl与干旱胁迫共同作用对其幼苗生长的影响，并观察盐旱逆境下黑果枸杞幼苗对外源水杨酸（SA）的生理响应，探究提高NaCl与干旱胁迫下黑果枸杞幼苗的存活率。结果表明：外源SA(0.1、0.5 mmol·L^-1)处理下，盐旱双重胁迫下黑果枸杞叶内可溶性糖、可溶性蛋白和脯氨酸含量有所增加，而丙二醛（MDA）含量显著降低（P<0.05）,过氧化氢酶（CAT）、过氧化物酶（POD）和超氧化物歧化酶（SOD）活性上升，且0.5 mmol·L^-1 SA处理效果优于0.1 mmol·L^-1 处理。综上结果可知，黑果枸杞对于轻度盐旱胁迫具有一定的适应能力，适宜浓度SA可提高盐旱逆境中黑果枸杞叶内渗透调节物质含量及抗氧化酶活性，该研究为进一步了解盐旱双重胁迫下黑果枸杞幼苗的生长发育提供相关理论依据。

Physiological responses of Lycium ruthenicum seedlings on exogenous salicylic acid under salt-drought mixed stress

Under drought and NaCl mixed stresses, the plant growth and development are affected significantly. In this study, to reveal the adaptability of Lycium ruthenicum to salt-drought mixed stress, we used pot culture test method to study the effects of salt and simulated drought interaction experiments on seedling growth, and observe the physiological responses by spraying different concentrations of salicylic acid(SA)that improve the survival rate of L. ruthenicum seedlings under salt-drought stress. The results showed that the contents of soluble sugar, soluble protein and proline of L. ruthenicum leaves were significantly increased from control treated with exogenous SA under salt-drought mixed stress, the malondialdehyede(MDA)content decreased(P<0.05), whereas the activities of catalase(CAT), peroxidase(POD), and superoxide(SOD)increased, among all concentrations, 0.5 mmol·L^-1 SA treatment had better effect than 0.1 mmol·L^-1 SA. To sum up, L. ruthenicum has a certain ability to adapt mild salt-drought stress, and moderate concentrations of SA can improve the osmotic regulatory substances and antioxidant enzymes activities in the leaves under salt-drought environment. The study results can provide the theoretical bases for deeply understanding the growing of L. ruthenicum under different stresses.