外源SA对盐胁迫下黄瓜幼苗的生理效应

 为了明确外源水杨酸(Salicylic acid,SA)提高蔬菜作物抗盐的生理生化机制,以黄瓜(Cucumis sativus L.)为材料,在200 mmol·L^-1NaCl胁迫条件下,采用根部注射结合叶面喷施的方法,研究了不同浓度外源SA对幼苗形态建成及其生理生化特性的影响。结果表明:外源SA能够显著提高幼苗的茎粗、全株干质量及含水量,显著降低盐害指数、丙二醛(MDA)含量和电解质渗出率,显著提高游离脯氨酸(Pro)和可溶性糖含量,显著增强超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)等植物细胞保护酶的活性,SA最佳处理浓度为150 mg·L^-1。说明适宜浓度的外源SA作为化学诱抗剂,可以诱导黄瓜幼苗的抗盐能力,减轻和缓解盐伤害。

Physiological Effects of Exogenous Salicylic Acid on Cucumber Seedlings under the Salt Stress

To ascertain physiological and biochemical mechanisms of exogenous salicylic acid improving salt resistance of vegetable,cucumber(Cucumis sativus L.) was used to study effects of different concentrations exogenous salicylic acid on its morphogenesis,physiological and biochemical characteristic under 200 mmol·L^-1 NaCl stress with root injection and foliar spray.The results showed that exogenous salicylic acid significantly improved stem diameter,total dry mass and dry mass water content of cucumber seedlings, decreased the salt stress index, content of malondialdehyde (MDA) and permeation rate of electrolyte, increased contents of p roline ( Pro) , soluble sugar and activities of p rotected enzymes such as superoxide dismutase ( SOD) , peroxidase ( POD) and catalase (CAT) , also showed the op timum treatment concentration being 150 mg·L ^{- 1}. It is p roposed that exogenous salicylic acid as chemical activator could induce salt resistance, salt tolerance and decrease alleviate damage degree of salt stress of cucumber seedlings.