中文摘要：

目的：研究外源SA对硝酸盐胁迫下辣椒幼苗抗氧化酶活性及渗透调节物质的影响。方法：以‘春秋椒霸’辣椒为材料,采用营养液培养,研究不同浓度外源水杨酸（SA）对140 mmol/L NO-3胁迫下辣椒幼苗抗氧化酶活性及渗透调节物质的影响。结果：140 mmol/L NO_3~-胁迫至7d时,外加0.1~0.3 mmol/L SA可不同程度提高辣椒幼苗超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性,降低脯氨酸（Pro）的积累、丙二醛（MDA）含量以及相对电导率,以SA浓度为0.3 mmol/L时对硝酸盐胁迫的缓解效果最显著,但外加0.4 mmol/L SA的处理除SOD外,POD、CAT活性均呈下降趋势,相对电导率、MDA含量及Pro含量均呈上升趋势。胁迫至14d时,仍以外加0.3 mmol/L SA的整体缓解效果最佳。结论：因此外加适宜浓度SA可提高硝酸盐胁迫下辣椒幼苗抗氧化酶活性,降低膜脂过氧化程度,一定程度上增强辣椒幼苗对硝酸盐胁迫的适应性。

英文摘要：

Objective： It aims to investigate the effects of exogenous salicylic acid on activities of antioxidant enzyme and osmolytes of pepper seedlings under nitrate stress. Method： In this study, pepper seedlings were cultivated in nitrate solution with different concentrations of salicylic acid, the effects of exogenous salicylic acid on activities of antioxidant enzyme and osmolytes of pepper seedlings under nitrate stress were investigated. Results： The results indicated that on the 7^th day under 140 mmol/L NO3^-, the activities of SOD, POD and CAT increased, while the content of MDA and Pro and the membrane relative permeability decreased significantly treated with 0.1 - 0.3 mmol/L SA, and the alleviating effect was the highest when the concentration of SA was 0.3 mmol/L. The activities of enzymes showed a decline trend except SOD, the content of MDA, Pro and membrane relative permeability rising trend when the concentration of SA was 0.4 mmol/L. However, the overall alleviating effect was still optimum when treated with 0.3 mmol/L SA for 14 days. Conclusion： The above results showed that the addition of certain concentration SA could enhance the activity of antioxidant enzymes, reduce the degree of membrane lipid peroxidation and increase the tolerance of pepper seedlings to nitrate stress.