高温胁迫下水杨酸对东北对开蕨幼苗耐热性的影响1）

为探讨高温胁迫下不同浓度水杨酸对东北对开蕨耐热性的影响，以2年生的东北对开蕨幼苗为试验材料，用浓度分别为0（ CK）、0．5（ T1）、1．0mmol · L－1（ T2）的水杨酸溶液进行叶面喷施。3 d后置于40℃高温下培养4d。研究不同浓度水杨酸对高温胁迫下东北对开蕨幼苗的可溶性糖质量分数、叶片的相对电导率、游离脯氨酸（ Pro）质量分数、超氧化物歧化酶（ SOD）活性及丙二醛（ MDA）质量摩尔浓度生理指标的影响。结果表明：高温胁迫下水杨酸可以降低东北对开蕨幼苗叶片相对电导率及丙二醛质量摩尔浓度，显著提高SOD活性及可溶性糖质量分数，提高游离脯氨酸质量分数，从而增强该植物耐热性；当处理浓度为0～1．0 mmol· L－1时，水杨酸浓度越高，上述效果越明显。

Effects of Salicylic Acid on the Heat Tolerance of Phyllitis japonica Seedlings under High Temperature Stress

We discussed the effects of different concentrations of salicylic acid on the heat tolerance of Phyllitis japonica seed-lings under high temperature stress with two-year old P.japonicaseedlings, and sprayed 0 (CK), 0.5 (T1), 1.0 mmol· L-1( T2) salicylic acid solution on the leaves of P.japonica seedlings.Three days later, the seedlings were put under the heat stress of 40℃to cultivate for four days.We studied the effects of different concentrations of salicylic acid on soluble sugar content, relative electrolytic leakage of leaves, free proline content, superoxide dismutase ( SOD) activity and ma-londialdehyde ( MDA) content in P.japonica seedlings leaves under temperature stress.The salicylic acid reduced relative conductivity and MDA contents, and increase SOD activity and soluble sugar content remarkably, enhanced free proline content and raise the heat tolerance of P.japonica.Besides, when the concentration of the salicylic acid varied in 0-1.0 mmol· L-1 , the higher concentration of salicylic acid was, the more obvious effect was.