外源水杨酸对低温胁迫下圆柏属植物幼苗生理特性的影响

Effect of exogenous salicylic acid on physiological characteristics of Sabina seedlings under low temperature stress

以3年生圆柏和祁连圆柏幼苗为材料,采用不同浓度水杨酸(SA)预处理两种圆柏属植物幼苗,测定-4℃低温胁迫处理第6天叶片相对含水量(RWC)、相对电导率(REC)、丙二醛(MDA)、可溶性糖(SS)、可溶性蛋白(SP)、脯氨酸(Pro)和类胡萝卜素(Car)含量及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸氧化酶(APX)和谷胱甘肽还原酶(GR)活性,分析外源SA对低温胁迫下圆柏属植物叶片膜脂过氧化、渗透调节物质及抗氧化酶系统的影响,为培育较多品种的抗冷冻常绿植物提供理论依据。结果表明:低温胁迫下,一定浓度的SA预处理能有效保护幼苗叶片膜系统的稳定性、增加渗透调节物质含量和提高抗氧化酶活性,其中200mg/L SA预处理对提高圆柏抗寒性效果最好,30mg/L SA预处理对提高祁连圆柏抗寒性效果最好,且在外源SA预处理下,祁连圆柏的抗寒性比圆柏的强。因此,施用适合浓度的SA在提高圆柏属植物抗寒性方面具有较好的应用价值。

The effect of exogenous SA on membrane lipid peroxidation,osmotic regulation substances and antioxidant enzyme activities in the leaves of Sabina species under low temperature stress at -4℃ for 6 d was analyzed by determining the relative water content（RWC）, relative electrical conductivity（REC）, contents of malondialdehyde（MDA）, soluble sugar（SS）,soluble protein（SP）,proline（Pro） and carotenoid（Car）,activities of superoxide dismutase（SOD）, peroxidase（POD） ,catalase（CAT）,ascorbic acid peroxidase（APX） and glutathione reductase（GR） in the leaves of 3 year-old seedlings of S. przewalsleii and S. chinensis pretreated with different concentrations of SA to provide a theo- retical basis {or fostering more anti-freeze evergreen varieties. The results indicated that certain concentrations of SA could maintain the stability of membrane system and increase the contents of osmotic regulators and antioxidant enzyme activities,enhance freezing tolerance of plant,the optimum SA concentration was found to be 200 mg/L for S. przewalskii and 30 mg/L for S. chinensis. The chilling tolerance of S. chinensis was stronger than that of S. przewalskii in the pretreatments with SA. Those results suggested that appropriate concentration of SA could help to increase the chilling resistance of Sabina species.