外源水杨酸(SA)对盐胁迫下黄连种子萌发及幼苗生理特性的影响

Effect of Exogenous Salicylic Acid on Seed Germination and Physiological Characteristics of Coptis chinensis Franch. Seedlings under NaCl Stress

[目的]通过对黄连种子萌发及幼苗生理特性的研究,寻找提高黄连种子及幼苗在盐胁迫条件下抗性能力的途径。[方法]用100mmol/L的Na Cl模拟盐胁迫,在外源水杨酸(SA)处理后,对黄连种子的发芽势(Gv)、发芽率(Gr)、发芽指数(Gi)、活力指数(Vi),以及黄连幼苗叶片细胞质膜透性、O2-·产生速率、H2O2含量、可溶性糖、可溶性蛋白、游离脯氨酸及丙二醛(MDA)含量、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性进行测定。[结果]Na Cl胁迫下的黄连种子萌发受到显著抑制,但在经过不同浓度的SA处理后,各萌发指标均有升高。试验结果表明,外源SA处理显著提高了黄连种子发芽势、发芽率、萌发指数和活力指数,明显提高了盐胁迫下黄连幼苗叶片可溶性糖、可溶性蛋白和脯氨酸含量,不同程度地提高了叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性,显著降低了叶片丙二醛(MDA)含量、质膜透性、O2-·产生速率及H2O2含量。[结论]外源SA通过提高黄连种子的萌发指数,提高渗透调节物质含量及抗氧化酶活性,降低细胞质膜氧化程度,有效地减缓Na Cl胁迫对黄连种子及幼苗产生的伤害,提高了种子及幼苗的抗盐能力。

[ Objective ] In order to get the method of improving the salt resistance of seeds and seedlings for Coptis chinensis Franch. underNaCI stress, seed germination and physiological characteristics of C. chinensis seedlings were studied. [ Method] Several physiological indexesof C. chinensis seeds and seedlings treated by exogenous salicylic acid under NaC1 stress like the germination vigor, germination rate, germina-tion index and vigor index were measured. And other indexes like the memberane permeability, H202 content, production rate of 02 - , thecontents of soluble surge, soluble protein, free proline, and malondialdehyde （ MDA ）, the activities of superoxide （ SOD ）, peroxidase（POD）, catalase （CAT） , and ascorbate peroxidase （APX） were also measured. The germination indexes of C. chinensis seeds under NaC1stress have an obvious inhibition. But after the treatment of salicylic acid, every germination indexes were all increased. [ Result] The resultshowed that the treatment of exogenous salicylic acid obviously improved the germination vigor, germination rate, germination index and vigorindex, increased the content of soluble sugars, free proline, and soluble protein, decreased the content of malondialdehyde （MDA）, H202contcnt, production rate of 02 - ~ Meanwhile, the results also indicated that salicylic acid improve the activities of superoxide （SOD）, peroxi-dase （POD）, catalase （CAT）, and ascorbate peroxidase （APX）. [ Conclusion] Exogenous salicylic acid with appropriate concentrationcould significantly alleviate the damages to the seeds and seedlings of C. chinensls under NaC1 stress and promote the salt resistance of theseeds and seedlings through improve the germination indexes and antioxidase activities, decrease the memberane permeability and so on.