外源亚精胺对黄瓜幼苗盐胁迫逆境的诱抗作用机理  

The Mechanism of Extraneous Spermidine Inducing Resistance on Cucumber Seedlings Under Salt Stress

作　　者：宋士清[1] 贺字典[1] 郭世荣[2] 尚庆茂[3] 张志刚[3] 

机构地区：[1]河北科技师范学院,河北秦皇岛066600 [2]南京农业大学园艺学院 [3]中国农业科学院蔬菜花卉研究所

出　　处：《河北科技师范学院学报》2006年第3期1-6,共6页Journal of Hebei Normal University of Science & Technology

基　　金：国家科技攻关计划项目(项目编号:2004BA521B01);江苏省自然科学基金项目(项目编号:BK2002110);河北省科技厅计划项目(项目编号:03220169D-2)的部分内容。

摘　　要：为明确外源亚精胺对黄瓜幼苗盐胁迫逆境的诱抗作用机理，采用根部基质注射结合叶面喷施的诱导方法，研究了不同质量浓度（50，100，150，200，250mg·L^-1）外源亚精胺对200mmol·L^-1NaCl胁迫条件下黄瓜幼苗生长及其生理生化特性的影响。结果表明：外源亚精胺各质量浓度处理能够显著降低幼苗盐害指数，最高降低幅度达28．7个百分点，抗盐效果最高达47．5％；显著提高幼苗茎粗、株高、第3真叶长、展开叶数、全株鲜重、全株干重及壮苗指数，壮苗指数最高提高幅度达26．3％；显著增强叶片过氧化物酶、过氧化氢酶活性，但对超氧化物歧化酶活性表现抑制作用；50～150mg·L^-1处理能够显著降低叶片丙二醛含量和电解质渗出率；200-250mg·L^-1处理能够提高叶片游离脯氨酸含量；对可溶性糖含量的作用比较复杂，但在盐胁迫后11d各处理对可溶性糖含量均有显著的提高作用。说明施用适宜质量浓度的外源亚精胺，可以提高黄瓜幼苗的抗盐能力，可以减轻和缓解盐伤害。The purpose of the study is to ascertain the mechanism of extraneous spermidine inducing resistance on cucumber seedlings under salt stress, and the effects of different concentrations of extraneous spermidine on cucumber seeding morphogenesis, physiological and biochemical characters under 200 mmol· L^-1 NaCl stress with root injection and foliar spray. The results showed that exogenous spermidine decreased significantly the salt stress index by 28.7 percent of cucumber seedlings and salt resistance was as high as 47.5 %. Stem diameter, plant height, 3rd leaf length, spreading leave, total dry weight, total fresh weight and seedling index of cucumber seedlings were also significantly enhanced, with the seedling index increased by 26. 3%. Activities of peroxidase and catalase were further increased markedly,while the activity of superoxide dismutase was inhibited. In the study with 50-150 mg · L^-1 extraneous spermidine, it decreased significantly the content of malondialdehyde and the permeation rate of electrolytes; and at the level of 200-250 mg · L^-1 , it also increased the contents of proline. However, the effect of extraneous spermidine on soluble sugar contents was more complex： for example, it could increase the soluble sugar content after 11 days when cucumber seedlings were treated with NaCl. Overall, the study indicated that extraneous spermidine in optimum concentrations could increase salt resistance and mitigate damage degree of salt stress of cucumber seedlings.

关 键 词：黄瓜 盐胁迫 亚精胺 诱抗作用 生理机制 

分 类 号：S642.201[农业科学—蔬菜学]