摘  要：本实验以芝麻种子为材料，采用水培法，研究了不同浓度（0、0.5、1.0、1.5、2.0mmol/L）水杨酸对（salicylic acid，SA）涝渍胁迫下芝麻幼苗生理特性的影响。通过SA预处理，研究受渍涝胁迫的芝麻幼苗的形态指标（株高，鲜重，干重以及根长）、叶绿素的含量、游离脯氨酸的含量、丙二醛的含量、超氧阴离子的产生速率以及幼苗过氧化物酶（POD）的活性，探讨SA对涝胁迫下芝麻幼苗叶片细胞膜透性和保护酶活性的影响，分析SA缓解芝麻幼苗涝害的机理。结果表明，涝渍胁迫下，芝麻幼苗的株高、鲜重、干重、根长以及叶绿素含量均减少，而丙二醛含量、游离脯氨酸含量、超氧阴离子产生速率以及叶片内POD活性均升高。通过外施一定浓度的水杨酸后芝麻幼苗的株高、鲜重、干重、根长、叶绿素含量、游离脯氨酸含量以及POD活性比对照组的有所增加，叶片内丙二醛含量和超氧阴离子产生速率则降低。由此说明，通过外施水杨酸能够提高芝麻幼苗抗氧化酶系统的活性，降低超氧阴离子、活性氧等对芝麻幼苗的危害，降低膜脂的过氧化程度，文持膜系统的稳定性，缓解涝渍胁迫对芝麻幼苗的伤害，并以1.0、1.5mmol/L外源水杨酸效果最好。9243
关键词：芝麻；涝渍胁迫；水杨酸；生理特性
Effects of Exogenous Salicylic Acid on seedling physiological characteristics of alfalfas seedlings under waterlogging stress
Abstract: This experiment uses alfalfas as materials to study the effects of different concentrations (0, 0.5, 1.0, 1.5, 2.0mmol/L) of salicylic acid on alfalfas seedlings under waterlogging stress by hydroponic culture. It studies morphological index(stem height, fresh weight, dry weight and root length), the chlorophyll content, MDA content , soluble protein content, the superoxide anion production rate and the POD activity of alfalfas seedlings that have been preprocessed with Salicylic Acid under waterlogging stress to discuss the effects of Salicylic Acid on membrane permeability and protective enzyme activity, and the analyze the mechanism of action of salicylic acid in alleviating alfalfas seedling under waterlogging stress. The results showed that under waterlogging stress the plant height, dry weight, fresh weight, root length, chlorophyll content of alfalfas seedlings were decreased than those of control group, but the MDA content, free proline content，peroxide anion production rate and POD activity were increased. Appling certain concentration of salicylic acid could increase the plant height, fresh weight, dry weight, root length, chlorophyll, free proline content, peroxide anion production rate and POD activity, and could reduce the accumulation of MDA. The study implies that it could improve the activity of the antioxidant enzyme system, and reduce the hazards of peroxide anion and reactive oxygen on alfalfas seedlings and the degree of peroxidation of membrane lipids to maintain the stability of the membrane system, which alleviate the damage to alfalfas seedlings caused by the drought stress, and the effect of 1.0, 1.5mmol/L SA were optimal.
Key Words：Alfalfas; waterlogging stress; Exogenous salicylic acid; Physiological property.
目    录
摘要：    1
引言    2
1材料与方法    3
1.1实验材料    3
1.2实验设计    3
1.3测定项目与方法    3
1.4数据统计与分析    3
2结果与分析    3
2.1外源SA对涝渍胁迫下芝麻幼苗鲜重的影响    4
2.2外源SA对涝渍胁迫下芝麻幼苗干重的影响    4
2.3外源SA对涝渍胁迫下芝麻幼苗株高的影响    5
2.4外源SA对涝渍胁迫下芝麻幼苗根长的影响    5 水杨酸对涝渍胁迫下芝麻幼苗生理特性的影响:http://www.751com.cn/shengwu/lunwen_7889.html