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题名	水盐胁迫对几种豆科植物种子萌发过程的影响
作者	李媛
学位类别	硕士
答辩日期	2008
授予单位	中国科学院．新疆生态与地理研究所
导师	尹林克，新疆生态与地理研究所
关键词	豆科植物
其他题名	Effect of water and salt stress on the seed germination progress of leguminous plants
中文摘要	以塔里木河下游荒漠河岸林中几种优势植物铃铛刺(Halimodendron halodendron)、疏叶骆驼刺(Alhagi sparsifolia)和胀果甘草(Glycyrrhiza inflata)种子作为研究对象，在不同浓度的NaC1溶液和不同浓度PEG-6000溶液条件下，研究了种子在萌发过程中游离脯氨酸（Pro）、丙二醛（MDA）和代谢酶（SOD、POD）活性的动态响应，在生理生化水平上讨论和比较了这3种植物的种子在萌发过程中对胁迫生境的适应机制。主要结论：（1）3种豆科植物种子发芽率在0.3 -0.7mol/L范围内，随着NaC1溶液浓度的增大而下降，种子发芽过程受到抑制。铃铛刺和胀果甘草种子在0.5 mol/L时不能萌发，而骆驼刺种子在0.7 mol/L时，仍然有49.33%的发芽率。当NaC1溶液浓度高于0.4 mol/L时，这三种植物发芽率变化差异极显著。在本研究中，三种豆科植物种子在萌发过程中对盐的耐受力从强到弱依次为：骆驼刺>铃铛刺>胀果甘草。（2）骆驼刺、胀果甘草和铃铛刺种子萌发5d后幼苗和种子的抗氧化酶（SOD和POD）活性、丙二醛和游离脯氨酸含量随着NaCl浓度的增加表现出相似的变化趋势：在NaCl浓度低于0.2 mol/L左右时随着NaCl浓度的升高而增加，在浓度高于这一浓度时，随着NaCl浓度的升高而下降的变化趋势。表明植物通过维持较高的SOD活性和游离脯氨酸含量来缓解一定的盐害效应，以适应盐胁迫的生长环境的抗逆性。但不同的植物种之间存在着一定的差异，铃铛刺的MDA含量和骆驼刺POD活性随盐浓度的升高，呈下降趋势。（3）骆驼刺和甘草种子的萌发率随PEG-6000溶液浓度的增大而下降，当水势为-1.2 MPa时，骆驼刺和甘草的萌发率分别为87.33%和56.67%，差异显著，表明骆驼刺在种子萌发阶段的抗旱性高于甘草。（4）不同浓度PEG-6000处理下，骆驼刺和甘草种子萌发5d后幼苗和种子的抗氧化酶（SOD和POD）活性、丙二醛和游离脯氨酸含量随着干旱胁迫程度的加深变化趋势相似。虽然由于不同植物抗旱能力不尽相同，两种植物的4个生理指标变化幅度存在一定差异，但均表现出在水势大于-0.2 MPa左右时，随着胁迫程度的升高而增加，在水势低于这一水势时，随着胁迫程度的升高而下降的变化趋势，表明疏叶骆驼刺和胀果甘草幼苗均通过维持较高的SOD、POD活性和游离脯氨酸含量来缓解一定的胁迫程度，以适应干旱胁迫的生长环境的抗逆性。The seeds of three dominant plants Halimodendron halodendron, Alhagi sparsifolia and Glycyrrhiza inflata of desert riparian forest were used as the research objectives. Under different concentrations of NaCl solution and PEG-6000 solution, the dynamic responses of free-proline, malondialdehyde (MDA) and activity of metabolic enzymes (SOD and POD) were studied in the process of seed germination. Adaptive mechanisms of the three plants during the process of seed germination were discussed and compared physiologically and biochemically. The main conclusions: (1) With the increasing of the concentration of NaCl solution, germination rates of the three leguminous plants’ seeds declined, meanwhile, the seed germination was inhibited. Under the concentration of NaCl solution of 0.5mol/L, the seeds of Halimodendron halodendron and Glycyrrhiza inflate couldn’t germinate at all, while the seed of Glycyrrhiza inflate had a germination rate of 49.33% under the concentration of 0.7mol/L. When the concentration of NaCl solution was higher than 0.4mol/L, the germination rates of the three plants were different significantly. Among the three leguminous plants, the seed of Alhagi sparsifolia had the strongest tolerance ability to salt during the process of seed germination, Halimodendron halodendron was the second and the seed of Glycyrrhiza inflate was the least. (2) Under the disposal of different concentrations of NaCl solution, after 5 days seeds germination of Halimodendron halodendron, Alhagi sparsifolia and Glycyrrhiza inflate, their seedlings’ and seeds’ activity of antioxidant enzyme (SOD and POD) and the contents of MDA and free-proline largely presented similar tendency with the aggravation of salt stress. When the concentration of NaCl solution was lower than 0.2mol/L, the three indexes increased with the increment of the concentration of NaCl solution. While, when the concentration of NaCl solution was higher than 0.2mol/L, the three indexes declined with the increasing of the concentration of NaCl solution. These indicated that plants could relieve the salt effect to some extent through maintaining high activity of SOD and high content of free-proline. In this way, plants could adapt to salt stress. But, there were differences among different plants. The content of MDA of Halimodendron halodendron and the activity of POD of Alhagi sparsifolia presented descending tendency with the increasing of salt concentration. (3) With the concentration of PEG-6000 solution increasing, the seed germination rates of Alhagi sparsifolia and Glycyrrhiza inflate declined. When the moisture potential was at -1.2MPa, the germination rates of Alhagi sparsifolia and Glycyrrhiza inflate were 87.33% and 56.67% respectively, and had a significant difference. This indicated that the drought-resistance of Alhagi sparsifolia was higher than that of the Glycyrrhiza inflate’. (4) Under the disposal of different concentrations of PEG-6000 solution, after 5 days seeds germination of Alhagi sparsifolia and Glycyrrhiza inflate, their seedlings’ and seeds’ activity of antioxidant enzyme (SOD and POD) and the contents of MDA and free-proline largely presented similar tendency with the aggravation of drought stress. Although different plants had different the drought resistance abilities, and 4 physiological indexes of the two plant species had differences to some extent. However, when water potential was higher than -0.2MPa, the 4 physiological indexes increased with the increment of drought stress. While, when the water potential was lower than -0.2MPa, the 4 physiological indexes declined with the drought stress increasing. These indicated that Alhagi sparsifolia and Glycyrrhiza inflate could relieve the drought stress to some extent through maintaining high activity of SOD and SOD and high content of free-proline. In this way, Alhagi sparsifolia and Glycyrrhiza inflate could adapt to drought resistance ability.
语种	中文
学科主题	植物生理学
公开日期	2010-11-12
页码	共63页
内容类型	学位论文
源URL	[http://ir.xjlas.org/handle/365004/8008]
专题	新疆生态与地理研究所_中国科学院新疆生态与地理研究所(2010年以前数据)
推荐引用方式 GB/T 7714	李媛. 水盐胁迫对几种豆科植物种子萌发过程的影响[D]. 中国科学院．新疆生态与地理研究所. 2008.

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