Cd、Pb单一及其复合胁迫对凤眼莲生长及生理生化的影响
时间:2018-09-17 21:14 来源:毕业论文 作者:毕业论文 点击:次
| 摘要：以凤眼莲为材料，采用水培方法，研究了不同浓度重金属铅（Pb）、镉（Cd）单一及复合胁迫对凤眼莲生理生化指标的影响。结果表明：单一胁迫处理下，低浓度Pb2+（150mg/L）处理凤眼莲时其光合色素、可溶性蛋白、可溶性糖、MDA含量无显著变化（P>0.05），POD、CAT活性出现最大值；随着浓度的提高，凤眼莲光合色素、可溶性蛋白、可溶性糖含量持续减少，MDA含量持续升高；凤眼莲酶活性机制受到不同程度抑制，SOD持续上升，浓度为200mg/L时，SOD活性达到最大，POD、CAT开始下降。Cd2+胁迫下，光合色素、可溶性蛋白、可溶性糖含量随浓度的提高而降低，呈明显的剂量—效应关系，MDA含量显著增加，抗氧化酶活性均随着Cd2+浓度呈先上升后下降的趋势，Cd2+浓度40 mg /L时，POD、CAT活性达到最大，浓度60mg/L时，SOD活性达到最大。Cd2+对凤眼莲的影响较Pb2+大，凤眼莲对Cd2+污染的抵御能力较差。高浓度的重金属胁迫时，SOD起主要的保护作用，POD、CAT保护作用相对降低。Cd2+、Pb 2+复合胁迫较单一胁迫对凤眼莲的影响大，二者表现为协同作用。28332 毕业论文关键字：Pb2+；Cd2+；复合胁迫；凤眼莲；生长；生理生化 Effects of Cd and Pb and Their Combination on Growth and Physiological and Biochemical Characteristics of Crassipes Abstract: Using Crassipes as the material,using hydroponic method,we studied the effects of different concentrations of Cd and Pb and Their Combination on Growth and Physiological and Biochemical Characteristics of crassipes. The results showed as follow：Under the single processing and low concentration of Pb2+(150 mg/L) , photosynthetic pigment soluble protein,soluble sugar and MDA content had no significant change (P>0.05), with activities of POD and CAT achieving the maximum ; With the increase of concentration, the contents of photosynthetic pigments, soluble protein and soluble sugar continued to reduce and the content of MDA continued to increase. The activities of enzyme were inhibited by different degrees: The activity of SOD continued to rise;When the concentration was 200mg/L, the activity of SOD achieved the maximum and the activities of POD and CAT started to decrease.Under the stress of Cd2+, the contents of photosynthetic pigments, soluble protein and soluble sugar decreased with the increase of the concentration;It is a significant dose - effect relationship. The content of MDA increased significantly;The activities of antioxidant enzymes rised first and fell soon with the increasing of Cd2+;When the concentration of Cd2+ was 40mg/L,activities of POD and CAT achieved to the maximum,SOD achieving to the most as the concentration of Cd2+ was 60mg/L. Cd2+ had more impact than Pb2+. Crassipes had less ability to defend the pollution of Cd2+.When high concentrations of heavy metal coerced,SOD acted as the main role of protection and the protection of POD and CAT fell relatively The combined effects of Cd2+ and Pb2+ on the plant were greater than their single,and the synergy effects of Cd2+ and Pb2+ were observed. Key Words：Pb2+；Cd2+；combined stress；Eichhornia crassipes；growth；physiological and biochemical characteristics 目 录 摘 要： 1 Abstract 1 引言 2 1 材料与方法 3 1.1 实验材料 3 1.2 处理方法 3 1.3 测定项目与方法 3 1.4 数据分析 3 2 结果与分析 4 2.1 Cd、Pb 单一及复合胁迫对凤眼莲光和色素的影响 4 2.2 Cd、Pb单一及其复合胁迫对凤眼莲可溶性糖含量的影响 4 2.3 Cd、Pb单一及其复合胁迫对凤眼莲可溶性蛋白含量的影响 5 (责任编辑：qin) |