中文摘要：

利用以水葫芦为代表的水生植物进行水体生态治理,具有环保、生态和可持续发展的优点.然而,在外源和内源污染尚未完全控制的情况下,夏季蓝藻水华仍然会频繁暴发.系统研究水生植物对藻华聚集后形成的逆境环境下的生理适应机制可为减轻藻华聚集的不良影响、充分发挥水生植物的水体净化功能发挥重要作用.以水葫芦为代表,采用模拟实验,研究在高温阶段（水温〉25℃）、水华聚集下对水葫芦关键酶活性的影响及其环境效应,以揭示蓝藻水华聚集后引起的浅水生态系统中水生植物消亡的深层机理.结果表明,藻华聚集会很快消耗掉水生植物根区内的溶解氧,水体呈现缺氧状态（溶解氧〈0.2 mg/L）;植物根区内氧化还原电位值出现明显下降,实验进行1 d后低于-100 m V,实验结束时达-199.9 m V,水体呈现强还原环境.植物叶片中丙二醛（MDA）、超氧化物歧化酶（SOD）、过氧化物酶（POD）含量呈现快速增加的变化趋势,至实验结束时添加120 g/L的处理组中其含量分别为2.17μmol/g（FW）、266.497 U/g、1988.60 U/（g·min）,而叶片中过氧化氢酶（CAT）呈现快速下降的趋势,至实验结束时其含量为6.09 U/（g·min）;根系中MDA、POD至实验结束时其含量分别为0.57μmol/g（FW）、525.161 U/（g·min）,呈现快速下降的趋势;SOD、CAT含量在实验结束时高达221.71 U/g、35.10 U/（g·min）,表现为快速增加的趋势.水葫芦关键抗氧化酶活性的变化,表明藻华长期聚集、腐解带来的水体缺氧等不良条件对植物产生了环境胁迫作用,较长时间影响（〉5 d）下对植物产生了严重的伤害作用;同时也表明藻华严重聚集及藻细胞腐解产生的环境胁迫是漂浮植物水葫芦无法生长乃至死亡的主要影响因素.因此,在利用水生植物进行水体净化的工程实践中,要避免蓝藻的严重堆积,以减轻藻华暴发对植物的不利影响和充分

英文摘要：

Using the floating plants water hyacinth（ Eichharnia crassipes） to purify the polluted water has possessed the advantages of environmental protection,ecological and sustainable development. However,the algae blooms are frequently occurred in the summer and caused the massive nutrients（ mainly phosphorus and nitrogen） accumulation,which often becomes the pollutionsources of water body. It is vital of systematic studying the physiological adaptation mechanism to the adverse environment formed by the algae blooms gathered,and is helpful to reduce the adverse effects of algal bloom,in order to give full play the purification effects of aquatic plants. In this simulation,the change of key enzymatic activity of floating plant water hyacinth was studied as the algae cells gathered at higher temperature（ water temperature 〉25℃）. The environmental effects on the water hyacinth after algae cells gathered were studied at the same time,which are helpful to reveal the deep mechanism of floating plants in shallow-water ecosystem caused the algae cells dead. The results showed that the dissolved oxygen in water in the root-zone of plant consumed quickly and became anxious in 2 h after algae cells gathered. The ORP decreased to lower- 100 mV in 1st day. It reduced to- 199. 9 mV and the water became the strong oxygen-reducing environment from the 2nd day to the end of the experiment. Concentrations of MDA,SOD,POD in leaf increased quickly after algae cells gathered,and the concentrations of the enzyme concentration of experiment treatment 2 in plant leaf rose to 2. 17 μmol / g（ FW）,266. 497 U / g,1988. 60 U /（ g·min） at the end,respectively. However,the concentration of CAT in leaf reduced quickly during the experiment,and its content reduced to 6. 09 U /（ g·min）. Also the concentration of MDA and POD in the root of the water hyacinth declined rapidly and its content reduced to0. 57 μmol / g（ FW） and 525. 161 U /（ g·min）,respectively. But the content of SOD and CAT in root increased to 221