【作者】 舒阳；

【导师】 刘振乾；

【作者基本信息】 暨南大学 ， 环境科学， 2006， 硕士

【摘要】 近年来由于有害赤潮的频繁发生，给人类带来了严重的危害，赤潮的治理研究也成为关注的焦点。利用水生植物体内的天然抑藻物质来治理赤潮是一种很有发展前景的方法。论文主要研究了水生植物凤眼莲浸出液对三种赤潮藻东海原甲藻、球形棕囊藻、锥状斯氏藻的抑制效应，比较了活体凤眼莲浸出液、干体凤眼莲浸出液和高温处理的活体凤眼莲浸出液对上述三种赤潮藻的抑制效应。研究表明，在实验所设置的浓度范围内（0.5-100g/L），活体凤眼莲浸出液和干体凤眼莲（80℃干燥48h）浸出液对三种赤潮藻都有很好的抑制作用，并且随着凤眼莲浸出液浓度的升高，其对各赤潮藻生长的抑制作用逐渐加强。研究得出活体凤眼莲浸出液对东海原甲藻、球形棕囊藻、锥状斯氏藻生长的96h的半致死浓度(LC₅₀)分别为0.93g/L、4.90g／L、9.80g/L；干体凤眼莲浸出液对东海原甲藻、球形棕囊藻、锥状斯氏藻生长的48h的致死浓度(LC₁₀₀)分别为20g/L、30g/L、100g／L。在浸出液浓度一定时，活体凤眼莲浸出液和干体凤眼莲浸出液对三种赤潮藻的抑制率存在一定的差别，但差别幅度都在15％之内，说明了在浓度一定时干体凤眼莲的浸出液仍然有很强的抑藻作用，为利用干体凤眼莲提供了一定的理论依据。在温度121℃条件下处理20min后的活体凤眼莲浸出液的抑制率对不同的赤潮藻有不同的改变，对东海原甲藻（浸出液浓度为2g／L）和锥状斯氏藻（浸出液浓度为10g/L）的抑制率下降，对球形棕囊藻（浸出液浓度为4g/L）的抑制率增强，表明高温使浸出液中化感物质的活性改变。研究表明，凤眼莲对三种赤潮藻的抑制效应是普遍存在的，凤眼莲植物体中存在能够杀灭赤潮藻的化学物质。由于藻种间的差异和化感物质的复杂性，不同的藻对凤眼莲浸出液中化感物质的响应不同。因此有必要对其组成和结构做进一步的研究，为开发抑藻剂提供一定的参考。更多还原

【Abstract】 In recent decades, harmful algal blooms （HABs） occur frequently in marine coastal waters worldwide. This has caused disastrous damages to economic and public health. Many studies have begun to concentrate on the control of undesired algal growth, and allelochemical compounds of aquatic macrophytes may be potential candidates for the control of HABs. The present study deals with inhibitory effects of extracts of Eichhornia crassipes on three harmful algae Prorocentrum donghaiense, Phaeocystis globosa and Scrippsiella trochoidea. Inhibitory effects of extracts of fresh tissue and dry powder of E. crassipes and extracts of fresh tissue after autoclaved for 20 minutes at121℃ on the growth of microalgae were studied in this essay. The results showed that the growth of all three microalgae species was strongly inhibited by fresh tissue and by dry powder of extracts of E. crassipes at exposure concentrations（0.5-100g/L）. The growth inhibition increased with the concentration of the extracts. It was found that LC50 of fresh tissue of E. crassipes to P. donghaiense, P. globosa and S. trochoidea were 0.93g/L, 4.90g/L and 9.80g/L at 96h of the experiment respectively and LC₁₀₀ of dry power of E. crassipes to P. donghaiense, P. globosa and S. trochoidea were 20g/L,30g/L and 100g/L at 48h of the experiment respectively. There was some difference in the growth inhibition of the extracts of fresh tissue and dry powder of E.crassipes to microalgae, but the difference was not beyond 15%. It suggested that dry powder of E. crassipes also contain allelochemicals. After the extracts of fresh tissue of E. crassipes were autoclaved for 20 minutes at 121℃, the inhibitory effects of the extracts to P.donghaiense（at 2g/L） and S. trochoidea（at 10g/L） were obviously reduced and that increased to P. globosa（at 4g/L）. The study have confirmed the inhibitory effects of extracts of E.crassipes on three harmful algae. Different microalgae showed different responses to the effects of the allelochemicals.更多还原