毒死蜱对斜生栅藻急、慢性毒性效应的研究

Acute and Chronic Toxicity of Chlorpyrifos to Scenedesmus obliquus

为了解有机磷农药毒死蜱污染对本土水生敏感性物种斜生栅藻的毒性效应,在实验室条件下采用静态毒性实验,研究了毒死蜱对斜生栅藻96 h急性毒性效应,并在急性试验基础上进行慢性试验,分析了不同浓度毒死蜱存在14 d后斜生栅藻叶绿素含量、可溶性蛋白以及丙二醛含量。结果表明,毒死蜱96 h EC50为8.4 mg/L;毒死蜱对斜生栅藻叶绿素a无明显毒性效应;但在前期短时间,低浓度作用下能促进可溶蛋白、MDA含量的上升,但在后期长时间胁迫作用下,总体可溶蛋白、MDA含量呈下降趋势;这说明,可溶蛋白和MDA这两个指标对毒死蜱敏感,可作为生物标志物来指示有机磷农药污染物对水生生物的影响,研究结果可为本土水生敏感性物种的保护和农药安全使用标准的制定提供理论依据。

To understand toxic effects of pollution by organophosphorus pesticide as chlorpyrifos on the local aquatic sensitive species as Scenedesmus obliquus,under laboratory conditions,based on the static toxicity test,the acute toxic effects of chlorpyrifos on Scenedesmus obliquus for 96h were investigated.Based on the acute test,the chronic experiments were also done,in which the contents of chlorophyll a,soluble protein and MDA in Scenedesmus obliquus were analyzed for different concentrations of chlorpyrifos in 14 d.Results showed that the 96 h EC50 of chlorpyrifos was 8.4 mg/L and no obvious toxic effect of chlorpyrifos was observed in chlorophyll a of Scenedesmus obliquus.However in the short time,the contents of solute protein and MDA were increased by low concentration of chlorpyrifos,but under the after effect of stress for a long time,the contents of total soluble protein and MDA could be reduced,which indicated that the two indexes of soluble protein and MDA were sensitive to chlorpyrifos such that they could be used as biological markers for influence of organophosphorus pesticide on aquatic organisms.Results could be considered as theoretical basis for protecting local aquatic sensitive species and establishing the criteria on safety use of pesticide.