除草剂莠去津对斜生栅藻种群的毒性效应

Toxicity Effects of Herbicide Atrazine on the Population Growth of Scenedesmus obliquus

[目的]评价除草剂莠去津对水生生态系统的影响。[方法]以斜生栅藻种群增长为指标,研究了莠去津的不同质量浓度(0、0.01、0.03、0.05、0.07、0.09mg/L对斜生栅藻的毒性效应。[结果]莠去津对斜生栅藻表现出较强的毒性效应,其24、48、72和96h的EC50分别为0.0406,0.0300,0.0221和0.0211mg/L。斜生栅藻种群增长受抑制的程度与莠去津的质量浓度呈正相关,显示明显的浓度-剂量相关性。当莠去津浓度高于0.03mg/L时,斜生栅藻的藻体细胞受到损害;当莠去津质量浓度超过0.07mg/L时,斜生栅藻的生长几乎受到完全抑制;当莠去津浓度为0.09mg/L时,24h后藻细胞密度表现为负增长。[结论]莠去津对斜生栅藻的毒性效应比较明显,斜生栅藻种群增长受抑制的程度随莠去津质量浓度的增加而增强。

[Objective] The purpose was to evaluate the effect of herbicide atrazine on aquatic ecosystem. [Method] With the increment of atrazine population as index, the toxicity effects of atrazine under different mass concn. （0, 0.01, 0.03, 0.05, 0.07, 0.09 mg/L） on the population growth of S. obliquus were studied. [Result] Atrazinea showed stronger toxicity effects on S. obliquus, with the ECso value for 24, 48, 72 and 96 h being 0.040 6, 0.030 0, 0.022 1, 0.021 1 mg/L resp. The repressive degree of the population growth of S. obliquus was positively related to the mass concn, of atrazine, displaying the obvious correlation of cencn.-dosage. When the mass concn, of atrazine was above 0.03 mg/L, the cells ofS. obliquus were damaged, when that was above 0.07 mg/L, the growth ofS. obliquus was almost completely inhibited and when that was higher than 0.09 mg/L the cell density of S. obliquus was negatively increased. [Conclusion] The toxicity effects of atrazinea on S. obliquus was more obvious and the repressive degree of the population growth of S. obliquus became stronger along with the increment of atrazine mass concn.