除草剂莠去津对斜生栅藻种群的毒性效应

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。

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

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 EC50 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 of S.obliquus were damaged,when that was above 0.07 mg/L,the growth of S.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.