氯氰菊酯对海洋卡盾藻的毒性效应

Toxic Effects of Cypermethrin on Chattonella marina

为了解拟除虫菊酯农药对海洋生态系统以及海洋初级生产力的影响,研究了氯氰菊酯对重要赤潮藻类海洋卡盾藻(Chattonella marina)的生长及生化指标的影响.结果表明,低浓度(≤10μg·L-1)的氯氰菊酯对海洋卡盾藻生长具有明显的促进作用,而高于50μg·L-1则产生较明显的抑制效应,但暴露后期会出现一定的超补偿效应.藻细胞内叶绿素a(Chl.a)、可溶性糖和可溶性蛋白含量及超氧化物歧化酶(SOD)活性在暴露初期变化较剧烈,24h或48h后趋于平稳.随着培养(暴露)时间的延长,低浓度暴露组以上指标均呈现先促进后恢复趋势,而高浓度暴露组则呈现先抑制后恢复趋势,丙二醛(MDA)含量随培养(暴露)时间的延长呈先促进后恢复趋势且随氯氰菊酯浓度升高而明显升高.在实验设计浓度下,氯氰菊酯对SOD活性和MDA含量的最低作用剂量为10μg·L-1,而对其他生长和生化指标的最低抑制浓度为50μg·L-1,SOD和MDA可作为监测环境中氯氰菊酯污染的敏感指标.

In order to understand the influence of pyrothoid pesticides on primary production of marine ecosystem, effects of cypermethrin on the growth and biochemical parameters of Chattonella marina were studied. Results showed that cypermethrin obviously accelerated the growth of Chattonella marina at concentration below 10μg ·L^-1, and inhibited the growth significantly over 50μg·L^-1 However over-compensation growth occurred in the late exposure period under high cypermethrin concentrations. The cellular contents of Chl. a, soluble sugar and soluble protein and superoxide disrantase （SOD）activity fluctuated greatly in the early exposure period, and tended to be stability after 24-48 hours exposure. These parameters were all induced at lower exposure concentrations, and were inhibited at high exposure concentrations within the initial 24 hours. Malonyldialdehyde （MDA） content increased significantly with the increasing of cypermethrin concentrations. With the proposed concentrations, the lowest effective concentration of cypermethrin to SOD activity and MDA content was 10μg ·L^-1, while was 50μg ·L^-1 for other growth and biochemical parameters. Therefore, SOD activity and MDA content were more sensitive parameters and were suggested to be the sensitive indexes for monitoring cypermethrin pollution in the environmental conditions.