三唑酮对大型溞21天慢性毒性效应

三唑类杀菌剂是一种在农业上广泛应用的广谱性杀菌剂。三唑类杀菌剂在农田施用后能够向土壤深处迁移和扩散,从而污染土壤和地下水体,因此三唑类杀菌剂对土壤生态环境能够造成一定的破坏。选择三唑酮为研究对象,参照经济合作与发展组织(Organization for Economic Co-operation and Developement,OECD)标准方法研究三唑酮对大型溞的慢性毒性效应。21d慢性毒性研究结果表明,大型溞繁殖指标-内禀增长率是对三唑酮最为敏感的毒性参数。其慢性毒性下限值(LCL)和慢性毒性上限值(UCL)分别为40和80μg·L-1。三唑酮对于第2代大型溞,染毒的影响比对第1代的影响更大。对第2代恢复的大型溞除了第1次产卵数没有显著性差异,其他指标都有所变化,这说明毒物被转移到子代中。

21-d Chronic Toxicity of Triadimefon to Daphnia magna

Shannnon-Weaver diversity index (H’),Pb/n index of water quality parameters and their cross-correlation were applied to assess the water quality improvement from May to December 2010 after operating the demonstration project of water quality control in Roma East Lake.The water quality on the upstream of the project was not greatly improved during this period.The amount of sensitive species of macro-zooplankton in Roma East Lake evidently increased,and H’ gradually changed from 0.6501 to 2.1342.Pb/n index showed that water quality was improved to slight pollution.Based on the cross-correlation between H’ and water quality parameters which both were obtained by self-organizing maps (SOM),the greater pH value (9.5) than that of other site (7.5) was mainly responsible for the change of H’.The results indicated that the water quality was greatly improved by the demonstration project.However,to realize the targets of overall improvement of water quality of Wenyu River,some other measures must be carried out to control the pollution source,and to repair the unter quality from local to river ecosystem.The cross-correlation analysis between H’ and the water parameters obtained by SOM may be a useful tool for the water quality assessment.