36种典型除草剂对绿藻的毒性研究

近年来,农药对生态系统的初级生产者——藻类的毒性及其生态毒理学研究引起了国内外学者的广泛关注。除草剂在生产中广泛应用,对藻类的毒性作用最强,其毒性效应远高于杀虫剂和杀菌剂。论文选择市场上具有典型代表性的36种除草剂原药,分析解读除草剂在国内的登记情况,以及在作物、旱田和水田的使用情况;明晰对藻类生长抑制急性毒性效应。结果表明:1)除草剂的作用方式和化学类别对绿藻毒性影响显著;对于抑制植物细胞分裂和作用于植物叶绿体的除草剂对绿藻毒性均较高,以人工合成植物生长素为代表的除草剂对绿藻毒性均较低;2)相同作用方式,不同化学类别的除草剂,对单一绿藻的毒性差异明显。在水稻上获得登记的除草剂对藻类毒性整体低于在旱田获得登记的除草剂对藻类的毒性。开展多种农药对水生生态毒性的研究,为农药的合理安全使用、农药在淡水环境中的生态效应评价以及保护淡水生态系统提供科学依据。

The Toxic Effects of Thirty-Six Typical Herbicides on Green Algae Growth

The impacts of pesticides on primary producers (i.e., algae) have raised global concerns. However, the toxic effects of herbicides on algae have been hypothesized to be much severe than those of insecticides and fungicides. To verify this hypothesis, this paper selected 36-brands herbicides to document their uses in China for crops of dry and paddy farmlands, and to investigate their effects on algae growth. The results showed that: 1) the effects of the herbicides on algae growth were dependent on their functional mechanisms and chemical composites; the herbicides that inhibit plant cell division and are applied on plant leaves were found to be more toxic that the herbicides that are made of artificially synthetic plant growth hormone; 2) for a given functional mechanism, the herbicides with difference chemical composites had different-level toxicities on green algae. The herbicides were less toxic on the paddy farmlands (e.g., rice) than the dry farmlands (e.g., wheat and corn). The results can be the important scientific information for better use of pesticides/herbicides, evaluation of their ecological effects, and protection of freshwater environment.