禾草灵的作用机制及环境生态效应研究进展

禾草灵 (diclofop-methyl)属芳氧苯氧丙酸类除草剂,广泛应用于禾本科杂草防除,其降解受到土壤有机质含量、pH值、氧气等众多因素的影响。母体化合物禾草灵及其主要降解产物禾草灵酸都具有除草活性,并会对环境中的一些非靶标生物产生急性或慢性毒性,是一类环境内分泌干扰物及过氧化物酶体增殖剂;同时,由于部分杂草产生抗性,进而演替成优势种群,迫使禾草灵的用量增加,更加重了其环境压力。文章就禾草灵的作用机制,其在环境中的降解、吸附等行为以及对非靶标生物的生态效应进行了综述,探讨了其中存在的一些问题,如生态毒理尤其是对映体差异性在毒性方面数据的缺乏等,并对今后的发展方向进行了展望。

Progress in the Mechanism of Action and Ecological Effects of the Herbicide Diclofop-methyl

Diclofop-methyl (DM) is an aryloxyphenoxypropanoic acid herbicide first registered by Farbwerke Hoechst AG for the control of wild oat and other annual grasses.It’s reported that while coming into contact with the soil,a rapid hydrolysis of DM to the corresponding acid form was followed by a much slower hydrolytic process to some trace breakdown products,which may be affected by soil organic matter,pH,aerobic and anaerobic conditions and other factors.Both the parent compound DM and the main degradation product diclofop acid(DC) are herbicidally bioactive,meanwhile cause ecological toxicity such as acute/chronic toxicity,endocrine disrupting effects and proliferation of peroxisomes to non-target organisms like fish and mammals.Furthermore,several biotypes resistant to DM were reported recently to be evolving as the predominant species,which consequently increase more environmental stress.The environmental behavior and ecological effects of DM as well as the mechanisms of resistance to DM were reviewed,and some problems,e.g.lack of data for the ecological toxicity especially in the enantioselectivity of DM,were discussed.Further research suggestions were proposed based on these findings.