The chiral selection of Quizalofop-p-ethyl enantiomers on toxicity daphnia magna | 喹禾灵对映体对大型溞毒性的手性选择性

Chinese. 喹禾灵含有R-对映体与S-对映体,其中只有R体有除草活性，S体是不具有除草活性。目前，喹禾灵都以R体的形式（精喹禾灵）生产并应用。为研究喹禾灵与精喹禾灵对水生生物的手性选择性毒性，对喹禾灵与精喹禾灵进行了大型溞急性和21d慢性毒性试验，慢性毒性试验观测了大型溞的存活率、生长速度、产卵量、产卵时间等生物学指标。研究发现，喹禾灵和精喹禾灵对大型溞48h EC50分别为8.44mg/L和6.08mg/L，为中毒；大型溞21d慢性毒性试验对照组未发现冬卵现象，但喹禾灵在高浓度0.50mg/L时出现的雄溞；母溞产第一胎后，在显微镜下观察幼溞，未发现异常；精喹禾灵和喹禾灵对大型溞的产卵时间、产卵数以及母蚤脱皮次数均有不同程度的影响，且二者在脱皮次数、产卵时间和产卵数等方面有显著差异，对于大型溞体长差异不大、不同浓度的处理组之间差异也不明显。试验结果表明喹禾灵与精喹禾灵对斑马鱼毒性有显著的手性选择性。

English. Quizalofop-p-ethyl includes R-enantiomer and S-enantiomer. R-enantiomer has herbicidal activity, but S-enantiomer is inactive. At present, quizalofop-p-ethyl is produced and applied in the form of R-enantiomer (that is quizalofop-P). To study the chiral selective toxicity of quizalofop-p-ethyl and quizalofop-P on the aquatic specials, Daphnia magna acute toxicity test and 21 d chronic toxicity test of quizalofop-p-ethyl and quizalofop-P were conducted. Through the chronic toxicity test, the biological indicators of survival rate, growth rate, fecundity and egg lying time were observed. The result showed that 48h-EC50 of quizalofop-p-ethyl and Quizalofop-P to Daphnia magna were 8.44 mg/L and 6.08 mg/L respectively, which indicated moderate toxicity. Winter egg phenomenon did not occure in 21d chronic toxicity test in the control group, but when it reached the high concentration of 0.50 mg/L of quizalofop-p-ethyl, male Daphnia magna occurred. The first zoea was normal under the microscope. The effects of Quizalofop-p-ethyl and Quizalofop-P on spawning time, number of eggs and numbers of molt were significantly different. The different effects on body length of Daphnia magna were noticeable. The differences in different concentrations of the treatment group were insignificant. As a result, it comes to a conclusion that quizalofop-p-ethyl and quizalofop-P show chiral selection to zebrafish.