咪鲜胺及其制剂和主要代谢物对三叶浮萍色素的影响

Influence of Prochloraz, Its Formulation Sportak and Major Metabolites on Pigments in Lesser Duckweed Lemna Paucicostata

为了全面地了解和评价咪鲜胺(Prochloraz)及其制剂施保克(Sportak)使用后的生态环境安全性,采用恒温光照培养试验,研究了Prochloraz及其制剂和主要代谢物(包括其初级代谢物BTS44595、BTS44596和次级代谢物BTS45186)对三叶浮萍色素含量及组成的影响。结果表明,随着处理浓度的增加和处理时间的延长,三叶浮萍体内的色素含量逐渐下降,Prochloraz和Sportak使叶绿素a/b比值逐渐下降,3种代谢物使叶绿素a/b比值逐渐上升。经分析,Prochloraz在处理时间为24h时对色素含量的影响比Sportak小,但随着处理时间的延长其对色素的影响则高于Sportak的影响;Prochloraz对叶绿素含量的影响高于BTS44595而低于BTS44596和BTS45186,但对类胡萝卜素含量的影响比3种代谢物都要大。

Prochloraz [1-（N-propyl-N-2-（2,4,6-trichlorophenoxy） ethyl carbamoyl） imidazole ] is an imidazole fungicide which is widely used to control the rice diseases. Effects of prochloraz and its formulation 25% emusifiable concentrate （sportak）and major metabolite including BTS44595 [N-propyl-N-（2-（2,4,6-trichlorophenoxy）ethyl）urea], BTS44596 [N-methoxyl-N′-propyl-N- （2-（2,4,6-trichlorophenoxy） ethyl）urea] and BqS45186 [2,4,6-trichlorophenol] on the contents and compositions of pigments in lesser duckweed L.paucicostata were studied using illuminating incubation method in the laboratory in order to assess the eco-environmental safety after application of prochloraz. Results showed that the pigment contents of the duckweeds decreased gradually with the increasing concentrations of the compounds and treatment time. The ratio of chlorophyll a/b decreased from 1.76 in the control to 1.63 in treatments with 0.1 -10 mg·L^-1 prochloraz and sportak, and increased from 1.77 in the control to 1.94 in BTS44595, BTS44596 and BQS45186 treatment. However, chlorophyll a was more sensitive to the compounds than chlorophyll b under the same conditions. Prochloraz had a greater effect on the duckweed pigments at 24 h after treatment than sportak, but an opposite result appeared with the prolonging treatment. The five compounds reduced the chlorophyll and carotenoid content of the duckweeds in the order of BTS45186 〉BTS44596 〉prochloraz 〉sportak 〉BTS44595 and prochloraz 〉sportak 〉 BTS45186〉BTS44596〉BTS44595, respectively.