Genetic Toxicological Effect On Pelophylax Nigromaculata And Fejervarya Multistriata Exposed To Several Pestieides

21Pesticides are widely used in agricultural production in China, which not only brings huge economic benefits to people, but also causes a certain degree of pollution to the ecological environment. Studies have showed that global decline in Anura population is related to the pesticide pollution. This study conducts a preliminary investigation on the diversity of amphibian species and dominant species within the paddy ecosystem in parts of Zhejiang Province and its applications of pesticide, and also tries to use genetic toxicology in the laboratory to analyze and reason the influence of pesticides on the diversity of Anura species and its effect of strength in screening dominant species. The findings show that Fejervarya multistriata in the sample areas are dominant species, while Pelophylax nigromaculata, Pelophylax plancyi, Microhyla ornate and Bufo bufo gargarizans are not, but the results also show that there is no relevance between paddy amphibian population density and pesticide application rate. The technique of single cell gel electrophoresis (SCGE, DNA damage Analysis, also called comet assay) and micronucleus test is used to detect five commonly used pesticides’ effect on the genetic toxicity of red blood cell for Fejervarya multistriata (dominant species) and Pelophylax nigromaculata (non-dominant species). The five commonly used pesticides are buprofezin, pymetrozine, imidacloprid, acetochlor and butachlor. It could be observed that all pesticides can significantly increase the DNA damage in erythrocytes of both frogs, and presented a dose effect. Three kinds of pesticides with the lowest concentration can increase the micronucleus frequency of Fejervarya multistriata, but this rate has no significant changes between the different concentrations. Butachlor can stimulate the increase of erythrocyte micronucleus frequency for Fejervarya multistriata, but acetochlor has no significant effect. Three kinds of pesticides with the lowest concentration cannot significantly increase the micronucleus frequency of Pelophylax nigromaculata, but this rate has significant changes between the different concentrations. At the certain range of the pesticide concentration, acetochlor and butachlor can stimulate the increase of erythrocyte micronucleus frequency for Pelophylax nigromaculata. Thus no matter whether pesticides exist or not, the erythrocyte micronucleus frequency of Pelophylax nigromaculata is higher than that of fejervarya multistriata, which suggests that the chromosome of pelophylax nigromaculata can be more easily damaged than that of Fejervarya multistriata. This finding, to a certain extent, helps explain why there are more Fejervarya multistriata than Pelophylax nigromaculata in sample areas.