苯醚甲环唑对大型溞慢性毒性和GST酶活性影响的研究

Study on Chronic Toxicity of Difenoconazle to Daphnia magna and Its Effect on GST Enzymatic Activity

研究苯醚甲环唑对大型溞两代14 d慢性毒性试验和子代恢复试验,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。并以苯醚甲环唑EC50浓度处理48 h,测定大型溞体内GST酶活力与时间和剂量的效应关系,探寻敏感性毒性指标。结果表明,苯醚甲环唑对大型溞的产卵时间、产卵量以及卵的孵化有明显的抑制作用,子代恢复试验发现存活下来的后代虽有一定的恢复,但是较高浓度处理组的一些敏感指标如产卵量、产卵时间等与对照组相比差异显著。苯醚甲环唑对GST酶活性影响随处理时间的延长和浓度的提高而逐渐增强,处理48 h后酶活力达到最高值。当苯醚甲环唑浓度为1.00 mg/L时,诱导率最大,达到324.84%,试验结果表明GST酶可以作为苯醚甲环唑对大型溞毒性影响的生物标志物。

The chronic toxicity evaluation of difenoconazole to Daphnia magna and two generations for 14 d were conducted.The study evaluated the biological indicators including rate of survival,growth rate,fecundity,the time of spawning and recovery test of off-spring of Daphnia magna.The relationship between GST activity of D.magna and time and application dosage was measured when D.magna was treated at the concentration level of EC50 and different concentration levels after 48 h.The results showed that the time of spawning,fecundity and body length etc.were all sensitive indicators.In the recovery test,the body length and reproduction index,such as number of young per two females,were recovered for F1(1st) and F1(3rd) individuals if the parents(F0) exposed to difenoconazle.But some sensitive indicators such as fecundity,days of spawning exposed to the higher concentration still show significant differences compared with the control group.The results showed that with the delay of time and the increase of concentration of difenoconazole,the GST activity increased significantly(P<0.05).The GST activity and difenoconazle had effect-time relationship and effect-dose relationship.The results indicated GST were suitable biomarkers to evaluate the toxicity of the two fungicides.