Eco-toxicity Effects Of Four Triazole Fungicides To Chironomus Kiiensis

In order to study Eco-toxicity effects of triazole fungicides on the Chironomus Kiiensis, the80%Tebuconazole waterborne dispersing agent,50%Hexaconazole waterborne dispersing agent, original drug of Cyproconazole and Tetraconazole were selected as research fungicides in this paper, of which the former three fungicides were chosen to find out the acute toxicity and responses of the antioxidant enzyme system to Chironomus Kiiensis larval. The last research was done to understand the the effects of Tetraconazole’s chronic toxicity on Chironomus Kiiensis’emergence rate, sex ratio and the emergence time. The results of these experiments were summarsied as follows:(1) The value of EC50(48h) of the80%Tebuconazole waterborne dispersing agent,50%Hexaconazole waterborne dispersing agent, and original drug of Cyproconazole for the first instar Chironomus Kiiensis larval were3.056,8.339and15.742mg/L respectively. The order of the three fungicides’eco-toxicity on the the first instar was:80%Tebuconazole waterborne dispersing agent>50%Hexaconazole waterborne dispersing agent> original drug of Cyproconazole.(2) The value of EC50(48h) of the80%Tebuconazole waterborne dispersing agent,50%Hexaconazole waterborne dispersing agent, and original drug of Cyproconazole for the fourth instar Chironomus Kiiensis larval were4.618,10.347and24.492mg/L respectively. The toxic order of the three fungicides on the the fourth instar was:80%Tebuconazole waterborne dispersing agent>50%Hexaconazole waterborne dispersing agent> original drug of Cyproconazole.(3) In different instars, the Chironomus Kiiensis larval didn’t appear with same sensitivity. The order of the three fungicides’ eco-toxicity all for:the first instar> the fourth instar.(4) The three fungicides had some influence on the antioxidant enzyme system of the Chironomus Kiiensis larval, the trend of antioxidant enzyme activity vary between each treatment. The influences of80%Tebuconazole waterborne dispersing agent on CAT and SOD activity were concluded as below:In48hours, the change law of low concentrations was decrease-increase-decrease, increase-decrease-unchanged respectively; however it kept decreasing in moderate and high concentrations.(5) The influences of50%Hexaconazole waterborne dispersing agent on CAT activity were:In48hours, the low concentration was increased in the beginning, and then decreased. The change law of moderate and high concentrations was decrease-increase-decrease. The influences on SOD activity were:In48hours, the low concentration was decreased firstly, and then recovered to control level. But in moderate and high concentrations it kept decreasing.(6) The influences of original drug of Cyproconazole on CAT activity were concluded as below:In48hours, the change law of low concentrations is increase-decrease-increase, while it increase in the beginning and then kept decreasing in moderate and high concentrations. The influences of original drug of Cyproconazole on SOD activity were:In48hours, low concentration kept increasing while moderate concentration was increased firstly, and then decreased. In high concentration, it kept decreasing from the beginning.(7) The value of EC50(48h) of the original drug of Tetraconazole for Chironomus Kiiensis’emergence time was75.568mg/kg. The original drug of Tetraconazole had no significant effect on Chironomus Kiiensis’sex ratio but it delayed adult emergence.