新型杀虫剂对蚯蚓的生化毒理学研究

THE BIOCHEMICAL TOXICITY OF IMIDACLOPRID AND RH-5849 ON EARTHWORS (EISENIA FOETIDA)

研究了吡虫啉与抑食肼对蚯蚓体内的蛋白含量、纤维素酶和SOD酶活性的影响 .结果显示吡虫啉在浓度低于 0 .2mg/L、抑食肼低于 2 5mg/L浓度范围内对蚯蚓纤维酶活力有抑制作用 .低浓度吡虫啉对蚯蚓超氧化物歧化酶活力有抑制作用 ,高浓度吡虫啉和抑食肼则有促进作用 .

In this paper, several biochemical toxicity tests were conducted to evaluate the biochemical toxicity of 2 new pesticides, imidacloprid and RH 5849 on earthworms (Eisenia foetida) in terms of their effects on the activites of cellulase and superoxide dismutase (SOD). The earthworms were exposed in the solution of pesticides under different exposure concentrations and during different exposure time. The results showed that imidacloprid could be observed to inhibit the activity of cellulase. The celluase activites in Eisenia foetida were decreased with an increase in the exposure concetrations of imidacloprid and had especially significant reduction ( P >0.01)when the concentrations of imidacloprid reached 0.1?mg/L. From the results of exposure to imidacloprid at the concentration of 0.2?mg/L over different time, we can find the same inhibition effect. The cellulase activities in Eisenia foetida were decreased with an increase in the exposure time of imidacloprid and had significant reduction ( P <0.05)when the exposure time reached 3 hours. However, when the concentration of imidacloprid was high as the 1/2?LC 50 (0.5?mg/L),the cellulase activity of Eisenia foetida repomoted to be higher than that of exopsed to 0.1?mg/L and lower than the control, which may be caused by the death of earthworm and auto lysis of earthworms. Rh 5840 showed the similar inhibition effects on the cellulase activity of Eisania foetida , but the results did not show signficant statistical differences. As to the effects of the two pesticides on the SOD activity in Eisania foetida , it can be seen that imidacloprid showed inhibition effect on the SOD activity at low concentration and promotion effect at higher concentrations. After 4 hours'exposure unber the concentration of 0.1?mg/L, the SOD activity decreased especially significantly ( P <0.01)and as the concentrations increased (0.2?mg/L,0.5?mg/L)the SOD activities began to increase and were higher than the control. As to the effect of imidacloprid over various exposure time, it showed inhibition effects on the SOD activity of earthworms in 1h, 2h and 3h, but promoted the SOD activities when the exposure time reached 4 hours. RH 5749 did not have inhibition effect in the SOD activity. The SOD activities were observed to have especially significant increase under the exposure concentration of 5?mg/L and continued to promoted with the increase of concentrations of RH 5849.Shown from the results of different exposure time under 25?mg/L?RH 5849, the SOD activities increased when the exposure time extended and the dose effect relationship displayed.