关键词: 斜纹夜蛾, 腈菌唑, 膜穿孔, 卵巢细胞, 通透性, 联合作用

Abstract: The effect of cell membrane perforation caused by myclobutanil on the cell membrane permeability of Spodoptera litura ovary cells (SL cells) that were cultured in vitro was assayed in this study. The results showed that a large number of fluorescent dye PI, which was macromolecular material and could not pass through the SL cell membrane, passed through the cell membrane and entered into cells with the myclobutanil. The increasing rates of cell fluorescence intensity were 25.80% and 11.95% respectively after SL cells were treated with 20 and 40 μg/mL myclobutanil for 12 h, and 27.77% and 57.49% respectively for 24 h. Myclobutanil significantly improved the leakage rate of lactate dehydrogenase which is the macromolecular material in SL cells. The leakage rates were 30.66% and 43.93% respectively after SL cells were treated with 20 and 40 μg/mL myclobutanil for 24 h, and 41.22% and 57.91% respectively for 48 h. Myclobutanil significantly increased the intracellular calcium ion content. Intracellular calcium fluorescence intensity was significantly different from control after SL cells were treated with 20 and 40 μg/mL myclobutanil for 24 and 48 h. After SL cells were treated with myclobutanil for 24 h, the LC50 was 35.84 μg/mL. The activity of myclobutanil was significantly higher than that of rotenone which was a typical cell toxicant. When the SL cells were treated with the mixture of myclobutanil and rotenone at the mass ratios of 1∶1 and 2∶1 for 24 h, the LC50 values were 43.92 and 26.09 μg/mL respectively, and the co-toxicity coefficients were 137.60 and 188.49 respectively. The results showed that the synergism of myclobutanil and rotenone is remarkable and increased with the myclobutanil content increasing. These results suggest that myclobutanil has a good inhibition on the SL cells, can get through the membrane barrier that limits materials to penetrate the cells, and so increases the effective utilization of pesticide active ingredients.

Key words: Spodoptera litura, myclobutanil, membrane perforation, ovary cell, permeability, synergism