三唑磷与氟虫腈复配对粘虫的增效机理研究

以粘虫Mythimna separate 4龄幼虫为试虫,从表皮穿透、生物转化、作用靶标3个方面研究了三唑磷·氟虫腈复配剂的增效机理。结果表明,三唑磷与氟虫腈复配后,相互促进了对方对粘虫表皮的穿透作用;三唑磷对酸性磷酸酯酶(ACPase)的竞争性抑制与氟虫腈对ACPase的非竞争性抑制与反竞争性抑制的混合型抑制相结合,使复配剂对ACPase的抑制能力大幅度提高;对谷胱甘肽S-转移酶(GSTs)的联合抑制系数(JIC)达到425.87,表现出显著的增效作用;三唑磷和氟虫腈对乙酰胆碱酯酶(AChE)只有微弱的交互作用。表皮穿透率的提高及其对ACPase和GSTs抑制能力的增强可能是该复配剂对粘虫增效的重要机理。

Study on Synergistic Mechanism of a Mixture of Triazophosand Fipronil to Mythimna separate

The synergistic mechanism of a mixture of triazophos and fipronil to the 4^th-instar larvae of Mythimna separate was studied by the analysis of interactions between triazophos and fipronil on cuticular penetration,biotransformation and target site.The results suggested that triazophos and fipronil promoted each other to penetrate the cuticle of Mythimna separate in the mixture.The interaction between triazophos which had competitive inhibition on acid phosphatase(ACPase)and fipronil which had mixture inhibition (non-competitive and counter-competitive inhibition) on ACPase caused the remarkable increase in the inhibition ability of the mixture on ACPase.Joint-inhibition coefficient of the mixture to glutathione S-transferase(GSTs) was 425.87,which indicated that the mixture was significantly synergistic to GSTs.The interaction between triazophos and fipronil on AchE was weak.The increase of cuticular penetration rate and the enhancement of inhibition to the activity of ACPase and GSTs may be the major synergistic mechanisms of the mixture of triazophos and fipronil to Mythimna separate.