斜纹夜蛾抗三氟甲吡醚近等基因系构建及抗性机制研究OA

[Aim]Spodoptera litura is a globally damaging insect pest that has developed high-level resistance to multiple commonly used insecticides.The aim of this study is to clarify the genetic mechanism of resistance in the S.litura strains with pyridalyl resistance.[Methods]Direct,reciprocal and pooled crosses were conducted between adults of the pyridalyl-resistant strain(YX)and laboratory susceptible strain(Lab-S)of S.litura,and the bioassay against the F1 larvae from the crossing treatments was conducted to reveal the genetic patterns of the resistance.Using YX and Lab-S as parental lines,a pyridalyl-resistant near-isogenic line(YX-NIL)was constructed through multiple generations of backcrossing and self crossing.The leaf-dipping method was used to assess the cross-resistance of YX-NIL and Lab-S to tetraniliprole,chlorantraniliprole,broflanilide,abamectin,cyantraniliprole and metaflumizone.The synergistic effects of synergists such as piperonyl butoxide(PBO),diethyl maleate(DEM)and triphenyl phosphate(TPP)on pyridalyl were determined,and the activities of three detoxifying enzymes,including glutathione S-transferase(GST),esterase(EST)and cytochrome P450 monooxygenase(P450)in the 3rd instar larvae of YX-NIL and Lab-S were measured.[Results]The resistance of YX of S.litura to pyridalyl was confirmed to be inherited autosomally with incompletely recessive dominance.A pyridalyl-resistant near-isogenic line(YX-NIL)was obtained via seven consecutive generations of backcrossing between the YX and Lab-S strains,followed by one generation of self-crossing,and its resistance ratio to pyridalyl was 58.1.YX-NIL showed high cross-resistance to chlorantraniliprole and moderate-level cross-resistance to metaflumizone and cyantraniliprole.The synergist PBO significantly inhibited the pyridalyl resistance in YX-NIL,with significantly elevated P450 activity relative to that in Lab-S.[Conclusion]The increased activity of P450 may be the primary factor contributing to the resistance of S.litura to pyridalyl.Rotation of pyridalyl with other insecticides that function through different modes of action could be especially useful for delaying pyridalyl resistance in S.litura.