抗Bt棉铃虫种群的交互抗性研究

Cross-resistance of Cry1Ac-resistant Heliocoverpa armigera Hübner

摘要: 分别用对 Cry1Ac抗性达 11.6倍的 Bt棉叶和 Bt粉剂 (Btk)汰选棉铃虫 (Helio-coverpa armigera)种群 (对 Btk的抗性指数为 5.2倍 ) ,测定了其对不同 Bt制剂、Bt毒素、化学农药的交互抗性。结果表明 :停止汰选后 ,Bt棉叶汰选种群对 Cry1Ac的抗性指数为 5.9倍 ,对Cry1Ac+1C的交互抗性为 3.7倍 ,对 Btk的敏感性降低 ,对 Bta、Cry2 A无交互抗性 ;Btk汰选种群对 Btk的抗性指数为 4 .1倍 ,对 Bta、Cry1Ac、Cry1Ac+1C的交互抗性为 2 .3、3.1、2 .3倍 ,对 Cry2 A无交互抗性 ;两汰选种群对化学农药灭多威、辛硫磷、氯氰菊酯的敏感性均有所增加。

Abstract: A population of cotton bollworm, H.armigera , selected for 26 generations with transgenic cotton producing Cry1Ac toxin developed 11.6-fold resistance to Cry1Ac, and another population was selected by Btk for 26 generations with 5.9-fold increase of LC50 s in laboratory. Cry1Ac resistant population with 5.4-fold to Cry1Ac caused 3.7-fold cross resistance to Cry1Ac+1C, no cross resistance to Btk, Bta, and Cry2A. Btk selected population with 4.1 fold to Btk caused 2.3- , 3.1- , 2.3-fold cross resistance to Bta, Cry1Ac, Cry1Ac+1C, respectively, and no cross resistance to Cry2A. There is no cross resistance to methomyl, phoxim, cypermethrin in these selected colonys. It suggested that conventional insecticides will be useful in Bt resistance management.