Transgenic corn and cotton expressing Cry and/or Vip3Aa proteins from Bacillus thuringiensis (Bt) have been planted for managing lepidopteran and coleopteran insect pests for more than two decades in the U.S. Evolution of insect resistance to these Bt proteins is a major threat for the continued efficacy of Bt technology. Understanding patterns of cross-resistance and dominance of resistance in target insects is essential for resistance management and pest control. The bollworm, also called corn earworm, Helicoverpa zea (Boddie), is a major target pest of pyramided Bt crops in the U.S. In this study, we evaluated the responses of Cry2Ab2-resistant (RR), susceptible (SS), and heterozygous (RS) strains of H. zea to the Cry1Ac, Cry1A.105, Cry2Ab2 and Vip3Aa39 proteins using diet-overlay bioassays. The Cry2Ab2-resistant H. zea also possessed high levels of resistance to Cry1Ac and Cry1A.105, but were very susceptible to Vip3Aa. The resistance to Cry1 and Cry2 proteins in RR H. zea varied from incompletely recessive to completely dominant depending on the protein concentration. These data suggest that the RR H. zea possess multiple non-recessive resistance to Cry1/Cry2 proteins. These results have significant implications for understanding field-evolved resistance of H. zea to Cry1 and Cry2 proteins in U.S. Bt corn and cotton fields and should contribute to developing effective management strategies for control of H. zea.

来自美国苏云金芽胞杆菌（Btillus thuringiensis）（Bt）的表达Cry和/或Vip3Aa蛋白的转基因玉米和棉花已在美国种植，用于防治鳞翅目和鞘翅目害虫，昆虫对这些Bt蛋白的抗性演变是持续威胁的主要威胁。 Bt技术的功效。了解目标昆虫的交叉抗性和抗性优势模式对于抗性管理和害虫控制至关重要。棉铃虫，也称为玉米耳虫，Helicoverpa zea（Boddie），是美国金字塔状Bt作物的主要目标害虫。在这项研究中，我们评估了抗Cry2Ab2（RR），易感性（SS）和杂合子（ RS）玉米使用饮食覆盖生物测定法检测Cry1Ac，Cry1A.105，Cry2Ab2和Vip3Aa39蛋白的表达。耐Cry2Ab2的-美洲棉铃虫也具有较高的水平对Cry1Ac和Cry1A.105的阻力，但都以Vip3Aa非常敏感。RR H. zea对Cry1和Cry2蛋白的抗性从不完全隐性到完全显性，视蛋白浓度而定。这些数据表明RR H. zea对Cry1 / Cry2蛋白具有多种非隐性抗性。这些结果对了解现场进化性显著影响美洲棉铃虫在美国Bt玉米和棉花领域CRY1和的Cry2蛋白，并应有助于开发用于控制有效的管理策略美洲棉铃虫。