Department of Entomology, Iowa State University, Ames, IA 50011, United States.
Curr Opin Insect Sci. 2016 Jun;15:111-5. doi: 10.1016/j.cois.2016.04.001. Epub 2016 Apr 13.
Western corn rootworm is a serious pest of maize. Beginning in 2003, management of western corn rootworm included transgenic maize that produces insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt). The first Bt maize hybrids produced Cry3Bb1, but additional Bt toxins have since been introduced, including eCry3.1Ab, mCry3A and Cry34/35Ab1. Laboratory selection experiments found that western corn rootworm could develop resistance to all types of Bt maize following three to seven generations of selection. By 2009 cases of field-evolved resistance to Cry3Bb1 maize had been identified, with populations also showing cross-resistance to mCry3A maize. Factors likely contributing to resistance were the lack of a high dose of Bt toxin for maize targeting rootworm and minimal fitness costs of resistance.
西方玉米根虫是玉米的严重害虫。自 2003 年以来，西方玉米根虫的管理包括转Bt 基因玉米，该玉米产生源自苏云金芽孢杆菌（Bt）的杀虫毒素。第一批 Bt 玉米杂交种产生了 Cry3Bb1，但此后又引入了其他 Bt 毒素，包括 eCry3.1Ab、mCry3A 和 Cry34/35Ab1。实验室选择实验发现，西方玉米根虫在经过三到七代的选择后，可能会对所有类型的 Bt 玉米产生抗性。到 2009 年，已经发现对 Cry3Bb1 玉米田间进化抗性的案例，并且种群也表现出对 mCry3A 玉米的交叉抗性。导致抗性的因素可能是针对根虫的玉米靶向 Bt 毒素的高剂量缺乏，以及抗性的最小适应成本。
