Downes Sharon, Mahon Rodney J, Rossiter Louise, Kauter Greg, Leven Tracey, Fitt Gary, Baker Geoff
CSIRO Entomology, Australian Cotton Research Institute Narrabri, NSW, Australia.
CSIRO Entomology Canberra, ACT, Australia.
Evol Appl. 2010 Sep;3(5-6):574-84. doi: 10.1111/j.1752-4571.2010.00146.x. Epub 2010 Jul 19.
In Australia, monitoring Helicoverpa species for resistance to the Cry2Ab toxin in second generation Bacillus thuringiensis (Bt) cotton has precisely fulfilled its intended function: to warn of increases in resistance frequencies that may lead to field failures of the technology. Prior to the widespread adoption of two-gene Bt cotton, the frequency of Cry2Ab resistance alleles was at least 0.001 in H. armigera and H. punctigera. In the 5 years hence, there has been a significant and apparently exponential increase in the frequency of alleles conferring Cry2Ab resistance in field populations of H. punctigera. Herein we review the history of deploying and managing resistance to Bt cotton in Australia, outline the characteristics of the isolated resistance that likely impact on resistance evolution, and use a simple model to predict likely imminent resistance frequencies. We then discuss potential strategies to mitigate further increases in resistance frequencies, until the release of a third generation product. These include mandating larger structured refuges, applying insecticide to crops late in the season, and restricting the area of Bollgard II® cotton. The area planted to Bt-crops is anticipated to continue to rise worldwide; therefore the strategies being considered in Australia are likely to relate to other situations.
在澳大利亚，监测棉铃虫对第二代苏云金芽孢杆菌（Bt）棉花中Cry2Ab毒素的抗性，已精准实现其预期功能：警示抗性频率增加，否则可能导致该技术在田间失效。在双基因Bt棉花广泛应用之前，棉铃虫和澳洲棉铃虫中Cry2Ab抗性等位基因的频率至少为0.001。在此后的5年里，澳洲棉铃虫田间种群中赋予Cry2Ab抗性的等位基因频率显著且呈指数增长。本文回顾了澳大利亚Bt棉花抗性部署和管理的历史，概述了可能影响抗性进化的分离抗性特征，并使用一个简单模型预测即将出现的抗性频率。然后，我们讨论了在第三代产品发布之前减缓抗性频率进一步增加的潜在策略。这些策略包括强制设置更大的结构化避难所、在作物生长季后期施用杀虫剂以及限制种植抗虫棉II代的面积。预计全球Bt作物种植面积将持续增加；因此，澳大利亚正在考虑的策略可能适用于其他情况。
