The fall armyworm, Spodoptera frugiperda (J.E. Smith), is an economically important crop pest and a major target of transgenic crops expressing Cry and/or Vip3Aa proteins. Widespread adoption of Bt crops has placed a strong selection pressure on the insect populations. Till now, seven lepidopteran and two coleopteran insect species have developed the field-evolved resistance to a Bt crop with practical consequences. Understanding the genetic basis of insect resistance to a Bt protein is essential for designing appropriate resistance management strategies. In this study, we firstly characterized the genetic basis of Vip3Aa resistance in S. frugiperda derived from Texas. Then, we compared the genetic basis of Vip3Aa resistance of this Texas population with a known Vip3Aa resistant population of S. frugiperda collected from Louisiana to determine whether the genetic basis of the resistance in these two resistant populations was the same. Finally, we evaluated the responses of the Vip3Aa-resistant population of S. frugiperda collected from Texas against Cry1F and Cry2Ab2 purified proteins. The results showed that the resistance to Vip3Aa protein in S. frugiperda collected from Texas was likely controlled by a single, functionally recessive and autosomal gene. In addition, the resistance to Vip3Aa in the Texas population of S. frugiperda was not cross-resistant to Cry1F and Cry2Ab2 proteins. The interstrain complementation tests between the Texas and Louisiana resistant populations indicated the genetic basis of the resistance to Vip3Aa in these two populations are different. Considering the rapid invasion of S. frugiperda and the adoption of Vip3Aa Bt crops in the United States and other countries, results generated from this study should provide important information for management of Vip3Aa resistance in S. frugiperda worldwide.

秋天的粘虫，Spodoptera frugiperda（JE Smith），是一种经济上重要的农作物害虫，是表达Cry和/或Vip3Aa蛋白的转基因作物的主要目标。Bt作物的广泛采用给昆虫种群带来了巨大的选择压力。到目前为止，已有七种鳞翅目昆虫和两种鞘翅目昆虫物种对Bt作物产生了田间进化的抗性，并产生了实际的后果。了解昆虫对Bt蛋白抗性的遗传基础对于设计适当的抗性管理策略至关重要。在这项研究中，我们首先表征了S. frugiperda中Vip3Aa抗性的遗传基础。来自德克萨斯州。然后，我们将该得克萨斯州人群的Vip3Aa抗性的遗传基础与从路易斯安那州收集到的已知S. frugiperda的Vip3Aa抗性种群进行了比较，以确定这两个抗性种群中抗性的遗传基础是否相同。最后，我们评估了从得克萨斯州收集的Sip frugiperda的Vip3Aa耐药种群对Cry1F和Cry2Ab2纯化蛋白的反应。结果表明，从得克萨斯州收集的S. frugiperda中对Vip3Aa蛋白的抗性可能受单个隐性和常染色体功能基因控制。此外，德州S. frugiperda种群对Vip3Aa的抗药性对Cry1F和Cry2Ab2蛋白没有交叉抗性。得克萨斯州和路易斯安那州抗性种群之间的株间互补测试表明，这两个种群中对Vip3Aa的抗性的遗传基础是不同的。考虑到美国和其他国家/地区对S. frugiperda的快速入侵和采用Vip3Aa Bt作物，该研究产生的结果应为管理Srug frugiperda在全球范围内对Vip3Aa的耐药性提供重要信息。