Inheritance and Fitness Costs of Resistance to Cry3Bb1 Corn by Western Corn Rootworm (Coleoptera: Chrysomelidae)
Inheritance and Fitness Costs of Resistance to Cry3Bb1 Corn by Western Corn Rootworm (Coleoptera: Chrysomelidae)
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DOI：
10.1093/jee/tov199
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发表时间：
2015-10-01
影响因子：
2.2
通讯作者：
Gassmann, Aaron J.
中科院分区：
文献类型：
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作者：
Ingber, David A.;Gassmann, Aaron J.
产生来自苏云金芽孢杆菌(Bt)的杀虫毒素的转基因作物被广泛种植以管理害虫。Bt玉米在美国的主要害虫之一是西部玉米根虫Diabrotica virgifera virgifera LeConte。用于管理西部玉米根虫的Cry3Bb1玉米于2003年商业化，从2009年开始，爱荷华州发现了对Cry3Bb1玉米具有田间进化抗性的西部玉米根虫种群。在这里，我们量化了两个品系(Hopkinton和Cresco)对Cry3Bb1玉米的抗性程度、遗传和适合度成本，这些品系来自进化出对Cry3Bb1玉米的抗性的田间群体。对于霍普金顿，我们发现了对Cry3Bb1玉米的完全抗性和非隐性遗传的证据。此外，霍普金顿没有检测到Cry3Bb1抗性的适合度成本。对于克雷斯科来说，抗性是不完全的和隐性的，我们检测到适合性成本影响着发育速度、成年期存活和繁殖力。这些结果表明，田间种群之间在抗性的遗传成本和伴随的适合度成本上都可能存在差异。在田间群体表现出非隐性遗传和缺乏适应成本的程度上，这将有利于比预期更快的抗性进化，因为抗性是功能隐性的，并伴随着适应成本。
Transgenic crops that produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) are widely planted to manage pest insects. One of the primary pests targeted by Bt corn in the United States is western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae). Cry3Bb1 corn for management of western corn rootworm was commercialized in 2003, and beginning in 2009, populations of western corn rootworm with field-evolved resistance to Cry3Bb1 corn were found in Iowa. Here we quantify the magnitude, inheritance, and fitness costs of resistance to Cry3Bb1 corn in two strains (Hopkinton and Cresco) derived from field populations that evolved resistance to Cry3Bb1 corn. For Hopkinton, we found evidence for complete resistance to Cry3Bb1 corn and nonrecessive inheritance. Additionally, no fitness costs of Cry3Bb1 resistance were detected for Hopkinton. For Cresco, resistance was incomplete and recessive, and we detected fitness costs affecting developmental rate, survival to adulthood, and fecundity. These results suggest that variation may exist among field populations in both the inheritance and accompanying fitness costs of resistance. To the extent that field populations exhibit nonrecessive inheritance and a lack of fitness cost, this will favor more rapid evolution of resistance than would be expected when resistance is functionally recessive and is accompanied by fitness costs.