Cao Guangchun, Feng Hongqiang, Guo Fang, Wu Kongming, Li Xianchun, Liang Gemei, Desneux Nicolas
1] State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China [2].
1] Institute of Plant Protection, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, China [2].
Sci Rep. 2014 Jul 9;4:5629. doi: 10.1038/srep05629.
Transgenic Bacillus thuringiensis (Bt) crops play an increasing role in pest control, and resistance management is a major issue in large-scale cultivation of Bt crops. The fitness cost of resistance in targeted pests is considered to be one of the main factors delaying resistance when using the refuge strategy. By comparing 10 resistant Helicoverpa armigera (Hubner) strains, showing various resistance levels to Bt toxin (Cry1Ac), to a susceptible strain, we showed an increasing fitness cost corresponding with increasing levels of resistance. The relationship between overall fitness cost C and the resistance ratio Rr could be described by C = 24.47/(1 + exp([1.57 - Log10Rr]/0.2)). This model predicted that the maximum overall fitness cost would be ~24% (± 5.22) in the strains with the highest resistance level. The overall fitness cost was closely linked to egg hatching rate, fecundity, emergence rate, larval survival rate, and developmental duration of adults. Among fitness components measured, fecundity was the most sensitive trait linked to the resistance selection. To integrate the results into simulation models would be valuable in evaluating how variation in fitness cost may influence the development of resistance in pest populations, thus helping to develop enhanced refuge strategies.
转基因苏云金芽孢杆菌（Bt）作物在害虫防治中发挥着越来越重要的作用，而抗性管理是Bt作物大规模种植中的一个主要问题。当采用避难所策略时，目标害虫抗性的适合度代价被认为是延缓抗性的主要因素之一。通过比较10个对Bt毒素（Cry1Ac）表现出不同抗性水平的棉铃虫抗性品系与一个敏感品系，我们发现适合度代价随着抗性水平的提高而增加。总体适合度代价C与抗性比率Rr之间的关系可以用C = 24.47/(1 + exp([1.57 - Log10Rr]/0.2))来描述。该模型预测，在抗性水平最高的品系中，最大总体适合度代价约为24%（±5.22）。总体适合度代价与卵孵化率、繁殖力、羽化率、幼虫存活率以及成虫发育历期密切相关。在所测量的适合度组分中，繁殖力是与抗性选择相关的最敏感性状。将这些结果整合到模拟模型中，对于评估适合度代价的变化如何影响害虫种群抗性的发展具有重要价值，从而有助于制定更好的避难所策略。
