Zhang W N, Ma L, Wang B J, Chen L, Khaing M M, Lu Y H, Liang G M, Guo Y Y
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China (
Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China (
J Econ Entomol. 2016 Dec;109(6):2534-2542. doi: 10.1093/jee/tow233. Epub 2016 Oct 23.
Transgenic Bacillus thuringiensis (Bt) crops are increasingly significant in pest control, but resistance development of target pests is a major issue in the sustainable deployment of Bt crops. The fitness cost of resistance in target pests is regarded as one of the main factors delaying resistance when adopting the refuge strategy. In this study, we compared the life-history traits of three independent sets of Helicoverpa armigera (Hübner, 1809) adults, of each there were a susceptible population and a Cry1Ac-resistant population derived by selection from it. Confirming to the previous studies, resistant individuals exhibited fewer progeny, less fecundity, lower egg hatching rate, and longer adult longevity. And poor fecundity in resistant strains was associated with the decline of the mature follicular amount, the ovarian weight ratio, and the length of the longest ovarian tubule. Interestingly, the juvenile hormone (JH) level appeared higher in resistant strains relative to susceptible strains. Application of methoprene (JH analogue) in vivo was effective in reducing fecundity and hatchability with the up-regulation of detected JH titer. These results suggested that resistance against Bt toxin reduced the reproductive capacity of H. armigera, and JH level is affected in the tradeoff between reproductive capacity and Bt resistance.
转基因苏云金芽孢杆菌（Bt）作物在害虫防治中日益重要，但目标害虫的抗性发展是Bt作物可持续应用的一个主要问题。当采用避难所策略时，目标害虫抗性的适合度代价被视为延缓抗性的主要因素之一。在本研究中，我们比较了三组独立的棉铃虫（Hübner，1809）成虫的生活史特征，每组均有一个敏感种群和一个由其选育出的Cry1Ac抗性种群。与先前的研究一致，抗性个体的后代数量较少、繁殖力较低、卵孵化率较低且成虫寿命较长。抗性品系繁殖力差与成熟卵泡数量、卵巢重量比以及最长卵巢小管长度的下降有关。有趣的是，相对于敏感品系，抗性品系中的保幼激素（JH）水平似乎更高。体内施用烯虫酯（JH类似物）可有效降低繁殖力和孵化率，并上调检测到的JH滴度。这些结果表明，对Bt毒素的抗性降低了棉铃虫的繁殖能力，并且JH水平在繁殖能力与Bt抗性之间的权衡中受到影响。
