Departamento de Biotecnología Microbiana y de Plantas, Centro de Investigaciones Biológicas Margaritas Salas, Madrid, Spain.
Departamento de Biología Celular y Molecular, Centro de Investigaciones Biológicas Margaritas Salas, Madrid, Spain.
Pest Manag Sci. 2020 Nov;76(11):3702-3710. doi: 10.1002/ps.5919. Epub 2020 Jun 4.
The sustainable control of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), is compromised by the development of resistance to malathion and lambda-cyhalothrin in Spanish field populations. At present, field populations remain susceptible to spinosad. However, the resistant strain JW-100s has been obtained under laboratory selection with spinosad, and resistance has been associated with the presence of different mutations causing truncated transcripts of the α6 subunit of the nicotinic acetylcholine receptor (nAChRα6).
An F1 screen assay followed by the molecular characterization of surviving flies has been used to search for spinosad-resistant alleles in field populations. Two different resistant alleles giving rise to truncated isoforms of Ccα6 have been identified, which corresponds to an estimated allelic frequency of at least 0.0023-0.0046. The fitness values of the resistant nAChRα6 alleles found in the laboratory strain JW-100s were estimated to be 0.4 for RR and 0.2 for SR. Mathematical modelling predicted that spinosad-resistant alleles will rapidly decline over time in field populations if their fitness cost was the same as estimated for laboratory-resistant alleles. However, they are predicted to increase in the field if their fitness cost is lower and resistance management strategies are not implemented.
Spinosad-resistant alleles have been detected in field populations for the first time. Our modelling simulations indicate that the best option to delay the appearance of spinosad resistance would be its rotation with other insecticides without cross-resistance. The integrated F1 screen/molecular genetic analysis presented here can be used for future monitoring studies. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
在地中海实蝇（Ceratitis capitata（Wiedemann））的可持续控制中，由于西班牙田间种群对马拉硫磷和氯氟氰菊酯产生了抗性，情况变得复杂。目前，田间种群仍对多杀菌素敏感。然而，实验室选择用多杀菌素已获得了抗性菌株 JW-100s，并且抗性与存在导致烟碱型乙酰胆碱受体（nAChRα6）α6 亚基截断转录本的不同突变有关。
我们采用 F1 筛选测定法，随后对存活的苍蝇进行分子特征分析，以在田间种群中寻找多杀菌素抗性等位基因。已经鉴定出两种不同的抗性等位基因，它们导致 Ccα6 的截断同工型，这相当于至少 0.0023-0.0046 的估计等位基因频率。在实验室菌株 JW-100s 中发现的抗性 nAChRα6 等位基因的适合度值估计为 RR 为 0.4，SR 为 0.2。数学模型预测，如果抗性等位基因的适合度成本与实验室抗性等位基因相同，则在田间种群中，它们将随着时间的推移迅速减少。但是，如果它们的适合度成本较低且不实施抗性管理策略，则它们在田间的数量预计会增加。
首次在田间种群中检测到多杀菌素抗性等位基因。我们的模拟表明，延迟出现多杀菌素抗性的最佳选择是将其与无交叉抗性的其他杀虫剂轮换使用。这里提出的 F1 筛选/分子遗传分析综合方法可用于未来的监测研究。©2020 作者。害虫管理科学由 John Wiley & Sons Ltd 代表化学工业协会出版。
