Anstead J A, Mallet J, Denholm I
Department of Plant and Invertebrate Ecology, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.
Bull Entomol Res. 2007 Jun;97(3):243-52. doi: 10.1017/S0007485307004889.
The peach-potato aphid, Myzus persicae (sulzer), is an important arable pest species throughout the world. Extensive use of insecticides has led to the selection of resistance to most chemical classes including organochlorines, organophosphates, carbamates and pyrethroids. Resistance to pyrethroids is often the result of mutations in the para-type sodium channel protein (knockdown resistance or kdr). In M. persicae, knockdown resistance is associated with two amino-acid substitutions, L1014F (kdr) and M918T (super-kdr). In this study, the temporal and spatial distributions of these mutations, diagnosed using an allelic discriminating polymerase chain reaction assay, were investigated alongside other resistance mechanisms (modified acetylcholinesterase (MACE) and elevated carboxylesterases). Samples were collected from the UK, mainland Europe, Zimbabwe and south-eastern Australia. The kdr mutation and elevated carboxylesterases were widely distributed and recorded from nearly every country. MACE and super-kdr were widespread in Europe but absent from Australian samples. The detection of a strongly significant heterozygote excess for both kdr and super-kdr throughout implies strong selection against individuals homozygous for these resistance mutations. The pattern of distribution found in the UK seemed to indicate strong selection against the super-kdr (but not the kdr) mutation in any genotype, in the absence of insecticide pressure. There was a significant association (linkage disequilibrium) between different resistance mechanisms, which was probably promoted by a lack of recombination due to parthenogenesis.
桃蚜，烟蚜（Myzus persicae (sulzer)）是全球重要的农田害虫。广泛使用杀虫剂导致其对包括有机氯、有机磷、氨基甲酸酯和拟除虫菊酯在内的大多数化学类别产生抗性。对拟除虫菊酯的抗性通常是由于对虾型钠通道蛋白的突变（击倒抗性或kdr）。在桃蚜中，击倒抗性与两个氨基酸替换有关，即L1014F（kdr）和M918T（超级kdr）。在本研究中，使用等位基因鉴别聚合酶链反应测定法诊断这些突变的时空分布，并同时研究其他抗性机制（修饰的乙酰胆碱酯酶（MACE）和羧酸酯酶升高）。样本采集自英国、欧洲大陆、津巴布韦和澳大利亚东南部。kdr突变和羧酸酯酶升高分布广泛，几乎在每个国家都有记录。MACE和超级kdr在欧洲广泛存在，但在澳大利亚样本中未出现。对kdr和超级kdr始终检测到显著的杂合子过剩，这意味着对这些抗性突变纯合个体有强烈的选择作用。在英国发现的分布模式似乎表明，在没有杀虫剂压力的情况下，对任何基因型中的超级kdr（而非kdr）突变有强烈的选择作用。不同抗性机制之间存在显著关联（连锁不平衡），这可能是由于孤雌生殖导致缺乏重组所促成的。
