Wilson A C C, Sunnucks P, Blackman R L, Hales D F
Division of Botany and Zoology, The Australian National University, ACT 0200 Australia.
Heredity (Edinb). 2002 Apr;88(4):258-66. doi: 10.1038/sj.hdy.6800037.
We examined the population structure of the introduced aphid, Myzus persicae collected mainly from its primary host, Prunus persica, in south-east Australia. Myzus persicae has been present in Australia since at least 1893. Samples were collected in the spring of 1998 from two mainland and three Tasmanian localities and isofemale lines were established in the laboratory. The reproductive mode (life cycle), karyotype and 17-locus microsatellite genotype of each clone were determined. All populations showed significant population differentiation (F(ST) 0.058-0.202) even over small geographic distances (<50 km). All clones were karyotypically normal except for a subset of clones from one site that was exposed to the carbamate insecticide, Pirimor, the week prior to sampling. Those clones were heterozygous for an autosomal 1,3 translocation frequently associated in M. persicae with insecticide resistance. In contrast to other loci and despite being on different chromosomes, loci myz2(A) and M55(A) showed general and significant linkage disequilibrium. These loci may be affected by epistatic selection. We discuss the observed high clonal diversity, moderate but significant population differentiation, general conformance to Hardy-Weinberg equilibria and low linkage disequilibria with particular focus on the global population biology of M. persicae.
我们研究了主要从其在澳大利亚东南部的主要寄主桃树采集的外来蚜虫——桃蚜的种群结构。桃蚜至少自1893年起就已在澳大利亚出现。1998年春季从澳大利亚大陆的两个地点和塔斯马尼亚的三个地点采集了样本，并在实验室建立了单雌系。确定了每个克隆的生殖模式（生命周期）、核型和17个位点的微卫星基因型。即使在很小的地理距离（<50公里）内，所有种群也都表现出显著的种群分化（F(ST) 0.058 - 0.202）。除了来自一个地点的一部分克隆外，所有克隆的核型均正常，这些克隆在采样前一周接触了氨基甲酸酯类杀虫剂抗蚜威。这些克隆对于常染色体1、3易位是杂合的，这种易位在桃蚜中经常与抗药性相关。与其他位点不同，尽管位于不同染色体上，但位点myz2(A)和M55(A)表现出普遍且显著的连锁不平衡。这些位点可能受到上位性选择的影响。我们讨论了观察到的高克隆多样性、中等但显著的种群分化、对哈迪 - 温伯格平衡的总体符合以及低连锁不平衡，特别关注桃蚜的全球种群生物学。
