Ferrari Julia, Via Sara, Godfray H Charles J
Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom.
Evolution. 2008 Oct;62(10):2508-24. doi: 10.1111/j.1558-5646.2008.00468.x. Epub 2008 Aug 28.
Phytophagous insects frequently use multiple host-plant species leading to the evolution of specialized host-adapted populations and sometimes eventually to speciation. Some insects are confronted with a large number of host-plant species, which may provide complex routes of gene flow between host-adapted populations. The pea aphid (Acyrthosiphon pisum) attacks a broad range of plants in the Fabaceae and it is known that populations on Trifolium pratense and Medicago sativa can be highly specialized at exploiting these species. To find out whether adaptation to a broad range of co-occurring hosts has occurred, we tested the performance of pea aphid clones collected from eight host-plant genera on all of these plants in a reciprocal transfer experiment. We provide evidence for pervasive host-plant specialization. The high performance of all aphid clones on Vicia faba suggests that this host plant could be a site of gene flow between different populations that could limit further host-associated divergence. The genetic variance in host-plant usage was partitioned into within- and among-population components, which represent different levels of host adaptation. Little evidence of within-population trade-offs in performance on different plant species was found.
植食性昆虫经常利用多种寄主植物，这导致了适应特定寄主的种群的进化，有时最终会导致物种形成。一些昆虫面临着大量的寄主植物物种，这可能为适应特定寄主的种群之间提供复杂的基因流动途径。豌豆蚜（Acyrthosiphon pisum）会攻击豆科的多种植物，而且已知在红车轴草和紫花苜蓿上的种群在利用这些物种方面可能高度特化。为了弄清楚是否已经发生了对多种共生寄主的适应，我们在一项相互转移实验中测试了从八个寄主植物属收集的豌豆蚜克隆在所有这些植物上的表现。我们提供了普遍存在寄主植物特化的证据。所有蚜虫克隆在蚕豆上的良好表现表明，这种寄主植物可能是不同种群之间基因流动的场所，这可能会限制进一步的寄主相关分化。寄主植物利用的遗传变异被划分为种群内和种群间成分，它们代表了不同水平的寄主适应性。几乎没有发现不同植物物种上种群内表现权衡的证据。
