Agosta S J, Klemens J A
Department of Biology, University of Pennsylvania, Philadelphia, PA, USA.
J Evol Biol. 2009 Apr;22(4):907-12. doi: 10.1111/j.1420-9101.2009.01694.x. Epub 2009 Feb 11.
We present a field test of the genetically based performance trade-off hypothesis for resource specialization in a population of the moth Rothschildia lebeau whose larvae primarily feed on three host plant species. Pairwise correlations between growth vs. growth, survival vs. survival and growth vs. survival across the different hosts were calculated, using families (sibships) as the units of analysis. Of 15 pairwise correlations, 14 were positive, 5 significantly so and none were negative. The same pattern was found using complementary growth and survival data from the laboratory. Overall, we found no evidence of negative genetic correlations in cross-host performance that would be indicative of performance trade-offs in this population. Rather, variation among families in performance appears to reflect 'general vigour' whereby families that perform well on one host perform well across multiple hosts. We discuss the implications of positive genetic correlations in cross-host performance in terms of the ecology and evolution of host range. We argue that this genetic architecture facilitates colonization of novel hosts and recolonization of historical hosts, therefore contributing to host shifts, host range expansions, biological invasions and introductions, and host ranges that are regionally broad but locally narrow.
我们针对一种蛾子——勒氏裳夜蛾（Rothschildia lebeau）种群中基于基因的资源专业化性能权衡假说进行了一项田间试验，该蛾幼虫主要以三种寄主植物为食。以家系（同胞关系）作为分析单位，计算了不同寄主上生长与生长、存活与存活以及生长与存活之间的成对相关性。在15对相关性中，14对为正相关，其中5对显著为正，无负相关。利用实验室补充的生长和存活数据也发现了相同的模式。总体而言，我们没有发现跨寄主性能存在负遗传相关性的证据，而负遗传相关性表明该种群存在性能权衡。相反，家系间性能的差异似乎反映了“一般活力”，即在一种寄主上表现良好的家系在多种寄主上都表现良好。我们从寄主范围的生态和进化角度讨论了跨寄主性能正遗传相关性的影响。我们认为，这种遗传结构有利于新寄主的定殖和历史寄主的重新定殖，因此有助于寄主转移、寄主范围扩大、生物入侵和引入，以及形成区域广泛但局部狭窄的寄主范围。
