Genetic variation changes the interactions between the parasitic plant-ecosystem engineer Rhinanthus and its hosts
Genetic variation changes the interactions between the parasitic plant-ecosystem engineer Rhinanthus and its hosts
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遗传变异改变了寄生植物生态系统工程师Rhinanthus与其宿主之间的相互作用
DOI：
10.1098/rstb.2010.0320
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
R. Preziosi
中科院分区：
文献类型：
--
作者：
J. Rowntree;D. Cameron;R. Preziosi
种内遗传变异是影响种间相互作用和群落结构的重要因素。半寄生植物Rhinanthus属具有生态系统工程师的作用，显著改变了草原地上和地下的群落结构。在这里，我们展示了单一寄主物种（大麦- hordeum vulgare）内基因型变异的重要性，以及两种寄生虫（Rhinanthus minor和Rhinanthus angustifolius）之间的种群水平变异对伴侣双方寄生虫感染结果的重要性。我们测量了宿主适应度（种子数量），并计算了寄生虫毒力，即感染和未感染宿主之间种子集的差异（与宿主耐受性相反）。毒力由寄主种内和寄主种间的遗传变异决定，但粗裂裂毛鼠的毒力始终高于小裂裂裂毛鼠。最耐受性的宿主具有最低的固有适应度，并且与其他受感染的宿主相比没有获得适应度优势。我们测量了寄生虫的大小作为传播能力（感染进一步宿主的能力）和宿主抗性的代理。寄生虫的大小取决于宿主基因型、寄生虫种类和寄生虫种群的特定组合，没有一种寄生虫总是更大。我们证明了感染的结果不仅取决于宿主物种，而且还取决于宿主和寄生虫的潜在遗传学。因此，宿主和寄生虫的遗传变异可能是犀牛改变生态系统影响的重要组成部分。
Within-species genetic variation is a potent factor influencing between-species interactions and community-level structure. Species of the hemi-parasitic plant genus Rhinanthus act as ecosystem engineers, significantly altering above- and below-ground community structure in grasslands. Here, we show the importance of genotypic variation within a single host species (barley—Hordeum vulgare), and population-level variation among two species of parasite (Rhinanthus minor and Rhinanthus angustifolius) on the outcome of parasite infection for both partners. We measured host fitness (number of seeds) and calculated parasite virulence as the difference in seed set between infected and uninfected hosts (the inverse of host tolerance). Virulence was determined by genetic variation within the host species and among the parasite species, but R. angustifolius was consistently more virulent than R. minor. The most tolerant host had the lowest inherent fitness and did not gain a fitness advantage over other infected hosts. We measured parasite size as a proxy for transmission ability (ability to infect further hosts) and host resistance. Parasite size depended on the specific combination of host genotype, parasite species and parasite population, and no species was consistently larger. We demonstrate that the outcome of infection by Rhinanthus depends not only on the host species, but also on the underlying genetics of both host and parasite. Thus, genetic variations within host and parasite are probably essential components of the ecosystem-altering effects of Rhinanthus.