Host ecotype generates evolutionary and epidemiological divergence across a pathogen metapopulation

The extent and speed at which pathogens adapt to host resistance varies considerably. This presents a challenge for predicting when—and where—pathogen evolution may occur. While gene flow and spatially heterogeneous environments are recognized to be critical for the evolutionary potential of pathogen populations, we lack an understanding of how the two jointly shape coevolutionary trajectories between hosts and pathogens. The rust pathogen Melampsora lini infects two ecotypes of its host plant Linum marginale that occur in close proximity yet in distinct populations and habitats. In this study, we found that within-population epidemics were different between the two habitats. We then tested for pathogen local adaptation at host population and ecotype level in a reciprocal inoculation study. Even after controlling for the effect of spatial structure on infection outcome, we found strong evidence of pathogen adaptation at the host ecotype level. Moreover, sequence analysis of two pathogen...病原体适应宿主抗性的范围与速率存在显著差异，这为预测病原体进化发生的时间与地点带来了挑战。尽管基因流（gene flow）与空间异质环境已被证实对病原体种群的进化潜力至关重要，但目前我们仍尚不明确二者如何共同塑造宿主与病原体间的共进化轨迹。锈病病原体Melampsora lini侵染宿主植物Linum marginale的两种生态型，该植物的两种生态型虽分布邻近，却分属不同的种群与生境。本研究发现，两种生境下的种群内流行病特征存在差异。随后我们通过互惠接种实验，在宿主种群与生态型层面检测了病原体的本地适应性。即便在控制了空间结构对感染结果的影响后，我们仍发现了病原体在宿主生态型层面具有适应性的有力证据。此外，针对两种病原体的序列分析……