Data from: Host resistance and pathogen aggressiveness are key determinants of coinfection in the wild

Coinfection, whereby the same host is infected by more than one pathogen strain, may favor faster host exploitation rates as strains compete for the same limited resources. Hence, coinfection is expected to have major consequences for pathogen evolution, virulence and epidemiology. Theory predicts genetic variation in host resistance and pathogen infectivity to play a key role in how coinfections are formed. The limited number of studies available have demonstrated coinfection to be a common phenomenon, but little is known about how coinfection varies in space, and what its determinants are. Our aim is to understand how variation in host resistance and pathogen infectivity and aggressiveness contribute to how coinfections are formed in the interaction between fungal pathogen Podosphaera plantaginis and Plantago lanceolata. Our phenotyping study reveals that more aggressive strains are more likely to form coinfections than less aggressive strains in the natural populations. In the natural populations most of the variation in coinfection is found at the individual plant level, and results from a common garden study confirm the prevalence of coinfection to vary significantly among host genotypes. These results show that genetic variation in both the host and pathogen populations are key determinants of coinfection in the wild

共感染（coinfection）指同一宿主被多种病原菌株侵染的现象，由于菌株间会争夺有限的宿主资源，该过程可能会加速病原对宿主的利用效率。因此，共感染被认为会对病原的进化、毒力以及流行病学特征产生重要影响。理论预测，宿主抗性与病原侵染性的遗传变异，在共感染的形成过程中发挥关键调控作用。现有相关研究数量有限，虽已证实共感染是一种普遍现象，但人们对其空间分布差异及其影响因子仍知之甚少。本研究旨在探究：在真菌病原物车前白粉菌（Podosphaera plantaginis）与长叶车前（Plantago lanceolata）的互作体系中，宿主抗性、病原侵染性与致病力的遗传变异，如何影响共感染的形成过程。本研究的表型分析结果显示，在自然种群中，致病力更强的病原菌株相比弱致病力菌株，更易形成共感染。在自然种群中，共感染的绝大多数变异来源于宿主个体层面；而同质园（common garden）实验的结果证实，共感染的发生率在不同宿主基因型间存在显著差异。上述结果表明，宿主与病原种群的遗传变异，是野外环境中共感染形成的关键决定因子。