Data from: Shifts in diversification rates and host jump frequencies shaped the diversity of host range among Sclerotiniaceae fungal plant pathogens

The range of hosts that a parasite can infect in nature is a trait determined by its own evolutionary history and that of its potential hosts. However, knowledge on host range diversity and evolution at the family level is often lacking. Here, we investigate host range variation and diversification trends within the Sclerotiniaceae, a family of Ascomycete fungi. Using a phylogenetic framework, we associate diversification rates, the frequency of host jump events, and host range variation during the evolution of this family. Variations in diversification rate during the evolution of the Sclerotiniaceae define three major macro-evolutionary regimes with contrasted proportions of species infecting a broad range of hosts. Host-parasite co-phylogenetic analyses pointed towards parasite radiation on distant hosts long after host speciation (host jump or duplication events) as the dominant mode of association with plants in the Sclerotiniaceae. The intermediate macro-evolutionary regime showed a low diversification rate, high frequency of duplication events, and the highest proportion of broad host range species. Our findings suggest that the emergence of broad host range fungal pathogens results largely from host jumps, as previously reported for oomycete parasites, probably combined with low speciation rates. These results have important implications for our understanding of fungal parasites evolution and are of particular relevance for the durable management of disease epidemics.自然条件下，寄生虫可侵染的宿主范围是由其自身演化历史与潜在宿主的演化历史共同决定的性状。然而，当前学界对科级分类单元的宿主范围多样性及其演化规律的认知仍存在显著缺口。本研究聚焦于子囊菌（Ascomycete）门下的核盘菌科（Sclerotiniaceae）真菌类群，探究其宿主范围变异与多样化演化趋势。研究依托系统发育框架（phylogenetic framework），将该科真菌演化过程中的多样化速率、宿主跃迁（host jump）事件发生频率与宿主范围变异三者进行关联分析。核盘菌科演化过程中的多样化速率差异，可划分为三大差异化的大进化模式（macro-evolutionary regimes），各类模式下侵染广谱宿主的物种占比存在显著差异。宿主-寄生虫协同系统发育分析（co-phylogenetic analyses）结果显示，核盘菌科真菌与植物的主要关联模式为：在宿主物种形成已久之后，寄生虫在远缘宿主类群中发生辐射演化（即宿主跃迁或宿主复制事件）。处于中间型的大进化模式类群，其多样化速率偏低、宿主复制事件发生频率较高，且广谱宿主范围物种的占比最高。本研究结果表明，广谱宿主型真菌病原菌的出现主要源于宿主跃迁事件——这与此前针对卵菌（oomycete）寄生虫的研究报道一致——且该过程大概率伴随较低的物种形成速率。上述研究结果不仅深化了我们对真菌寄生虫演化机制的认知，同时对病害流行的可持续防控具有重要的指导意义。