Data from: Population structure and diversity of an invasive pine needle pathogen reflects anthropogenic activity

Dothistroma septosporum is a haploid fungal pathogen that causes a serious needle blight disease of pines, particularly as an invasive alien species on Pinus radiata in the Southern Hemisphere. During the course of the last two decades, the pathogen has also incited unexpected epidemics on native and non-native pine hosts in the Northern Hemisphere. Although the biology and ecology of the pathogen has been well documented, there is a distinct lack of knowledge regarding its movement or genetic diversity in many of the countries where it is found. In this study we determined the global population diversity and structure of 458 isolates of D. septosporum from 14 countries on six continents using microsatellite markers. Populations of the pathogen in the Northern Hemisphere, where pines are native, displayed high genetic diversities and included both mating types. Most of the populations from Europe showed evidence for random mating, little population differentiation and gene flow between countries. Populations in North America (USA) and Asia (Bhutan) were genetically distinct but migration between these continents and Europe was evident. In the Southern Hemisphere, the population structure and diversity of D. septosporum reflected the anthropogenic history of the introduction and establishment of plantation forestry, particularly with Pinus radiata. Three introductory lineages in the Southern Hemisphere were observed. Countries in Africa, that have had the longest history of pine introductions, displayed the greatest diversity in the pathogen population, indicating multiple introductions. More recent introductions have occurred separately in South America and Australasia where the pathogen population is currently reproducing clonally due to the presence of only one mating type.松针枯病原菌（Dothistroma septosporum）是一种单倍体真菌病原菌，可引发严重的松树针枯病，在南半球作为外来入侵物种对辐射松（Pinus radiata）造成的危害尤为突出。近二十年来，该病原菌在北半球也引发了针对本土及非本土松树寄主的意外病害流行。尽管该病原菌的生物学与生态学特征已得到充分记载，但在其分布的诸多国家中，学界对其传播路径与遗传多样性仍存在显著的认知空白。本研究利用微卫星（microsatellite）标记，对六大洲14个国家的458株D. septosporum分离株开展了全球种群多样性与种群结构分析。在松树原生分布的北半球，该病原菌种群展现出较高的遗传多样性，且包含两种交配型。欧洲多数种群呈现随机交配的特征，种群间分化程度较低，国家间存在基因流。北美（美国）与亚洲（不丹）的种群遗传特征独特，但这些大陆与欧洲之间存在明显的基因迁移现象。在南半球，D. septosporum的种群结构与多样性反映了人工林引种与营建的人为历史进程，尤以辐射松种植为典型。本研究在南半球共观测到三个引入谱系。拥有最长松树引种历史的非洲国家，其病原菌种群多样性最高，表明存在多次引种事件。南美与澳大拉西亚地区则出现了较晚的独立引种事件，由于仅存在单一交配型，当前该区域的病原菌种群以无性繁殖方式繁衍。