Abstract Trichaptum abietinum and Trichaptum fuscoviolaceum (Hymenochaetales, Basidiomycota) are closely related saprotrophic fungi, widely distributed on coniferous wood in temperate regions worldwide. Three intersterility groups have previously been detected in T. abietinum, while no prezygotic barriers have been proven within T. fuscoviolaceum. The aim of this study was to reveal the phylogeography and genetic relationship between these two closely related species and to explore whether the previously observed intersterility groups in T. abietinum are reflected in the genetic data. We assembled worldwide fruit body collections of both species (N = 314) and generated DNA sequences from three nuclear (ITS2, LSU, IGS) and one mitochondrial rDNA region (mtLSU). The two species are genetically well separated in all analyses. In correspondence with observations from earlier mating studies, our results revealed that T. fuscoviolaceum is genetically more uniform than T. abietinum. Multiple genetic sub-groups exist in T. abietinum that may correspond to the previously observed intersterility groups. However, there is low consistency across the investigated loci in delimiting the different sub-groups, except for a consistent North American group. As for many other widespread fungi, a complex phylogeographic pattern is found in T. abietinum which may have been formed by geographic, as well as multiple genetic intersterility barriers.

中文翻译：

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对比密切相关的担子菌 Trichaptum abietinum 和 T. fuscoviolaceum (Hymenochaetales) 的遗传结构

摘要 Trichaptum abietinum 和Trichaptum fuscoviolaceum (Hymenochaetales, Basidiomycota) 是亲缘关系密切的腐生真菌，广泛分布于全球温带地区的针叶林中。之前在 T. abietinum 中检测到了三个不育组，而在 T. fuscoviolaceum 中没有证明合子前屏障。本研究的目的是揭示这两个密切相关物种之间的系统地理学和遗传关系，并探讨先前观察到的 T. abietinum 中的不育组是否反映在遗传数据中。我们组装了这两个物种的全球子实体集合（N = 314），并从三个核（ITS2、LSU、IGS）和一个线粒体 rDNA 区域 (mtLSU) 生成 DNA 序列。在所有分析中，这两个物种在遗传上都很好地分离。与早期交配研究的观察结果一致，我们的结果显示 T. fuscoviolaceum 在遗传上比 T. abietinum 更均匀。T. abietinum 中存在多个遗传亚组，它们可能对应于先前观察到的不育组。然而，除了一致的北美组外，所调查的基因座在划分不同亚组方面的一致性较低。对于许多其他广泛分布的真菌，在 T. abietinum 中发现了复杂的系统地理学模式，这可能是由地理以及多个遗传不育障碍形成的。abietinum 可能对应于先前观察到的不育组。然而，除了一致的北美组外，所调查的基因座在划分不同亚组方面的一致性较低。对于许多其他广泛分布的真菌，在 T. abietinum 中发现了复杂的系统地理学模式，这可能是由地理以及多个遗传不育障碍形成的。abietinum 可能对应于先前观察到的不育组。然而，除了一致的北美组外，所调查的基因座在划分不同亚组方面的一致性较低。对于许多其他广泛分布的真菌，在 T. abietinum 中发现了复杂的系统地理学模式，这可能是由地理以及多个遗传不育障碍形成的。