Extensive gene flow over Europe and possible speciation over Eurasia in the ectomycorrhizal basidiomycete Laccaria amethystina complex
Extensive gene flow over Europe and possible speciation over Eurasia in the ectomycorrhizal basidiomycete Laccaria amethystina complex
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DOI：
10.1111/j.1365-294x.2011.05392.x
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发表时间：
2012-01
影响因子：
4.9
通讯作者：
L. Vincenot;K. Nara;Christopher M. Sthultz;J. Labbé;M. Dubois;L. Tedersoo;F. Martin;M. Selosse
中科院分区：
文献类型：
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作者：
L. Vincenot;K. Nara;Christopher M. Sthultz;J. Labbé;M. Dubois;L. Tedersoo;F. Martin;M. Selosse
尽管外生菌根共生具有重要的生态和经济意义，但对外生菌根真菌的生物地理格局和大规模遗传结构的研究很少。我们将种群遗传学和系统发育方法结合起来，以了解大陆范围内真菌种群的空间结构。利用9个微卫星标记，我们研究了欧洲(2900公里以上)广泛分布的担子菌漆树菌(Laccaria Amthystina)16个种群间的基因流动。我们还将范围扩大到另外两个来自日本的种群(104公里外)，并利用三个核基因(NAR、G6PD和核糖体DNA)和两个线粒体核糖体基因，通过微卫星标记和多位点系统发育分析，将它们与欧洲种群进行了比较。欧洲紫锥菊种群分化有限(平均Fst=0.041)，距离隔离度很低。这种泛欧模式可能源于孢子的有效空中传播、种群的高度遗传多样性以及与多个宿主的互惠互动，这些都有利于迁徙。基于核基因的多位点系统发育分析证实，日本和欧洲的标本关系密切，但在地理上是聚在一起的。通过使用微卫星标记，我们发现日本人与欧洲人有很强的分化(fst=0.416)，通过推断欧洲人的IBD模式，比预期的要多。人口结构分析清楚地将人口分为两个集群，即欧洲集群和日本集群。我们讨论了IBD在连续种群中(考虑到北半球环状物种的一些证据)与欧亚大陆异地物种形成的可能性，使紫晶乳杆菌成为未来研究的洲际物种模型。
Biogeographical patterns and large‐scale genetic structure have been little studied in ectomycorrhizal (EM) fungi, despite the ecological and economic importance of EM symbioses. We coupled population genetics and phylogenetic approaches to understand spatial structure in fungal populations on a continental scale. Using nine microsatellite markers, we characterized gene flow among 16 populations of the widespread EM basidiomycete Laccaria amethystina over Europe (i.e. over 2900 km). We also widened our scope to two additional populations from Japan (104 km away) and compared them with European populations through microsatellite markers and multilocus phylogenies, using three nuclear genes (NAR, G6PD and ribosomal DNA) and two mitochondrial ribosomal genes. European L. amethystina populations displayed limited differentiation (average FST = 0.041) and very weak isolation by distance (IBD). This panmictic European pattern may result from effective aerial dispersal of spores, high genetic diversity in populations and mutualistic interactions with multiple hosts that all facilitate migration. The multilocus phylogeny based on nuclear genes confirmed that Japanese and European specimens were closely related but clustered on a geographical basis. By using microsatellite markers, we found that Japanese populations were strongly differentiated from the European populations (FST = 0.416), more than expected by extrapolating the European pattern of IBD. Population structure analyses clearly separated the populations into two clusters, i.e. European and Japanese clusters. We discuss the possibility of IBD in a continuous population (considering some evidence for a ring species over the Northern Hemisphere) vs. an allopatric speciation over Eurasia, making L. amethystina a promising model of intercontinental species for future studies.