Persoh Derek, Melcher Martina, Graf Katrin, Fournier Jacques, Stadler Marc, Rambold Gerhard
University of Bayreuth, Department of Mycology, Universitätsstrasse 30, D-95447 Bayreuth, Germany.
Mycologia. 2009 Mar-Apr;101(2):256-68. doi: 10.3852/08-108.
Xylaria hypoxylon, the type species of Xylaria (Xylariaceae, Sordariomycetes), was first described by Linnaeus as Clavaria hypoxylon from Sweden. Saccardo and other mycologists assumed a cosmopolitan distribution for this species. However, contradictory reports in the literature on its morphoanatomical characters and strongly inconsistent rDNA sequence data attributed to this species in GenBank suggested the existence of an unresolved species complex. To address this lack of clarity, molecular and morphological characters of numerous specimens and corresponding cultures of X. hypoxylon and related taxa from Europe were studied. Newly obtained 5.8S/ITS nrDNA sequence data were compared with published data and sequences of reference strains. European populations of X. hypoxylon from various hosts exhibited consistent rDNA sequence data and a relatively uniform holomorphic morphology, except for one specimen from Sweden that deviated in its ascospore morphology. Some samples from western United States showed DNA sequence data being identical to those of specimens from Europe, confirming a North American occurrence of X. hypoxylon. DNA sequences and morphology of other extra-European material however showed substantial deviations. Definitely not conspecific with the European material examined in this study is a strain, assigned to X. hypoxylon, the DNA sequence data of which have been used in various phylogenetic studies as a representative of Xylariaceae and Xylariales respectively. This material probably represents X longiana.
炭角菌（Xylaria hypoxylon）是炭角菌属（Xylariaceae，粪壳菌纲）的模式种，最初由林奈从瑞典描述为低柄棒瑚菌（Clavaria hypoxylon）。萨卡多和其他真菌学家认为该物种分布于全球。然而，文献中关于其形态解剖特征的相互矛盾的报道以及GenBank中归因于该物种的rDNA序列数据的强烈不一致表明存在一个未解决的物种复合体。为了解决这种不明确性，对来自欧洲的炭角菌及相关分类群的大量标本和相应培养物的分子和形态特征进行了研究。将新获得的5.8S/ITS nrDNA序列数据与已发表的数据以及参考菌株的序列进行了比较。除了一个来自瑞典的标本，其子囊孢子形态有所偏差外，来自欧洲不同寄主的炭角菌种群表现出一致的rDNA序列数据和相对统一的全形形态。来自美国西部的一些样本显示其DNA序列数据与来自欧洲的标本相同，证实了北美存在炭角菌。然而，其他欧洲以外材料的DNA序列和形态显示出很大差异。在本研究中检测的欧洲材料肯定与一种被归为炭角菌的菌株不同种，该菌株的DNA序列数据在各种系统发育研究中分别被用作炭角菌科和炭角菌目的代表。这种材料可能代表长柄炭角菌（X longiana）。
