Jacobs Karin, Solheim Halvor, Wingfield Brenda D, Wingfield Michael J
Department of Genetics, Tree Protection Co-operative Programme, Forestry and Agricultural Biotechnology Institute, University of Pretoria, South Africa.
Mycol Res. 2005 Oct;109(Pt 10):1149-61. doi: 10.1017/s0953756205003618.
The genus Leptographium was described in 1927 and currently includes 48 species, with L. lundbergii as the type species. In recent years, the taxonomic status of L. lundbergii has not been uniformly agreed upon and it has been the topic of considerable debate. The problem was compounded by the absence of a type specimen, and the species was epitypified at a later stage. Unfortunately, the whereabouts of the epitype is now unknown. In 1983, Wingfield & Marasas described L. truncatum, which is morphologically similar to L. lundbergii. Based on DNA comparisons and similarities in their morphology, this fungus was reduced to synonymy with L. lundbergii. The loss of the type specimen as well as variation in the morphology of strains identified as L. lundbergii prompted us to re-examine the taxonomic status of this species. A number of strains from various geographic areas were studied. These include a strain of L. lundbergii deposited at CBS by Melin in 1929 (CBS 352.29) as well as the ex-type strain of L. truncatum. The strains were compared based on morphology and comparison of multiple gene sequences. Three genes or genic regions, ITS2 and part of the 28S gene, partial beta-tubulin and partial elongation factor 1-alpha were compared. Strains currently identified as L. lundbergii, represented a complex of species. Strains initially described as L. truncatum clustered separately from other L. lundbergii strains, could be distinguished morphologically and should be treated as a distinct taxon. L. lundbergii is provided with a new and expanded description based on a neotype designated for it. A third group was also identified as separate from the main L. lundbergii clade and had a distinct Hyalorhinocladiella-type anamorph, described here as H. pinicola sp. nov.
细基格孢属（Leptographium）于1927年被描述，目前包括48个物种，以伦德伯格细基格孢（L. lundbergii）为模式种。近年来，伦德伯格细基格孢的分类地位尚未得到统一认可，一直是相当多争论的话题。由于缺乏模式标本，这个问题变得更加复杂，该物种在后期被指定了后选模式。不幸的是，后选模式的下落现在不明。1983年，温菲尔德和马拉萨斯描述了截形细基格孢（L. truncatum），它在形态上与伦德伯格细基格孢相似。基于DNA比较及其形态上的相似性，这种真菌被归为伦德伯格细基格孢的同物异名。模式标本的丢失以及被鉴定为伦德伯格细基格孢的菌株形态上的变异促使我们重新审视该物种的分类地位。研究了来自不同地理区域的一些菌株。这些包括1929年梅林保藏在CBS的一株伦德伯格细基格孢（CBS 352.29）以及截形细基格孢的模式菌株。基于形态学和多个基因序列的比较对这些菌株进行了比较。比较了三个基因或基因区域，即ITS2和28S基因的一部分、部分β-微管蛋白和部分延伸因子1-α。目前被鉴定为伦德伯格细基格孢的菌株代表了一个复合物种。最初被描述为截形细基格孢的菌株与其他伦德伯格细基格孢菌株分开聚类，在形态上可以区分，应被视为一个不同的分类单元。基于为其指定的新模式标本，对伦德伯格细基格孢进行了新的、更详细的描述。还鉴定出第三组与主要的伦德伯格细基格孢分支分开，具有独特的透明鼻枝孢型无性型，在此描述为新种松生透明鼻枝孢（H. pinicola）。
