Taxonomic re-evaluation of Leptographium lundbergii based on DNA sequence comparisons and morphology
Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa; Norwegian Forest Research Institute, Skogforsk, Høgskoleveien 8, 1432 Ås, Norway; Department of Microbiology, University of Stellenbosch, Stellenbosch 7602, South Africa
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 β-tubulin and partial elongation factor 1-α 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. © The British Mycological Society.
fungal DNA; ribosomal spacer DNA; ribosome RNA; tubulin; fungus; genetic analysis; morphology; taxonomy; article; Ascomycetes; chemistry; classification; DNA sequence; genetics; nucleotide sequence; phase contrast microscopy; phylogeny; polymerase chain reaction; sequence alignment; ultrastructure; Ascomycota; Base Sequence; DNA, Fungal; DNA, Ribosomal Spacer; Microscopy, Interference; Microscopy, Phase-Contrast; Phylogeny; Polymerase Chain Reaction; RNA, Ribosomal; Sequence Alignment; Sequence Analysis, DNA; Tubulin; Fungi; Hyalorhinocladiella; Leptographium; Leptographium lundbergii