Submitted to: Mycological Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/7/2002
Publication Date: 2/1/2003
Citation: BRAUN, U., CROUS, P.C., DUGAN, F.M., GROENEWALD, J.Z., HOOG, G.S. PHYLOGENY AND TAXONOMY OF CLADOSPORIUM-LIKE HYPHOMYCETES, INCLUDING DAVIDIELLA GEN. NOV., THE TELEOMORPH OF CLADOSPORIUM S.STR.. Mycological Progress. 2003.
Interpretive Summary: As previously constituted, the genus Cladosporium included many fungi of importance to clinical medicine, plant pathology, product deterioration and other disciplines. Fungal taxonomists have segregated the clinical species into other genera (mainly Cladophialophora) and some of the plant pathological species are now in genera like Fusicladium and Passalora. Other species of importance to plant pathology are still considered "true" Cladosporium species (i.e., Cladosporium in the strict sense). This article establishes further criteria for inclusion as a "true" Cladosporium, and gives a new name (Davidiella, after the mycologist John David, a specialist in Cladosporium taxonomy) to those fungi constituting the sexual stages of "true" Cladosporium species. One fungus in particular, Cladosporium malorum, was discovered by the authors to have a rare spore state closely resembling the fungus Alternaria, and the authors have confirmed by molecular genetics that C. malorum is indeed best classified in Alternaria. Alternaria ("Cladosporium") malorum has been isolated from various hosts over a broad geographic range and was at one time a common fungal contaminant of market wheat from Washington state.
Technical Abstract: A phylogenetic study employing sequence data from the internal transcribed spacer (ITS1, ITS2) and 5.8S gene, as well as 18S rRNA gene of various cladosporium-like hyphomycetes revealed Cladosporium s.l. to be heterogeneous. The genus Cladosporium s.str. was shown to represent a sister clade to Mycosphaerella, for which the teleomorph genus Davidiella is proposed. The morphology, phylogeny and taxonomy of the cladosporioid fungi are discussed on the basis of this phylogeny, which consists of several clades representing cladosporium-like genera. Cladosporium is confined to Davidiella (Mycosphaerellaceae) anamorphs with coronate conidiogenous loci and conidial hila. Pseudo-cladosporium is confined to anamorphs of Caproventuria (Venturiaceae). Cladosporium-like anamorphs of the Venturiaceae (conidia catenate) are referred to Fusicladium. Human-pathogenic Cladosporium species belong in Cladophialophora (Capronia, Herpotrichiellaceae) and Cladosporium fulvum is representative of the Mycosphaerella /Passalora clade (Mycosphaerellaceae). Cladosporium malorum proved to be the correct name for Pseudocladosporium kellermanianum (Phaeoramularia kellermaniana, Cladophialophora kellermaniana) as well as Cladosporium porophorum. Based on differences in conidiogenesis and the structure of the conidiogenous loci, further supported by molecular data, C. malorum is allocated to Alternaria.