Submitted to: Studies in Mycology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2010
Publication Date: 8/1/2010
Citation: Bensch, K., Groenewald, J.Z., Dijksterhuis, J., Starink-Willemse, M., Anderson, B., Summerell, B.A., Shin, H.D., Dugan, F.M., Schroers, H.J., Braun, U., Crous, P.W. 2010. Species and ecological diversity within the Cladosporium cladosporioides complex (Davidiellaceae, Capnodiales). Studies in Mycology 67: 1-94. Interpretive Summary: The fungal species Cladosporium cladosporioides is a cosmopolitan, ubiquitous saprophyte and opportunistic plant pathogen. Recent research utilizing isolates from various sources, including numerous isolates from WRPIS, have demonstrated that C. cladosporioides is a species complex consisting of C. cladosporioides sensu stricto plus several additional taxa. Phylogenetic analyses based on DNA sequences for ITS1, ITS2, partial actin and elongation factor regions have enabled distinction of multiple new taxa, some of which are described as new species.
Technical Abstract: The genus Cladosporium is one of the largest genera of dematiaceous hyphomycetes, and is characterised by a coronate scar structure, conidia in acropetal chains and Davidiella teleomorphs. Based on morphology and DNA phylogeny, the species complexes of C. herbarum and C. sphaerospermum have been resolved, resulting in the elucidation of numerous new taxa. In the present study, more than 200 isolates belonging to the C. cladosporioides complex are examined and phylogenetically analysed on the basis of DNA sequences of the nuclear ribosomal RNA gene operon, including the internal transcribed spacer regions ITS1 and ITS2, the 5.8S nrDNA (ITS), as well as partial actin and translation elongation factor 1-a gene sequences. For the saprobic, widely distributed species Cladosporium cladosporioides, both a neotype and epitype are designated in order to specify a well established circumscription and concept of this species. Cladosporium tenuissimum and C. oxysporum, two saprobes mainly abundant in the tropics, are epitypified and shown to be allied to but distinct from C. cladosporioides. Twenty-two species are newly described on the basis of phylogenetic characters and cryptic morphological differences. The most important phenotypic characters for distinguishing species within the C. cladosporioides complex which represents a monophyletic subclade within the genus, are shape, width, length as well as septation and surface ornamentation of conidia and conidiophores, length and branching patterns of conidial chains and hyphal shape, width and arrangement. Many of the treated species, e.g., C. acalyphae, C. angustisporum, C. australiense, C. basiinflatum, C. chalastosporoides, C. colocasiae, C. cucumerinum, C. exasperatum, C. exile, C. flabelliforme, C. gamsianum, and C. globisporum are currently known only from specific hosts, or have a restricted geographical distribution. A key to all species currently recognised within the C. cladosporioides complex is provided.