The dematiaceous hyphomycete genera Cadophora and Phialocephala are anamorphs associated with mollisioid inoperculate discomycetes (Helotiales) and are delineated based on the complexity of the phialide arrangement with members of Cadophora producing solitary phialides and species of Phialocephala producing complex heads of multiple phialides. A third phylogenetically related taxon, Leptodontidium orchidicola, produces mostly indehiscent conidia that may represent non-functional phialides. Morphological characteristics of both sexual and asexual states of these and other fungi in a focal group of helotialean taxa were re-examined, in light of relationships shown by molecular phylogenetic analyses of rDNA ITS sequences, to determine the evolutionary significance of phialide arrangement.
View Article and Find Full Text PDFThree darkly pigmented species of conidial fungi of the family Pleosporaceae isolated from plants colonizing the Saskatchewan Glacier forefield were examined for potential roles in the degradation of moss gametophytes. Curvularia inaequalis and Ulocladium atrum isolated from bryophytes Ditrichum flexicaule and Tortella tortuosa , respectively, and Chalastospora gossypii from Saxifraga oppositifolia were inoculated onto autoclaved gametophytes of the moss Hylocomium splendens. All three species of fungi caused mass losses of the moss gametophytes.
View Article and Find Full Text PDFDuring a survey of bryophilous fungi from boreal and montane habitats, 12 isolates of a hitherto unknown plant pathogenic member of the Pleosporales were recovered from Aulacomnium palustre, Hylocomium splendens, and Polytrichum juniperinum, and described as Atradidymella muscivora gen. et sp. nov.
View Article and Find Full Text PDFAtradidymella muscivora (Pleosporales) is a bryophyte pathogen that infects the mosses Aulacomnium palustre, Hylocomium splendens, and Polytrichum juniperinum. Light and scanning electron microscopy and extracellular enzyme production were used to characterize the interactions between this fungus and its native hosts and the model host Funaria hygrometrica. Penetration was direct via hyphae or appressoria, and hosts responded by forming layered, darkly pigmented deposits at penetration sites, similar to the papillae formed by vascular plants in response to fungal infection.
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