Publications (2)1.4 Total impact
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Article: Devriesia, a new hyphomycete genus to accommodate heat-resistant, cladosporium-like fungi
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ABSTRACT: Three new species of heat-resistant fungi related to the hyphomycete Cladosporium staurophorum (Kendrick) M.B. Ellis were isolated from heat-treated soil from commercial lowbush blueberry fields and other sites in eastern Canada. Cladosporium staurophorum and the three new species produce characteristic dark, multicelled chlamy dospores. Phylogenetic analysis of nuclear ribosomal internal transcribed spacer DNA sequences suggest that these four species form a monophyletic group that is marginal in the Mycosphaerellaceae and phylogenetically distinct from Cladosporium sensu stricto. The new genus Devriesia is described for C. staurophorum, the three new species, and a fifth species originally described as Cladosporium chlamydosporis. A key to distinguish the five accepted species is provided. The species of the genus are dimorphic and share similar cladosporium-like conidial anamorphs consisting of pale brown, short, acropetally produced chains of cylindrical to fusiform, zero- or one-septate conidia and ramoconidia, diagnostic chlamydosporic synanamorphs, and a soil-borne, heat-resistant ecology. Devriesia acadiensis N.L. Nickerson & Seifert, with clover-shaped chlamydospores, Devriesia shelburniensis N.L. Nickerson & Seifert, with large, multi celled chlamydospores, and Devriesia thermodurans N.L. Nickerson & Seifert, with few-celled, clavate chlamy dospores, are described as new species. Chlamydospores from cultures of D. acadiensis, Devriesia staurophora, and D. thermodurans germinated after exposure to 75 °C for 30 min. Germination of these spores was activated by a heat shock. Chlamydospores from cultures of C. shelburniensis did not germinate after heat exposure.Key words: dematiaceous hyphomycetes, heat-resistant fungi, lowbush blueberries, Vaccinium angustifolium, ITS rDNA phylogeny.Canadian Journal of Botany 02/2011; 82(7):914-926. · 1.40 Impact Factor -
Article: Leohumicola, a new genus of heat-resistant hyphomycetes
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ABSTRACT: The new anamorph genus Leohumicola (hyphomycetes) is described for four species, including three new species isolated after heat treatment of soils collected in Canada. The species produce slow-growing agar colonies that eventually produce lateral or terminal aleurioconidia, with a dark brown terminal cell, and the remains of a paler basal cell that fractures during secession. The genus is compared with Humicola, Trichocladium, Thermomyces, Complexipes and some other morphologically similar genera. Nuclear ribosomal small subunit (SSU) ribosomal DNA sequences demonstrate that Leohumicola is a monophyletic group in the Leotiomycetes, distinct from Humicola and Trichocladium (Sordariales), and Thermomyces (Eurotiales). Internal transcribed spacer sequences (ITS) support our recognition of four species of Leohumicola, each with distinct colony and micromorphological characters. The existence of additional species is probable based on our own ITS sequences and some retrieved from GenBank. The type species L. verrucosa, was recovered from a variety of soil types across Canada, and has sympodially proliferating conidiogenous cells that produce conidia with verrucose terminal cells that measure 4–5.5 x 4–5.5 µm. The SSU of some strains of this species have five long Group I introns that extend the length to more than 3700 nt. Leohumicola lenta produces very slowly growing colonies on agar media and larger conidia than L. verrucosa, and L. terminalis produces only terminal conidia. The latter two species are represented by single strains. The fourth species, L. minima is based on Trichocladium minimum, originally isolated from volcanic ash soil from Chile. Internal transcribed specer (ITS) sequences suggest that Humicola is a synonym of Trichocladium, a finding that may require conservation of Humicola. Dichotomous keys are provided to the accepted species of Leohumicola, and to morphologically similar aleurioconidial genera.Studies in Mycology. 01/2005;
