A new endoconidial black meristematic genus,Atramixtia, associated with declining white spruce and phylogenetically allied to a lineage of dothidealean conifer pathogens

Abstract

An endoconidial, black meristematic taxon Atramixtia arboricola gen. et. sp. nov. (Dothideales) from the black subicula found on twigs of declining white spruce, Picea glauca (Moench) Voss, in Alberta is described. It is morphologically distinguishable from other endoconidial taxa by the conidioma composed of clumps of endoconidial conidiogenous cells, scattered meristematically dividing cells, dematiaceous hyphae, abundant brown, granular matrix materials, and sometimes plant tissue. Endoconidia also occur in conidiogenous cellular clumps that are not organized into a conidioma but develop directly from stromatic cells on the bark. In culture, it forms similar endoconidial conidiomata and also a mycelial, blastic synanamorph that superficially resembles Hormonema . Atramixtia arboricola is a member of the Dothideales and shows phylogenetic affinities to a clade of conifer-stem and -needle pathogens, including Sydowia and Delphinella , although no teleomorph was found either on the natural substrate or in culture. It has not been determined whether A. arboricola is pathogenic to its host, but the occurrence of abundant intracellular hyphae in the host periderm suggests that the fungus is at least parasitic.

Isolation and identification of Sydowia polyspora and its pathogenicity on Pinus yunnanensis in Southwestern China

“…Among them, S. pityophila , H . macrosporum and H. dematioide were asexual states of S. polyspora (De Hoog et al., ; Tsuneda, Davey, & Currah, ; Yurlova, De Hoog, & Van den Ende, ). A. arboricola had a conidioma structure and endoconidia, although the shape and size of the blastic conidia were similar to those of S. polyspora, while S. polyspora only formed endocoindia occasionally in the intercalary cells of hyphae, and A. arboricola could be assumed as another anamorph of S .…”

“…In this gene trees of ITS-5.8S-ITS2, S. pityophila, H. macrosporum, H. dematioide and A. arboricola were nested with S. polyspopra in the same large clade. Among them, S. pityophila, H. macrosporum and H. dematioide were asexual states of S. polyspora Tsuneda, Davey, & Currah, 2011;Yurlova, De Hoog, & Van den Ende, 1999). A. arboricola had a conidioma structure and endoconidia, although the shape and size of the blastic conidia were similar to those of S. polyspora, while S. polyspora only formed endocoindia occasionally in the intercalary cells of hyphae, and A. arboricola could be assumed as another anamorph of S. polysora (Hermanides-Nijhof, 1977;Robak, 1952;Sutton, 1980;Yurlova et al, 1999).…”

An overview of the genusGlyphiumand its phylogenetic placement in Patellariales

“…We also included a subset of taxa from Eurotiomycetes in our analysis to provide a context for previous phylogenetic placements of Glyphium based on CBS 268.34, showing its close affinities to Knufia perforans , as supported by Gueidan et al (2008), Tsuneda et al (2011) and Réblová et al (2013).…”

“…The unexpected placement of Glyphium in Chaetothyriales was restated in a number of studies based on CBS 268.34. However, subsequent work by Gueidan et al (2008), Tsuneda et al (2011) and Réblová et al (2013) positioned this CBS culture within Knufia in Chaetothyriales, resulting in the relabeling of the sequence accessions at GenBank corresponding to CBS 268.34 as “Knufia sp. CBS 268.34”.…”

The genera of Hyphomycetes – 2011 update

“…Several patterns are worth noting. Plant endophytes ( Sun & Guo 2010 , Steiner et al 2011 ), and slow-growing, darkly pigmented fungi from arid substrates such as rocks and tree bark ( Tsuneda et al 2011 ), continue to be a source of new fungal biodiversity. Some of these fungi are essentially sterile or have very reduced sporulating micromorphology, but the provision of formal names is justified by their phylogenetic distinctiveness.…”