RESUMO
This paper is a contribution to the current knowledge of taxonomy, ecology and distribution of South American Cortinarius (Pers.) Gray. Cortinarius is among the most widely distributed and species-rich basidiomycete genera occurring with South American Nothofagaceae and species are found in many distinct habitats, including shrublands and forests. Due to their ectomycorrhizal role, Cortinarius species are critical for nutrient cycling in forests, especially at higher latitudes. Some species have also been reported as edible fungi with high nutritional quality. Our aim is to unravel the taxonomy of selected Cortinarius belonging to phlegmacioid and myxotelamonioid species based on morphological and molecular data. After widely sampling Cortinarius specimens in Patagonian Nothofagaceae forests and comparing them to reference collections (including holotypes), we propose five new species of Cortinarius in this work. Phylogenetic analyses of concatenated rDNA ITS-LSU and RPB1 sequences failed to place these new species into known Cortinarius sections or lineages. These findings highlight our knowledge gaps regarding the fungal diversity of South American Nothofagaceae forests. Due to the high diversity of endemic Patagonian taxa, it is clear that the South American Cortinarius diversity needs to be discovered and described in order to understand the evolutionary history of Cortinarius on a global scale.
RESUMO
We studied the South American species of Cortinarius section Thaumasti based on morphological and molecular data. Members of this group can easily be identified in the field because the basidiomata are small and Phlegmacium-like with a bulbous stipe and the universal veil in most species forms a distinct volva at the base of the stipe. The phylogenetic delimitation of the clade was mostly in concordance with the earlier, morphology-based grouping of the South American taxa except that C. chrysophaeus was resolved outside of the clade. Altogether nine species were recognized in the section. Four species, C. chlorophanus, C. coleopus, C. cosmoxanthus, and C. vaginatus, were previously described by other authors, whereas three species, C. chlorosplendidus, C. olivaceovaginatus, and C. subcosmoxanthus, are described here as new. We were able to identify two remaining taxa, but we do not have sufficient morphological data to allow for a formal description. All of the species in C. section Thaumasti form ectomycorrhizal associations with Nothofagaceae. They have been documented from South America and New Zealand. The Patagonian species are considered endemic to the region. A key to the described species is provided.
Assuntos
Agaricales/classificação , Fagales/microbiologia , Micorrizas , Agaricales/citologia , Agaricales/genética , Agaricales/isolamento & purificação , DNA Espaçador Ribossômico , Florestas , Genes Fúngicos , Nova Zelândia , Filogenia , América do SulRESUMO
In this study, we document and describe the new Cortinarius section Austroamericani. Our results reveal high species diversity within this clade, with a total of 12 recognized species. Of these, only C. rufus was previously documented. Seven species are described as new based on basidiomata collections. The four remaining species are only known from environmental sequences. All examined species form ectomycorrhizal associations with species of Nothofagaceae and are currently only known from Argentinean and Chilean Patagonia. The phylogenetic analysis based on the nuc rDNA internal transcriber spacer (ITS1-5.8S-ITS2 = ITS) and partial 28S gene (28S) sequences shows that this section is related to other taxa from the Southern Hemisphere. Species in this group do not belong to subg. Telamonia, where C. rufus was initially placed. Cortinarius rufus and the newly described C. subrufus form a basal clade within sect. Austroamericani that has a weakly supported relationship with the core clade. Because the two species are morphologically similar to species from the core clade and share their distribution and Nothofagaceae associations, we include them here as part of sect. Austroamericani sensu lato (s.l.) until more material is available to refine the delimitation.