Cortinarius magellanicus Spegazzini and its look-alikes: the most widely distributed edible Cortinarius of Patagonia is a species complex.

SALGADO SALOMÓN M.E.; DRESCH P.; BARROETAVEÑA C; PEINTNER U.

Innsbruck

Simposio; 1st Mycology Tyrol Mini-Symposium.; 2017

Institute of Microbiology University of Innsbruck

Presentación oralCortinarius magellanicus Spegazzini (1887) is an edible mushroom, which is usually consumed in Patagonia. This beautiful mushroom can be recognized by the conspicuously violet, slender fruitbodies, which are glutinous all over, as typical for Cortinarius subgenus Myxacium. Spegazzini´s original material was lost; for that reason Cortinarius magellanicus was re-described and validated with a neotype by Moser & Horak (1975). Since then, Cortinarius magellanicus was considered a living fossil of Nothofagaceae forests, as it is the most frequent and widely distributed species of Cortinarius in the Southern hemisphere (Argentina, Chile and New Zealand). However, our knowledge on PatagonianCortinarius diversity is still poor and mainly based on Moser & Horak´s work from the early 1960ties. Therefore, we carried out an extensive sampling of Cortinarius species growing in Argentinian Nothofagaceae forests during March-May 2017. Twelve collections representing C. magellanicus based on classical morpho-anatomical characters were used for a phylogenetic analysis based on rDNAITS sequences. Sequences from Cortinarius Typus material and closely related sequences from GenBank were also included in the study. Our results showed that Cortinarius magellanicus represents a complex of species composed of at least 4 phylogenetic lineages, each with strong regionalism and distinct host associations. This complex is closely related to C. janthinophaeus, with has dry pilei and stipe, thus being a typical representative of the subgenus Telamonia. This highlights that, especially in Southern hemisphere, many groups of Cortinarius have the tendency to form slimy layers on pileus and stipe. Thus, the subgenus Myxacium is paraphyletic and artificial. Cortinarius magellanicusSpegazzini is re-defined and described based on the neotype material. Moreover, C. magellanicoalbus and C. roblerauli are proposed as new species based on consistent morph-anatomical characters and a typical ecology. The clear definition of taxa in the C. magellanicus species complex is of high relevance, given the abundance of these fungi, their ectomycorrhizal role in Nothofagaceae forests and the fact they are regularly collected and consumed.