Contributions to the current discussion of sections of the genus Cortinarius:contributions to the controversial section Myxotelamonia associated with the Nothofagaceae forests of South America

SALGADO SALOMON M.E.; BARROETAVEÑA, C.; PEINTNER, URSULA

Santiago

Congreso; X Congreso Latinoamericano deMicología; 2020

Asociación latinoamericana de micología

Presentación oral.Cortinarius (Pers.) Gray is the most species-rich and widely distributed genera in South American Nothofagaceae forests. Due its ectomycorrhizal role, the genus is critical for nutrient cycling in these forests. Additionally, some species as C. magellanicus complex and C. xiphidipus have been reported as edible, with interesting nutritional and nutraceutical properties. Even though several authors have contributed to the knowledge of Cortinarius’ richness associated to South American Nothofagaceae forests, its diversity remains insufficiently studied, constituting a biodiversity hotspot. Following the macroscopic features of the section Myxotelamonia proposed by Moser in 1975 for glutinous “Telamonia” specimens found in South America, the present study searched for specimens comprising this characteristics, and seeks to unravel species richness and propose plausible infrageneric relationships. Samples were collected in Nothofagaceae forests from Chubut, Río Negro and Neuquén provinces, following macro Myxotelamonia section characteristics. Macro and microscopical descriptions were made from fresh basidiomata. Phylogenetic relationships were analysed through ITS-rDNA, RPB1 and LSU sequences. Five new species of Cortinarius were described with clearly consistent morphological and molecular features. Cortinarius neuquensis, associated to N. antarctica and mix Lophozonia forest, presents light ochre, glutinous pileus, pale argillaceous lamella, and elliptical (7.3–8.3 x 3.6–4.1µm), finely dotted basidiospores. Cortinarius gracilentus, associated to N. dombeyi and N. antarctica, have glutinous, discolour brown pileus, cocoa brown lamellae and elliptical (11.1±0.7 x 7.1±0.5 µm), verrucose basidiospores. Cortinarius pseudoxiphidipus, associated to N. dombeyi, is characterized by glutinous, honey brown pileus, radicant stipes, with elliptical (11.4±0.8 x 5.6±0.3 µm), finely verrucose basidiospores, bigger than C. xiphidipus. Cortinarius voluptatis, associated to Lophozonia forests, shows glutinous, red wine coloured pileus, lilash lamellae, big, elliptical (13.1±0.7 x 8±0.5 µm), verrucose basidiospores, and hymenial cheilocystdia. Cortinarius egoni, associated with N. dombeyi, have glutinous, discolour, pale yellow pileus, and elliptical (7.5–8.9 x 4.8–5.5 µm), dotted basidiospores. Clarifying taxonomic identities of this highly diverse genus is relevant and necessary for ecological analyses and also for mushrooms uses as edible products and ectomycorrhizal inoculum.