Hypogeous species of Ascomycota and Basidiomycota from the Nothofagus forests of Chile and Argentina

LAURA S. DOMÍNGUEZ; MATT SMITH; EDUARDO NOUHRA; D. PFISTER; JAMES M. TRAPPE

San Carlos de Bariloche

Congreso; VI Southern Connection Congress; 2010

Univ. N. del Comahue; CONICET; INTA

Despite important collections by Thaxter (1906) and Horak (1979), the hypogeous fungi of South American temperate forests remain mostly unexplored. Our objective was to collect and describe new taxa in the Nothofagus-dominated forests of Argentina and Chile. By raking the forest soil along transects located within pure and mixed Nothofagus spp. stands, several interesting truffles and secotioid basidiomycetes were encountered. Among the Ascomycota, only one native truffle, Hydnocystis singeri, has been described from South America. Our survey detected undescribed Pezizales truffles in the genera Genea, Peziza (Galactinia clade) and Ruhlandiella as well as putative species of Amylascus and Gymnohydnotrya. This assemblage is an interesting mix of primarily holoartic genera (Genea, Peziza) and genera previously known only from Australia (Amylascus, Gymnohydnotrya, Ruhlandiella). Morphological analyses as well as DNA sequencing of the ITS and 28s ribosomal DNA indicate that these pezizalean truffles fall within primarily ectomycorrhizal clades. Our survey also revealed a wide diversity of Basidiomycota truffles, such as Hallingia and Hysterangium (Hysterangiales), Gautieria (Gomphales),Gymnopaxillus, Octaviania and Scleroderma (Boletales), Radiigera (Geastrales), Setchelliogaster and many species of Thaxterogaster (Agaricales). At least one species of Scleroderma, Radiigera and Setchelliogaster and few species within Octaviania and Thaxterogaster are likely undescribed taxa