title: The Paxillus involutus (Boletales, Paxillaceae) complex in Europe: genetic diversity and morphological description of the new species Paxillus cuprinus, typification of P. involutus s.s., and synthesis of species boundaries.
abstract: Paxillus involutus is a model species for ecological or physiological studies of ectomycorrhizal agaricomycetes. Three to six groups or species linked to it have been ecologically and morphologically distinguished. Phylogenetic studies have revealed the existence of four species in Europe: Paxillus ammoniavirescens, Paxillus obscurisporus, P. involutus, and a fourth as yet not described species. We studied 47 collections from 24 French and Italian locations, supplemented with GenBank data, in order to genetically and taxonomically delineate these species. Phylogenetic analyses of three nuclear DNA regions (rDNA internal transcribed spacer (ITS), tef1-α, and gpd) confirmed the four European species. Morphology, culture, and ecology features allowed us to delineate species boundaries and to describe the fourth species we named Paxillus cuprinus since it turns coppery with age. As there is no existing original herbarium specimen for P. involutus, one of our collections was chosen as the epitype. The low genetic diversity found in P. cuprinus correlates with stable morphological traits (basidiome colour, ovoid-amygdaliform spores with an apical constriction) and with ecological preferences (association with Betulaceae in open and temperate areas). In contrast, P. ammoniavirescens is characterized by a high genetic diversity and a high variation of its morphological and ecological features.
authors.affiliation: Université Paul Sabatier, CNRS, ENFA, UMR5174 EDB (Laboratoire Evolution et Diversité Biologique), 118 route de Narbonne, F-31062 Toulouse, France; CNRS, Université Paul Sabatier, UMR5174 EDB, F-31062 Toulouse, France. Electronic address: patricia.jargeat@univ-tlse3.fr.
authors.forename: Patricia
authors.initials: P
authors.lastname: Jargeat
authors.affiliation: 74 Avenue Pierre de Montesquiou, F-32000 Auch, France.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Chaumeton
authors.affiliation: Université Paul Sabatier, CNRS, ENFA, UMR5174 EDB (Laboratoire Evolution et Diversité Biologique), 118 route de Narbonne, F-31062 Toulouse, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Navaud
authors.affiliation: Dipartimento di Scienze della Vita e Biologia dei Sistemi, Università di Torino, Viale P.A. Mattioli 25, I-10125 Torino, Italy.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Vizzini
authors.affiliation: Université Paul Sabatier, CNRS, ENFA, UMR5174 EDB (Laboratoire Evolution et Diversité Biologique), 118 route de Narbonne, F-31062 Toulouse, France; CNRS, Université Paul Sabatier, UMR5174 EDB, F-31062 Toulouse, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Gryta
mesh_terms: D001487:Basidiomycota / Q000145:classification* / Q000235:genetics; D016000:Cluster Analysis; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005602:France; D005656:Fungal Proteins / Q000235:genetics; D014644:Genetic Variation; D007558:Italy; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D004271:DNA, Fungal; D005656:Fungal Proteins
keywords: Barcoding; Ecological traits; Ectomycorrhizal fungi; Morphometry; Taxonomy