Alignments and tree files

The agaricomycete order Cantharellales contains approximately 1000 species of fungi characterized by diverse morphological forms, ecological guilds, and nutritional modes. Examples include coralloid lichens that form symbioses with unicellular green algae, bulbil-forming lichenicolous species, corticioid free-living fungi that degrade dead sources of organic carbon, pathogens that cause plant disease, orchid root endosymbionts, and ectomycorrhizal fungi including popular edible mushrooms. However, evolutionary relationships in the Cantharellales remain poorly understood due to conflicting estimates based on ribosomal rDNA loci. We constructed a five-gene phylogeny of the Cantharellales using data from 301 specimens across the order to evaluate family-level relationships and test the hypothesis of multiple independent origins of ectomycorrhizal, lichenicolous, and orchid mycorrhizal ecologies in the order. Four monophyletic families were recovered with strong measures of statistical support: Botryobasidiaceae, Ceratobasidiaceae, Hydnaceae sensu lato, and Tulasnellaceae, with Hydnaceae containing the greatest species richness and morphological diversity. The Cantharellales diverged during the Carboniferous period with subsequent diversification following the Permian-Triassic extinction. Ancestral state reconstruction supports a saprotrophic common ancestor of Cantharellales with at least three transitions to an ectomycorrhizal ecology, multiple transitions to a lichenicolous habit with one or more subsequent transitions to mutualistic nutritional modes, four transitions to an orchid mycorrhizal ecology, and two transitions to a lichenized lifestyle. Nine disparate clades contained samples of the polyphyletic genus Sistotrema, six of which will require taxonomic reassignment to other genera. This study represents the first comprehensive examination of the evolution of form and function across this ecologically and morphologically diverse order of fungi.