Resolving the phylogenetic position of the Wallemiomycetes: an enigmatic major lineage of Basidiomycota

Abstract

The Wallemiomycetes includes three species of molds from the genus Wallemia . These fungi are adapted to environments of high osmotic stress, contaminate various foods, cause respiratory disease, and have an unusual mode of asexual reproduction. Wallemia was recently proposed as a new class based on 18S ribosomal RNA gene sequences to accommodate the isolated position of the clade in the Basidiomycota. We analyzed the phylogenetic position of the Wallemiomycetes using 3451 nucleotide characters of the 18S, 25S, and 5.8S ribosomal RNA genes and 1282 amino acid positions of rpb1, rpb2, and tef1 nuclear protein-coding genes across 91 taxa. Different gene regions and methods of phylogenetic inference produce mildly conflicting placements of the Wallemiomycetes. Parsimony analyses of nrDNA data suggest that the Wallemiomycetes is an early diverging lineage of Basidiomycota, occupying a basal position near the Entorrhizomycetidae. Ultrastructural data, some Bayesian analyses, and amino acid sequences suggest the Wallemiomycetes may be the sister group of the Agaricomycotina or Ustilaginomycotina. The combined gene tree supports the Wallemiomycetes as a lineage basal to a core clade of Pucciniomycotina, Ustilaginomycotina, and Agaricomycotina with robust measures of branch support. This study reinforces the isolated position of Wallemia in the Basidiomycota using molecular data from six nuclear genes. In total, five major lineages of Basidiomycota are recognized: the Agaricomycotina, Ustilaginomycotina, Pucciniomycotina, Entorrhizomycetidae, and the Wallemiomycetes.

A higher-level phylogenetic classification of the Fungi

“…There are several nodes resolved in the tree figures that are not reflected in the classification. These unnamed clades, for which there is strong to moderate support in recent studies, include the Dacrymycetes plus Agaricomycetes (Basidiomycota) (Matheny et al , 2007a, Saccharomycotina plus Pezizomycotina (Ascomycota) Spatafora et al 2007), and the inoperculate euascomycetes (Ascomycota) (e.g. Lumbsch et al 2002).…”

“…So far, only ribosomal RNA genes have been sequenced in Entorrhizomycetes. Analyses with broad sampling across all groups of Basidiomycota and including Ascomycota and Glomeromycota as outgroups suggest that Entorrhizomycetes is not nested within any subphylum, and may be the sister group of the rest of the Basidiomycota (Matheny et al 2007a; also see Begerow et al 1997).…”

Two new records of smut fungi for Panama and new combinations into the genus Tolyposporium

“…AJ236142 (Piepenbring et al, 1999), Cintractia axicola (Berk.) Cornu DQ631906 (Matheny et al, 2006), Cintractia cf. limitata G.P.…”

“…Schröt.) Vánky DQ831011 (Matheny et al, 2006), Piepenbring et al, 1999), Stegocintractia spadicea (Liro) M. Piepenbr. & Begerow AJ236155 (Piepenbring et al, 1999), Tolyposporium isolepidis EU246949 (Vánky & Lutz, 2008), Tolyposporium junci AF009876 (Begerow et al, 1997), Tolyposporium neillii EU246952 (Vánky & Lutz, 2008), Tolyposporium piluliforme AF009871 (as Heterotolyposporium piluliforme, Begerow et al, 1997), Ustanciosporium gigantosporum (Liro) M. Piepenbr.…”

Notulae to the Italian flora of algae, bryophytes, fungi and lichens: 4

“…Entorrhiza aschersoniana is so far known from Europe, Central America and New Zealand (Vánky 2012). The phylogenetic position of Entorrhiza has long been debated (Begerow et al 2006, Matheny et al 2006, Hibbett et al 2007. Recently, Bauer et al (2015) proposed to include the genus in the new fungal phylum Entorrhizomycota.…”