Mazaedium evolution in the Ascomycota (Fungi) and the classification of mazaediate groups of formerly unclear relationship

Abstract

Calicioid or mazaediate fungi constitute a heterogeneous assemblage of fungi sharing the presence of a mazaedium. These fungi were once treated as an order (Caliciales) of the Ascomycota but many are now known to be nested within the Arthoniomycetes, Eurotiomycetes, Lecanoromycetes and Leotiomycetes. In this study we employ multigene phylogenetic analyses of main mazaediate groups (based on nuclear 18S, 28S, 5.8S rDNA, mitochondrial 16S, and the protein coding RPB1 and Mcm7) of 116 taxa corresponding to most major groups of the inoperculate ascomycetes (“Leotiomyceta”) and a selection of Pezizomycetes, to trace the evolution of the mazaedium in the Pezizomycotina (the “Euascomycetes”). In particular, we studied the placement of three calicioid groups of uncertain position, Calycidiaceae, Coniocybaceae and Microcaliciaceae. Here, we show that the Calycidiaceae is closely related to the Sphaerophoraceae in the Lecanoromycetidae (Lecanoromycetes), as supported by overall morphology and the production of sphaerophorin. The Coniocybaceae constitute an early divergent line in the inoperculate ascomycetes and here we propose to recognize this group formally as the new class and order Coniocybomycetes, Coniocybales. The Microcaliciaceae is nested within the Ostropomycetidae (Lecanoromycetes). Both Coniocybaceae and Microcaliciaceae, although highly distinctive, lack morphological similarities to related main fungal groups. Ancestral state reconstruction suggests that the ancestor of all inoperculate ascomycetes and the ancestor of all main inoperculate ascomycete groups, with the exception of the Coniocybomycetes, was non‐mazediate, and thus confirms the large amount of parallel evolution and independent gains of the mazaedium in the history of the Ascomycota.

Unravelling the diversity of European Caliciopsis (Coryneliaceae, Ascomycota): Caliciopsis valentina sp. nov. and C. beckhausii comb. nov., with a worldwide key to Caliciopsis

“…Recent research on the evolution of the mazaedium, a type of passively spore-dispersion structure, confirmed that the genus Caliciopsis Peck (Coryneliales, Ascomycota) belongs to the Eurotiomycetes (Prieto et al 2013). This was previously suggested in several comprehensive phylogenetic studies (Geiser et al 2006;Spatafora et al 2006).…”

A multigene phylogenetic synthesis for the class Lecanoromycetes (Ascomycota): 1307 fungi representing 1139 infrageneric taxa, 317 genera and 66 families

“…2), but never with bootstrap support above 70%. Previous large-scale phylogenies for the Lecanoromycetes show support for two contradicting relationships among these three subclasses: a sister relationship between the Ostropomycetidae and Umbilicariomycetideae (PP = 0.98 in Lutzoni et al, 2004, for the phylogeny based on three genes), and between the Lecanoromycetidae and Ostropomycetidae (PP = 1.00 and ML-BP = 80% in Bendiksby and Timdal, 2013; and PP = 0.99 in Prieto et al, 2012). The recognition of the Umbilicariomycetidae as a separate subclass enables the tracking of this phylogenetic uncertainty.…”

“…In Wedin et al (2005) the Acarosporomycetidae and paraphyletic ‘Candelariomycetidae’ (sensu Bendiksby and Timdal, 2013) form a monophyletic group closely related to the outgoup taxa (Eurotiomycetes; however, without support). Most recently, Prieto et al (2012) presented a Bayesian tree based on four ribosomal and two protein-coding genes ( MCM7 and RPB1 ) where Candelariales is separated from the Lecanoromycetes and placed as an independent lineage among early diverging Leotiomyceta. However, this placement, as well as many other deep phylogenetic relationships associated with the Leotiomyceta radiation, did not receive strong support (Lutzoni et al, 2004).…”

Polyphyly of the genus Canoparmelia—uncovering incongruences between phenotype-based classification and molecular phylogeny within lichenized Ascomycota (Parmeliaceae)

“…Further, morphological and chemical features have also been shown to be highly plastic in other groups of lichenized fungi (e.g. Caliciales, Prieto et al 2013;Cladoniaceae, Parnmen et al 2010;Collemataceae, Otálora et al 2013;Graphidaceae, Rivas Plata & Lumbsch 2011;Roccellaceae, Tehler & Irestedt 2007). Therefore, it is not surprising that the monophyly of Canoparmelia based on phenotypic feature was not recovered in our molecular phylogenetic analyses.…”