New insights into classification and evolution of the Lecanoromycetes (Pezizomycotina, Ascomycota) from phylogenetic analyses of three ribosomal RNA- and two protein-coding genes

Abstract

The Lecanoromycetes includes most of the lichen-forming fungal species (> 13500) and is therefore one of the most diverse class of all Fungi in terms of phenotypic complexity. We report phylogenetic relationships within the Lecanoromycetes resulting from Bayesian and maximum likelihood analyses with complementary posterior probabilities and bootstrap support values based on three combined multilocus datasets using a supermatrix approach. Nine of 10 orders and 43 of 64 families currently recognized in Eriksson's classification of the Lecanoromycetes (Outline of Ascomycota--2006 Myconet 12:1-82) were represented in this sampling. Our analyses strongly support the Acarosporomycetidae and Ostropomycetidae as monophyletic, whereas the delimitation of the largest subclass, the Lecanoromycetidae, remains uncertain. Independent of future delimitation of the Lecanoromycetidae, the Rhizocarpaceae and Umbilicariaceae should be elevated to the ordinal level. This study shows that recent classifications include several nonmonophyletic taxa at different ranks that need to be recircumscribed. Our phylogenies confirm that ascus morphology cannot be applied consistently to shape the classification of lichen-forming fungi. The increasing amount of missing data associated with the progressive addition of taxa resulted in some cases in the expected loss of support, but we also observed an improvement in statistical support for many internodes. We conclude that a phylogenetic synthesis for a chosen taxonomic group should include a comprehensive assessment of phylogenetic confidence based on multiple estimates using different methods and on a progressive taxon sampling with an increasing number of taxa, even if it involves an increasing amount of missing data.

Journey from the West: Did tropical Graphidaceae (lichenized Ascomycota: Ostropales) evolve from a saxicolous ancestor along the American Pacific coast?

“…Rivas Plata et al, unpublished manuscript ). This hypothesis is consistent with the fi nding that in several cases, saxicolous lichens or even nonlichenized rock fungi are basal or sister to the main lichenized lineages ( Miadlikowska et al, 2006 ;Hofstetter et al, 2007 ;Gueidan et al, 2008 ;Schoch et al, 2009 ). In many lichenized lineages, however, the immediate sister group is not known, which makes assumptions about their early evolution speculative.…”

The sister-group relationships of the largest family of lichenized fungi, Parmeliaceae (Lecanorales, Ascomycota)

“…Members of the Cladoniaceae were selected as outgroup for the analysis because previous studies suggested that these families are closely related to Parmeliaceae (Miadlikowska et al 2006;Crespo et al 2007). Details of the studied material, including GenBank accession numbers are shown in Table 1.…”

Collema fasciculare belongs in Arctomiaceae

“…In the lichenforming Ascomycetes associating with cyanobacteria (cyanolichens), several recent major taxonomic changes have been proposed Wedin et al 2009;Otálora et al 2010;Muggia et al 2011;Spribille & Muggia 2012). Molecular phylogenies suggest that cyanolichens form three distinct and distantly related lineages: Arctomiaceae Wedin et al 2005) and the Peltigerales (Wedin et al 2005;Miądlikowska et al 2006) in the Lecanoromycetes, and Lichinales in the Lichinomycetes (Reeb et al 2004).…”