Phylogenetic placement within Lecanoromycetes of lichenicolous fungi associated with Cladonia and some other genera.

Though most of the lichenicolous fungi belong to the Ascomycetes, their phylogenetic placement based on molecular data is lacking for numerous species. In this study the phylogenetic placement of 19 species of lichenicolous fungi was determined using four loci (LSU rDNA, SSU rDNA, ITS rDNA and mtSSU). The phylogenetic analyses revealed that the studied lichenicolous fungi are widespread across the phylogeny of Lecanoromycetes. One species is placed in Acarosporales, Sarcogyne sphaerospora; five species in Dactylosporaceae, Dactylospora ahtii, D. deminuta, D. glaucoides, D. parasitica and Dactylospora sp.; four species belong to Lecanorales, Lichenosticta alcicorniaria, Epicladonia simplex, E. stenospora and Scutula epiblastematica. The genus Epicladonia is polyphyletic and the type E. sandstedei belongs to Leotiomycetes. Phaeopyxis punctum and Bachmanniomyces uncialicola form a well supported clade in the Ostropomycetidae. Epigloea soleiformis is related to Arthrorhaphis and Anzina. Four species are placed in Ostropales, Corticifraga peltigerae, Cryptodiscus epicladonia, C. galaninae and C. cladoniicola comb. nov. (= Lettauia cladoniicola). Three new species are described, Dactylospora ahtii, Cryptodiscus epicladonia and C. galaninae.

Sharpening the species boundaries in the Cladonia mediterranea complex (Cladoniaceae, Ascomycota).

The complex Cladonia mediterranea belongs to the section Impexae and is formed by C. azorica, C. macaronesica and C.mediterranea. These species are basically distributed in the Mediterranean and Macaronesian Regions. In the present work the limits between the species of this complex are re-examined. To this end, the morphological characters were studied along with the secondary metabolites and the DNA sequences from three loci (ITS rDNA, IGS rDNA and rpb2). The morphological data were studied by principal component analysis (PCA), while the DNA sequences were analyzed using several approaches available to delimit species: genealogical concordance phylogenetic species recognition, species tree (BEAST* and spedeSTEM) and cohesion species recognition. In addition, the genealogical sorting index was used in order to assess the monophyly of the species. The different procedures used in our study turned out to be highly congruent with respect to the limits they establish, but these limits are not the ones separating the prior species. Either the morphological analysis or the different approaches to species delimitation indicate that C. mediterranea is a different species from C. macaronesica, while C. azorica and C. macaronesica, which are reduced to synonyms of C. portentosa, constitute a separate lineage.

Small insertions at a shared position in the SSU rDNA of lecanorales (lichen-forming ascomycetes).

Small insertions are reported from the SSU rDNA of the genera Cladonia, Cladina, Stereocaulon, Pertusaria and Physcia (lichen-forming Lecanorales, Ascomycetes). The insertions range in length from 56 to 81 nucleotides, and occur at a shared position, 330 (relative to Escherichia coli), in a semi-conserved region of the SSU rDNA. These small insertions have a simple secondary structure with two stem-loops, and may represent degenerate group-I introns. Species of the same genus often have small insertions of similar lengths, secondary structures and sequences. These similarities suggest that the insertions are homologous and can provide phylogenetic information to support current classifications. Variable sequences of rDNA, such as the small insertions and group-I introns, may be powerful tools for resolving evolutionary relationships among genera and species.

SSU rDNA phylogeny of cladoniiform lichens.

To examine phylogenetic relationships among the "cladoniiform" lichenized fungi, i.e., the families Cladoniaceae, Baeomycetaceae, Icmadophilaceae, Stereocaulaceae, and Siphulaceae, and to provide evidence for the anticipated independent origins of podetia and pseudopodetia, we conducted phylogenetic analyses of SSU (small subunit) rDNA sequences from 39 lichen-forming fungi. These fungi represent all of the major growth forms of lichen associations, fruticose (including "cladoniiform"), foliose, and crustose. Our analysis suggests that lichen-forming fungi with a "cladoniiform" morphology arose multiple times within the ascomycetes. Additionally, each of the other thallus growth forms, crustose, foliose, and fruticose, have originated multiple times. It also seems to be clear that neither all podetiate nor all pseudopodetiate taxa form a monophyletic group. Therefore the term "podetium" should be restricted to homologous structures that are most probably limited to the genera Cladonia, Cladina, Pycnothelia, and allies. The "pseudopodetia" of Stereocaulon (Stereocaulaceae) and Cladia (Cladiaceae) may represent different states of the same homologous character. Our phylogenetic hypothesis supports the monophyletic origin of the order Lecanorales sensu stricto, including representatives of five suborders Cladoniineae, Lecanorineae, Teloschistineae, Agyriineae and Peltigerineae, but excluding representatives of the suborders Acarosporineae (Acarospora schleicheri and Megaspora verrucosa), Pertusariineae (Pertusaria trachythallina), and Umbilicarineae. The suborder Cladoniineae and the family Cladoniaceae both appear to be polyphyletic assemblages.