Towards a revised generic classification of lecanoroid lichens(Lecanoraceae,Ascomycota)based on molecular,morphological and chemical evidence

Abstract The phylogenetic relationship of lecanoroid lichens is studied using two data sets:1)a 2-locus data set including 251 OTUs representing 150 species,and 2)a 6-locus data set with 82 OTUs representing 53 species.The genus Lecanora as currently circumscribed is shown to be highly polyphyletic and several genera,including Adelolecia,Arctopeltis,Bryonora,Carbonea,Frutidella,Lecidella,Miriquidica,Palicella,Protoparmeliopsis,Pyrrhospora,and Rhizoplaca are nested within Lecanora sensu lato.A core group of Lecanora is supported as monophyletic and includes species of the L.carpinea,L.rupicola,and L.subcarnea groups,and a core group of the L.subfusca group.Three monophyletic clades that are well supported in our analyses and well characterized by phenotypical characters are accepted here:1)Myriolecis to accommodate the Lecanora dispersa group and Arctopeltis;2)Protoparmeliopsis for the L.muralis group;and 3)Rhizoplaca is emended to include three placodioid taxa previously classified in Lecanora(L.novomexicana.L.opiniconensis,L.phaedrophthalma),whereas R.aspidophora and R.peltata are excluded from Rhizoplaca.The latter is transferred into Protoparmeliopsis.Lecidella is strongly supported as a monophyletic group.Our studies indicate the presence of additional clades of species currently placed in Lecanora sensu lato that warrant taxonomic recognition but additional data will be necessary before the circumscription of these entities is fully understood.37 new combinations are proposed into the genera Myriolecis(30),Protoparmeliopsis(2),and Rhizoplaca(5).

Hidden diversity of marine borderline lichens and a new order of fungi:Collemopsidiales(Dothideomyceta)

The fungal genus Collemopsidium comprises species that develop so-called borderline lichen symbioses with algae or cyanobacteria.Together with morphologically similar pyrenocarpous fungi it has been assigned to the family Xanthopyreniaceae.The adscription of this family to higher taxonomic ranks remain uncertain.Using sequence data of five nuclear genomic regions(nuLSU,nuSSU,tef1-α,rpb1 and rpb2)and onemitochondrial locus(mtSSU)we found that the studied representatives of this family are placed in the Dothideomyceta,yet relationships with the classes Dothideomycetes and Arthoniomycetes remain uncertain.We describe the new order Collemopsidiales to accommodate the genus Collemopsidium(paraphyletic as currently understood)and the lichenicolous genus Zwackhiomyces.Using five fungal fossils as calibrations points,we infer an age of c.230 Mya for the crown of Collemopsidiales.Based on two molecular markers,we also provide insight into the global diversity of marine species of the genus Collemopsidium.According to the species delimitation algorithm GMYC,c.26 putative species exist,far more than the six species recognized hitherto.We have confirmed this result by comparing the two alternative species models by means of Bayes factors,using path sampling and stepping-stone sampling algorithms to estimate the marginal likelihood of each model.Finally,our observations suggest rock-boring ability evolved in parallel in the different lineages within this group of fungi.

Global assessment of genetic variation and phenotypic plasticity in the lichen-forming species Tephromela atra

Understanding how many species exist and the processes by which they form remains a central topic of ecological and evolutionary biology,but represents a special challenge within microbial groups.The lichen-forming fungi represent one of the best examples in which species evolution and diversity create patterns of high phenotypic plasticity coupled with wide geographic distributions.We sampled the lichen-forming species Tephromela atra and related species at a world-wide scale to reconstruct a phylogenetic hypothesis using three nuclear markers.Samples were also studied for morphological and chemical traits to assess how well the phenotypic relationships with species,previously segregated from T.atra,agrees with molecular data.We used a genealogical concordance approach and identified 15 monophyletic clades,which may represent independent lineages.By combining morphological and chemical characters,ecological preferences and geographic origin we distinguish six different species.Although subtle phenotypical traits are frequently used for describing previously cryptic species in fungi,the continuum of variability found in morphology and chemical patterns in T.atra prevents the description of new taxa with characteristic traits.We observed that phenotypic characters arise in parallel at local or regional scale but are not correlated with genetic isolation.Therefore,they are insufficient for characterizing species with broad geographic ranges within T.atra.

Extremotolerant fungi from alpine rock lichens and their phylogenetic relationships

Fungi other than the lichen mycobiont frequently co-occur within lichen thalli and on the same rock in harsh environments.In these situations dark-pigmented mycelial structures are commonly observed on lichen thalli,where they persist under the same stressful conditions as their hosts.Here we used a comprehensive sampling of lichen-associated fungi from an alpine habitat to assess their phylogenetic relationships with fungi previously known from other niches.The multilocus phylogenetic analyses suggest that most of the 248 isolates belong to the Chaetothyriomycetes and Dothideomycetes,while a minor fraction represents Sordariomycetes and Leotiomycetes.As many lichens also were infected by phenotypically distinct lichenicolous fungi of diverse lineages,it remains difficult to assess whether the culture isolates represent these fungi or are from additional cryptic,extremotolerant fungi within the thalli.Some of these strains represent yet undescribed lineages within Chaethothyriomycetes and Dothideomycetes,whereas other strains belong to genera of fungi,that are known as lichen colonizers,plant and human pathogens,rock-inhabiting fungi,parasites and saprotrophs.The symbiotic structures of the lichen thalli appear to be a shared habitat of phylogenetically diverse stress-tolerant fungi,which potentially benefit from the lichen niche in otherwise hostile habitats.