Helmut Mayrhofer

Basidiomycete yeasts in the cortex of ascomycete macrolichens

Lichens assemble in three parts Lichen growth forms cannot be recapitulated in the laboratory by culturing the plant and fungal partners together. Spribille et al. have discovered that the classical binary view of lichens is too simple. Instead, North American beard-like lichens are constituted of not two but three symbiotic partners: an ascomycetous fungus, a photosynthetic alga, and, unexpectedly, a basidiomycetous yeast. The yeast cells form the characteristic cortex of the lichen thallus and may be important for its shape. The yeasts are ubiquitous and essential partners for most lichens and not the result of lichens being colonized or parasitized by other organisms. Science, this issue p. 488 Complete functioning lichen thalli have three partners: alga and ascomycete, plus a basidiomycete yeast. For over 140 years, lichens have been regarded as a symbiosis between a single fungus, usually an ascomycete, and a photosynthesizing partner. Other fungi have long been known to occur as occasional parasites or endophytes, but the one lichen–one fungus paradigm has seldom been questioned. Here we show that many common lichens are composed of the known ascomycete, the photosynthesizing partner, and, unexpectedly, specific basidiomycete yeasts. These yeasts are embedded in the cortex, and their abundance correlates with previously unexplained variations in phenotype. Basidiomycete lineages maintain close associations with specific lichen species over large geographical distances and have been found on six continents. The structurally important lichen cortex, long treated as a zone of differentiated ascomycete cells, appears to consistently contain two unrelated fungi.

On the ascus types in thePhysciaceae (Lecanorales)

Comparative studies in thePhysciaceae revealed that characters of the apical apparatus of asci differ between the various genera. Two major ascus types are observable in this family. They are found to correspond with certain ascospore types.

A phylogenetic analysis of the boreal lichen Mycoblastus sanguinarius (Mycoblastaceae, lichenized Ascomycota) reveals cryptic clades correlated with fatty acid profiles.

Graphical abstract Highlights ► The ‘bloody heart lichen’ Mycoblastus sanguinarius consists of two, widespread, cryptic species. ► Mycoblastus sanguinarioides, previously thought confined to Tasmania, is widely distributed. ► Low level clades within both of the cryptic species are correlated with fatty acid profiles. ► Early chemical differentiation may play a role in incipient speciation events.

Corticolous Species of the Genus Rinodina (Lichenized Ascomycetes, Physciaceae) in Southern Africa

Abstract: Mayrhofer, H., Obermayer, W. & Wetschnig, W. 2014. Corticolous species of the genus Rinodina (lichenized Ascomycetes, Physciaceae) in southern Africa. — Herzogia 27: 1–12. Four corticolous species of Rinodina are recorded from southern Africa: Rinodina albocincta, R. australiensis, R. capensis and R. ficta. Rinodina boleana is regarded as a synonym of R. ficta. A key to the species is provided. Characters, distribution and habitats are discussed.

Über Cyanotrophie bei Flechten

AbstractIn contrast to the well-known blue-green algal containing lichens several green algal containing lichens, belonging to very different genera, show regular connections to free-living or ± lichenized blue-green algae, mainlyStigonema. Most of these lichens have squamulose thalli. This lichen-algal relationship, regarded as cyanotrophy, may be either facultative or obligate. Some of the species occur only on very poor, acidic rocks onStigonema, while they occur independent ofStigonema in high nutrient biotops. Obligate species cover the blue-green algae with hyphae and some of these species cover the algae so extensively that one can call these connections paracephalodia. — Two species and one variety are new to science from the mainly Himalayan genusBryonora. They occur in high elevations in Nepal and are cyanotrophic.Bryonora selenospora has thick, halfmoon-shaped to slightly twisted ascospores. The other two new taxa areB. reducta andB. rhypariza var.cyanotropha. There are several other cyanotrophic lichen taxa besides the ones described here. They will be introduced at a later occasion.

Hitchhiking with forests: population genetics of the epiphytic lichen Lobaria pulmonaria in primeval and managed forests in southeastern Europe

Availability of suitable trees is a primary determinant of range contractions and expansions of epiphytic species. However, switches between carrier tree species may blur co-phylogeographic patterns. We identified glacial refugia in southeastern Europe for the tree-colonizing lichen Lobaria pulmonaria, studied the importance of primeval forest reserves for the conservation of genetically diverse populations and analyzed differences in spatial genetic structure between primeval and managed forests with fungus-specific microsatellite markers. Populations belonged to either of two genepools or were admixed. Gene diversity was higher in primeval than in managed forests. At small distances up to 170 m, genotype diversity was lower in managed compared with primeval forests. We found significant associations between groups of tree species and two L. pulmonaria genepools, which may indicate “hitchhiking” of L. pulmonaria on forest communities during postglacial migration. Genepool B of L. pulmonaria was associated with European Beech (Fagus sylvatica) and we can hypothesize that genepool B survived the last glaciation associated within the refuge of European Beech on the Coastal and Central Dinarides. The allelic richness of genepool A was highest in the Alps, which is the evidence for a northern refuge of L. pulmonaria. Vicariant altitudinal distributions of the two genepools suggest intraspecific ecological differentiation.

Diagnostics for a troubled backbone: testing topological hypotheses of trapelioid lichenized fungi in a large-scale phylogeny of Ostropomycetidae (Lecanoromycetes)

Trapelioid fungi constitute a widespread group of mostly crust-forming lichen mycobionts that are key to understanding the early evolutionary splits in the Ostropomycetidae, the second-most species-rich subclass of lichenized Ascomycota. The uncertain phylogenetic resolution of the approximately 170 species referred to this group contributes to a poorly resolved backbone for the entire subclass. Based on a data set including 657 newly generated sequences from four ribosomal and four protein-coding gene loci, we tested a series of a priori and new evolutionary hypotheses regarding the relationships of trapelioid clades within Ostropomycetidae. We found strong support for a monophyletic group of nine core trapelioid genera but no statistical support to reject the long-standing hypothesis that trapelioid genera are sister to Baeomycetaceae or Hymeneliaceae. However, we can reject a sister group relationship to Ostropales with high confidence. Our data also shed light on several long-standing questions, recovering Anamylopsoraceae nested within Baeomycetaceae, elucidating two major monophyletic groups within trapelioids (recognized here as Trapeliaceae and Xylographaceae), and rejecting the monophyly of the genus Rimularia. We transfer eleven species of the latter genus to Lambiella and describe the genus Parainoa to accommodate a previously misunderstood species of Trapeliopsis. Past phylogenetic studies in Ostropomycetidae have invoked “divergence order” for drawing taxonomic conclusions on higher level taxa. Our data show that if backbone support is lacking, contrasting solutions may be recovered with different or added data. We accordingly urge caution in concluding evolutionary relationships from unresolved phylogenies.

Molecular support for the recognition of the Mycoblastus fucatus group as the new genus Violella (Tephromelataceae, Lecanorales).

The crustose lichen genus Mycoblastus in the Northern Hemisphere includes eight recognized species sharing large, simple ascospores produced 1-2 per ascus in strongly pigmented biatorine apothecia. The monophyly of Mycoblastus and the relationship of its various species to Tephromelataceae have never been studied in detail. Data from ITS rDNA and the genes coding for translation elongation factor 1-α and DNA replication licensing factor mini-chromosome maintenance complex 7 support the distinctness of Mycoblastus s. str. from the core of the Tephromelataceae, but recover M. fucatus and an undescribed Asian species as strongly supported within the latter group. We propose accommodating these two species in a new genus, Violella, which is characterized by its brownish inner ascospore walls, Fucatus-violet hymenial pigment granules and secondary chemistry, and discuss the position of Violella relative to Calvitimela and Tephromela. We describe the new species Violella wangii T. Sprib. & Goffinet to accommodate a new species with roccellic acid from Bhutan, China, India and the Russian Far East. We also exclude Mycoblastus indicus Awasthi & Agarwal from the genus Mycoblastus and propose for it the new combination Malmidea indica (Awasthi & Agarwal) Hafellner & T. Sprib.

Mobergia (Physciaceae, Lichenized Ascomycetes), a New Genus Endemic to Western North America

The genus Mobergia Mayrh. & Sheard is characterized by crustose thalli with plane to convex or inflated areoles, lecanorine apothecial characters, the presence of a phenocortex, norstictic acid, ascospores ofthe physcia-type with warted walls, and short, acutely or bluntly ellipsoid to obovate spermatia. The new genus is based on two species formerly included in the genus Rinodina (Ach.) Gray-M. angelica (Stizenb. in Hasse) comb. nov. and M. calculiformis (W. Weber) comb. nov. Rinodina bolodes Tuck. ex Fink and R. dirinoides Zahlbr. in Hasse are synonyms ofMobergia angelica, and R. platyloba Willey in Fink is a synonym of M. calculiformis.

New species of Rinodina (Physciaceae, Lichenized Ascomycetes) from Western North America

Abstract Fourteen new species are described from western North America– Rinodina aurantiaca, R. badiexcipula, R. boulderensis, R. californiensis, R. endospora, R. grandilocularis, R. innata, R. juniperina, R. lignicola, R. lobulata, R. macrospora, R. pacifica, R. perreagens, and R. verruciformis. Characters on which they are based are discussed in detail and a new spore type for Rinodina is introduced. The new species are compared to others, with which they might be confused and a key provided. Rinodina dolichospora is recorded for the first time from North America.