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Arbeit an der Bibliothek noch nicht eingelangt - Daten nicht geprüft Abweichender Titel laut Übersetzung des Verfassers/der Verfasserin Karl-Franzens-Universität Graz, Univ., Dissertation, 2016

Antonia Fleischhacker Zsfassung in dt. und engl. Sprache Graz, Univ., Dipl.-Arb., 2011

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. Electronic supplementary material The online version of this article (doi:10.1007/s13225-015-0343-8) contains supplementary material, which is available to authorized users.

Lichens are frequently colonized by specialized, lichenicolous fungi. Symptomatic lichenicolous fungi usually display typical phenotypes and reproductive structures on the lichen hosts. The classification based on these structures revealed different host specificity patterns. Other fungi occur asymptomatically in the lichen thalli and are much less known. We aimed at studying the diversity of lichen-associated fungi in specific, lichen-rich communities on rocks in the Alps. We tested whether lichenicolous fungi developing symptomatically on their known hosts also occur asymptomatically in other thalli of the same or of different host species. We collected lichen thalli according to a uniform sampling design comprising individuals adjacent to thalli that showed symptoms of lichenicolous fungal infections. The total fungal communities in the selected lichen thalli were further studied by single-strand conformation polymorphism (SSCP) fingerprinting analyses and sequencing of internal transcribed spacer (ITS) fragments. The systematic, stratified sampling strategy helped to recover 17 previously undocumented lichenicolous fungi and almost exhaustively the species diversity of symptomatic lichenicolous fungi in the studied region. The results from SSCP and the sequencing analyses did not reveal asymptomatic occurrence of normally symptomatic lichenicolous fungi in thalli of both the same and different lichen host species. The fungal diversity did not correlate with the species diversity of the symptomatic lichenicolous fungus-lichen host associations. The complex fingerprint patterns recovered here for fungal communities, in associations of well-delimited lichen thalli, suggest lichen symbiosis as suitable subjects for fungal metacommunity studies.