Message - 7th IAL Symposium

The 7 th International Association for Lichenology Symposium 2012
ORAL SESSION
1I: Exploring the lichen microbiome and its multifaceted interactions
(1I-O1) Submission ID: IAL0085-00001
LICHENICOLOUS FUNGI: DESCRIBED AND CRYPTIC FUNGAL COMPONENTS OF THE
LICHEN MICROBIOME
Lawrey J. 1 , Diederich P. 2
1 Environmental Science and Policy, George Mason University, Fairfax, Virginia, United States
2 Mycology, Musée National d’Histoire Naturelle, Luxembourg, Luxembourg
Lichenicolous fungi live exclusively inside and on lichens, most commonly as host-specific parasites,
but also as broad-spectrum pathogens, saprotrophs or commensals. Over 1,800 species have been described
throughout the Ascomycota and Basidiomycota, and estimates are that 3,000-5,000 species will eventually be
described. Most are ascomycetes, widely distributed in 7 classes and 19 orders; fewer than 5% are
basidiomycetes, but these are also diverse, representing four classes and eight orders. Since few species
have been cultured or sequenced, their identity, evolutionary origin and phylogenetic position cannot always be
determined with certainty. However, it appears that lichenicolous ascomycetes are common in, and probably
descended from, lichens in lichen-dominated lineages, but entirely unrelated to lichens in many other groups.
The origin and direction of these transitions may depend on the nature of the parasitism. Recent culture-based
and culture-independent studies indicate the presence of large numbers of obligate fungal inhabitants of
lichens, some of which may represent asymptomatic lichenicolous fungi. The identity, origin, and diversity of these
species will become apparent as more isolates are obtained and sequenced.
(1I-O2) Submission ID: IAL0274-00001
DIVERSITY AND BIOGEOGRAPHY OF ENDOPHYTIC AND ENDOLICHENIC FUNGAL
COMMUNITIES
Uren J. 1 , Lutzoni F. 2 , Miadlikowska J. 2 , Arnold A. 1
1 School of Plant Sciences, University of Arizona, Tucson AZ, United States
2 Biology, Duke University, Durham NC, United States
Endophytic and endolichenic fungi occur in healthy tissues of every plant and lichen species surveyed
to date. Phylogenetic analyses suggest a close evolutionary relationship between these guilds, but previous
sampling has been insufficient to evaluate the distinctiveness of these symbiotrophs and has not comprehensively
assessed the biogeographic and abiotic factors that structure their communities. Using molecular data
(ITSrDNA-partial LSUrDNA) we examined the diversity, taxonomic composition, and distributions of 4,154
endophytic and endolichenic isolates of Pezizomycotina (Ascomycota) cultured from replicate surveys of ca.
20 phylogenetically diverse plant and lichen species in each of five North American sites (Madrean coniferous
forest, Arizona; montane semi-deciduous forest, North Carolina; subtropical scrub forest, Florida; Beringian
tundra and forest, western Alaska; and subalpine tundra, east-central Alaska). Our surveys reveal that these
symbiotroph communities differ significantly at the species level among sites, and that different classes of Pezizomycotina
dominate related hosts in different locations. Fungal communities located closer together are more
similar than communities located farther apart, but differences reflect environmental characteristics more
strongly than geographic distance alone. Abiotic factors such as mean annual temperature and precipitation
contribute differently to endophyte and endolichenic abundance and diversity. Endolichenic fungi are distinctive
relative to most endophytes of vascular plants, but genotypes occurring in lichens frequently are found in mosses
as well. Overall, our study illustrates the high richness and diversity of endophytic and endolichenic fungi at a
continental scale, and reveals their unique patterns of host-, climatic-, and geographic affiliation.
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