Message - 7th IAL Symposium

Lichen: from genome to ecosystem in a changing world
2I-P
(2I-P9) Submission ID: IAL0223-00001
UMBILICARIA DECUSSATA - A PLEOMORPHIC LICHEN
Davydov E. A. 1
1 South Siberian Botanical Garden, Altai State University, Barnaul, Russia
Several species pairs can be found in the Umbilicariaceae, and one taxon of a pair may produce high
numbers of mitospores (“anamorphic stage”), while the other taxon exclusively develops apothecia (“teleomorphic
stage”). The existence of such paired taxa may have at least three interpretations: the “taxa” represent different
phenotypes of a single taxon; taxa share a close common ancestor but are now more or less reproductively
isolated; taxa have attained their similarity through convergent evolution (Hestmark 1991). Morphological and
molecular investigations were made to interpret the current status of the species pair Umbilicaria decussata – U.
polaris. Molecular phylogeny seems to be the most appropriate tool to test the monophyly of taxa, which may
be interpreted in terms of evolutionary relationships. Three data sets (nrITS, mtLSU, and nrITS+mtLSU) were
analyzed using MP and ML algorithms to test the hypothesis of monophyly for the species pair. In all analyses,
sequences of all U. decussata and U. polaris accessions were combined into a cluster which is well supported
statistically. However, neither of the two species appeared monophyletic. According to the resulting cladograms,
it is most plausible that mentioned taxa actually represent two morphotypes of one biological species, individuals
of which are switched on earlier stages of ontogenesis to anamorph or teleomorph. Divergence by alternation
of the reproduction mode, as shown for several species pairs (Poelt 1977; Hestmark 1991), may therefore be a
result of fixing this shift in the phylogenesis and subsequent isolation of anamorph or teleomorph populations.
According to this work, U. polaris is the teleomorph of U. decussata. Despite U. decussata and U. polaris being
well separated morphologically, they should be treated as one species represented by two morphotypes according
to the principal (anamorph or teleomorph) reproductive stage. Such a situation is well known for non-lichenized
ascomycetes. Different morphs of a pleomorphic fungus may occur in different conditions (e.g. on different
hosts or at different seasons). For U. decussata, such ecological factors as temperature and humidity may play
an important role in anamorph / teleomorph switching. The investigation was supported by Russian Foundation
of Basic Research (grant no. 11-04-90704).
(2I-P10) Submission ID: IAL0280-00001
ARTHONIALEAN CHALLENGE
Frisch A. 1 , Grube M. 2 , Ertz D. 3 , Thor G. 4
1 Botany, National Museum of Nature and Science, Tsukuba, Japan
2 Institute of Plant Sciences, Karl-Franzens-University Graz, Graz, Austria
3 Lichenology, National Botanical Garden, Meise, Belgium
4 Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
Arthoniomycetes with the single order Arthoniales (c. 1,500 species) is the largest group of mainly lichenised
fungi beside Lecanoromycetes and might represent an independent case of lichenisation in Ascomycota.
Most species are associated with algae of the Trentepohliales, but there are also species which form thalli with
coccal green algae. Moreover, many species are non-lichenised and living either as saprobes on wood or as
inhabitants (commensals to parasites) of other lichens, with different degree of host-specificity. The interrelationships
of crustose species, especially of tropical taxa, are still rather unclear. There is a tremendous variation in
ascomatal characters, which are otherwise used to distinguish genera or even families. We have started to explore
the phylogeny of crustose Arthoniales using phylogenetic methods in more detail. The initial results reveal
the non-monophyly of many genera and show also unexpected relationships. For example, Chrysotrichaceae
can no longer by characterized by characters of pigmentation. Our analysis of the yet understudied Arthoniomycetes
gives new insights in phenotypic and lifestyle evolution and help to refine the concept of genera.
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