Book of Abstracts (PDF) - International Mycological Association

IMC7 Thursday August 15th Lectures
report here that the Ostropales, in their current
circumscription, are paraphyletic, and that the Ostropales
s.l. include the Gyalectales and the Trapeliaceae. Dimerella
and Coenogonium are congeneric, and Petractis
thelotremella and P. hypoleuca are reunited with members
of the genus Gyalecta. The ontogeny of the ascomata is
variable within the Ostropales and can be used to further
subdivide different lineages within this large and
challenging order. Ascoma ontogeny, apothecial anatomy
and molecular data support the separation of Coenogonium
(incl. Dimerella) as family Coenogoniaceae from the
Gyalectaceae. In addition to requiring less computational
time, Bayesian inference of phylogeny recovered the same
topology as a conventional heuristic search using Max.
Likelihood as the optimization criterion, and seems
superior to bootstrapping in estimating support for short
internal branches.
288 - Molecular evaluation of the generic concepts in
the Pertusariaceae (lichenized ascomycota)
I. Schmitt * & H.T. Lumbsch
FB9/Botanik, Universität Essen, Universitätsstr. 5, 45117
Essen, Germany. - E-mail: imke.schmitt@uni-essen.de
The Pertusariaceae is a rather large and diverse family of
crustose lichens. Its members are characterized by
hemiangiocarpous ascoma development, thick-walled
amyloid asci and relatively large ascospores. The group
boasts a great diversity of secondary lichen compounds.
Because several taxa are quite heterogeneous,
morphologically and anatomically variable and often
sterile, there has been a lot of discussion on the taxonomy
of the family. In the present study we analysed nuclear
LSU, mitochondrial SSU and LSU sequence data of 45
species to re-evaluate the generic concepts in the
Pertusariaceae. We ran maximum parsimony and Bayesian
(MCMC) analyses and tested for monophyly of the genus
Pertusaria. Our results suggest that the genus Pertusaria is
polyphyletic comprising the Pertusaria s.str.-, the
Monomurata- and Varicellaria-groups. The Monomuratagroup
is a sister taxon to Ochrolechia; both are closely
related to the Varicellaria-group. The genera Loxosporopsis
and Melanaria are included in Pertusaria s.str. in the
molecular genealogies. Morphological, anatomical and
chemical characters are re-evaluated in the light of the
molecular study.
289 - Character evolution in Phacopsis inferred from
nrDNA sequences
D. Persoh
Lehrstuhl Pflanzensystematik, Universität Bayreuth,
Universitätsstraße 30 - NW I, D-95440 Bayreuth,
Germany. - E-mail: derek.persoh@uni-bayreuth.de
92
Book of Abstracts
Phylogenetic analyses of SSU nrDNA sequence data of
two species of the lichenicolous genus Phacopsis (P.
huuskonenii and P. oxyspora) revealed their membership of
the lichen family Parmeliaceae. Studies of the ITS nrDNA
of the family additionally included Phacopsis vulpina.
While the monophyletic origin of the three lichenicolous
species could not be rejected by the 'approximately
unbiased test', phylogenetic trees calculated with
parsimony and likelihood algorithms indicate no closer
relationship among the investigated species of Phacopsis.
Based on these facts, the evolution and adaptive value of
selected morphological characters within the Parmeliaceae
in the enlarged concept is discussed. Aside from
characteristics of asco- and pycnospores, the 'cupulate'
hypothecial layer is notable because it is present in
Parmeliacean taxa and in P. oxyspora, but not in P. vulpina
and P. huuskonenii. Furthermore, the hypothetical ways of
thallus reduction and delichenisation are addressed. The
loss of lichenisation (in the sense of a mutualistic
interaction between a fungal and an algal partner) does
most likely not occur in members of the genus Phacopsis.
290 - Evaluation of morphological characters in the
genus Usnea with the help of molecular data
K. Articus 1* , M. Grube 2 , M. Wedin 3 & L. Tibell 1
1 EBC, Systematic Botany, Norbyvagen 18D, SE-75236
Uppsala, Sweden. - 2 Institut für Botanik, Karl-Franzens-
Universität Graz, Holteigasse 6, 8010 Graz, Austria. -
3 Department of Ecology and Environmental Science, Umeå
University, SE-901 87 Umeå, Sweden. - E-mail:
kristina.articus@ebc.uu.se
A molecular phylogeny of a group of Usnea species was
constructed utilising two independent gene loci, nITS-LSU
rDNA and ß-tubulin. This phylogeny was used to 1) test if
the traditionally used morphological species-characters
actually characterize monophyletic groups, and 2) to
analyse the species delimitation of the closely related
pendant Usnea barbata, U. chaetophora, U. filipendula and
U. rigida. The morphological characters most commonly
used for species identification were mapped onto the
molecular tree to assess their usefulness for characterizing
monophyletic groups. Other species included were: Usnea
articulata, U. ceratina, U. florida, U. hirta, U. longissima,
U. subfloridana and U. wasmuthii. The species in focus
form three monophyletic groups. Usnea barbata and U.
rigida form one group with intermixed specimens. Most of
the Usnea chaetophora specimens form a well supported
group. The third group contains all U. filipendula
specimens and several U. barbata and U. chaetophora
specimens. There are some morphological characters that
support these groups (such as branch shape and branching
type in the U. chaetophora-group, and isidiomorph and
isidia occurrence in the U. filipendula-group). Many
character, though, e.g. the shape and number or papillae
and fibrils, are inconsistent with the molecular phylogeny.