Book of Abstracts (PDF) - International Mycological Association

IMC7 Friday August 16th Lectures
spruce forests (more than 50% reduction), whereas
common species were modestly affected. The Corticoid
species seemed more adversely affected than the
Polypores. These results indicate that many woodinhabiting
species in spruce forests are adversely affected
by temporal (continuity) gaps in the supply of dead wood,
whereas the species in pine forests seem more adapted to
forest disturbances. This implies that forest management
practices should secure sites with a continuous supply of
dead wood in spruce forests.
395 - Conceptual problems of Ecological Continuity and
its bioindicators
B. Nordén
Botanical Inst. Göteborg University, Box 461, 405 30
Göteborg, Sweden. - E-mail: bjorn.norden@systbot.gu.se
Old, undisturbed forest stands may be important for
biodiversity through their content of microhabitats or for
the long periods available for colonisation. The term
Ecological Continuity (EC) has been used to ascribe value
to old forest stands, but its use may lead to underestimation
of the importance of forest dynamics and dispersal. If bioindicators
of EC are to be used, species with low dispersal
capacity should be chosen. However, many lichens and
other fungi seem to have a patch-tracking lifestyle, and to
merely indicate specific microhabitats. This is exemplified
with data from two papers on wood-inhabiting ascomycetes
and basidiomycetes in temperate deciduous woodland. In
the first paper, a negative correlation between species
richness and stand age in hazel woodland was reported.
The number of Red List species was not affected by stand
age. In the second paper, fine woody debris (FWD; diam 1-
10 cm) was found to be very important for species richness
in oak dominated woodland. This finding is discussed in
relation to the required time for microhabitat formation.
75% of the ascomycetes were found only on FWD,
compared to 35% for basidiomycetes. The volume of CWD
(coarse woody debris; diam > 10 cm) and FWD, and the
number of Red List species on CWD and FWD were
similar. Indicators of EC should be sought among
microhabitats (logs), terrestrial molluscs, vascular forest
plants, bryophytes and lichenized fungi which are
'perennial stayers', and perhaps ground-floor fungi.
396 - Cortinarius subgenus Myxacium: phylogeny and
distribution in North America
M.T. Seidl
University of Washington, Dept. of Botany, Box 351330,
Seattle, WA, U.S.A. - E-mail: seidl@u.washington.edu
Subgenus Myxacium is a relatively small group within
Cortinarius, the largest genus of agarics. The subgenus in
North America presently comprises 3-4 sections with 15-25
species. A review of names used for Myxacium taxa will be
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Book of Abstracts
presented. Distribution maps will be shown for selected
taxa within this region. To begin understanding
relationships within Myxacium phylogenetic analyses were
performed using nuclear DNA sequences from the internal
transcribed spacers (ITS1 and ITS2) and the 5.8S rRNA
gene on 23 Cortinarius taxa representing 7 subgenera, and
later on 42 taxa from the Northern Hemisphere. Evidence
from these studies suggests the subgenus Myxacium is
polyphyletic as currently recognized. A summary of
current knowledge of phylogenetic relationships within
Myxacium will be discussed together with individual
species and their probable taxonomic placement.
397 - Multiple-gene phylogenies indicate a recent
radiation of Cortinarius
U. Peintner 1* , J.-M. Moncalvo 2 , R. Vilgalys 2 & M. Moser 1
1 University Innsbruck, Technikerstr. 25, A-6020 Innsbruck,
Austria. - 2 Duke University, P.O. Box 90338, U.S.A. - Email:
Ursula.Peintner@uibk.ac.at
The main obstacle for a broadly acceptable classification of
Cortinarius (Agaricales, Basidiomycetes) is the huge
number of species, and the lack of good, non-transitional
characters. In this study, we tested suitability and power of
three protein coding genes in combination with nuclear
rDNA to resolve deeper relationships within Cortinarius.
We also compare the resolving power of increased taxon
sampling versus increased character sampling. To address
these questions, portions of ATPase subunit 6 (ATP6),
elongation factor 1-alpha (EF1-alpha), NADH-ubiquinone
oxidoreductase chain 5 (NADH5) and nuclear rDNA (ITS
and LSU) were sequenced for 18-132 taxa, respectively.
Sequences of 44 species were combined totalling 4955 bp
of DNA. Datasets were analyzed separately and combined
with Maximum Likelihood and Maximum Parsimony with
different weighting schemes. Ribosomal DNA and proteincoding
genes failed to provide adequate discriminatory
power for deeper relationships. The combined gene
genealogy yielded the best resolution and thus provides the
most robust initial hypothesis of phylogenetic relationships
within Cortinarius. We suggest that the difficulties to
resolve the evolutionary relationships of Cortinarius are
linked to two sequential rapid radiation events in the
evolution of this ectomycorrhizal mushroom. Thus,
unresolved branching orders during these time periods may
represent an accurate representation of the evolutionary
history of Cortinarius.
398 - Taxonomy of genus Cortinarius based on
phylogeny obtained from nuclear rDNA sequences
K. Høiland 1* , K. Røberg 1 , A. Holst-Jensen 2 & K.T.
Hansen 3
1 Department of Biology, University of Oslo, P.O. Box
1066, N-0316 Oslo, Norway. - 2 National Veterinary
Institute, P.O. Box 8156 Dep., N-0033 Oslo, Norway. -
3 Norwegian Polar Institute, P.O. Box 720, N-9171