Book of Abstracts (PDF) - International Mycological Association

IMC7 Wednesday August 14th Lectures
209 - Phylogenetic relationships in Homobasidiomycetes
R.G. Thorn 1* , M. Binder 2 & D.S. Hibbett 2
1 Department of Biology, University of Western Ontario,
London, Ontario, N6A 5B7, Canada. - 2 Department of
Biology, Clark University, 950 Main Street, Worcester,
Massachusetts 01610-1477, U.S.A. - E-mail:
rgthorn@uwo.ca
The time since IMC6 has seen a dramatic increase in
molecular phylogenetic studies of homobasidiomycetes.
This talk offers the opportunity for a general overview of
recent results from our labs as well as published and
unpublished results from other research groups. The eight
major clades of homobasidiomycetes identified by Hibbett
et al. (1997, PNAS 94:12002) have generally held up to
more recent analyses but, despite the increased
phylogenetic information of additional sequence data,
support for basal divisions, particularly the polyporoid
clade, remains weak and placement of some terminal taxa
remains equivocal. A picture is emerging of rapid
radiations among the basal lineages, echoed by rapid
radiations among more recently evolved groups such as the
secotioid and gasteroid members of agaric and bolete
clades. The consequences of the former are the difficulty of
firmly establishing the relationships among major clades
and the evolution of fundamental ecological characters
such as ectomycorrhizal habit and rot type. The
consequences of the more recent radiations in fruiting body
morphology include the potential for havoc in our
classification system and great fun in the mycology
classroom. In any case, molecular phylogenetic studies of
homobasidiomycetes are both answering questions of
systematics and ecology, and raising many new ones.
210 - Phylogenetic relationships in the euagarics
(Agaricales): insights into morphological and ecological
evolution in mushrooms
J.-M. Moncalvo 1* , R. Vilgalys 1 & S.A. Redhead 2
1 Department of Biology, Duke University, Durham, NC
27708, U.S.A. - 2 Systematic Mycology and Botany Section,
Eastern Cereal and Oilseed Research, Agriculture and
Agri-Food Canada, Ottawa, Ontario K1A 0C6, Canada. -
E-mail: jeanmarc@duke.edu
Molecular phylogenetics support the view that gilled
mushrooms have evolved multiple times from
morphologically diverse ancestors, making the Agaricales
polyphyletic. Molecular data also show that poroid,
sequestrate (e.g., puffballs and secotioids) and reduced
(e.g., cyphelloids) forms have evolved several times from
gilled basidiocarps. Here we present results from molecular
phylogenetic analyses that sampled about one tenth of the
total number of species known in the largest natural group
of homobasidiomycetes, the euagarics clade (ca. 8400
known species). In many cases, it was possible to resolve
natural relationships of several gilled fungi for which
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Book of Abstracts
taxonomic position has been controversial in the past, and
also to unambiguously resolve among the euagarics the
systematic placement of many gasteromycetes and reduced
forms. The mapping of characters onto phylogenetic trees
indicates that ecology, biochemistry and/or physiology
rather than morphology often support natural groups of
euagarics. Newly discovered phylogenetic affinities
include for instance relationships of the true puffballs
(Lycoperdales) with the Agaricaceae, of Panellus and the
poroid fungi Dictyopanus and Favolaschia with Mycena,
and of the reduced fungus Caripia with Gymnopus.
Examples of newly discovered monophyletic groups of
euagarics include the clades resupinatus, lentinuloideae,
Tricholomataceae, Mycenaceae, Agaricaceae, psychedelia,
and Pleurotaceae.
211 - Phylogeny and ecology - what can primitive
homobasidioid fungi tell us?
E. Langer
Universitaet Kassel, FB 19, FG Oekologie, Heinrich-Plett-
Str. 40, 34132 Kassel, Germany. - E-mail:
ewald.langer@uni-kassel.de
With special emphasis on Aphyllophorales, this study was
carried out to verify hitherto published phylogenies of
Hymenomycetes by nuclear large subunit rDNA sequences
and comparative morphology. Preferably Aphyllophorales
with dolipores having the imperforate parenthesome-type
were used to remedy the imbalance in taxa composition of
former analyses. The results support the hypothesis of a
monophyletic origin of homobasidiomycetes having
dolipore parenthesomes perforated by many small holes,
including gilled, non-gilled mushrooms and
gasteromycetes. Only a minor part of the formally settled
orders or families could be verified by this analysis in full
respect. Especially the Agaricales ss Singer contain many
different related Aphyllophorales. A monophylum
comprising non-gilled mushrooms from certain
Corticiaceae and Hymenochaetales, having solely dolipores
with imperforate parenthesomes is the sistergroup of the
homobasidiomycetes having dolipores with perforated
parenthesomes. The borderline between
heterobasidiomycetes and homobasidiomycetes was
detected to be unsharp, because of repeatedly loss of
secondary ballistospores in a monophylum nesting the
Tulasnellales, Botryobasidiales and cantharelloid taxa.
212 - Phylogenetic relationships among corticioid fungi
K.-H. Larsson 1* , E. Larsson 1 & U. Kõljalg 2
1 Goteborg University, Botanical Institute, P.O. Box 461,
SE 405 30 Göteborg, Sweden. - 2 University of Tartu,
Institute of Botany and Ecology, 40 Lai str., 51005 Tartu,
Estonia. - E-mail: karl-henrik.larsson@systbot.gu.se