Book of Abstracts (PDF) - International Mycological Association

IMC7 Monday August 12th Lectures
new systematic arrangements came from molecular studies.
(c) There was a renaissance for ontogenetic studies in
culture. Thus, life-history experiments provided new
insights in most of heterobasidiomyxcetous taxa, especially
in smuts, tremelloid fungi and yeasts. (d) Coevolutionary
processes play an important role in diverse
heterobasidiomycetous taxa. Therefore, systematics of
hosts have to be included in fungal character sets. (e)
Fortunately, most phylogentic interpretations are now
based on several datasets, suggesting possibilities for
improved evolutionary hypotheses.
8 - Ultrastructure of heterobasidiomycetous fungi
R. Bauer
Universität Tübingen, Lehrstuhl Spezielle Botanik und
Mykologie, Auf der Morgenstelle 1, D-72076 Tübingen,
Germany. - E-mail: robert.bauer@uni-tuebingen.de
Significant ultrastructural characteristics of
heterobasidiomycetes, such as nuclear and spindle pole
body behaviour, septal pore apparatus, colacosomes,
symplechosomes as well as myco- and phytoparasitic
interactions will be discussed with special regard to their
role as phylogenetic markers.
9 - Heterobasidiomycetous yeasts: diversity, phylogeny
and classification
J.P. Sampaio 1* , R. Bauer 2 , M. Weiß 2 & M. Gadanho 1
1 Centro de Recursos Microbiológicos, Secção Autónoma
de Biotecnologia, Faculdade de Ciências e Tecnologia,
Universidade Nova de Lisboa, 2829-516, Portugal. -
2 Universität Tübingen, Institut für Biologie I, Lehrstuhl
Spezielle Botanik und Mykologie, Auf der Morgenstelle, 1,
D-72076, Tübingen, Germany. - E-mail:
jss@mail.fct.unl.pt
Basidiomycetous yeasts form a remarkably diverse group
of fungi and are distributed throughout the three main
lineages of the Basidiomycota: Urediniomycetes,
Ustilaginomycetes and Hymenomycetes. Traditionally, the
yeast stages of plant or mycoparasitic basidiomycetes and
the unicellular forms of fruitbody-producing taxa have
been excluded from the yeast domain. When these nonconventional
basidiomycetous yeasts are cultivated in
laboratory media, the usual growth form is unicellular and
corresponds to the haploid and/or saprophytic phases. Nonconventional
dimorphic basidiomycetes rarely develop
their complete life cycle in culture, contrary to typical
basidiomycetous yeasts. This artificial separation of taxa,
mainly for historical reasons, prevents an integrated
assessment of the diversity of these groups and the
implementation of a natural classification system. The
objectives of this presentation are two-fold: (i) to advocate
a new concept of 'basidiomycetous yeasts' encompassing
all dimorphic basidiomycetes, regardless of their life cycle
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Book of Abstracts
and (ii) to present and discuss new developments
concerning the systematics of asexual (Rhodotorula) and
sexual (Leucosporidium, Mastigobasidium,
Rhodosporidium and Sporidiobolus) taxa of the sub-class
Microbotryomycetidae. The polyphyletic nature of
Rhodotorula and the relationship between Leucosporidium
/ Mastigobasidium and the Microbotryales will be
addressed.
10 - Molecular phylogeny of rusts
W. Maier
Universität Tübingen, Spezielle Botanik/Mykologie, Auf der
Morgenstelle 1; 72076 Tübingen, Germany. - E-mail:
w.maier@uni-tuebingen.de
Sequence data from nuclear large subunit ribosomal DNA
was used to infer phylogenetic relationships of selected
genera of the rust fungi and to test the monophyly of these
genera. Neighbor joining analysis and a Bayesian method
of phylogenetic inference using Monte Carlo Markov
chains confirm that (1) Puccinia, Uromyces, Cumminsiella
and Endophyllum have a common origin. (2) The
autoecious Rosaceae-rusts Phragmidium, Kuehneola,
Triphragmium, and Trachyspora are a monophyletic group,
representing Phragmidiaceae. (3) The gasteroid genus
Ochropsora is closely related to Tranzschelia. The
monophyly of the following genera could be confirmed:
Chrysomyxa, Coleosporium, Cronartium,
Gymnosporangium, Melampsora, Phragmidium, and
Tranzschelia, whereas the genera Puccinia, Pucciniastrum,
Thekopsora and Uromyces are polyphyletic. The molecular
phylogenetic hypotheses are compared to morphologybased
systematics with special emphasis on spermogonial
and teliospore morphology, and the usefulness of these
characters on different systematic levels is discussed.
11 - Evolution in smuts
D. Begerow * & R. Bauer
University of Tübingen, Botanisches Institut; Auf der
Morgenstelle 1, Germany. - E-mail:
ustilaginomycetes@uni-tuebingen.de
Many changes in the view of smut phylogeny have been
discussed within the last decade. An overview of the main
lineages of that plant parasitic group is presented. Based on
an integrated phylogeny hypotheses of the major traits of
evolutionary mechanisms will be discussed. New
morphological, ecological, and coevolutionary aspects of
smut evolution are in focus of present studies and will be
highlighted.