Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme II: SYSTEMATICS, PHYLOGENY AND EVOLUTION Posters
shaped, 3-5 septate, 26.0 - 64.8 × 1.8 - 3.1 µm.
Chlamydospores absent. Pathogenicity test was conducted
on rice seeds (RD6 ). It was found that the inoculated rice
seedlings were elongated in double of the control treatment
after 6 days of inoculation.
768 - The nature of the lichen symbiosis: Evidence for
mutualism
L.L. St. Clair * & K.B. Knight
193 MLBM Brigham Young University, Provo, Utah
84602, U.S.A. - E-mail: larry_stclair@byu.edu
In 1869 the German botanist Simon Schwendener put forth
his dual hypothesis proposing for the first time the
symbiotic nature of lichenized fungi. The structural and
metabolic complexity of many lichens suggests a longterm,
synergistic interaction between the symbionts.
Certainly, the lichenized condition, at least in its most basic
form, has been in place since the advent of the symbiotic
partners. Traditionally, lichens have been held up as the
ultimate example of symbiotic mutualism; however, many
lichenologists characterize the association as one of
controlled parasitism or helotism where the mycobiont
exploits or enslaves the photobiont, extracting organic
carbon and in some cases organic nitrogen. This
interpretation has received widespread support; and clearly
applies to more primitive (poorly organized) lichen species.
However, more highly evolved species demonstrate a
complex array of mycobiont adaptations that facilitate and
accommodate the photobiont and promote the dispersal and
propagation of the lichen. By definition mutualism requires
that both symbionts are benefited by the relationship, with
each partner evolving discernable structural and/or
metabolic adaptations that enhance the performance of the
other symbiont. Clearly, many lichen associations meet
these criteria, and therefore, should be considered
mutualistic.
769 - Morphological and ultrastructural characteristics
of Daldinia species
M. Stadler 1* , M. Baumgartner 1 , G. Venturella 2 & H.
Wollweber 3
1 Bayer AG, Pharma Research, Bayer Pharma Research
Center, P.O.B. 101709, D-42096 Wuppertal, Germany. -
2 Universitá di Palermo, Dipartimento di Scienze
Botaniche, Via Archirafi 38, I-90123 Palermo, Italy. -
3 Naturwissenschaftlicher Verein Wuppertal, Mykologische
Sektion, In den Birken 73, D-42113 Wuppertal, Germany. -
E-mail: marc.stadler@t-online.de
In our investigation of Daldinia Ces & De Not.
(Xylariaceae), morphological characters of anamorphs as
defined in the last world monograph by Ju et al.
(Mycotaxon 61: 243f., 1997) proved valuable for
segregation of species. Moreover, SEM was employed to
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Book of Abstracts
study the surface structures and other features of
ascospores (Mycolog. Progress 1: 31f., 2002).
Aforementioned characters were employed to validate the
results obtained by recently evolved PCR methodology and
chemotaxonomy based on HPLC-UV/visual and HPLC-
MS metabolite patterns (Mycolog. Res. 105, 1191f., 2001).
The results of our recent studies of specimens similar to the
pantropical D. eschscholzii (Ehrenb.: Fr.) Rehm from
Sicily, the Channel Islands and the Canary Islands suggest
that the variability within the genus may actually be much
higher than we had suspected some time ago. The present
contribution is intended to illustrate characteristic features
of some well-known and some recently described Daldinia
spp. Morphological and ultrastructural data also provide
evidence that a polyphasic taxonomical approach is
feasible to detect cryptic species and evaluate the
biological diversity of Daldinia.
770 - The ITS phylogeny highlights the evolution of
morphological characters and ecological traits in
Cordyceps
Ø. Stensrud 1* , I. Bjorvand Engh 2 , N.L. Hywel-Jones 3 & T.
Schumacher 1
1 Div. of Botany and Plant Physiology, Dept. of Biology,
University of Oslo, P.O.Box 1045, Blindern, 0316 Oslo,
Norway. - 2 Mycoteam AS, Forskningsvn. 3B, P.O.Box 5,
Blindern, 0313 Oslo, Norway. - 3 BIOTEC-Mycology, Yothi
Laboratories, 73/1 Rama VI Road, Rajdhevee, Bangkok
10400, Thailand. - E-mail: oyvind.stensrud@bio.uio.no
The phylogenetic relationships of 46 Cordyceps spp. and
24 anamorphic taxa with known or suspected affinity to
Cordyceps were inferred from ITS nrDNA sequence data.
The ITS phylogeny recognized four evolutionary lineages
and some strongly supported subclades when
representatives of the four clades were subjected to new
alignments and analysed separately. Morphological
characters traditionally used to define subgenera of
Cordyceps were found to have limited phylogenetic
information if compared to the ITS phylogenetic tree. The
ITS tree also questions the present systematics of several
anamorphic species, e.g. the genera Beauveria and
Tolypocladium are both polyphyletic. The ITS phylogeny
confirms the results of some earlier nrDNA studies (SSU,
LSU) that the plant pathogenic species Claviceps purpurea
and Epichloë typhina are derived within Cordyceps,
consequently making the genus Cordyceps paraphyletic.
We discuss important non-molecular characters, e.g.
perithecium morphology, host preferences and anamorphic
affiliation in the light of the inferred ITS phylogeny. We
conclude that the paraphyletic Cordyceps and its allies
(anamorphs) deserve a new classification based on a
combination of molecular and non-molecular evidence.