Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme III: PATHOGENS AND NUISANCES, FOOD AND MEDICINE Posters
pathogens of wheat were Pyrenophora tritici-repentis and
Phaeosphaeria nodorum (anam. Stagonospora nodorum)
in 2000. Mycosphaerella graminicola (anam. Septoria
tritici) was the most common fungus isolated from the
wheat leaf spot samples collected in 2001. Didymella
exitialis (anam. Ascochyta sp.) was one of the most
important pathogens in 2001. Probably it has not been
described in the Czech Republic yet. This study was
supported by the Grant Agency of the Czech Republic
(project No. 521/00/0226).
883 - The grass endophyte gene for the first step in
ergot alkaloid biosynthesis
C.L. Schardl 1* , C. Machado 1 , J. Wang 1 & D.G.
Panaccione 2
1 University of Kentucky, Dept. Plant Pathology, Lexington,
KY 40546, U.S.A. - 2 West Virginia University, Div. Plant &
Soil Sci., Morgantown, WV 26506, U.S.A. - E-mail:
schardl@uky.edu
The endophytic Neotyphodium spp. grow in aerial tissues
of grass hosts where they cause no symptoms and exhibit
no signs; yet, often they help protect against insects,
nematodes and vertebrate herbivores, increase drought
tolerance, and improve plant growth and nutrient
acquisition. Several endophyte alkaloids are variously
active against insects and/or vertebrates. Among these are
ergot alkaloids, including lysergic acid and its peptine
derivative, ergovaline. Ergovaline is closely related to
ergotamine, which is produced by the infamous ergot
fungus (Claviceps purpurea), and is a potent mycotoxin
(but a useful pharmaceutical at low doses). Ergovaline is
thought to be responsible for toxicoses and reproductive
problems in livestock that ingest certain endophyteinfected
fescues and ryegrasses. The dmaW gene, encoding
the probable first step in ergot alkaloid biosynthesis
(dimethylallyltryptophan synthase), was cloned from
Claviceps fusiformis and C. purpurea, then from the tall
fescue endophyte, N. coenophialum, and a Neotyphodium
sp. (Lp1) from perennial ryegrass. There were two dmaW
genes in N. coenophialum, but only one in Lp1. Markerexchange
mutagenesis of dmaW in Lp1 eliminated
production of ergovaline as well as simpler ergot alkaloids,
confirming the role of the dmaW gene. Mutagenesis of
toxin-production genes in this manner presents
opportunities to develop forage grass cultivars with
protective endophytes that lack anti-livestock activities.
884 - A polyphasic study of Fusarium species in the
section Sporotrichiella - different approaches for
distinguishing closely related fungal species
H. Schmidt 1* , A. Holst-Jensen 2 , S.S. Klemsdal 3 , C.M.
Kullnig-Gradinger 4 , C.P. Kubicek 4 , R.L. Mach 4 , L.
Niessen 1 , H.I. Nirenberg 5 , U. Thrane 6 , M. Torp 3 , T. Yli-
Mattila 7 & R.F. Vogel 1
266
Book of Abstracts
1 TU München, Lehrstuhl für Technische Mikrobiologie,
Weihenstephaner Steig 16, 85350 Freising, Germany. -
2 National Veterinary Institute, Section of Food and Feed
Microbiology, P. O. Box 8156 Dep, 0033 Oslo, Norway. -
3 The Norwegian Crop Research Institute, Plant Protection
Centre, Høgskoleveien 7, N1432 Ås, Norway. - 4 Institute
for Chemical Enginering, Microbial Biochemistry and
Gene Technology Group, Technical University of Vienna,
Getreidemarkt 9/166, A1060 Vienna, Austria. - 5 Institute of
Blant Virology, Microbiology, and Biological Safety,
Federal Biological Research Center for Agriculture and
Forestry, Königin-Kuise-Str. 19, 1195 Berlin, Germany. -
6 Technical University of Denmark, Department of
Biotechnology, Bldg 221, DK-2800 Lyngby, Denmark. -
7 Laboratory of Plant Physiology and Molecular Biology,
Department of Biology, University of Turku, FIN-20014
Turku, Finland. - E-mail: Holger.schmidt@bl.tum.de
An integrated systematic study was carried out to clarify
the taxonomic position and relationship of Fusarium
langsethiae Torp and Nirenberg, ined. within the Fusarium
section Sporotrichiella. Different isolates of this species
were compared with strains of the closely related species F.
poae and F. sporotrichioides using a composite data set.
This set consisted of DNA sequences derived from the
intergenic spacer region (IGS), the internal transcribed
spacer region (ITS) and partial sequences of the b-tubulin
and the elongation factor-1 alpha (EF-1a) gene, AFLP
fingerprints, chromatographic data on secondary
metabolites and morphology. From these combined data a
consensus matrix was calculated. This was used as the
basis for the construction of an UPGMA dendrogram and a
multidimensional scaling which both revealed a clear
separation of these three taxa. The discriminatory power of
the different approaches varied significantly. The
correlation of the clustering obtained by analysis of the
combined data and that one obtained by an individual
experiment was worst with ITS sequences, whereas AFLP
appeared to reflect the composite data matrix best.
885 - Development of SCAR-PCR primers for the
detection of ochratoxinogenic Aspergilli
H. Schmidt * , L. Niessen & R.F. Vogel
TU München, Lehrstuhl für Technische Mikrobiologie,
Weihenstephaner Steig 16, 85350 Freising, Germany. - Email:
Holger.schmidt@bl.tum.de
The production of ochratoxin A (OTA) is described for
Penicillium verrucosum, P. nordicum and a wide variety of
Aspergillus species belonging to different sections. Besides
the taxonomic inhomogenity of OTA producing fungi the
ability to synthesize OTA is highly variable even within a
species. AFLP (amplified fragment length polymorphism)
typing revealed, that no clear correlation of the ability of a
strain to produce the toxin and the taxonomic position can
be found. As a consequence it was decided to develop
group specific PCR primers for potential OTA producing
Aspergillus species. The strains were screened for
polymorphic DNA markers using AFLP. Bands that were
considerd to be characteristic for a specific group were cut
out from silverstaind polyacrylamide gels. The DNA was