Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme III: PATHOGENS AND NUISANCES, FOOD AND MEDICINE Posters
wet and dry weights of roots and shoots as well as the
number of inflorescences, significantly. A combined
inoculum of Puccinia punctiformis and P. hedericola was
less effective than P. hedericola inoculated singly. The
most effective inoculum was an inoculum mixture of the
four perthotrophs. Further experiments should concentrate
on formulation of the pathogens and application in field
experiments.
831 - Real-time PCR procedure to reliably detect and
quantitate the pathogen Heterobasidion parviporum in
infected spruce tissue culture clones
A. Hietala, M. Eikenes, H. Kvaalen, H. Solheim & C.G.
Fossdal *
Norwegian Forest Research Institute, Høgskoleveien 12 N-
1432 Ås, Norway. - E-mail: carl.fossdal@skogforsk.no
One of our main interests is to learn about the molecular
basis of host defense responses, using the coniferous host
Norway spruce infected with the pathogen Heterobasidion
parviporum as the experimental system. This
basidiomycete and the closely related pathogen H.
annosum are the major root rot causing pathogens in
conifers. To screen host material for differential resistance
towards H. parviporum, it is a necessity to quantify the
fungal colonization of the host tissues. Therefore, we
aimed to develop and compare the sensitivity of a real-time
PCR to an ergosterol based method for determining the rate
of colonization. We developed a quantitative multiplex
real-time PCR procedure that reliably detecting down to
1pg H. parviporum DNA and 1ng host DNA. There was a
very high correlation between the fungal-biomass/totalbiomass
and fungal-DNA/total-DNA rankings obtained
with ergosterol and real-time PCR, strengthening the
credibility of both methods. The results indicate that this
real-time procedure can be a useful method to screen
different spruce material for their relative resistance to the
pathogen H. parviporum.
832 - A TaqMan TM real-time PCR assay for detection
and quantification of T-2/HT-2 toxin producing
Fusarium species in cereal matrices
A. Holst-Jensen * , A. Løvseth, A.K. Knutsen, M. Torp &
K.G. Berdal
National Veterinary Institute, Section of Feed and Food
Microbiology, Ullevålsveien 68, P.O.Box 8156 Dep., 0033
Oslo, Norway. - E-mail: arne.holst-jensen@vetinst.no
Fusarium sporotrichiodes and Fusarium langsethiae Torp
& Nirenberg ined. are known producers of T-2/HT-2 toxin.
However, these taxa may easily be confused with other
taxa of Fusarium, e.g. F. poae, that very rarely have been
reported to produce the toxin. The toxin is one of the most
important mycotoxins in cereal products in the Norhern
part of Europe, and it is therefore considered to be
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Book of Abstracts
important to detect and quantify the presence of producers
of the toxin. Based on partial translation elongation factor
1á gene sequences and phylogenetic analyses, we have
identified diagnostic sequence motifs and successively
developed a quantitative real-time PCR assay for detection
of these two taxa in cereal matrices, using TaqMan TM
chemistry. The assay and its performance will be
presented.
833 - A multi-target environmental approach to control
growth and mycotoxin production by Fusarium species
using essential oils and antioxidants
R. Hope * & N. Magan
Applied Mycology Group, Biotechnology Centre, Cranfield
University, Silsoe, Bedford MK45 4DT, U.K.
This study investigated how Fusarium culmorum and F.
graminearum isolates from the UK are affected by aw,
temperature, and fungicidal agents. The combined effects
of these different variables were also investigated. In
addition to how the morphology and ecology of the species
is affected by the environmental conditions, the effect on
mycotoxin production (in particular deoxynivalenol) was
also determined. Essential oils and antioxidants were
screened for antifungal properties in vitro using clearing
zone assays and temporal growth studies. The five most
effective agents identified by the in vitro screen were tested
further in situ on irradiated wheat grain under different
environmental conditions and a w levels. Growth rates of F.
culmorum and F. graminearum were significantly effected
by temperature,a w and antifungal agent. Efficacy of
essential oils and antioxidants agents at inhibiting fungal
growth was dose and type dependent. At least 500 ppm was
required for significant inhibition of growth. Cinnamon and
clove essential oils were the most effective growth
inhibitors of the five agents across all the conditions. Of
antioxidants, PP and BHA were most effective. The effect
on DON and Nivalenol mycotoxins was variable with
effects better at 500 ppm of essential oils than 100
regradless of aw level. The potential for using these
alternative food grade preservatives in stored cereals will
be discussed.
834 - A study of the trypsin genes in Metarhizium
G. Hu * & R.J. St. Leger
University of Maryland, Rm 4112 Plant Sciences Building,
college park, MD 20742, U.S.A. - E-mail:
gh70@umail.umd.edu
Metarhizium anisopliae var. anisopliae produces 3 trypsins
among a variety of other cuticle degrading enzymes. As
well as animals, the trypsin family of Metarhizium has
homologs in streptomycetes and four related pathogenic
pyrenomycetous ascomycetes. The limited distribution of
trypsins in a small group of related fungi is consistent with