Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme III: PATHOGENS AND NUISANCES, FOOD AND MEDICINE Posters
864 - Simultaneous detection of GFP- and GUS-marked
fungi of different formae speciales of Fusarium
oxysporum on plant roots
T. Nonomura * , Y. Matsuda & H. Toyoda
Laboratory of Plant Pathology and Biotechnology, Faculty
of Agriculture, Kinki University, 3327-204 Nakamachi
Nara 631-8505, Japan. - E-mail:
nonomura@nara.kindai.ac.jp
In our attempt to visualize infection behavior of the fungal
wilt pathogens inoculated onto plant roots, the fungi were
genetically marked with two reporter genes. F. oxysporum
f. sp. lycopersici (FOL) and F. o. f. sp. melonis (FOM)
were transformed with the green fluorescence protein gene
(GFP) and the β-glucuronidase gene (GUS), respectively.
In the present study, we focused mainly on the attachment
and subsequent hyphal elongation by microconidia
inoculated onto roots of tomato and melon seedling. In
addition, we attempted to directly distinguish different
formae speciales of F. oxysporum onto the same plant roots
by expression of different marker genes. Microconidia of
GFP-marked FOL (KFOL-001) and GUS-marked FOM
(KFOM-002) were inoculated onto roots of cotyledonal
seedlings, and inoculated roots were first observed under a
fluorescence microscope to detect KFOL-001 and then
stained with X-gluc (substrate for GUS assay) to detect
KFOM-002 under a light microscope. Consequently, both
transformed pathogens could be clearly distinguished at the
same site of inoculation. These results suggest that dual
transformation of F. oxysporum is useful for analyzing
behavior of nonpathogenic F. oxysporum challengeinoculated
with pathogenic F. oxysporum.
865 - Biscogniauxia and Daldinia; latent pathogens of
deciduous trees
L.K. Nugent * , G.P. Sharples & A.J.S. Whalley
School of Biomoleculr Sciences, Liverpool John Moores
University, Byrom Street, Liverpool L3 3AF, U.K. - E-mail:
beslnuge@livjm.ac.uk
Biscogniauxia Kuntze and Daldinia Ces. and De Not. are
two wood inhabiting xylariaceous genera. Biscogniauxia
species are frequently linked with canker diseases in
stressed hosts e.g. B. mediterranea causes coal canker in
Quercus suber (cork oak) and B. nummularia canker in
Fagus (beech) while D. concentrica (Bolt. ex. Fr.) causes
calico wood in Fraxinus (ash). Studies on ascospore
germination and development of the anamorphs in culture
in response to host extracts is presented. Biscogniauxia
nummularia and Daldinia concentrica. have been isolated
from their respective host leaves and branches and there are
frequency of isolation maybe linked to ascospore
production. The presence of Daldinia in leaves and in
wood has been investigated microscopically, chemically
and by molecular techniques, in addition to traditional
isolation techniques following surface sterilisation. The
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Book of Abstracts
presence of latent pathogens and their relationship to stress
of the host is presented. Experimentation on conditions
leading to the latent invasion and subsequent development
of teliomorphs are being undertaken in both field and
laboratory.
866 - Establishment of the first Karnal Bunt testing
laboratory in South Africa
O.M. O'Brien, I.H. Rong * & E.J. van der Linde
ARC-Plant Protection Research Institute, Private Bag
X134, Pretoria 0001, South Africa.
The fungal wheat disease Tilletia indica, commonly known
as Karnal Bunt (KB), was detected in a limited area of one
of South Africa's wheat producing regions during 1999.
Aimed at managing T. indica, a national survey to
determine the occurrence of the disease was initiated by the
Directorate Plant, Health and Quality, National Department
of Agriculture. To this end, the Mycology Unit, ARC-Plant
Protection Research Institute, Pretoria was tasked with
setting up a laboratory for the analyses of seed and grain
samples. Due consideration was given to the geographical
distance of the laboratory from the main wheat producing
areas of the country. The KB protocol, as recommended by
the USDA/APHIS, was followed with some adaptations.
Analyses were conducted for two consecutive years,
providing valuable experience in managing a quarantine
analytical facility of this nature. Protocols and procedures
representing different phases of the process were devised
for each workstation. These phases included: reception and
registering of samples, sub-sampling, washing and sieving,
centrifuging and preparing of microscope slides, detection
of T. indica, data processing and reporting, and waste
management. Laboratory procedures, problems
encountered and the development of novel techniques, as
well as the management and maintenance of the quarantine
facility, are discussed.
867 - Aflatoxins in the weaning food of Kenyan children
S.A. Okoth
Botany Department, University of Nairobi, P. O. Box
30197, Nairobi, Kenya. - E-mail: dorisokoth@yahoo.com
Cereal grains run a high risk of mycotoxin contamination
yet they form the basis of gruels used in weaning children
in Kenya. To these grains (maize, sorghum, millet)
supplements such as cassava, groundnuts, beans, and fish
are added and ground together, depending on the means
and education of the parents. Among the mycotoxins,
aflatoxins have been implicated in human diseases,
including kwashiorkor. Sampling for aflatoxin
contamination was done in Kisumu District, Kenya, an area
with high relative humidity and temperatures, high
incidence of kwashiorkor and the highest prevalence of
absolute poverty, 63%, in the country. A total of 180