Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme III: PATHOGENS AND NUISANCES, FOOD AND MEDICINE Posters
(UNAM), Cd. Universitaria, 04510 México D.F., Mexico. -
E-mail: tavaltor@servidor.unam.mx
The monocaryotic components (neohaplonts) of 10
Pleurotus spp. strains (ECS127, ECS187, IB67, 1E202,
IE200, IE201, INI8, POROS, RP y P15) producing fruit
bodies of contrasting colors were obtained by chemical
dedicaryotization. By pairing these neohaplonts, 5
intersterile groups were recognized. Four strains belong to
the first group, IB67 (gray), IE200 (white), PORO (pink) y
RP (pink) and their neohaplonts showed compatibility
factors AmBm, and AnBn, respectively. In the second
group, a white (IE201) and a pink (IE202) strain were
found; their nehohaplonts could have either completely
different compatibility factors AoBo and ApBp or the
complementing factors of the first group, AmBn and
AnBm. In the third group, 2 gray strains, INI8 and
ECS127, were found with compatibility factors AqBq and
ArBr, while a yellow strain, ECS187, was found in the
fourth group with compatibility factors AsBs and AtBt.
Finally, a gray strain, P15, was found in the fifth group
with compatibility factors AuBu and AvBv. Thirteen
hybrid dikaryons were obtained by cross mating
neohaplonts from groups 1 and 2 and they were grown on a
commercial Pleurotus sp. substrate (feremented straw).
Gray fruit bodies were obtained from 11 hybrids and,
unexpectedly, yellow fruit bodies were produced by two
hybrids resulting from matings of neohaplonts from a white
strain (IE201) and a pink one (IE202). Regulation of gene
expression or extrachromosomal factors to explain such
results is discussed.
913 - New plant pathogenic fungus from the sterile
white basidiomycete complex
O. Vinnere * , J. Fatehi & B. Gerhardson
Plant Pathology and Biocontrol Unit, SLU, P.O. Box 7035,
S-75007, Uppsala, Sweden. - E-mail:
olga.vinnere@vpat.slu.se
An isolate of Sterile White Basidiomycete (SWB) was
obtained from the visually healthy roots of buffalo grass
(Pennisetum landistinum), growing in a natural bush land
in Perth, Western Australia. The greenhouse pathogenicity
tests revealed that the fungus is able to infect 12 different
plant species. This isolate was compared with a strain of
SWB, obtained from the American Type Culture
Collection (ATCC 28344), originated from Florida, United
States, which has been reported as an aggressive pathogen
on 16 genera of agricultural crops. Mycelial features,
growth rate, as well as pathogenicity pattern and inoculum
potential of these two pathogens were distinctly different.
In addition, sequence analysis of the Internal Transcribed
Spacer (ITS) regions, 5.8S and the first 800 bp of the 25S
ribosomal RNA genes strongly supported that the
Australian fungus was clearly different from the American
isolate. The sequence data confirmed the previous report by
another research group that the American SWB strain
belonged to Marasmius graminearum. Further studies are
carried out in order to resolve the taxonomic position of the
Australian SWB.
914 - The biodiversity of microfungi from selected
organically produced fruit and vegetable commodities
from Norway
N.W. Waipara 1* & M. Torp 2
1 HortResearch, Canterbury Research Centre, P.O.Box 51,
Lincoln, New Zealand. - 2 National Veterinary Institute, Box
8156 Dep., 0033 Oslo, Norway. - E-mail:
nwaipara@hortresearch.co.nz
The mycofloras of four organically produced fruit and
vegetable commodities; dried fruit, strawberry, corn and
carrot, for sale in Norway were examined. The species of
fungi obtained from each food commodity were mostly
saprophytic. Xerophilic fungi such as Eurotium spp.,
Aspergillus spp., and Wallemia sebi were isolated in many
dried fruit samples along with fungi capable of food
spoilage such as, Rhizopus spp. and Zygosaccharomyces
rouxii. Mycotoxin- producing Aspergillus flavus was also
isolated, and aflatoxins were also detected in low levels in
these samples. The fruit spoilage pathogen, Botrytis
cinerea, was frequently isolated from all strawberry
samples along with two other strawberry pathogens Idriella
lunata and Colletotrichum gloeosporioides, which were
less frequently isolated. Most fungi obtained from corncob
kernels were aerial contamination species such as
Cladosporium and Epicoccum, Zygomycetes and yeasts.
The fungi obtained from carrot samples were common
saprophytic species frequently reported from soil and roots,
although carrot spoilage pathogens such as Thielaviopsis
basicola and Rhizoctonia carotae were also isolated in low
numbers.
915 - Physiological regulation of biomass and
polysaccharides production by medicinal mushrooms
S.P. Wasser 1 , V.I. Elisashvili 2* , M. Stajic 1 & M. Didukh 1
1 Institute of Evolution, University of Haifa, Haifa 31905,
Israel. - 2 Institute of Biochemistry and Biotechnology,
Tbilisi 380059, Georgia. - E-mail:
velisashvili@hotmail.com
Agaricus nevoi, Inonotus levis, Phellinus igniarius, Ph.
robustus, Pleurotus ostreatus, and Tremella mesenterica
biomass and polysaccharide production in dependence on
the carbon and nitrogen sources have been investigated. All
strains grew well in the presence of glucose, maltose or
mannitol in the medium yielding in shake flasks
experiments up to 13-18.9 g l -1 of crude biomasspolysaccharide
ethanol precipitate. Among carbon sources
studied, glucose appeared to be the best for the
polysaccharide production by I. levis, Ph. igniarius, Ph.
robustus, P. ostreatus, whereas T. mesenterica produced
the highest level of polysaccharide during growth in the
presence of sucrose and mannitol. It has been shown that
the yield of polysaccharides correlated with carbon source
concentration in the medium. Among nitrogen sources
studied, organic compounds and ammonium sulfate
Book of Abstracts 275