Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme IV: POPULATION DYNAMICS AND ECOLOGY Posters
10, 30, 60 ppm of copper. Biosorption equilibrium was
established in 5 minutes at pH 3 and 25 °C. The
biosorption is pH-dependent but indipendent from
temperature. The results comfirm the previous ascertained
ability of A. polytricha to chelate heavy metals. The
optimal condition for copper biosorption were determined
at pH 3, when 100 mg of biomass were incubated with 30
ppm of copper. Fungal biomass was also immobilised on a
PVA matrix for further applications on heavy metal
polluted streams.
956 - The co-introduction of Australian
ectomycorrhizal fungi with eucalypt plantations in the
Mediterranean. Potential environmental risks
J. Diez * , G. Moreno & J.L. Manjon
Dpto. de Biología Vegetal, Universidad de Alcalá, E-28871
Alcalá de Henares, Spain. - E-mail: jesus.diez@uah.es
A growing evidence supports the recent dispersion of
Australian ectomycorrhizal fungi with plantations of
eucalypts and Australasian acacias worldwide. The effects
of such introduction on the natural ecosystems have been
poorly studied. In the Iberian Peninsula, such cointroduction
seems to facilitate the adaptation of eucalypts
to the soils of plantation sites. Consequently, the
replacement of eucalypts for native sclerophyllous species
is difficult and causes high costs in areas where eucalypts
were extensively planted, such as the Natural Park of
Monfragüe in Cáceres (Spain). In eucalypt plantations
close to Monfragüe, we have found fruit-bodies of
ectomycorrhizal fungi specific to Australasian trees, such
as Hydnangium carneum, Hymenogaster albus,
Hysterangium inflatum, Setchelliogaster rheophyllus and
eucalypt-specific strains of the Pisolithus species complex.
Other exotic ectomycorrhizal fungi, unable to fruit outside
its natural geographic range, can have gone undetected
belowground. Whether these exotic fungi extend beyong
the eucalypt plantations will depend on their compatibility
with native hosts and their ability to compete with native
mycosymbionts; i.e. of the Australian species Laccaria
fraterna (=L. lateritia), which was found in Mediterranean
shrublands under ectomycorrhizal Cistus species. Further
studies will be necessary, if we are to predict potential risks
involved with the large-scale use of eucalypts in the
Mediterranean.
957 - Development of extraradical mycelia of
ectomycorrhizal fungi and interaction with
saprotrophic and root pathogenic fungi in soil
microcosms
D.P. Donnelly 1* , J.R. Leake 2 & L. Boddy 1
1 Cardiff School of Biosciences, Cardiff University, PO Box
915, Park Place, Cardiff, CF10 3TL, U.K. - 2 Department of
Animal and Plant Sciences, Alfred Denny Building,
University of Sheffield, Sheffield, S10 2TN, U.K. - E-mail:
donnellyd@cardiff.ac.uk
288
Book of Abstracts
Our recent studies of mycelial systems in soil microcosms
using combined image analysis, radioisotope tracers and
digital autoradiography, have provided new insights into
their structure and function. Nutrient foraging and transport
by mycorrhizal mycelia, together with the patterns of
carbon allocation from plants to mycorrhizal mycelia have
been visualised and quantified using 33P and 14C tracers.
Fungal morphology (mycelial fanning and cord formation)
and area cover of ectomycorrhizal mycelial systems of
Paxillus involutus and Suillus bovinus varied between
isolates and species over 27d. Encounter with pine litter
patches significantly increased mycelial cover to 230% of
controls. Extraradical mycelial morphology also influenced
ingress by saprotrophic fungi. Dense mycelial systems of
P. involutus resisted invasive cords of Phanerochaete
velutina, but led to allocation of host-derived carbon away
from the interaction zone. In contrast, the more aggregated
mycelia of Suillus bovinus had less mycelial density,
vigour and allocation of host derived carbon to the entire
extraradical mycelium when over grown by P. velutina
mycelia, compared to controls. We are currently
investigating the mechanisms by which extraradical
mycelia may also provide protection from migratory and
non-migratory root pathogenic fungi. We hypothesise that
differences in extraradical mycelial morphology and
function will determine degree of protection of host roots
from pathogen infections.
958 - Amplified Fragment Length Microsatellites
(AFLM): A simple method to develop microsatellite
markers in fastidious microorganisms applied to AM
fungi
G.W. Douhan * & D.M. Rizzo
University of California, Davis, Department of Plant
Pathology, One Shields Avenue, Davis, CA 95616, U.S.A. -
E-mail: gwdouhan@ucdavis.edu
Microsatellites are abundant, highly mutable arrays of
simple DNA sequence repeats which are powerful
molecular markers to study population and evolutionary
biology. Developing microsatellite markers for organisms
that cannot, or are not, easily manipulated under laboratory
conditions can be difficult because sequence information is
needed. To overcome this problem in the arbuscular
mycorrhizal (AM) fungi Glomus etunicatum and
Gigaspora gigantea, global amplification of the genomes
of each species were performed using linker-adaptor-PCR
from single spores. Amplified fragments were enriched for
microsatellite motifs using biotinylated oligonucleotides
and recovered by magnetic streptavidin beads. The
recovered fragments were reamplified, run on denaturing
polyacrylamide gels, and sixteen selected bands were
excised, cloned, and sequenced. Seven microsatellite
motifs were detected from six clones (efficiency rate of
43.8%). Primers were designed for all putative
microsatellite loci and most were successfully amplified
from three single spore preparations and from pools of 5,
10, and 20 spores after global amplification. We term this
technique amplified fragment length micosatellites and
propose that they can be useful markers for fastidious
microorganisms, such as Glomalean fungi. However, the