Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme IV: POPULATION DYNAMICS AND ECOLOGY Posters
Ascomycetes. The driftwood collected was mainly
comprised of pieces of Rhizophora mangle and
Conocarpus erectus. The predominant species, by
frequency of occurrence, include the Ascomycetes
Hypoxylon oceanicum (8.3%), Leptosphaeria australiensis
(15.2%), Lulworthia grandispora (6.8%), and Nais glitra
(8.3%) as well as the Deuteromycete Humicola
alopallonella (7.6%). In addition, two new species of
Ascomycetes were collected and will be presented. New
records for Florida include the Ascomycetes Lineolata
rhizophorae and Massarina velatospora. A new host
record for Phaeosphaeria gessneri occurring on R. mangle
is reported. Overall, the marine mycota of South Florida
appears to be very similar to that reported for other tropical
and subtropical regions.
1053 - An ecological study of woody and leafy
endophytes in the tropical mangrove tree, Kandelia
candel
L.L.P. Vrijmoed * , N. Plaingam & E.B.G. Jones
Department of Biology and Chemistry, City University of
Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong
S.A.R., China. - E-mail: bhlilian@cityu.edu.hk
Kandelia candel is the only tree member of the
Rhizophoraceae which occurs in the subtropical Asian
Pacific mangroves. We have undertaken a preliminary
survey of endophytes in woody and leafy tissues of K.
candel in Hong Kong. Samplings were carried out in two
distinct climatic period so as to evaluate possible effects on
their occurrence. Four fully grown trees were selected.
Wood sections were cut from branches of different
diameters and separated into bark and xylem tissue
segments. Leafy tissue segments were also removed from
mature leaves of branches sampled. All segments were
incubated in malt extract agar after surface sterilisation. A
total of 987 strains of fungi was isolated from 1280 bark
tissues, 1280 xylem tissues and 320 leafy tissues segments,
with infection rates of 60, 12 and 25% respectively. This is
represented by 22 identified genera and 28 morpho-types.
The dominant species in bark included Pestalotiopsis spp.,
Tryblidiopycnis sp., Xylaria sp., morpho-types 3 and 5.
Frequent xylem endophytes were Phoma sp., some
unidentified pycnidial coelomycetes, Geniculosporium sp.,
and morpho-type 13. Guignardia sp. and morpho-type 26
were abundant on leaves. These initial results confirm
endophytic infection in trees is not vertical and each tissue
type is colonised by a distinct group of endophytes.
1054 - Lichen genotyping with fungus specific
microsatellites
J.-C. Walser 1* , C. Sperisen 1 , M. Soliva 2 & C. Scheidegger 1
1 Swiss Federal Research Institute WSL, Zuercherstrasse
111, CH-8903 Birmensdorf, Switzerland. - 2 Geobotanical
Institute ETH Zurich, Zollikerstr. 107, CH-8008 Zürich,
Switzerland. - E-mail: jean-claude.walser@wsl.ch
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Book of Abstracts
Little is known about the genetic variation of lichenforming
fungi. Yet, corresponding knowledge would be
required for the accurate delimitation of individuals,
populations, or species and for studies of reproductive
systems and dispersal strategies. This will also help to
develop and evaluate measures for conserving lichen
biodiversity. Lacking genetic variation and, hence, low
adaptability to environmental changes such as habitat
fragmentation may explain why many epiphytic lichens are
declining over much of Europe. We suppose that
population genetic studies on lichen-forming fungi are
mainly limited by the lack of suitable molecular markers.
An ideal genetic marker type for population studies of
lichen-forming fungi would combine the detection of high
levels of genetic variation with the fungal specific
amplification of DNA. Both requirements would be
fulfilled by microsatellite markers. Microsatellites consist
of short tandemly repeated sequences and proved to be
highly informative markers in evolutionary, population
genetic and conservation biological studies. We show that
highly polymorphic, fungus-specific microsatellite loci also
exist in the epiphytic lichen species Lobaria pulmonaria.
Their fungus specific nature, their potential to identify
multiple alleles and their transferability make these STMS
markers a powerful and reliable new tool for genetic
mapping, large and small scale genetic diversity analyses
of L. pulmonaria and related species.
1055 - Nutrients are released during mycelial
interactions in soil
J.M. Wells * , L. Boddy & H.K. West
Cardiff School of Biosciences, Cardiff University Po Box
915, Cardiff Cf10 3TL, U.K. - E-mail: john@grade-sixsupplies.co.uk.
Cord-forming saprotrophic basidiomycetes represent a
major nutrient resevoir within forest ecosystems and appear
to be highly conservative of acquired nutrients. At some
stage they must release nutrients to soil, but information on
this is lacking. We have investigated nutrient release in the
wood decay fungi Hypholoma fasciculare and
Phanerochaete velutina. These were grown in soil
microcosms in the laboratory in unpaired, self-paired and
competing combinations. Inocula were prelabelled 32P
orthophosphate, and losses from the soil systems were
quantified by analysing water which had percolated
through different areas of the systems following simulated
rainfall events. 32P was released in unpaired systems and,
though amounting to to less than 1% of total recovery, is
direct demonstration of nutrient release to soil. Interaction
with self resulted in significant mobilization of
accumulated P, and significant increases in losses to soil.
Interaction with non-self mycelia usually resulted in greater
P mobilization than in interactions with self, even in the
case of interaction between different isolates of the same
species. P. velutina and one isolate of H. fasciculare
preferentially translocated mobilized P to the interaction
zone, but a another isolate of the latter preferentially
translocated P away from the interaction zone.