Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme IV: POPULATION DYNAMICS AND ECOLOGY Posters
oak (Q. agrifolia) ecosystem. After a year in the field, the
seedlings, accompanied by soil cores from their immediate
environments, were harvested and analyzed. We found that
the position of planting strongly determined the EM or AM
status of the seedling; seedlings transplanted under a
mature oak canopy become colonized with ectomycorrhizal
(EM) fungi, while those planted into surrounding grassland
areas typically showed arbuscular mycorrhizal (AM)
colonization. Morphotyping and RFLP data showed that
the presence and position of EM species on mature oaks
strongly predicted EM diversity on seedlings. Several
species of EM fungi dominated the site and were present
on both seedlings and mature trees, although many rare
types were also found. The diversity and identity of
mycorrhizae associated with transplanted oak seedlings
appear to be largely regulated by position of planting, and
not by any mycorrhizal preferences of the three oaks
species.
1001 - Population structure of Heterobasidion annosum
in birch plantations, replanted on infested sites
V. Lygis * , R. Vasiliauskas & J. Stenlid
Department of Forest Mycology and Pathology, Swedish
University of Agricultural Sciences, P.O.Box 7026, SE-750
07 UPPSALA, Sweden. - E-mail: irklas2000@yahoo.com
The persistence of Heterobasidion annosum on infested
areas and its transfer to a new forest generation was studied
in three forest sites with similar histories. The sites
represented H. annosum disease centres (each 0.2 ha in
size) in 50-60 year-old Pinus sylvestris stands, which were
clear-felled and replanted with Betula pendula 25 years
previously. Fungal isolation from trees and stumps on each
site encompassed both replanted B. pendula and
surrounding P. sylvestris from the previous generation. A
total of 121 isolates of H. annosum was obtained from
spatially separated resource units. All of them belonged to
the P intersterility group. Each isolation locality was put on
a local map. Vegetative compatibility tests with the isolates
revealed extensive territorial clonality: from the first site,
23 isolates clustered into 5 clones (4.6 isolate per clone),
from the second - 63 into 6 (10.5), and from the third - 35
into 5 (7.0). Three largest clones consisted of 30, 18 and 10
isolates and covered the respective areas up to 25, 32 and
48 m across. It was not uncommon for the territorial clone
to cover areas that encompassed both P. sylvestris and B.
pendula forest generations. The results of this study show
that H. annosum is able to persist on infested sites for
decades and readily attack replanted trees of the new forest
generation. This is the first extensive study dealing with the
population structure of H. annosum P group in birch stands.
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Book of Abstracts
1002 - Chytridium lagenula Scheffel is a parasite of
Tribonema gayanum Pash. (Xanthophyceae)
M.A. Mamkaeva * , A.V. Pljushc & K.A. Mamkaeva
Biological Research Institute of St.Petersburg University,
Oranienbaumskoye sch.2, Stary Petergof, 198504,
St.Petersburg, Russia. - E-mail: mamkasha@yandex.ru
Development of Chytridium lagenula was observed in the
cultures inoculated by water samples. This parasite
develops only on the alive cells of alga. We observed
development of C. lagenula on Tribonema gayanum and T.
vulgare Pasch. We did not observed development of this
parasite on dead cells and there was not growth on the
pine's pollen and on the free medium (without alga), that is
why we think, that C. lagenula is obligate parasite of algae.
C. lagenula has a sessile upright or slightly titled
sporangium with a thin smooth wall. Growing sporangium
is globular, ripening pear-shaped, 8-13 µm length, 4-6 µm
breadth. Zoospores of the parasite are globular with one big
oil droplet. The diameter of zoospore is 3-4 µm. C.
lagenula is able to form globular resting spores, 6 µm in
diameter. Endobiotic system of C. lagenula consist of a
rhizoid. Also we have a facts about quantity circulation of
C. lagenula in nature. The number of infectious units of C.
lagenula was evaluated in Ladoga lake and adjacent water
bodies. It was 10 stations examinated. C. lagenula was
detected in 4 stations examined. Quantity of infective units
(sporangium, zoospores) was varied from 0.1 to 0.36. (It is
need to take into account, that concentrations were low,
because water was filtered). Reservoir it is possible to
speak, that C. lagenula is widespread parasite of alga in
nature, which mainly inoculate genus Tribonema.
1003 - Single sequence repeats markers reflect
population diversity and geographic barriers of
Ceratocystis polonica in Eurasia
M. Marin 1* , O. Preisig 1 , B.D. Wingfield 2 , T. Kirisits 3 &
M.J. Wingfield 1
1 Department of Microbiology and Plant Pathology,
Forestry and Agricultural Biotechnology Institute (FABI),
University of Pretoria, Pretoria 0002, South Africa. -
2 Department of Genetics, Forestry and Agricultural
Biotechnology Institute (FABI), University of Pretoria,
Pretoria 0002, South Africa. - 3 Institute of Forest
Entomology, Forest Pathology and Forest Protection,
Universität für Bodenkultur Wien, Hasenauerstrasse 38,
1190 Vienna, Austria. - E-mail:
Mauricio.Marin@fabi.up.ac.za
The blue stain fungus Ceratocystis polonica and its
associated bark beetle vectors, in particular Ips
typographus, cause huge losses to spruce (Picea abies) in
Eurasia. The aim of this study was to develop Single
sequence repeats markers (SSRs) in order to determine the
population structure and genetic diversity of C. polonica in
Europe and Japan. RAMS primers were used to target