Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme IV: POPULATION DYNAMICS AND ECOLOGY Posters
965 - Mycorrhiza of blueberry and control of
Verticillium wilt on strawberry: Two examples of
rhizosphere microbial steady states in agricultural land
use
J. Golldack 1* , P. Schubert 2 , H. Schwärzel 2 , P. Lentzsch 1 &
B. Münzenberger 1
1
Centre for Agricultural Landscape and Land Use
Research, Eberswalder Str. 84, D-15374 Müncheberg,
Germany. -
2
Landesamt für Verbraucherschutz und
Landwirtschaft, Eberswalder Str. 84, D-15374
Müncheberg, Germany. - E-mail: jgolldack@zalf.de
The roots of blueberry are mycorrhizal, but on sandy
agriculturally used soils, the mycorrhizal symbiosis has to
be stabilized by a specific management of the mulch layer
which provides organic C- and N-compounds. In long-term
plot studies, a high sensitivity of this symbiosis depending
on the mulch layer, particularly tree species of wood chips
and time of application was found. Thus, the microbial
population structure of the rhizosphere of variety 'Reka'
varied considerably. In one plant rhizosphere, the microbial
community was similar to the rhizosphere community of a
natural peaty soil which was correlated with the highest
fruit mass. This leads to the assumption that the
mycorrhizal symbiosis of highbush blueberry depends on
an appropriate fungus-bacteria-rhizosphere community
which can be influenced by the management of the mulch
layer. Strategies to achieve an appropriate microbial steady
state can be used to control the Verticillium wilt on
strawberry. The effect of different Verticillium strains and
antagonistic bacteria is going to be analysed under
controlled climatic conditions and in field trials. On
different agriculturally used sites, Verticillium strains will
be isolated to select the regionally best adapted
antagonistic bacteria to control the Verticillium wilt.
966 - Influences of T4-lysozyme producing potato plants
on the endophytic fungi of the roots studied by a
classical and a molecular approach
M. Götz 1* , J. Lottmann 2 , G. Berg 2 , H.I. Nirenberg 3 & K.
Smalla 1
1 Federal Biological Research Centre for Agriculture and
Forestry, Institute for Plant Virology, Microbiology and
Biosafety, Messeweg 11/12, 38104 Braunschweig,
Germany. - 2 University of Rostock, Gertrudenstraße 11a,
18051 Rostock, Germany. - 3 Federal Biological Research
Centre for Agriculture and Forestry, Institute for Plant
Virology, Microbiology and Biosafety, Königin-Luise-
Straße 19, 14195 Berlin, Germany. - E-mail:
m.goetz@bba.de
T4-lysozyme expressed in potato plants seems to be a
promising strategy to enhance the plants' resistance against
phytopathogenic bacteria like Erwinia carotovora.
However, lysozyme has unspecific effects on other bacteria
and on fungi. The monitoring of bacterial and fungal
rhizosphere communities of transgenic and non-transgenic
plants with a cultivation-independent molecular
fingerprinting technique (PCR-DGGE) revealed in no cases
a plant line dependent influence. The lysozyme is secreted
into the apoplastic space where its concentration should be
higher than in the rhizosphere. Therefore, the influence on
endophytes which live inside of the apoplast could be
stronger than that on the microorganisms in the
rhizosphere. Endophytic fungi were isolated from roots of
the parental and a transgenic line after surface sterilisation.
The isolates were cultivated, identified and characterised
by molecular methods. Here significant differences
between the parental and the transgenic line could be
found: the roots of the parental line were colonised with
Verticillium dahliae around three times higher than those
of the transgenic line. Additionally the surface sterilised
roots were examined by PCR-DGGE. Fingerprints of the
endophytic fungi could be shown for the first time. To
associate the bands to fungal isolates clones were generated
and sequenced. The results of the two methods of
investigation are compared and discussed.
967 - Substrate selectivity of corticioid fungi from
Nothofagus forests in Patagonia (Argentina)
A.G. Greslebin
Centro de Investigación y Extensión Forestal Andino
Patagónico, CC 14, 9200, Esquel, Chubut, Argentina. - Email:
alina@ciefap.cyt.edu.ar
Corticioid fungi (Aphyllophorales, Basidiomycetes) grow
on almost every type of woody substrate, but species
usually show preferences on certain features of the
substrate such as the decay stage and/or the part of the tree
involved. These preferences determine the spatial and
temporal arrangement of these organisms along the
degradation process. During an intensive floristic survey of
Corticiaceae growing on 3 Nothofagus spp. in the
Patagonian Andes forests, the habitat preferences and the
degree of selectivity of 42 species in relation to three
substrate features (decay stage, part of the tree and
diameter of the detritus) were evaluated. Decay stage was
classified into six categories according to hardness and
other features. Part of the tree was classified as bark,
sapwood, hardwood or the combination of bark/sapwood or
sapwood/hardwood. Diameter was classified as 0-5, 6-10,
11-20, 21-30 or >30 cm (from small branches to big
trunks). The differential distribution (not aleatory) of the
species according to the characteristics of the substrate was
statistically tested (X 2 ). 95% of the species showed a
differential distribution in relation to the decay stage, 64%
in relation to the part of the tree and 54% in relation to the
diameter. In order to evaluate the degree of selectivity, the
range of categories where a species was recorded for each
variable was analyzed. Species with a range ≤ 3 were
considered highly selective for that variable.
Book of Abstracts 291