Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme IV: POPULATION DYNAMICS AND ECOLOGY Posters
1023 - Temporal distribution of ectomycorhizae in
Quercus rubra L. plantations of the Basque Country
and evaluation of their infective potential
N. Rodriguez, I. Salcedo * , E. Sarrionandia & M.K.
Duñabeitia
Dpt. Plant Biology and ecology. University of the Basque
Country, Apdo. 644. 48080 Bilbao, Spain. - E-mail:
gvpsalai@lg.ehu.es
Due to its fast growth and the commercial value of the
wood, Q. rubra has been used in many Basque Country
plantations which have been located in Q. robur L.
habitats. The evaluation of infection ability and density of
the mycorhizal propagules is one of the main factors to
take into account in reforestation and restoration
programmes (Kendrick 1988). The principal aim of this
study is to explore the temporal variation throughout a year
(2000-01) of the species richness and diversity of
ectomycorhizae in six localities. Likewise, greenhouse's
experiments were carried out in order to determine the
infective potential of the forest soils. Maximum values of
diversity were recorded during autumn and winter; whereas
the minimum was in summer. The ubiquitous Cenococcum
geophilum is one of the few morphotypes that appears
throughout the year. According to the mycorhization rate
biometric and physiological variables of the seedlings
grown in soil of different localities of Q. rubra forests were
determined. A positive correlation has been found between
mycorhization rate and measured variables.
1024 - Growth promoting effects of endophytic
colonisation of the roots of larch seedlings (Larix
decidua) with Cryptosporiopsis sp. and Phialophora sp.
A.-K. Römmert 1* , M. Oros-Sichler 2 , T. Lange 3 , H.J. Aust 1
& B. Schulz 1
1
Institut für Mikrobiologie der Technischen Universität
Braunschweig, Spielmannstr. 7, 38106 Braunschweig,
Germany. - 2 Biologische Bundesanstalt für Land- und
Forstwirtschaft, Messeweg 11-12, 38104 Braunschweig,
Germany. -
3 Botanisches Institut der Technischen
Universität Braunschweig, Mendelssohnstr. 4, 38106
Braunschweig, Germany. - E-mail: ak.roemmert@tu-bs.de
Symbiotic associations of endophytic fungi with their hosts
vary from mutualistic to latently pathogenic. In order to
discern the nature of endophytic infections of the roots,
those of axenically cultured larch seedlings were inoculated
either with one of two endophytes, Cryptosporiopsis sp. or
Phialophora sp., previously isolated from roots of larch, or
with the pathogen Heterobasidion annosum. All three
isolates colonised the roots systemically and both inter- and
intracellularly. Whereas colonisation with each of the fungi
significantly improved growth of the seedlings in
comparison to the non-inoculated control, the greatest
improvement resulted from endophytic colonisation.
However, in contrast to colonisation with the endophytes,
infection with H. annosum also led to development of
disease symptoms. Application of a mycelium extract of
Phialophora sp. to roots of the host also improved growth
of the roots and seedlings. The capability of all three fungi
to produce IAA may explain the growth enhancing effects
of the mycelium extract and of colonisation. Additional
virulence factors may be responsible for pathogenicity of
H. annosum. In conclusion, endophytic colonisations of the
roots of larch with Cryptosporiopsis sp. or Phialophora sp.
are mutualistic symbioses and we hypothesise that
endophytic colonisation of the roots, in contrast to that of
the shoots, is generally systemic and mutualistic1. 1Boyle,
Götz, Dammann-Tugend & Schulz (2001). Symbiosis 31:
259-281.
1025 - Spatial and temporal genetic variation among
arbuscular mycorrhizal fungi from undisturbed
vegetation
S. Rosendahl
Department of Mycology, University of Copenhagen, Oster
Farimagsgade 2D, DK-1353 Copenhagen K, Denmark. -
E-mail: soerenr@bot.ku.dk
Mycorrhizal roots from Hieracium pilosella in a Danish
coastal grassland were sampled in May, August, October
and November along a 50 m transect. Arbuscular
mycorrhizal fungi in the roots were characterised from
partial LSU rDNA sequences obtained by nested PCR. In
the specific PCR, the primers were designed to amplify a
clade within Glomus including species as G. mosseae, G.
caledonium, and G. intraradices. Three sequence types
were found to be common. One type showed high
similarity with Glomus intraradices, whereas the other
could not be grouped with known AM species. The
sequences showed some variation, but the same sequence
could be sampled from several plants along the transect.
Most of the variation in sequence types could be attributed
to the sampling time. The results showed that the high
degree of sequence variation reported from spores, could
not be found in roots from undisturbed vegetation systems.
1026 - A novel cotton swab sampling method for fungal
spores
C. Roux 1 , P.C. van der Merwe 1 , M. Smith 1 & I.H. Rong 2*
1 Mycology Unit, Biosystematics Division, ARC - Plant
Protection Research Institute, Private Bag X134, Pretoria
0001, South Africa. - 2 ARC - Biometry, Private Bag X519,
Silverton 0127, South Africa.
A sampling method for continual monitoring of fungal
spores, from various surfaces, such as bins in silos,
harvesters and other farm implements has been developed
with the use of standard cotton swabs (Johnson & Johnson
Cotton balls TM ). The swabs are used to lift all spores from
the surfaces sampled. The swabs are then washed with a
Book of Abstracts 309