Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme II: SYSTEMATICS, PHYLOGENY AND EVOLUTION Posters
in the propagation of ectomycorrhizal fungi is not yet fully
acknowledged. Seedlings inoculated with noble truffle
species are often infected with less valuable white truffle
species (e. g. Tuber dryophilum), either in the nursery or in
the field, sometimes without plausible explanation for the
way of infection. The existence of an alternative way of
propagation in the genus Tuber indicates that additional
precaution against cross contamination in inoculation
experiments is required.
778 - Differentiation of Leptographium spp. found in
Canada
A. Uzunovic 1* , S. Alamouti 2 , J.-J. Kim 2 & C. Breuil 2
1 Forintek Canada Corp., 2665 East Mall, Vancouver, B.C.,
Canada. - 2 University of British Columbia, Department of
Wood Science, Vancouver, Canada. - E-mail:
adnan@van.forintek.ca
Leptographium is one of the most commonly found genera
of fungi causing bluestain in conifers. Some species are
known to be tree pathogens. Some Leptographium spp are
linked to specific wood infesting insects, especially bark
beetles, however their biology, including their potential to
grow in fresh woody substrates and to cause stain, is not
fully known. The taxonomy of Leptographium spp is
complex, and identification to species is often difficult
when based on the existing taxonomy keys. Molecular
biology tools are being developed but are not yet available.
We looked at number of reference Leptographium isolates
from existing culture collections and we included those
collected in Canada over the last decade. We investigated
additional attributes that could assist species delineation.
This included growth rates on 2% malt extract agar at
different temperatures and colony morphology at different
stages of growth. We also compared the ability of some of
the isolates to colonize freshly cut lodgepole pine phloem
and to stain the sapwood. The results of these experiments
and our observations are reported here.
779 - Lactarius well-represented in West-Africa? Benin
explored!
A. Verbeken 1* , A. De Kesel 2 & P. Van Rooij 1
1 Ghent University, Dpt. Biology, Group Mycology, K.L.
Ledeganckstraat 35, B-9000 Gent, Belgium. - 2 National
Botanic Garden of Belgium (BR), Dpt. Thallophyta,
Domein van Bouchout, B-1860 Meise, Belgium. - E-mail:
mieke.verbeken@rug.ac.be
The up to now 80 Lactarius species described from tropical
Africa are particularly well-represented in the Guineo-
Congolian rain forests (Congo-Kinshasa) and the
Zambezian miombo woodlands (Zimbabwe, Zambia,
Burundi). In these ecosystems the genus Lactarius is one of
the most important ectomycorrhiza formers. The Sudanian
woodlands cover large parts of West-Africa and are,
compared to the Zambezian woodlands, poorly explored.
They are often dominated by the ectotrophs Isoberlinia and
Uapaca, while they lack the typical Zambezian trees
Brachystegia and Julbernardia. Therefore, it seemed logic
that the species diversity in the Sudanian woodlands would
be less important than in East-Africa. Some scattered
records of miombo woodland species in West-Africa
already suggested an overlap in the Lactarius mycoflora,
but more studies were needed. Intensive collecting in the
Isoberlinia and Uapaca savanna woodlands in Benin,
resulted in at least 24 Lactarius species, including some
undescribed taxa. In spite of the differences in dominant
ectotrophs, most Lactarius species from the studied area
are also known from Zambezian woodlands. This study is
the first to reveal a marked overlap of the Zambezian and
Sudanian ectomycorrhizal mycoflora. It also indicates the
absence of the Sudanian species in the Central African rain
forests (Guineo-Congolian) and consequently suggests a
disjunct distribution of the savanna woodland species of
Lactarius throughout Africa.
780 - Taxonomy and phylogeny of Septoria
G.J.M. Verkley, A. Van Iperen & M. Starink-Willemse *
Centraalbureau voor Schimmelcultures, P.O.Box 85167,
NL-3508 AD, The Netherlands.
In the anamorph genus Septoria Sacc. over 2000 names
have been described. Most taxa cause leaf spot on the host
plant. Known teleomorphs belong in Mycosphaerella
Johanson (Dothideales, Ascomycota), a cosmopolitan
genus with over 20 reported anamorph genera. Crous et al.
(2001, Mycologia 93: 1081-1101) showed that
Mycosphaerella is monophyletic, based on ITS rDNA
sequences. Both strains of S. aceris (teleom. M. latebrosa)
studied clustered in a clade with Cercospora, separate from
S. tritici (teleom. M. graminicola), indicating that Septoria
anamorphs may have evolved in several lineages. We
further investigated the phylogenetic position of Septoria
anamorphs using ITS and partial 28S rDNA sequences of a
larger set of taxa, some with known teleomorphs, isolated
from a wide array of plant families. An additional eight
anamorph genera linked to Mycosphaerella were also
represented in the analyses. The results show that Septoria
spp. all evolved within Mycosphaerella, but not as a result
of a single event. The data support a clade comprising S.
tritici and S. passerini from grasses, close to Ramularia
spp. Septoria spp. from several deciduous trees represent
relatively distant lineages. In contrast, many of the Septoria
spp. from various herbaceous plant families have almost
identical ITS sequences, and also often very similar
morphologies in vitro and in planta, indicating that they are
closely related. They are grouped with Cercospora spp. in
a large, unresolved cluster.
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