Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme II: SYSTEMATICS, PHYLOGENY AND EVOLUTION Posters
sister taxon, the F. oxysporum complex, in having long,
slender monophialides and polyphialides when cultured in
complete darkness. Based on the combined DNA sequence
data from translation elongation factor and the
mitochondrial small subunit ribosomal DNA, the fifteen
isolates of F. commune analysed formed a strongly
supported clade closely related to but independent of the F.
oxysporum and the Gibberella fujikuroi species complexes.
765 - Identifying species in the genus Botryosphaeria
B. Slippers 1* , T.A. Coutinho 1 , B.D. Wingfield 2 , P.W.
Crous 3 & M.J. Wingfield 1
1
Forestry and Agricultural Biotechnology Insititute (FABI),
Dept of Microbiology and Plant Pathology, University of
2
Pretoria, Pretoria, South Africa. - Forestry and
Agricultural Biotechnology Insititute (FABI), Dept of
Genetics, University of Pretoria, Pretoria, South Africa. -
3
Centraalbureau voor Schimmelcultures (CBS),
Uppsalalaan 8, 3584 CT Utrecht, The Netherlands. - Email:
bernard.slippers@fabi.up.ac.za
Botryosphaeria species are common endophytes and
opportunistic pathogens of woody hosts, world-wide.
Approximately 150 Botryosphaeria species have been
described, but their taxonomy is often confused due to
limited morphological variation and the wide host range of
some species. Recent studies have successfully combined
rDNA sequence and morphological data to define and
describe species. These characters, however, need to be
evaluated for their use in defining species boundaries
between closely related species and species complexes. In
this study, we combined sequence and PCR-RFLP data
from the ITS rDNA, β-tubulin and elongation factor-1-α,
with traditional morphological and ecological criteria, to
delimit various Botryosphaeria spp. The ITS region was
sufficiently variable to distinguish all species groups.
However, some closely related species such as B. ribis and
B. parva could not be separated. Combined data sets of the
three sequenced regions, however, clearly separated the
different species. Morphological characters were found to
be variable in nature. But under controlled laboratory
conditions, conidial and cultural morphology could be used
to recognise most species. Ecological data were also useful
in defining taxa, as many species are restricted to a
particular host or environment. The combination of
morphology, habitat data and DNA sequences produced a
reliable basis for the characterisation of Botryosphaeria
spp., both at the phylogenetic and diagnostic levels.
766 - Phylogenetic position of the Caloplaca aurantia
group
U. Søchting 1 & U. Arup 2*
1 Dept. of Mycology, Botanical Institute, University of
Copenhagen, O. Farimagsgade 2D, DK-1353 Copenhagen
K, Denmark. - 2 Institute of Systematic Botany, Lund
University, Ö. Vallgatan 18, SE-223 61 Lund, Sweden. - Email:
ulf.arup@sysbot.lu.se
The Caloplaca aurantia group, consisting of the species C.
aurantia, C. flavescens and C. thallincola, was formerly
included in the subgenus Gasparrinia, but is distinguished
from most other Gasparrinia's by having more or less
citriform spores. Based on molecular data a phylogenetic
hypothesis is presented, which places the Caloplaca
aurantia group apart from most species in Caloplaca
subgenus Gasparrinia, but close to the Caloplaca velana
group.
767 - Characterization of Fusarium proliferatum
(Matsushima) Nirenberg, the causal agent of bakanae
disease of rice
P. Sontirat 1* , P. Aranyanart 2 & S. Hiranpradit 3
1
Mycology Group, Plant Pathology and Microbiology
Division, Department of Agriculture, Paholyothin Road,
Jatujak, Bangkok 10900, Thailand. - 2 Rice Pathology
Research Group, Plant Pathology and Microbiology
Division, Department of Agriculture, Paholyothin Road,
Jatujak, Bangkok 10900, Thailand. -
3 Applied
Microbiology Group, Plant Pathology and Microbiology
Division, Department of Agriculture, Paholyothin Road,
Jatujak, Bangkok 10900, Thailand. - E-mail:
wantanee@doa.go.th
Sixty-four samples of bakanae disease of rice were
collected from different locations in Thailand during the
years 1997-2000. Cultural and morphological
characteristics of 38 isolates were studied and examined
scrutinizedly using Nelson et al. (1983)'s methods. The
result revealed that both cultural and morphological
appearances of all isolates were identical and identified as
F. proliferatum (Matsushima) Nirenberg, when considering
the production of polyphialides. Colonies on PDA floccose,
white when young, and became pinkish orange to reddish
or bluish purple when old (7-14 days ). Culture were often
tinged with light blue; reverse pale orange to light or dark
blue. Some isolates showed blue spots of sclerotia. On
CLA, microconidia were abundant, formed in chains of
varying length and in false heads on monophialides and
polyphialides which often appeared in 'V' shape. They are
primary single cells, oval to club-shaped with flattened
base, 6.5 - 11.6 × 2.1 - 3.4 µm. Macroconidia were
abundant, produced from monophialides on branched
conidiophores in sporodochia, hyaline, slightly sickleshaped
to almost straight with basal and ventral surfaces
parallel. The walls were thin and the basal cells were foot-
Book of Abstracts 231