Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme II: SYSTEMATICS, PHYLOGENY AND EVOLUTION Posters
J. Miadlikowska * & F. Lutzoni
Department of Biology, Duke University, Durham, NC
27707, U.S.A. - E-mail: jolantam@duke.edu
The Peltigera canina species complex represents the most
recently derived section within the genus Peltigera.
Morphology and secondary compounds were the only
taxonomic evidences used to circumscribe the species
forming this complex of highly polymorphic group of
foliose lichens. To evaluate the putative morphospecies
within the canina complex, maximum parsimony (MP) and
maximum likelihood (ML) phylogenetic analyses were
conducted on separate and combined ITS and LSU nrDNA
sequences for 17 recognized species and eight potential
taxa, represented by 65 individuals. Patterns of variation in
length and structure found within a hypervariable region of
ITS1 were used as supplementary data for delimiting
genetic boundaries among closely related species. In
addition to 20 coded characters derived from ambiguously
aligned portions of alignments (INAASE), 24 coded
discrete characters were provided by the hypervariable
ITS1 marker. Based on optimal topologies derived from
MP and ML searches we found complete concordance
between phylogenetic and morphological species
circumscription for 13 Peltigera species from this complex.
Phylogenetic distinctness between North American and
European populations of the morphologically uniform
species P. degenii was detected and highly supported. Our
results confirm recognition of three newly proposed
undescribed species. No evidence for recombination was
found in the ITS and LSU regions within the P. canina
complex.
731 - PCR-RELP analysis of intergenic spacer(IGS) of
ribosomal DNA among Fusarium oxysporum formae
speciales
B.R. Min 1* & Y.K. Choi 2
1 Dept. of Biology, Sangmyung Univ., 7 Hongji-Dong,
Chongno-Gu, Seoul, Korea. - 2 Dept. of Life science,
Hanyang Univ., 17 Haengdang-Dong, Seongdong-Gu,
Seoul, Korea. - E-mail: genebang@sangmyung.ac.kr
Nuclear rDNA provides useful inter- and intra-specific
polymorphism eukaryotic organism. The intergenic spacer
(IGS) or non-transcribed spacer (NTS) lies between the
large subunit and small subunit encoding regions of
consecutive cistrons. Closely related species may show
considerable diversity in IGS of few reflecting both length
and sequence variation. Fusarium oxysporum has one of
the broadest host ranges of many plant pathogenic fungi
and over go different formae speciales of F. oxysporum are
recognized. Variation within the intergenic spacer (IGS) of
the ribosomal DNA gene for twnety-two strains of F.
oxysporum and its formae speciales was examined by PCR,
compled with RELP analysis. The length of the amplified
IGS region was about 2.6 Kb in all strains except F.
oxysporum f. sp. cucumerium from Korea and F.
oxysporum f. sp. niveum from Japan. Those two strains
were 2.5 Kb long. Restriction digestion of IGS-RELP
regions by EcoRI, NruI, HincII, SalI, SmaI, BgeII, HindIII,
XhoI, and KpnI gave rise to nine IGS haplotypes among all
strains. Cluster analysis based on the prosence or absence
of comingrating restriction fragments show the two groups
based on 44% genetic similarity. These results
demonstrated that analysis of IGS showed some difference
within and between F. oxysporum formae speciales.
732 - Variability analysis of the Fumonisin producing
species F. verticillioides using the IGS region
S. Mirete 1* , B. Patiño 2 , C. Vázquez 2 & M.T. González-
Jaén 1
1 Dp. Genetics, University Complutense of Madrid, Fac.
Biology, Ciudad Universitaria, 28040-Madrid, Spain. -
2 Dp. Microbiology III, University Complutense of Madrid,
Fac. Biology, Ciudad Universitaria, 28040-Madrid, Spain.
- E-mail: smirete@bio.ucm.es
F. verticillioides, included in the so-called Gibberella
fujikuroi species complex, is one of the most important
source of fumonisins contaminating food products because
of the widespread occurrence of this fungus on maize,
among other crops. Detection methods rely on the previous
knowledge about the degree of intraspecific variability. In
this work we have analysed the partial sequence of the
intergenic spacer of rDNA (IGS) of a wide sample of F.
verticillioides strains from different geographic location,
hosts, mating type and fumonisin production. considering
the incidence of asexual reproduction. The analysis
revealed the existence of two groups of strains: fumonisin
producing and fumonisin non producing strains which
would indicate that some divergence is taking place within
F. verticillioides. Within the group of fumonisin producing
strains no clustering of isolates regarding geographic origin
nor host could be detected. The variability observed was
compared with data from other Fusarium species taking
into account their mode of reproduction.
733 - Contribution to the knowledge of Termitomyces
(tropical basidiomycetes) from Cameroon: Ecology and
systematics
D.C. Mossebo
University of Yaoundé 1, Mycological Laboratory, B.P.
1456 Yaoundé, Cameroon. - E-mail:
mossebo@uycdc.uninet.cm
Species of the genus Termitomyces (Agaricales,
Pluteaceae) are good edible tropical mushrooms
characterized by a small to very large pileus generally
bearing a more or less prominent umbo called
perforatorium and a central and solid stipe producing a
more or less long underground pseudorrhiza. Their other
main characteristic is that they are exclusively symbiotic
species living in symbiosis with termites on or around
termitaries built by the latter. They arise from funguscombs
within these termitaries. The first description of
Book of Abstracts 221