Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme II: SYSTEMATICS, PHYLOGENY AND EVOLUTION Posters
716 - Molecular characterization of red yeasts from
aquatic environments in Patagonia, Argentina
D. Libkind 1 , S. Brizzio 1 , A. Ruffini 1 , M. Gadanho 2 , M. van
Broock 1 & J.P. Sampaio 2*
1 Laboratorio de Microbiología Aplicada y Biotecnología,
Universidad Nacional del Comahue - Consejo Nacional de
Investigaciones Científicas y Tecnológicas (CONICET),
Centro Regional Universitario Bariloche, Quintral 1250,
Bariloche, Río Negro CP(8400), Argentina. - 2 Centro de
Recursos Microbiológicos, Secção Autónoma de
Biotecnologia, Faculdade de Ciências e Tecnologia,
Universidade Nova de Lisboa, 2829-516, Portugal. - Email:
jss@mail.fct.unl.pt
Main features of aquatic environments of glacial origin in
Patagonia (Argentina) are low pollution level and ultraoligotrophy.
Eight of these aquatic reservoirs were
surveyed for the occurrence of red yeasts. Subsurface water
samples were filtered and used for colony counting and
yeast isolation. A set of 64 isolates was characterised based
on the mini/micro satellite-primed technique (MSP-PCR).
DNA fingerprinting with M13 and (GTG)5 primers
allowed the grouping of 34% and 56% of all isolates,
respectively. Comparison of representative fingerprints of
each group with those of type strains of various pigmented
yeast, made possible the quick identification of an 87% of
isolates. The 26S rDNA (D1/D2 domain) sequence analysis
was performed for one representative of the remaining
unidentified groups. Rhodotorula mucilaginosa was found
in almost all samples and represented ca. 50% of the
isolates studied. Less frequent species corresponded to 6
genera and 16 species including five new yeast species of
the genera Rhodotorula (2), Cryptococcus (1) and
Sporobolomyces (2). Total yeast counting usually ranged 1-
150 CFU l-1 and rarely exceeded 200 CFU l-1. In contrast
with other studies on yeast biodiversity in freshwater, red
yeasts did not often predominated in our water samples.
This study represents the first report on red yeast
occurrence and biodiversity in North-western Patagonia.
717 - Polyphasic taxonomy of the genus Rhizopus
G.-Y. Liou * , S.-R. Chen, H.-M. Fu, F.-L. Lee & G.-F.
Yuan
Food Industry Research & Development Institute, P. O.
Box 246, Hsinchu 300, Taiwan. - E-mail: gyl@firdi.org.tw
Rhizopus Ehrenberg, established by Ehrenberg in 1820,
was monographed by Schipper & Stalpers, who divided the
genus into three groups, the R. stolonifer-, R. oryzae-, and
R. microsporus-groups, according to characteristics of the
sporangial apparatus and growth temperatures. Thereafter,
the characteristics of morphology, growth temperature and
the data from mating experiments became the basic criteria
for species delimitation of Rhizopus. In the zymogram,
three distinct groups, the same as those obtained by
traditional methods are recognizable. On the other hand, a
number of specific taxonomic problems were addressed.
Then, sequencing of 28S rDNA D1 & D2 regions, G+C
content, and DNA-DNA hybridization were proceeded.
The analyses of 28S rDNA sequences resolved the
Rhizopus strains into three divergent phylogenetic clades
consistent with the morphological characteristics and
zymogram. The results of G+C content and DNA-DNA
hybridization support the recognition of R. azygosporus
and R. reflexus. Taxonomy of the genus Rhizopus was
reevaluated.
718 - Phylogenetic analysis of selected Aschersonia
(Hypocrella) species and their allies
M. Liu * & K.T. Hodge
Cornell University, 334 Plant Science Bldg., Ithaca, NY
14850, U.S.A. - E-mail: ml276@cornell.edu
Despite its potential in biocontrol of scale insects and
whiteflies, Aschersonia (teleomorph: Hypocrella) has
seldom been included in phylogenetic studies.
Nevertheless, it sits in an important position in the family
of Clavicipitaceae. In this study, we investigated the
phylogenetic relationships among Aschersonia
(Hypocrella) isolates and species from related genera based
on several genes. Parsimony analysis based on molecular
data shows that Aschersonia (Hypocrella) isolates form a
monophyletic clade, which is sister to an insect pathogen
clade including Cordyceps and allies. A third clade
represents grass endophytes. Within the Aschersonia clade,
A. aleyrodis and A. goldiana form a clade; while another
isolate referred to A. goldiana exists in another clade that
includes A. andropogonis. Some authors have considered
A. aleyrodis and A. goldiana to be conspecific, while others
treat them as separate species based on morphological
characters, especially pigmentation. We intend to clarify
the relationships between these two species using
molecular data and detailed morphological study.
719 - A revision of the terverticillate Penicillia
F. Lund 1* , J.A.M.P. Houbraken 2 , A.F.A Kuijpers 2 , R.A.
Samson 2 & J.C. Frisvad 1
1 Mycology Group, BioCentrum-DTU, Building 221,
Technical University of Denmark, DK-2800 Kgs. Lyngby,
Denmark. - 2 Centraalbureau voor Schimmelcultures, P.O.
Box 85167, NL-3508 AD Utrecht, The Netherlands. - Email:
fl@biocentrum.dtu.dk
Some of the most common fungi in stored foods are the
terverticillate Penicillia. Correct identification of these
Penicillia is important in order to predict and avoid fungal
spoilage and mycotoxin contamination of foods, feeds and
in indoor environments. A revision of these species is
overdue. We have chosen a polyphasic approach for
classifying and cladifying these Penicillia (approximately
50 species), using a series of morphological, physiological
Book of Abstracts 217