1993 - Mycological Society of America

Ribosomal DNA internal transaibed spacers, ITS I and ITS II, have
been investigated among 6 isolates of the 3 species. Support for the
synonomy of Scedosporium injlatum with La2entospo~a prolficmrs was
found based on identical restriction fragment patterns and DNA
sequence analysis of ITS. However, Scedosporium upiospennum differed
approximately 17% from both Scedosporium inflaturn and Lomentospora
proIificrms in ITS I sequence. The sequence data generated in this
study, along with data from more isolates of these species, will be
useful for phylogenetic analysis of these fungi. DNA probes of
species-specific ITS regions will be valuable in clinical settings for
distinguishing these fungi.
Symposium; Sunday, 930 am
Patch Clamping Techniques: A case study
using Saprolegnia
Ro~er R. Lew. Biology Dept., York Univ., 4700 Keele Street,
North York, Ontario M3J 1P3 Canada.
The development of the patch damp technique now makes it possible
to monitor the activity of ion channels of the cell plasma membrane
and vacuolar membrane in fungi. At present, ion-channels appear to
function in ion uptake (K+ channels) and in sensing external obstacles
or the process of tip pwth (stretch-activated channels). A general
description of the ~e&niquewill be presented. Studies on the fungi
Suprolegnia will be highhghted to demonstrate application of the
technique.
In Saprolegnia, K+ channels and stretch-activated channels (Ca2*-per-
meable) have been identified. Both function in tip growth and exhibit
different distributions: K+ channels are homom-teouslv distributed
along the hypha, inhibiting them transiently &bits &ll growth;
stretch-activated channels are selectively located at the hyphal tip,
inhibiting them blocks growth completely. The K+ channels appear to
function in K+ uptake causing turgor-driven growth. The stretch-
activated channels appear to act as growth sensors.
The patch clamp technique is making it possible to integrate the func-
tion of individual protein molecules with the physiological functions
of the fungi; thus, opening up the research area of molecular
physiology.
Tuesday, 930 am
Ultrastructural evidence for a linkage of the truffle
genus Genea to the epigeous ~tideaceae (Pezizales)
Li-Tzu and James W: Kimbrough. Plant Pathology Dept.,
Univ. of Florida, Gainesville, FL 32611.
The truffle species Genea gmdnerii was first described by Gilkey in 1916
and is found in both North America and Europe. The ascomata are
wrinkled and folded, with a simple hollow or canalconnected cavity
surrounded by a thin cortical layer. The canals are compressed and
result in doublesided hymenial areas, which are composed of palisade
arranged, cylindrical, eightspored axi and paraphys&, and eventual-
ly joined at the apical opening. Because of the existence of a distinct
hymenium, this genus still remains in Geneaceae. The ontogeny of
ascospore wall, ornament development and septa of vegetative and
reproductive hyphae were studied by transmission electron micro-
scopy. Ultrastructural and cytological features of G. gmdnerii reveal a
number of characters that link Genea to the transitional type of epige
ous Otideaceae in the Pezizales. The evidence indudes the presence of
fanshaped septa1 plugging structure with two translucent bands at
each side of the plug at the base of the ascus and a transitional type of
- a
spore wall dep&iti;n similar to Lachneae of the Otideaceae.
Poster C22; Sunday pm
Canonical correspondence analysis of the airborne
fungal spora and its relationships to environmental
factors in Kitchener-Waterloo, southern Ontario
Be-Wei Li and Bryce Kendrick. Dept. of Biology, Univ. of
Waterloo, Waterloo, Ontario, Canada N2L 3G1.
Outdoor air-sampling surveys were conducted in February, May,
August and December 1992 with a Samplair-MK1 partide sample at 50
randomly chosen sites in the Kitchener-Waterloo area of southern
Ontario. Results from Canonical Correspondence Analysis revealed
that the influence of some environmental factors on the airborne fungal
spora varied with season. Among 16 environmental factors measured
at each sampling time, the most important were found to be: relative
humidity, rain, vegetation, cloud, temperature and winde speed. Com-
position of the airborne fungal spora also changed with the season. The
dominant Cludospm'um, Altemmiu, and Aspergillus + Penicillium were
found at all seasons, but Gunodemu, Leptosphueriu, Copnnus and Poly-
thrinicium were prominent only in summer. Positive correlations were
revealed betwee, on the one hand, (la) relative humidity, (lb) rain, (lc)
cloud and (Id) temperature, and, on the other hand, (2) high spore
counts of Leptosph, Xylariaceae, unidentified ascomycetes, and
Ganodoma. A similar correlation was detected between (1) vegetation
and (2) Alter- and Oidium. (1) Higher wind speeds were positively
correlated with (2) hyphal fragments and large spores, such as those of
Drechslern, Nigrospora, Periconia and Oidium. Canonical Correspond-
ence Analysis provides both a new approach to analysis of aeromyco-
logical data and informative graphical presentations of results.
Post, D3; Sunday pm
Multiplex PCR of ribosomal DNA internal
transcribed spacers from Pkytophtkora:
P. cinnamomi, P. palmivora, P. capsici and
P. megaka y a as a potential diagnostic tool
Min Liu and Steven B. Lee. Dept. of Biological Sciences, Univ.
of Northern Colorado, Greeley CO 80639.
Phyfuphthorn contains some of the most important and destructive
plant'pathogens. The accurate and rapid identification of isolates of
Phyfophthora to species is important for predicting the most effective
and control measures to apply.
We have developed a rapid multiplex PCR/RFLP approach that
exploits the species speafic ITS of four Phyfophthorn pathogens: P.
cinnmnomi, P. palmiurn, P. urpsici and P. megukuya. ITS restriction
fragment patterns following digestion of the co-amplified products
could be used to distinguish all four species. Due to the sensitivity of
PCR, this approach may be useful for deteding host plants even before
disease symptoms appear.
Sunday, 1030 am
Phylogenetic relationship of Trickocoma
paradoxa to other ascomycetous genera with
Penicillium anamorphic states
-e F. LoBu io, Mary L. Berbee*, and John W. Taylor.
Univ. of California, Berkeley, CA, and *Univ. of Vancouver,
Vancouver, B.C., Canada.
The family Trichocomaceae is based on the species Trichowm paradox11
Junghuhn, Raemissa FL Crypt. Javae Ins. 1: 9.1838. The production of
a typical biverticillate ~eni&llium anamo'ph by T. purud& suggests an
intrafamilial relationship with other ascomvcetes which produce Penidlium
anamorphs, such' as Tuluromyces and ~u~enicilliun;. The ascomata
of T. pmadoxa can attain a height of 30 mm, and are comprised of a
woody cup-shaped base which supports a mass of parallel hyphal