Inoculum 56(4) - Mycological Society of America

esults have shown evidence of reproductive isolation between genotypes, and
that certain cultural characteristics are consistent between strains. However, no
difference in growth rate, hyphal diameter or spore size was found. Evidence for
A-B-C type speciation is discussed. poster
Kennedy, Louis E. 1 , Hallen, Heather E. 2 * and Henkel, Terry W. 1 1 Department of
Biological Sciences, Humboldt State University, Arcata, CA 95512, USA, 2 Department
of Plant Biology, Michigan State University, East Lansing, MI 48824,
USA. hallenhe@msu.edu. HPLC analysis of Amanita species from Guyana.
The mushroom genus Amanita is known worldwide for its toxins. Amanita
toxins include the hallucinogenic ibotenic acid and muscimol (Amanita section
Amanita, e.g. A. muscaria and A. pantherina), and the cyclic peptide amatoxins
and phallotoxins (Amanita section Phalloideae, e.g. A. phalloides and the A. bisporigera
species complex, the death cap and destroying angels). Amatoxins are
responsible for upwards of 90% of fatal mushroom poisonings in humans. We
used high-performance liquid chromatography (HPLC) to assess 21 individuals,
in 20 species, collected during the past two years from tropical rain forests in
Guyana. The majority of these are undescribed species. One species is eaten by
indigenous people; the remainder are avoided. Neither amatoxins nor phallotoxins
were detected in nineteen of the collections sampled. Two Guyana collections
yielded HPLC peaks consistent with amatoxins and phallotoxins; the presence of
these toxins was subsequently ruled out for one of these collections by mass spectrometry.
poster
Kennedy, Peter G.* and Bruns, Thomas D. Department of Plant and Microbial Biology,
321 Koshland Hall, University of California, Berkeley, Berkeley, CA
94720, USA. pkennedy@berkeley.edu. The role of interspecific competition in
ectomycorrhizal interactions.
Competition is often considered a fundamental process influencing the
structure of species assemblages, yet little is known about competition among ectomycorrhizal
(EM) fungi. We examined competitive interactions between Rhizopogon
occidentalis and Rhizopogon salebrosus in a six-month microcosm
study. Pinus muricata seedlings were grown in three EM treatments; R. occidentalis,
R. salebrosus, and R. occidentalis and R. salebrosus. At two, four, and six
months, five seedlings per treatment were harvested and EM root tip biomass of
each species was determined. Root tips in the two-species treatment were identified
using molecular techniques. R. occidentalis had similar EM root tip biomass
when grown alone or in the presence of R. salebrosus. In contrast, R. salebrosus
had significantly lower EM root tip biomass when grown with R. occidentalis
than when grown alone, indicating it was a competitive inferior under the conditions
tested. Competition was driven by differences in timing of colonization resulting
in a strong priority effect for R. occidentalis. Our results, together with two
earlier studies, indicate competition may play a more important role in EM interactions
than previously recognized. contributed presentation
Kerekes, Jennifer F.* and Desjardin, Dennis E. Dept. of Biology, San Francisco
State University, San Francisco, CA 94132, USA. kerekesj@yahoo.com. A
monographic treatment of the genus Crinipellis from Southeast Asia.
In this monographic treatment, the diversity, geographic distribution and
phylogenetic relationships of species in the genus Crinipellis (Basidiomycota, euagarics)
in Southeast Asia will be documented. To date, only fourteen species of
Crinipellis have been reported from the region, although many more occur there.
We have collected seventy specimens from Indonesia, Malaysia and Thailand,
and these are compared to numerous type specimens and herbarium exsiccati.
Taxonomically significant macro- and micromorphological characteristics are
documented and analyzed. Crinipellis is distinguished morphologically from the
allied genera Marasmius and Chaetocalathus by stipitate basidiomes with
pileipelli composed of thick-walled, dextrinoid, hair-like hyphae. To understand
better the infrageneric classification of Crinipellis and its relationship with allied
taxa (such as Chaetocalathus), molecular sequence data from the nuclear ribosomal
Internal Transcribed Spacer (ITS) region is analyzed using species of Marasmius
s.s. as an outgroup. poster
Kerekes, Jennifer F. 1 *, Christensen, Catherine 2 , Tanner, Kimberly 1 , Stubbs, John 1
and Desjardin, Dennis E. 1 1 Dept. Biology, San Francisco State Univ., San Francisco,
CA 94132, USA, 2 3151 Ortega St., San Francisco CA 94122-4051, USA.
kerekesj@yahoo.com. K-12 Educational Partnership: Bringing FUNgi into
the Classroom.
Would you like to share your enthusiasm for science and fungi with young
people? Presented here is an example of educational outreach to a San Francisco
urban middle school classroom on fungi developed between a 7th grade life science
teacher and a graduate student involved with the National Science Foundation
GK-12 Fellowship program. The original hands-on and inquiry-based lessons
provide an introduction to the kingdom fungi, the ecological and economic importance
of fungi, and the diversity of fungi. The lessons allow students to experience
science research and to be a mycologist for a day. Analyzed data of written
student responses before and after the lessons are presented. poster
Kerrigan, Julia 1 *, Stone, Jeffrey 1 , Manter, Daniel K. 2 and Winton, Loretta M. 3
1 Department of Botany and Plant Pathology, Oregon State University, Corvallis,
MSA ABSTRACTS
OR 97701-2902, USA, 2 Soil Plant Nutrient Research, USDA Agricultural Research
Service, Fort Collins, CO 80526, USA, 3 Subarctic Agricultural Research
Unit, USDA Agricultural Research Service, Fairbanks, AK 99775, USA. kerriju@science.oregonstate.edu.
Microfungi and canopy biology: The distribution
of an endemic foliar pathogen and its effects on carbon dioxide flux.
Phaeocryptopus gaeumannii, causal organism of the foliar disease Swiss
needle cast of Douglas-fir, is endemic to the Pacific Northwest and widely distributed
throughout the natural range of its host. The fungus produces fruiting
bodies, pseudothecia, which emerge through and occlude stomata. To contribute
to an understanding of how canopy fungi influence canopy processes, we measured
the distribution of P. gaeumannii, determined the identity of fungal lineages,
and assessed the effects of different colonization levels on gas exchange in the
Wind River Experimental Forest in Washington, USA. Incidence of P. gaeumannii
in young stands averages approximately 2-5 times greater than in mature
and old-growth stands. Population genetic studies have shown that P. gaeumannii
is two genetically differentiated, non-recombining sympatric lineages. We
found that both lineages are present in the Wind River stands sampled, and that
both lineages may occur within the same tree and same needle. One lineage is
widespread while the second lineage had only been found in western Oregon prior
to this study. A positive linear relationship between the amount of pseudothecia
present and a decline in carbon dioxide assimilation rates was recorded. Declines
in whole-tree carbon dioxide assimilation rates, ranging from 5-45%, are attributed
to colonization by this microscopic fungus. contributed presentation
Kerrigan, Richard W. 1 *, Callac, Philippe 2 , Guinberteau, Jacques 2 , Challen,
Michael P. 3 and Parra, Luis A. 4 1 Sylvan Research, 198 Nolte Dr., Kittanning, PA
16201, USA, 2 INRA, MYCSA (Mycologie et securite des aliments) BP 81,
33883 Villenave d’Ornon cedex, France, 3 Warwick HRI, Univ. of Warwick,
Wellesbourne, Warks, CV35 9EF, UK, 4 Avda. Padre Claret no º7, 5º G, 09400
Aranda de Duero, Burgos, Spain. rwk@sylvaninc.com. A phylogenetic reconstruction
of Agaricus section Xanthodermatei.
Agaricus section Xanthodermatei comprises a group of species allied to A.
xanthodermus and generally characterized by basidiomata having phenolic odors,
transiently yellowing discolorations in some parts of the basidiome, Schaeffer’s
reaction negative, and mild to substantial toxicity. The section has a global distribution,
while most included species have distributions restricted to regions of single
continents. Using specimens and cultures from Europe, North America, and
Hawai`i, we analyzed DNA sequences from the ITS1+2 region of the nuclear
rDNA to identify and characterize phylogenetically distinct entities and to construct
a hypothesis of relationships, both among members of the section and with
representative taxa from other sections of the genus. 61 sequences from affiliated
taxa, plus 20 from six (or seven) other sections of Agaricus, and one Micropsalliota
sequence, were evaluated under distance, maximum parsimony and maximum
likelihood methods. We recognized 21 discrete entities in Xanthodermatei,
including 14 established species and 7 new ones, three of which are described
elsewhere. Four species from California, New Mexico, and France deserve further
study before they are described. Section Xanthodermatei formed a single
clade in most analyses, indicating that the traditional sectional characters noted
above are good unifying characters that appear to have arisen only once within
Agaricus. Deep divisions within the sequence-derived structure of the section
could be interpreted as subsections in Xanthodermatei; however, low species richness
and a lack of unifying characters in these relatively basal lineages led us to
refrain from proposing new supraspecific taxa. The nearest neighbors of section
Xanthodermatei are in section Duploannulati. contributed presentation
Keyhani, Nemat O. University of Florida, Microbiology and Cell Science,
Gainesville, FL 32611, USA. keyhani@ufl.edu. Beauveria bassiana versus ticks
(Acari:Ixodidae): molecular mechanisms of fungal pathogenicity.
The entomopathogenic fungus, Beauveria bassiana, displays varying degrees
of virulence towards several important disease-agents carrying tick species
including Ixodes scapularis. The overall process of infection involves many steps
most of which remain unknown particularly at the molecular level. These include
complex systems for: (1) adhering to the exoskeletal substrata, (2) evading host defenses,
(3) penetrating and degrading the cuticle, (4) transporting to the cytoplasm
and catabolizing necessary nutrients, and (5) dispersing from the catabolized
host(s). The proteins and toxic compounds that contribute to this process include
glycosidases, proteases, lipases, adhesion factors, transporters, developmental regulators,
fungal arthropod toxins, oxalic acid, and numerous other secondary
metabolites. These factors can be secreted, found in the cell envelope, in vesicles,
vacuoles, and the cytoplasm. Furthermore, during the infection process, fungi produce
specialized structures, such as germ tubes, appressoria, penetrant pegs, plates,
hyphae, and hyphal bodies. Finally, once inside the host hemolymph, fungi differentiate
into in vivo blastospores, which may help the organism evade the host immune
response. These processes can be viewed as a developmental program coordinated
by intricate regulatory mechanisms. B. bassiana is presented as a model
organism for studying these processes. As part of our studies, a series of cDNA libraries
were constructed from B. bassiana cell types and a robust expressed sequence
tagged (EST) dataset has been generated. symposium presentation
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Inoculum 56(4), November 2005 31