Inoculum 56(4) - Mycological Society of America

MSA ABSTRACTS
Mayor, Jordan R. 1 *, Henkel, Terry W. 1 and Aime, M. Catherine 2 . 1 Department of
Biological Sciences, Humboldt State University, Arcata, CA 95521, USA,
2 USDA-ARS, Systematic Botany and Mycology Lab, Beltsville, Maryland
20705, USA. jrm46@humboldt.edu. Ectomycorrhizae accelerate calcium acquisition
from leaf litter in a monodominant Dicymbe corymbosa (Caesalpiniaceae)
forest in Guyana.
We tested the hypothesis that ectomycorrhizae (EM) alter mineral nutrient
concentrations and decomposition of leaf litter within a monodominant forest of
the ectomycorrhizal, canopy tree Dicymbe corymbosa Spruce ex Benth. in
Guyana. A root-exclusion experiment and a reciprocal transplant experiment were
performed to determine how the exclusion of ectomycorrhizae would influence
decomposition of D. corymbosa leaves. Mass loss of D. corymbosa leaf litter was
determined on three occasions during a 12 month period, and was unaffected by
the presence of ectomycorrhizae. Elemental analysis of N, P, K, Ca, and Mg was
performed on the residual D. corymbosa leaf litter after 12 months. Both experiments
demonstrated that, at 12 months, leaf litter Ca concentrations were significantly
reduced in the presence of ectomycorrhizae. These results suggested an ectomycorrhizal
enzymatic mode of Ca mobilization which may facilitate continued
root growth and domination of litter layers by ectomycorrhizae. Additionally,
saprotrophic fungi that specialize on Dicymbe leaves have been identified through
multi-year plot sampling; these foliicolous specialists may facilitate rapid decomposition
of D. corymbosa leaves within monodominant forests and, in conjunction
with ectomycorrhizae, contribute to rapid mineral nutrient recycling in the
system. poster
McAlpin, Cesaria E. and *Wicklow, Donald T. USDA, ARS, National Center for
Agricultural Utilization Research, Peoria IL, USA. wicklodt@ncaur.usda.gov.
DNA fingerprinting analysis of Petromyces alliaceus section Flavi.
The objective of this study was to evaluate the Aspergillus flavus pAF28
DNA probe’s ability to produce DNA fingerprints for distinguishing among genotypes
of Petromyces alliaceus section Flavi, a fungus considered responsible for
the ochratoxin A contamination that is occasionally observed in California fig orchards.
Petromyces alliaceus, P. albertensis and 7 species in Aspergillus section
Circumdati were analyzed by DNA fingerprinting using a repetitive sequence
DNA probe pAF28 derived from A. flavus. The presence of hybridization bands
with the DNA probe and the P. alliaceus or P. albertensis genomic DNA indicates
a close relationship between A. flavus and Petromyces alliaceus section
Flavi. Twelve distinct DNA fingerprint groups or genotypes were identified
among 15 isolates of Petromyces. Species belonging to Aspergillus section Circumdati
hybridized only slightly at the 7.0 kb region with the repetitive DNA
probe, suggesting very little DNA homology. The pAF28 DNA probe offers a
tool for typing and monitoring specific P. alliaceus clonal populations and for estimating
the genotypic diversity of P. alliaceus in orchards, vinyards or crop
fields. poster
McKay, Doni 1 *, Jennings, Tara 2 and Smith, Jane E. 1 . 1 USDA Forest Service, Pacific
Northwest Research Station, Corvallis, OR 97331, USA, 2 Department of
Forest Science, Oregon State University, Corvallis, OR 97331, USA. dmckay@fs.fed.us.
Life in red soils: Investigating forest recovery after wildfire.
Post-fire forest recovery is dependent on functioning soil fungal communities.
To examine effects of burn severity on soil recovery we are measuring total
fungal diversity and nutrients from soil from the 2003 Booth & Bear Butte fire
complex in the Cascade Range of Oregon. Soil samples were collected immediately
after fire and 3 times during the post-fire year from 24 paired plots of detrimentally
(severely) and moderately burned soils. Using TRFLP techniques, we
show that soil fungal diversity is low for the detrimentally burned soils and typically
higher in the moderately burned soils. The detrimentally burned soils were
higher in pH than the moderately burned soils, whereas the moderately burned
soils had higher measures of ammonium, nitrate, carbon, total nitrogen and phosphorous,
and CEC. Soils were also collected for a microcosm seedling bioassay.
Roots were assessed for percent colonization of dark septate and ectomycorrhizal
fungi (EMF); molecular PCR methods were used to identify EMF and assess fungal
community recovery. Our results show that fires resulting in large areas of
detrimentally burned soil decrease nutrient availability, reduce mycorrhizal colonization
of regenerating seedlings, and negatively impact post-fire site productivity.
poster
McLaughlin, David J. Dept. of Plant Biology, University of Minnesota, St. Paul,
MN 55108, USA. davem@umn.edu. The Advance of the Basidiomycota: The
View across the Plasma Membrane
During the last 50 years there have been remarkable advances in our knowledge
of evolution within the Basidiomycota, new concepts of the basidium and
basidiospore release, and an expansion in both taxonomic and structural diversity.
But we remain a long way from a complete understanding of evolutionary relationships
within the phylum, and further still from a full elucidation of basidiomycete
structure and its functional significance. This review of subcellular
structure will begin with the basidium and ballistosporic mechanism. Subcellular
characters have aided us in establishing monophyletic classes, and have been used
to assess relationships between the Ascomycota and Basidiomycota. I will discuss
the latter by reviewing the origin of the Uredinales, mitosis in ascomycetous and
40 Inoculum 56(4), August 2005
basidiomycetous yeasts, and Woronin bodies. The availability of molecular sequence
data in the 1990’s made possible genetic assessment of phylogenies, provided
guidance on interpretation of subcellular characters, and made possible the
integration of molecular and subcellular characters in phylogenetic analysis. Now
the development of bioinformatic databases of both molecular and structural characters
will permit the analysis of ever larger data sets. These databases also reveal
the scarcity and incompleteness of structural studies and provide guidance in filling
gaps in the data. I will consider cystidia as an example of understudied structures
with potential phylogenetic utility. In analyzing the Basidiomycota both evolutionary
and cell biologists need to look across the plasma membrane, the former
to understand the implications of cell diversity for explaining organismal function,
and the latter to recognize the value of comparative studies in understanding cell
function. MSA Presidential Address
McLenon, Terri 1 *, Skillman, Jane 1 , Taylor, Jonathan 1 , Provart, Nicholas 1 and
Moncalvo, Jean-Marc 1,2 . 1 University of Toronto, Department of Botany, 25 Willcocks
Street, Toronto, ON M5S 3B2, Canada, 2 Royal Ontario Museum, Department
of Natural History, Mycology, 100 Queens Park, Toronto, ON M5S 2C6,
Canada. terri.mclenon@utoronto.ca. Documenting fungal communities in soil:
DNA sampling strategies and development of bioinformatic tools for automated
phylogenetic identification.
We have compared bulked and point sampling methods for assessing fungal
diversity and community structure in coniferous forest soil from southern Ontario.
Ten nLSU clone libraries were generated to produce at least 50 sequences
per library for a total of ca. 800 sequences. Similar sequencing effort recovered a
greater number of distinct nLSU sequences from bulked sampling than from point
sampling; however, similar phylogenetic groups were recovered from each library,
although with very little species overlap. Sampling curves did not show any
sign of saturation after sequencing 148 clones from a single PCR amplification
nor when all the data were pooled together. Overall, our results suggest that while
a vast sequencing effort is needed to fully document the community of fungi in a
forest plot, limited sequencing efforts may be sufficient to quickly document the
presence of dominant phylogenetic and ecological groups in a soil horizon at a
given time. We present the prototype of a novel bioinformatic tool (FungID) that
addresses some of the known difficulties with these types of analyses by automatically
integrating an unknown sequence and its top BLAST hits into their corresponding
clade in the fungal tree of life. We also discuss how phylogeneticallybased
comparative methods may overcome problems associated with species (or
OTU) circumscription. symposium presentation
Medina, Cristina 1,2 *, González, María C. 1 , Cifuentes, Joaquín 2 , Vidal,
Guadalupe 2 , Sierra, Sigfrido 2 and Medina, Pedro 3 . 1 Universidad Nal. Aut. México,
Instituto de Biología, Depto. Botánica, México, DF 04510, México, 2 Secc.
Micología, Herbario FCME, Facultad de Ciencias, México DF 04510, México,
3 Univ. de Guadalajara, Centro Univ. de la Costa, Depto. Ciencias, Puerto Vallarta,
Jalisco, CP 48280, Mexico. mcgv@ibiologia.unam.mx. Preliminary study of
gorgonian fungi from Marietas Islands coral reef, Mexico.
Some microscopic fungi associated with Gorgonia sp. from Marietas Islands
coral reef are reported. The mycota associated with coral reef ecosystems
has been little explored and only few studies have been conducted about fungi associated
with pathogenic disease symptoms in various host organisms, usually in
the form of tissue necrosis or biomineralisation. Fungi have been observed inhabiting
several coral species including gogonians in the Caribbean and South Pacific.
A sample of Gorgonia sp. was collected via SCUBA from Burbuja Cave.
Each sample was placed wet into a sterile plastic bag and transported to the laboratory.
Sections of 0.5 square cm were excised from each sample unit. Cut sections
(4 per plate) were surface-sterilised and then were placed onto Petri dishes
containing selective media prepared with sea water with added antibiotics to diminish
bacterial contamination. The inoculated plates were incubated 15 d at
room temperature and with ambient light and each plate was checked daily for the
emergence of fungal hyphae, which were transferred to fresh media and purified.
The fungal isolates were grouped according to10 morphological characters and
then each distinctive isolate was chosen for taxonomic identification. Some
recorded fungi were Aspergillus, Cladosporium, Epiccocum, Paecilomyces and
Penicillium. poster
Miadlikowska, Jolanta 1 *, Arnold, A. Elizabeth 2 , Higgins, K. Lindsay 1 , Sarvate,
Senehal 3 , Gugger, Paul 4 , Way, Amanda 1 , Hofstetter, Valérie 1 and Lutzoni,
François 1 . 1 Duke University, Durham, NC, USA, 2 University of Arizona, Tucson,
AZ, USA, 3 University of Virginia Health System, Charlottesville, VA, USA,
4 University of Minnesota, St. Paul, MN, USA. jolantam@duke.edu. Endolichenic
fungi: random inhabitants or symbiotic partners.
Studies of lichenicolous fungi (secondary fungi associated with lichen thalli)
have been restricted, almost exclusively, to fungal species with visible reproductive
structures on lichen surfaces. These visible fungi are abundant in nature
and taxonomically diverse. However, the potential for fungi to occur asymptomatically
within thalli (i.e., as endolichenic fungi, analogous to endophytes of
plants) remains mostly unexplored. We used a gradient of surface-sterilization to
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