March 2008 - Mycological Society of America

communities of a particular parasitoid wasp, Comperia merceti (Hymenoptera:
Encyrtidae), and the cockroach it parasitizes, Supella longipalpa
(Blattaria: Blattellidae), are examined using both molecular- and
culture-based methods. From LSU cloning data there is evidence of
two fungi in the wasps (basidiomycete relatives), and three fungi in the
cockroaches. Two of the cockroach fungal symbionts are identical to
the basidiomycete relatives recovered from wasps and there is an additional
lecanoromycete relative. Using general 16S primers, Blattabacterium
and Wolbachia are also recovered from the cockroaches. Culturing
efforts reveal that only one of the basidiomycete-like fungi from
the wasps is cultivable and an additional (possibly nitrogen fixing) bacterium
is cultivable from the cockroaches. The characterization of the
microbial associates in this system lays the foundation for understanding
symbiont contributions to these wasps and cockroaches. This research
reveals cryptic fungal diversity in an understudied niche, insect
hosts, as well as demonstrates the role that fungi could have in shaping
the evolution of host-parasitoid interactions. Poster
Gillevet, Patrick, M., Sikaroodi, M. and Torzilli, Albert, P.* Department
of Environmental Science and Policy, George Mason University,
Fairfax, VA 22030, USA. atorzill@gmu.edu. Analysing salt-marsh
fungal community diversity: community ARISA fingerprinting vs.
community clone sequencing. Fungi are important decomposers in
the detrital-based food webs of temperate salt-marsh ecosystems.
Knowing the composition of salt-marsh fungal communities is essential
for understanding how detritus processing is affected by changes in
community dynamics. Previous results from our laboratory have
shown that different salt-marsh plants harbor distinct fungal communities
as judged by automated ribosomal intergenic spacer analysis
(ARISA) of fungal DNA amplified from the different plant hosts.
ARISA fingerprinting data provide non-taxon-specific snapshots of
community structure where each peak in a community profile represents
an operational taxonomic unit (OTU) of a given amplicon size. In
order to associate specific taxa with community OTUs we cloned, fingerprinted,
and sequenced the fungal community DNA from each plant
in order to match the size and sequence of specific clones with the community
OTU sizes. BLAST results indicated that a given OTU amplicon
may represent more than one species, confirming earlier observations.
Also, the ability to assign a specific taxon to a community
amplicon by matching amplicon sizes was limited by the extent of
species coverage in the BLAST database. Furthermore, differences in
the relative abundances between community fingerprint amplicons and
comparable clone abundances suggested significant biases during the
cloning process. Nonetheless, the cloning and sequencing data did confirm
the conclusion from fingerprinting that plant (substrate) type is an
important factor in determining fungal community composition. Poster
Goldmann, Lauren* and Weir, Alex. Department of Environmental &
Forest Biology, SUNY College of Environmental Science & Forestry,
241 Illick Hall, 1 Forestry Drive, Syracuse, NY 13210, USA. lmgold01@syr.edu.
Laboulbeniales from western Russia. As a part of
the SUNY-ESF Moscow State University Exchange Program we had
the opportunity in summer 2006 to collect Laboulbeniales fungi at the
Zvenigorod Biological Station, some 50km west of Moscow, and at the
White Sea Biological Station near Poiakonda. The most recent literature
of the Laboulbeniales of the western portion of Russia is that by Hulden
(1983), who records 41 species. Our collections have added an additional
10 species, including 3 new genera for the region; Aphanandromyces,
Euzodiomyces, and Rhadinomyces. Of particular interest was
our observation of very high levels of infection at both these sites with
15% of collected beetles infected at Zvenigorod, and 14% at the White
Sea. These figures are much higher than those recorded by Hulden (1%)
and may be related to the range of microhabitats sampled. Poster
Gonzalez, Maria C. 1 * and Enriquez, Diana. 21 Departamento de Botanica
AP 70-233, Instituto de Biologia, Universidad Nacional Autonoma
de Mexico, Ciudad de Mexico DF 04510, Mexico, 2 Instituto de
Oceanologia, Agencia del Medio Ambiente, Ministerio de Ciencia, Tecnologia
y Medio Ambiente de Cuba (CITMA), La Habana, Cuba.
18 Inoculum 59(2), March 2008
mcgv@ibiologia.unam.mx. Microfungi diversity in the coastal sand
beach environment of Mexico and Cuba. The marine interstitial microfungi
living in sandy sediments between the tide lines of the beaches
are important ecologically because they are major decomposers of the
vegetable organic matter that enter this marine ecosystem. In this particular
environment, named endopsammon, the microbial production is
dominated by eumycotes, mainly by ascomycetes. Arenicolous microfungi
have a distinctive physiology, morphology, and adaptation to the
endopsammophilous medium. The characteristics that the arenicolous
species exhibit are: carbonaceous ascocarps attached to sand grains with
a subiculum, papilla with an ostiole opening close to the subiculum, a
pseudoparenchyma of thin walled cells with pit-like thickenings, deliquescent
asci without an apical structure, and appendaged ascospores.
The genus Corollospora is considered as one of the most diverse genera
adapted to arenicolous habitats and is distributed widely from tropical to
temperate regions. During the past decade, a surge has taken place in the
investigation of the Mexican and Cuban arenicolous microfungi biodiversity.
At present, these countries have an active interest in describing,
preserving, and using the biodiversity of marine fungi. The advances in
recording the distribution of species from several beaches of Mexico
and Cuba are presented. Symposium Presentation
Gross, Stephanie*, Suh, Sung-Oui and Blackwell, Meredith. Department
of Biological Sciences, Louisiana State University, Baton Rouge,
Louisiana 70803, USA. sgross2@lsu.edu. Diet and its effect on the
abundance of endosymbiotic gut yeast found in a wood-boring beetle
Odontotaenius disjunctus: Passalidae. Pichia stipitis, a xylose fermenting
and assimilating yeast, has consistently been isolated from the
gut of over 400 adult, wood-boring beetles (Odontotaenius disjunctus:
Passalidae). We examined the affect of beetle diet on gut yeasts by varying
nutrients provided for the host beetles. Beetles were provided only
autoclaved water and starved for 6 da and then were fed different diets,
(e.g., decayed wood, sterilized decayed wood, and artificial diet containing
polysaccharides and other nutritional resources). Beetles were
dissected periodically and yeast colony counts were made on selective
agar media. Colonies on each plate were identified based on morphology,
and some were confirmed as P. stipitis by use of specific primers.
After 6 da starvation, the abundance of P. stipitis in the gut decreased
substantially when compared to pre-starvation numbers. However, 5 da
after reintroduction of food, yeast numbers in the gut increased to approximately
pre-starvation levels. We observed no significant difference
in colony numbers between beetles fed unsterilized and sterilized wood,
but beetles fed certain diets sometimes had low levels of yeasts compared
to those fed wood. From this study, we concluded that within the
O. disjunctus gut environment P. stipitis is dependent on nutrients provided
by the insect diet. Contributed Presentation
Guardia Valle, Laia 1 and Cafaro, Matias J. 2 * 1 Unitat Botanica Dep.
BABVE F. Ciences, Universitat Autonoma de Barcelona, 08193 Bellaterra,
Spain, 2 Department of Biology, University of Puerto Rico –
Mayaguez, PR 00681. matcaf@gmail.com. First observation of zygospores
in Asellariales (Trichomycetes). The ecological group of
gut endosymbionts trichomycetes (sensu lato) includes two fungal orders,
Harpellales and Asellariales, and two protistan orders, Amoebidiales
and Eccrinales. Asellariales inhabit the digestive tract of aquatic,
terrestrial and marine isopods as well as springtails (Collembola). They
have branched and septated thalli and reproduce asexually by
arthrospore-like cells. No sexual reproduction has been reported until
now. In a recent survey of islands in the Carribean, a new unnamed
species of Asellaria has been found in terrestrial isopods in Puerto Rico
and Dominican Republic. Conjugating tubes and zygospores were observed
in this Asellaria sp. Zygospores are spherical and hyaline in contrast
to the ones in Harpellales, which are conical or biconical. Asellariales
zygospores share characteristics with those of Dimargaritales and
Kickxellales as well as their septal pore structure, which is present in
all three orders plus the Harpellales, thus giving morphological support
to this monophyletic group, recently established through DNA analyses.
The spherical shape of Asellaria zygospores reveals a possible ter-
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