Inoculum 56(4) - Mycological Society of America

Johnston, Peter R. Landcare Research, Private Bag 92170, Auckland, New
Zealand. johnstonp@landcareresearch.co.nz. Estimating fungal diversity - answers
from the subantarctic.
The number of fungal species in the world remains an intriguing question
in mycology. Given the level of alpha-taxonomic knowledge in most regions, this
number needs to be estimated indirectly. Data from intensively surveyed sites in
the temperate Northern Hemisphere has been used to suggest that fungal diversity
can be estimated by a comparison with plant diversity. A ratio of 6 fungal
species to each plant species is often used. However, the highest levels of plant diversity
are in tropical regions. Does the ratio between plant and fungal diversity
estimated from temperate regions also hold for tropical regions? What is the impact
of changing levels of plant diversity on the 6 fungal:1 plant species ratio? The
subantarctic islands of New Zealand, with strong gradients in latitude and plant
species diversity, will be used to address this question. Catalogues of fungi for
these islands remain hopelessly incomplete, making it impossible to use allspecies
lists to compare fungal diversity between islands. This talk will discuss a
phylogenetic approach to estimating fungal diversity, using data that suggests
alpha-taxonomic knowedge in the New Zealand region for one intensively surveyed
family, the Rhytismataceae, is close to complete. This data will be used to
assess the impact that changing levels of plant diversity might have on estimates
of fungal diversity. symposium presentation
Johnston, Peter R. Landcare Research, Private Bag 92170, Auckland, New
Zealand. johnstonp@landcareresearch.co.nz. Pacific journeys – the dispersal
and evolution of Metrosideros-associated fungi.
The rapid dispersal of Metrosideros across the Pacific Ocean over the last
2-3 million years provides an opportunity to address questions about the dispersal
and evolution of fungal communities. The widely dispersed Metrosideros communities
of the Pacific are thought to have radiated out from the New Zealand.
Metrosideros in New Zealand is associated with a large and distinctive fungal
biota. Some fungi are known to have the ability to disperse over long distances.
Have the Metrosideros-adapted fungi of New Zealand followed along behind
Metrosideros as it has dispersed? Alternatively, has Metrosideros evolved a series
of novel, independent forest communities at each of the island’s where it has established?
Preliminary observations of fungi associated with ohi’a in Hawai`i suggest
that the second scenario may be correct. Ohi’a does have a set of distinctive
and characteristic fungi. Where did they come from? How did they become adapted
to life on ohi’a? What opportunities does the arrival of a new host plant present
to fungi already present at a locality? contributed presentation
Jumpponen, Ari. Division of Biology, Kansas State Univeristy, Manhattan, KS
66502, USA. ari@ksu.edu. Pitfalls and utilities of using molecular detection of
fungi. Molecular tools are becoming more popular in studying the ecology of fungi.
Comparisons of a sporocarp survey, on site or bait-seedling mycorrhiza assays, and
direct amplification of soil DNA indicate that all but sporocarp survey methods provide
largely congruent views of the mycorrhizal community at a low-diversity study
site. Although results using different methods appear congruent, example data sets
indicate that studies sequencing PCR amplicons from environmental samples are
burdened by chimeric molecules that constitute up to 30% of all obtained data. Similarly,
choice of primers can have a substantial impact on the inferred community
structure. Regardless of these potential shortcomings, two case studies show that environmental
DNA data can provide novel insights to fungal community dynamics.
1) A study on soil-inhabiting fungal communities in tallgrass prairie demonstrated
a vast species richness of fungi and identified a group of potentially novel Ascomycetes
that occurred more frequently in soil than therein imbedded roots. 2) A
study of arbuscular mycorrhizal fungi (AMF) colonizing tallgrass prairie plant communities
showed a community level response to nitrogen amendment, although root
colonization by AMF was affected only minimally. symposium presentation
Kageyama, Stacie A.*, Bottomley, Peter J., Cromack, Kermit and Myrold, David
D. Oregon State University, Corvallis, OR 97331, USA. stacie.kageyama@oregonstate.edu.
Changes in soil fungal communities across meadow-forest transects
in the western Cascades mountains of Oregon, USA.
Molecular analysis of ectomycorrhizal root tips and collection of sporocarps
in Pacific Northwest coniferous forests indicate that fungal communities are spatially
heterogeneous. The goal of this study was to use molecular techniques to examine
changes in the total belowground fungal community along forest-meadow
transects. We collected soil cores along three transects at two paired high montane
forest-meadow sites at the H. J. Andrews Experimental Forest in the Western Cascade
Mountains of Oregon, USA. We used fungal ITS rDNA primers with length
heterogeneity PCR amplification of DNA extracted from soil. Our results agree
with earlier root tip and sporocarp studies that indicate that the forest communities
are spatially heterogeneous. In contrast, the meadow fungal communities exhibit
much more homogeneity in their composition. poster
Kajimura, Hisashi. Lab. of Forest Protection, Graduate School of Bioagricultural
Sciences, Nagoya University, Chikusa, Nagoya 464-860, Japan.
k46326a@nucc.cc.nagoya-u.ac.jp. Symbiotic secrets in ambrosia beetle-fungal
systems.
MSA ABSTRACTS
About 3400 species of ambrosia beetles are found in 10 tribes of two subfamilies
of the Curculionidae, the Platypodinae and the Scolytinae. Ambrosia beetles
vary in life history, but all carry and maintain ectosymbiotic “ambrosia” fungus
spores in specialized organs termed mycangia. They bore tunnels (galleries)
mainly in the sapwood of recently killed trees, disseminating the spores over the
wall of gallery system. They are considered to have species- specific associations
with primary ambrosia fungi (PAF), on which larvae feed for their development.
Many of ambrosia fungi are placed in the anamorph genera Ambrosiella or Raffaelea.
However, the fungal symbionts of only a small percentage of the ambrosia
beetles have been isolated, and it is not clear if the isolated fungi are the PAF. Few
studies also have elucidated relationships between the beetles and the fungi: how
do they encounter and how do they act each other, in spite of great importance to
comprehending the symbiotic associations. I review the current state of knowledge
on ambrosia beetle-fungal interactions, particularly in the Scolytinae of
Japan. I also present recent data on the contributions of the fungi to the beetle success,
and lay a special emphasis on the fact that PAF associated with one species
of ambrosia beetles could have a nutritional potential as food resource for larvae
of other beetle species. symposium presentation
Kamada, Takashi. Dept. of Biology, Fac. of Science, Okayama University,
Okayama 700-8530, Japan. kamada@cc.okayama-u.ac.jp. Genomic studies in
the homobasidiomycete Coprinus cinereus.
The homobasidiomycete Coprinus cinereus has been used as a model to
study fungal development and regulation, because of its ease of cultivation, its
amenability to genetic analysis, rapid development of its multicellular structure,
the mushroom, and its naturally synchronous meiosis in the mushroom. This fungus
has a total genome size of ~37.5 Mb, which is organized into 13 chromosomes,
ranging in size from 5 to 1 Mb. The genome project on this fungus has
been done as part of the Fungal Genome Initiative in the Whitehead Institute and
the 10X sequence assembly of the genome of C. cinereus strain Okayama-7 has
been released. Also, a BAC library of Okayama-7, component clones of which
have been positioned on the sequence assembly, as well as chromosome-specific
cosmid libraries, is available. These lines of information, coupled with a wealth of
developmental mutants identified and existing molecular techniques such as efficient
DNA-mediated transformation, RNAi and detailed gene mapping using
RAPD markers, will facilitate both forward and reverse genetics of development
and regulation in this fungus. symposium presentation
Kaminskyj, Susan 1 and Dahms, Tanya E.S. 2 1 Dept. Biology, University of
Saskatchewan, 112 Science Place, Saskatoon, SK S7N 5E2, Canada, 2 Dept.
Chemistry and Biochemistry, University of Regina, 3737, Wascana Parkway,
Regina, Saskatchewan, S4S 0A2, Canada. susan.kaminskyj@usask.ca. Probing
life at the hyphal tip: adventures in microscopy.
What we observe and how we interpret it depends on our vantage point.
Since the late 1500s, the development of and subsequent technological improvements
in microscopy have changed the fundamentals of biology. Microscopy is
important for mycology due to the small size of fungal organisms and/or their taxonomically
diagnostic parts, and is relevant to cell biology in general particularly
as fungi are superb model systems. Until the late 1950s, improvements to microscopy
were mostly in resolution (better optical systems, development of electron
microscopy), contrast control (differential staining, optical contrasting methods
such as DIC) and information capture (photography). More recently, antibody
tagging (fluorescence and gold), molecular tagging (GFP and chemically-selective
probes), computer enhanced epifluorescent imaging (confocal) and electronic
image capture and analysis have combined to provide in situ identification and
monitoring of dynamic biological processes. We are combining established and
newer imaging methods to extend our understanding of tip growth in Aspergillus
nidulans hyphae. For example, atomic force microscopy (AFM) can image at
high resolution (comparable to SEM, and better for depth discrimination) and also
examine surface properties by force spectroscopy. Notably, we have used AFM
on growing hyphae, imaging and collecting data on wall properties during tip
growth. Consistent with general models, we demonstrate that the walls at growing
hyphal tips and branches are more significantly more force compliant than
mature regions. symposium presentation
Kaneko, Shuhei. Fukuoka pref. Forest Res. & Exten. Center Japan 1438-2 Toyoda
Yamamoto Kurume-city Fukuoka 839-0827, Japan. shu-k@try-net.or.jp. Cultivation
of Pholiota adiposa in the Sugi (Cryptomeria japonica saw dust based
media).
Cultivation of the edible mushroom, Pholiota adiposa in the Sugi (Cryptomeria
japonica)saw dust based substrate containing Sugi saw dust, cotton hull,
corn-cob meal and rice bran (Sccr) was investigated. The optimal temperature
range for mycelial growth of P.adiposa wild strains was 20-30 C and the optimal
temperature was around 26 C. Growth did not occur at 40 C and all but one strain
named Oninome-B died after 5 days. The optimal initial pH value of the cultivation
medium was around 6.5 and various initial pH values converged to 3.5-5.5
after cultivation. The C/N ratio and pH value of the Sugi saw dust based substrate
(Sccr) were suitable for mycelial growth and fruit body formation of P.adiposa.
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