1985 - Mycological Society of America

Nematodes, both parasitic and saprophytic,
can cause yield reductions. Arthrobotrys
species can be effective, although proper
sanitation is a simpler remedy. Work is
beginning on the control of Verticillium
disease and bacterial mummy disease with the
use of bacterial antagonists. The greatest
success to date has been the control of
bacterial blotch disease with antagonistic
strains of Pseudomonas fluorescens selected
by Dr. Peter Fahy in Australia. Cooperative
trials are underway in the U.S. for disease
control in mushroom houses and also for
increased postharvest quality of mushrooms.
6. E. & H. V. T. COTiER. Department of Biology,
Virginia Polytechnic Institute and State University,
Blacksburg, VA 24061, U. S. A.
Can sporocarp pattern measure the spatial pattern of
the vegetative mycelium? - A test using the bolete,
Boletinellus merulioida.
Ecological studies of higher fungi have depended on
sporocarps as a measure of fungal presence,
productivity, or dominance. A major criticism of these
studies has been that the relationship of the
sporocarps to the vegetative mycelium is unknown. The
accuracy of a sporocarp-determined distribution pattern
was tested by using sclerotia as a marker of the
vegetative mycelium of Boletinellus rerulioidea. The
spatial pattern of the vegetative mycelium was
determined in 64 2 x 2 q contiguous quadrats and was
compared to the spatial pattern of sporocarps produced
in the quadrats over a 4-year period. Year-to-year
sporocarp frequency in the quadrats varied greatly, and
and sporocarp frequency for a single year was an
unreliable indication of the pattern of the vegetative
mycelium. However, cumulative sporocarp frequency over
the 4-year period provided a good estimate of the
spatial pattern of the mycelium. Sporocarp and
sclerotial densities were centered around and declined
outward from Fraxinus americam trees. In a nearby,
second set of contiguous quadrats, no sporocarps were
observed over the four years; neither were sclerotia
present in the plot despite the presence of E.
emeric-. The relationship between B. peruliow and
E. meric- is also discussed.
MEREDITH BLACKWELL, ANTHONY J. KINNEY, PAUL T.
RADFORD, and CATHERINE M. DUGAS. Department of
Botany, Louisiana State University, Baton Rouge,
Louisiana 70803, and R. L. GILBERTSON. Department
of Plant Pathology, University of Arizona, Tucson,
Arizona 85721. The chemical basis of Melzer's
reaction.
For the last hundred years mycologists have used
Melzer's reaction as a taxonomic character. Two
previous studies attribute the blue staining
(amyloid) reaction to the presence of amylose in
five species of Basidiomycetes. We have verified
the presence of amylose and a correlated amyloid
reaction in additional species of Basidiomycetes
and in an ascomycete. Amylose and amylopectin were
not detected in species which showed a red
(dextrinoid) reaction. Species with a dextrinoid
reaction did appear to have high concentrations of
certain quarternary ammonium compounds (QACs),
which are known to form a red periodide complex
with KI The QACs were measured quantitatively,
after &A extraction of the fungus, by a
spectrophotometric technique. They were tentatively
identified as choline and glycine betaine by a
combination of ion-exchange chromatography and
2-dimensional thin layer chromatography. Con-
firmation of this identification is at present
being sought utilizing mass spectrometry. It is
interesting to note that QAC accumulation,
especially accumulation of glycine betaine, has
been associated with salt and water stresses in
angiosperms. QACs could be of ecological
significance in fungi.
MEREDITH BLACKWELL and G. MIKE W. ADAMS.
Department of Botany, Louisiana State University,
Baton Rouge, Louisiana 70803. The exudate of
Inonotus dryadeus.
Inonotus dryadeus is a common root parasite of
hardwoods in the Gulf Coast region. Basidiocarp
development is characterized by the transport of a
watery exudate to the maturing basidiocarp surface.
As much as 5 ml of exudate can be transported in 12
hrs. While the mechanism of transport is
uncertain, it is known that the exudate moves in
thick-walled hyphae which lack cytoplasm and
contain few septa; these hyphae end 1-2 mm from the
basidiocarp surface. Cytoplasm is restricted to
thin-walled hyphae which extend to the margin of
the basidiocarp. Similar transport hyphae are also
present in Laetiporus sulphureus, d. persicinus,
and other polypores which produce exudates.
Exudate of i. dtiadeus from both living and dead
trees of different species in characterized by low
pH, high organic salt content, several free amino
acids in low concentrations, and a variety of
unidentified proteins. The unconcentrated exudate
has antibiotic activity at room temperature against
all gram positive bacteria tested as well as
Pseudomonas aeru~inosa. Activity is confined to a
heat stable, low (