Inoculum 56(4) - Mycological Society of America

MSA ABSTRACTS
Aaltonen, Ronald E.*, Barrow, Jerry R., Lucero, Mary L., Osuna-Avila, Pedro
and Reyes-Vera, Isaac. USDA-ARS Jornada Experimental Range, Las Cruces,
NM 88003, USA. jbarrow@nmsu.edu. The microscopic identification of vertically
transferred symbiotic fungi intrinsically integrated with cells, tissues
and organs of host plants.
Dual staining methodology and analysis with light microscopy and scanning
electron microscopy were used to determine the nature and extent of symbiotic
fungi with native desert grasses shrubs. Trypan Blue that targets fungal chitin
and sudan IV that targets lipid bodies attached to fungal structures were used to
stain cleared roots and leaves. Trypan blue revealed a densely stained fungal network,
bound to the plasmalema of meristematic cells, that were transferred to cells
in culture, tissues and all plant organs. Fungal structures were atypical and were
substantially different than commonly observed fungal structures such as hyphae,
spores, etc. Fungal associations with meristem cells facilitate their distribution and
vertical transfer to all parts of the plant, seed and to succeeding generations. Significant
are fungal associations with vascular tissue, photosynthetic cells and with
the stomatal complex and suggests significant plant-fungus interactions within
these critical plant cells. poster
Abdelzaher, Hani M. A. Faculty of Science, El-Minia University 61519, Egypt.
abdelzaher@link.net. Biological control of damping-off and root rot diseases
of soybean caused by Pythium spinosum Sawada var. spinosum using three
rhizosphere species of soil fungi.
Pythium spinosum was isolated from rhizosphere soil and rhizoplane of
healthy and infected soybean roots cultivated in an agricultural field located in
Shahean district, El-Minia city, Egypt in June 2003. Rhizosphere and rhizoplane
mycoflora isolated from the same sites were tested for their antagonism toward
Pythium spinosum in agar plates. Among the isolated fungi, Aspergillus sulphureus,
Penicillium islandicum and Paecilomyces variotii were chosen according
to their antagonism on agar plates for experimentation to test their effectiveness
for biological control in either autoclaved or nonsterilized soil. Coating
soybean seeds and roots with spores and mycelia of these three antagonists gave
germinating seeds and seedlings a very good protection from root-rot, pre- and
post-emergence damping-off caused by P. spinosum. Applying these biocontrol
agents to autoclaved and nonsterilized soil infested with P. spinosum provided an
excellent way of protection. contributed presentation
Abe, Jun-ichi P. University of Tsukuba, Graduate School of Life and Environmental
Science, 1-1, Tennoudai 1 chome, Tsukuba, Ibaraki 305-8572, Japan. jave@sakura.cc.tsukuba.ac.jp.
An arbuscular mycorrhizal genus in the Ericaceae.
Enkianthus is an ericaceous genus with about 17 spp. of shrubs and small
trees, commonly distributed in Japan and southern China. Four Japanese native
species of the genus Enkianthus (E. campanulatus, E. cernuus f. rubens, E. perulatus,
E. subsessilis) were examined to determine the mycorrhizal status by comparing
with typical ericoid mycorrhizal roots of Rhododendron kaempferi. The
roots of all species were collected from trees of natural stands or public gardens
and from seedlings of E. cernuus f. rubens grown in controlled conditions. These
roots were observed with a compound light microscope and SEM. All examined
roots of Enkianthus spp. formed only arbuscular mycorrhiza of the Paris-type.
The fine roots of these species were usually thicker (approx. 150 µm) than the hair
roots of R. kaempferi (approx. 80 µm). Short root hair- like structures with thick
walls (approx. 5 µm) were observed occasionally on the fine roots of all
Enkianthus spp. and root hairs were observed in E. subsessilis. Consequently, the
mycorrhizal and root morphology of these four species are completely different
from R. kaempferi. This result reveals that at least these four species of Enkianthus
seem to be arbuscular mycorrhizal and lack ericoid mycorrhiza. These findings
and the mycorrhizal status of the ancient ericaceous species are discussed. contributed
presentation
Aime, M. Catherine. USDA-Agricultural Research Service, Systematic Botany &
Mycology Lab, Beltsville, MD 20705, USA. cathie@nt.ars-grin.gov. Molecular
systematics of Uredinales.
Rust fungi (Basidiomycota, Uredinales) consist of > 7000 species of obligate
plant pathogens that possess some of the most complex life cycles in the Eumycota.
Traditionally, phylogenetic inference within the Uredinales has been
hampered by a lack of morphological characters and incomplete life cycle and
host-specificity data. The application of modern molecular characters to rust systematics
has been limited by several factors, including, to name a few, the inability
to pure culture most rusts or unequivocally separate rust from host cells and
other associated fungi in a specimen. Previous molecular systematic studies of
rusts have focused on analyses of 28S or 18S ribosomal DNA, but current contradictions
in rust systematics, especially in the deeper nodes, have not yet been
resolved. In this study, several genes (including 18S, 28S, and EF1alpha) were examined
across the breadth of the Uredinales to resolve systematic conflicts and
provide a framework for the group. It is concluded that morphology alone is a
poor predictor of rust relationships at most levels and strict morphology-based
classifications and species-delimitations appear obsolete. Host selection, on the
other hand, has played a significant role in rust evolution. The difficulties and utility
of analyzing protein-coding genes vs. rDNA in rust systematics are also discussed.
symposium presentation
6 Inoculum 56(4), August 2005
Aime, M. Catherine 1 * and Henkel, Terry W. 21 USDA-Agricultural Research Service,
Systematic Botany & Mycology Lab, Beltsville, MD 20705, USA, 2 Humboldt
State University, Dept. of Biological Sciences, Arcata, CA 95521, USA.
cathie@nt.ars-grin.gov. Strategies for bioinventory: lessons from Guyana.
Bioinventory, the identification and enumeration of taxa within a given
area, provides the foundation for numerous biological and ecological studies. Yet
fungal inventories are vastly underrepresented in the literature, and the conduction
of such inventories presents a host of unique difficulties and problems. Special
problems faced in conducting fungal inventories include deciding at which level
to record units (e.g., fruiting bodies, cultures, and/or environmental sequences);
how to construct significant sampling strategies (e.g. plot studies, transects, and/or
sweeps); and, especially, how to conduct the alpha-taxonomy. We have completed
five years of comparative plot studies for fungi in a remote, rain-forested region
of west-central Guyana. To date we have documented nearly 1,000 species
or morphospecies of macromycetes, both ectomycorrhizal and saprotrophic, and
counted >20,000 fruiting bodies. Yet the most time-consuming aspect of this
study is the taxonomy. To date, we have been able to identify and publish less than
10% of the Guyanese taxa; > 40% of these have been species or genera new to
science. Some ideas for recording, analyzing, and identifying fungal taxa from
previously under-sampled areas will be discussed. symposium presentation
Akamatsu, Y. and Saikawa, Masatoshi*. Department of Environmental Science,
Tokyo Gakugei University, Koganei-shi, Tokyo 184-8501, Japan. saikawa@ugakugei.ac.jp.
Giant mycelium by Sommerstorffia spinosa.
Since 1984, Sommerstorffia spinosa was obtained several times from samples
of debris floating on the water of a fire reservoir located in the campus of
Tokyo Gakugei University. The species has been known as a rotifer-parasite, to
have the ability to capture the animals with a peg, a distal narrow protuberance of
hypha, or to parasitize them with a bowling-pin shaped sporeling developed from
an encysted, secondary zoospore. In all the strains reported up to now, each of the
isolates finished capturing animals after 3 to 7 times of capture by the peg and became
solely to produce zoospores. Thus the mycelium was quite limited in size in
all cases. However, in spring, 2004, we obtained a strain of the species, the
mycelium of which did not finish capturing rotifers (Lepadella oblonga) and grew
unlimitedly to establish a giant mycelium. At 30 days of cultivation under water,
it could be seen with a naked eye, because the size being 0.5-3.0 mm in diameter.
The hyphae (7-9 µm wide) constituting the giant mycelium were empty except
only their distal portion terminated with a peg (6-8 µm long, 3-5 µm wide). After
capturing a rotifer, the peg grew into an endozoic thallus that developed one or
two hyphae externally and transformed itself into a zoosporangium with an evacuation
tube (50-80 µm long, 8-10 µm wide). The primary zoospores encysted at
the mouth of the evacuation tube to form a mass of cysts (7-9 µm). In normal
strains, each of the primary cysts soon produces a secondary zoospore, though the
cyst of our strain did not produce it, but lost its content, or, in rare occasion, developed
a sporeling (ca. 17 µm long, 8 µm wide). The giant mycelium of our
strain also captured two testaceous rhizopods of Cryptodifflugia and Euglypha.
contributed presentation
Almeida-Leñero, Lucia 1 , Ludlow-Wiechers, Beatriz 1 , Geel, Bas van 2 , González,
María C. 3 * and Aptroot, André. 4 1 Dept. Ecología y Rec. Nat, Fac. Ciencias,
UNAM, Mexico DF 04510, 2 IBED, Paleoecology and Landscape Ecology, Univ.
Amsterdam Kruislaan 318, 1098 SM Amsterdam The Netherlands, 3 Inst. Biología,
UNAM, Mexico, 4 Centraalbureau voor Schimmelcultures (CBS), Fungal
Biodiversity Centre, P.O. Box 85167, 3508 AD Utrecht, The Netherlands.
mcgv@ibiologia.unam.mx. Records of mid-Holocene fungi from Lake Zempoala,
Central Mexico.
The aim of the present study is to describe and illustrate fungal spores
recorded on Zempoala lake at 2800 m altitude. The studied interval is of mid-
Holocene age. The lake with submerged aquatical and hydroseral shore vegetation,
lie today in the Abies religiosa dominated forest belt. The samples were prepared
using standard techniques for palynological studies. A number of selected
fungal spores have been identified, described and illustrated. Ecological environmental
preferences of present fungi are also given. Among the fungi type spores
analysed are 2 basidiospores: Enthorriza (type 527), and Urocystis, 3 ascospores:
Astrosphaeriella, Ustulina, Valsaria, and 10 mitospores: Acrodictys, Antennatula,
Brachydesmiella, Endophragmiella, Monodictys, Trichocladium type 1 and 2,
Papulospora, and Virgatospora. These fungus occur together with pollen elements
that define a landscape of forest and a water body. Antennatula confirm an
Abies sp. forest, Acrodictys suggests species of Populus sp., Virgatospora of
broad leaved tree forest, and Ustulina the presence of deciduous trees. Enthorriza,
and Trichocladium are evidence of freshwater. Environment conditions may be
presumed of high air humidity considering the presence of decaying plant debris
and soil forming fungi such as Monodictys and Papulospora. The fungi were
recorded for first time in paleoecological studies in Mexico. poster
An, Zhiqiang. Merck Research Laboratories, West Point, PA, USA. Polyketide
synthase genes in the pneumocandin-producing fungus Glarea lozoyensis.
Glarea lozoyensis is the producer of pneumocandin B0, a potent inhibitor
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