1993 - Mycological Society of America
1993 - Mycological Society of America
1993 - Mycological Society of America
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Poster C8; Sunday pm<br />
Mycorrhizal colonization <strong>of</strong> grasses and spore<br />
abundance in semi-arid regions <strong>of</strong> west ex as<br />
. . and John C. Zak. Ecology Group, Dept.<br />
Shivcham S. Dhllllm<br />
<strong>of</strong> Biological Sciences, Texas Tech Univ., Lubbock, Texas<br />
79409-3131.<br />
Root colonization <strong>of</strong> Schizachynum scoparium, Andropoga halli, Spore<br />
bolos nyhndrus, Aristida pu&rea and Erapfis sp; by vesiculararbuscular<br />
mvcorrhizal fund and the abundance <strong>of</strong> mvcomhizal<br />
spores in CR6 (~onservatioi Reserve Program) grassland and sandshinnery<br />
oak (Quercus haomdifl communities were examined for one<br />
year. VAM fungal sporulation in both communities showed similar<br />
seasonal patterns, although abundance <strong>of</strong> spores in CRP soil was<br />
higher than that on sand-shinnery oak site. Colonization levels were<br />
significantly higher in the roots <strong>of</strong> S. scoparium, A. halli and S. cryptandrus,<br />
than in A. purpuren and Eragrosfis sp. on both sites. Seasonal<br />
pattern in colonization varied according to species and were essentially<br />
similar for each species in both sites. Mycorrhizal inoculum<br />
potential varied according to species and site. The results suggest that<br />
within a semi-arid region different species <strong>of</strong> grasses and VAM fungi<br />
may show similar seasonal patterns, although colonization levels <strong>of</strong><br />
individual species and abundance <strong>of</strong> spores <strong>of</strong> VAM species can vary.<br />
Mycorrhizal inoculum potential data suggest that CRP site is a higher<br />
inoculum source than the native sand shinnery oak site.<br />
Aquatic fungi associated with<br />
West Virginia mountain streams<br />
Tuesday, 4:s pm<br />
Tara Dubev, Steven L. Stephenson, and Pamela J. Edwards.<br />
Dept. <strong>of</strong> Biology, West Virginia Institute <strong>of</strong> Technology,<br />
Montgomery, WV 25136; Dept. <strong>of</strong> Biology, Fairmont State<br />
College, Fainnont, WV 26554; and USDA Forest Service,<br />
Timber and Watershed Laboratory, Parsons, WV 26287.<br />
The distribution pattern <strong>of</strong> the aquatic fungi occurring in six streams<br />
located on or near the Femow Experimental Forest in Tucker County,<br />
West Virginia, were studied d d g the 1991 and 1992 field seasons.<br />
Water pH averad >5.5 in three <strong>of</strong> the streams, whereas the others<br />
were relatively more acidic (average pH = 4.2,3.9 and 3.2, respectively).<br />
Sampling methods used induded (1) isolating conidia from stream<br />
water by me-= <strong>of</strong> a membrane filtration techniqie, (2) placing litter<br />
bags prepared with leaves from four different tree species in the<br />
streams for periods ranging from 14 to 112 days, and (3) "baiting" the<br />
streams with various types <strong>of</strong> organic material. The myc<strong>of</strong>lora <strong>of</strong> the<br />
streams we sampled indudes at least 142 taxa (44 chytridiaceous fungi<br />
and water molds, 49 non-Ingoldian hyphomycetes, and 49 Ingoldian<br />
hyphomycetes). The total numbee total number (27 taxa) <strong>of</strong> chytridiaceous<br />
fungi and water molds present in the stream with the highest<br />
pH (7.9) was appreciably higher than the numbers (15-18 taxa)<br />
recorded for the other streams. The general pattern for aquatic hyphomycetes,<br />
based on the presence <strong>of</strong> conidia filtered from water samples,<br />
was for the number <strong>of</strong> taxa to decrease with decreasing pH, whereas<br />
the lowest numbers <strong>of</strong> conidia per 1000 ml <strong>of</strong> water were recorded at<br />
the two extremes <strong>of</strong> the pH gradient. Red oak (Quercus rubra) litter was<br />
colonized by an average <strong>of</strong> 14.6 taxa <strong>of</strong> aquatic hyphomycetes in the six<br />
streams, sugar maple (Am saccharurn) litter by 12.6 taxa, and mixed<br />
red maple (A. rubrum) and beech (Fagus grandifilia) litter by 10.6 taxa.<br />
For all three types <strong>of</strong> litter, numbers were generally high& for the less<br />
acidic streams and lower for the more acidic streams. (Supported - - in<br />
part by funds provided by the USDA Forest Service.)<br />
Wednesday, 9:OO am<br />
The possible effects <strong>of</strong> Diflubenzuron on<br />
the growth, sporulation, and enzymatic<br />
activities <strong>of</strong> aquatic hyphomycetes<br />
Tara Dubey, Steven L. Stephenson, and Pamela J. Edwards.<br />
Dept. <strong>of</strong> Biology, West Virginia Institute <strong>of</strong> Technology,<br />
Montgomery, WV 25136; Dept. <strong>of</strong> Biology, Fairmont State<br />
College, Fairmont, WV 26554; and USDA Forest Service,<br />
Timber and Watershed Laboratory, Parsons, WV 26287.<br />
The possible effects <strong>of</strong> Diflu-n (DFB) on the growth, sporulation,<br />
and leaf litter colonization <strong>of</strong> aquatic hyphomycetes under<br />
natural conditions were studied by (1) isolating conidia from samples<br />
<strong>of</strong> stream water by means <strong>of</strong> a membrane filtration technique and (2)<br />
direct microscopic and (2) direct microscopic examination <strong>of</strong> the fungi<br />
cole nizing litter bags containing leaves <strong>of</strong> red oak (Quercus rubra) and<br />
sugar maple (Am sacdrmum) placed in two treated and two control<br />
watersheds <strong>of</strong> the Femow Experimental Forest prior to the application<br />
<strong>of</strong> this chemical insecticide. In addition, mycelial mowth and cellulase<br />
enzyme activity <strong>of</strong> six species <strong>of</strong> hyphomycetes isolated from the<br />
watersheds were studied in the laboratory. Cellulase enzyme activity<br />
was assessed using a depth <strong>of</strong> clearance @C) test and spectrophotometric<br />
analysis <strong>of</strong> the reducing sugars produced as a result <strong>of</strong> exoglucanase<br />
and endoglucanase activities. Appreciable increases in (1) the<br />
numbers <strong>of</strong> conidia filtered from water samples and (2) the extent <strong>of</strong><br />
colonization <strong>of</strong> litter bags were noted two days after application <strong>of</strong><br />
DFB to the treated watersheds. The tolerance <strong>of</strong> aquatic hyphomycetes<br />
to different concentrations <strong>of</strong> DFB varied among the species tested, but<br />
DC was maximum at 5 ppm for five <strong>of</strong> the six species tested. In liquid<br />
culture an increase in endoglucanase activity at 20 ppm <strong>of</strong> DFEI was<br />
noted for four <strong>of</strong> the six species, whereas three species displayed a<br />
decrease in ex~~lucanaseactivity in the presence <strong>of</strong> DFEI. (Supported in<br />
part by funds provided by the USDA Forest Senrice.)<br />
Wednesday, 1030 am<br />
Unusual fungi isolated from cherry fruits<br />
Frank M. Dusn and Rodney G. Roberts. USDA, ARS, Tree ,<br />
Fruit Research Laboratory, 1104 N. Western Ave., Wenatchee,<br />
WA 98801.<br />
Fruits <strong>of</strong> Pnmus aoium L. cv. 'Bing' were surface disinfested and incu-<br />
bated for recovery <strong>of</strong> potentially pathogenic fungi. A small number <strong>of</strong><br />
isolates were provisionally classified as Leptodiscelln africana, Cladospaspa-<br />
urn pomphorum and Sporonnia subticinensis. These fungi are seldom<br />
reported and not previously isolated from cherry; C. porophorum<br />
demonstrated pathogenicity to fruit. Other unusual isolates were<br />
assigned to Phaeolamukrrin and Mycmllosielh. The Phaeormnulnria dif-<br />
fered from P. hachijoensis chiefly in the relative proportions <strong>of</strong> septate<br />
and nonseptate conidia.<br />
Tuesday, 10:15 am<br />
Adhesives in fungi: the adhesive lcnob<br />
<strong>of</strong> capilliconidia <strong>of</strong> Basidiobolus ranarum<br />
exhibits unique ultrastructural features<br />
-. College <strong>of</strong> Veterinary Medicine, North<br />
Carolina State Univ., Raleigh, NC 27606.<br />
Adhesives are <strong>of</strong> major importance to fungi for dispersal purposes as<br />
well as attachment to potential substrates prior to penetration. Nematode-trapping<br />
fungi capture prey with adhesives, plant pathogens<br />
produce materials to attach to host surfaces prior to penetration, and<br />
~pkaerobolus produces adhesive materials atthe surfice <strong>of</strong> the glebal<br />
mass, allowing it to attach to potential substrates following discharge.<br />
The capilliconidia <strong>of</strong> Basidiobolus rrmmum produce an apical droplet <strong>of</strong>