The main objectives of this study were to determine the
effect of certain environmental conditions on the quantity of poly-galacturonase (PG) produced by V. albo-atrum, and to partially
purify and characterize the PGs produced by this fungus in culture
and in infected tomato plants.
V. albo-atrum produced twenty times as...
Mycelial growth of Endothia parasitica was
stimulated by
relatively high concentrations of CuSO₄ in potato dextrose agar
medium (PDA).
Stimulation of E. parasitica by the high levels of
CuSO₄ and the relatively poor growth of this fungus on
standard culture
media suggested that stimulation might be due to
interaction of...
This study was initiated to determine the tolerance to copper
of Aspergillus niger, Stemphylium sarcinaeforme, Monilinia
fructicola and Fusarium oxysporum f. sp. lycopersici. Included
were strains of the latter two fungi that were induced to tolerate
relatively high levels of copper by continual culture on sublethal
levels of the toxicant....
Experiments were conducted to determine both the influence of wood
moisture content on the fungitoxicity of methylisothiocyanate (MIT) to the
wood-decay fungus Poria carbonica, and the ability of gelatin to safely en-capsulate MIT for efficient treatment of wood products.
The fungitoxicity of MIT was studied by determining the product of...
Polygalacturonase produced by Fusarium oxysporum f. sp.
lycopersici was purified by chromatography on DEAE cellulose, CM
cellulose, and hydroxylapatite. Removal of large amounts of carbohydrate
by chromatography on hydroxylapatite did not affect heat
stability of the enzyme. A large proportion of the remaining carbohydrate
appeared to be covalently linked to...
The demand for new fungicides to control plant diseases has
led to experimentation with both previously used and newly developed
fungicides. Silver, an older but little used fungicide, was selected for
evaluation because of its high toxicity to microorganisms. Silver
nitrate and a silver electrolytic cell were tested as potential...
An assay for fungicidal activity of sodium N-methyldithiocarbamate
(Na-MDC) and its decomposition products was developed
in which there was a minimum influence due to the widely varying
physical properties of the compounds (i.e. vapor pressure and water
solubility). Decomposition of the toxicant during the tests was
measured and held to...
This investigation was undertaken to determine 1) the effects
of various carbon sources in defined media on pectolytic enzyme production,
2) the effect of the incubation period on pectolytic enzyme
activity, and 3) the development of improved methods for the purification
and characterization of the polygalacturonases (PG) produced
by Fusarium...
This study was undertaken to determine the sorts of polygalacturonases
present in the culture filtrate of Fusarium oxysporum
f. sp. lycopersici, to purify and characterize these enzymes, and to
study any complexes that may form between polygalacturonase and
carbohydrate not degraded by the enzyme.
The polygalacturonase in culture filtrate consists...
Bioassays of acetone extracts from xylem tissue in tomato stems
and corresponding reductions in Fusarium oxysporum f.sp. lycopersici
race 1 or 2 populations within the stems suggest that fungitoxic
materials within the xylem vessels of Bonny Best, Jefferson, and Marglobe
tomato cultivars initially kill a portion of the inoculum conidia....
The fungitoxicity of acetone extracts from the xylem of Fusarium
wilt disease resistant tomato plants (cv. Jefferson) inoculated with Fusarium
oxysporum f. sp. lycopersici was greatly influenced by environmental
factors. Extracts obtained from plants 1 h after watering were 4-times
more toxic than extracts from plants subjected to water stress...
Influence of temperature and wood moisture content on
spore germination and colonization of Douglas-fir
(Pseudotsuga jnenziesii) heartwood by Poria carbonica
basidiospores and chlamydospores was studied. Both spore
types germinated and colonized wood at moisture contents
above the fiber saturation point, but not below.
Germination and wood colonization occurred at 22°C...
Douglas-fir utility poles are routinely air seasoned before
treatment with chemical preservatives. Basidiomycetous fungi invade
these poles and may cause strength loss during air seasoning or later
if treatment temperatures are insufficient to kill the decay fungi.
The purpose of this study was to develop a rapid test to asses...
The effects of pH and time on the formation of hydroxy-Al, Fe,
and Mg interlayer were compared for montmorillonite and vermiculite.
The stability of interlayers was evaluated by sequentially increasing
the severity of dissolution treatments and by subjecting the inter-layers to an HC1 treatment. The interlayer formation and stability
were...
Soils developed on volcanic ash exhibit several unique properties
not commonly observed in soils formed on other geologic
material. Low thermal conductivities, low volumetric heat capacities,
slow transport phenomena, excess macro-drainage and
development of unique suites of clay minerals are some properties
thought to be directly related to the vesicular...
A study was conducted to determine the mineralogy and chemical
properties of "Ando-like" western Oregon soils. The samples
were collected from 13 sites which formed mainly from basaltic
rocks, a contact metamorphic rock, sedimentary rocks, and
alluvium derived from sedimentary rock and from volcanic rock. All
samples contained small amounts...
Previous studies of pumiceous soils in Oregon indicated that
their physical and chemical properties were strongly related to the
porous nature of the pumice matrix. Soils developed on air-fall
pumice from the eruption of Mt. Mazama (Crater Lake, Oregon) had
low thermal conductivities and low volumetric heat capacities. Values
for...
Soil samples from the Mazama tephra deposit were collected
from the AC and C2 horizons at five different locations along the axis
of the main depositional lobe. The clay fraction from the samples
was recovered and studied by means of chemical, x-ray, DTA and
electron microscopy methods in order to...
Investigations were conducted to (1) determine the original
pattern of deposition and thickness of ash in the Ochoco and Blue
Mountain areas of Oregon, (2) determine if discontinuities exist in
the parent material of these soils, (3) determine the degree of mixing
of ash with other materials and evaluate reworking...
The northern part of the Southeast Three Sisters quadrangle straddles
the crest of the central High Cascades of Oregon. The area is
covered by Pleistocene and Holocene volcanic and volcaniclastic rocks
that were extruded from a number of composite cones, shield volcanoes,
and cinder cones. The principal eruptive centers include...
The Summer Coon intrusive center is located seven miles
north of Del Norte, Colorado, on the eastern edge of the San Juan
Mountains. The intrusive center is the core of a dissected calcalkaline
composite volcano of middle Oligocene age. The Summer
Coon rocks belong to the Conejos Formation which is...
This study determined the independent effects of various homogenization cycles and
precipitation treatments on the elevated temperature workability and the final ambient
temperature mechanical properties of AA2024 aluminum alloy and on the T3 tensile
properties of 2014 aluminum alloy as well as T6 tensile properties of 2618 and 2618 (Curich)...
Ti-6Al-2Sn-4Zr-2Mo-0.1Si specimens were shaped by repeated cycles of heating
(to 954 °C) and hammer or press forging followed by a solution anneal that varied from
968 to 998 °C. The coupons were originally extracted from billets forged below the beta
trans us ( 1009 °C) and slow cooled to ambient...
The effects of broadcast gypsum on infiltration rates, crusting,
aggregate stability, and runoff and sediment yields were analyzed
during the winter months on three West Oregon soils. The results were
used to evaluate its utility as a management tool to help control
erosion.
An application rate of two metric tons...
Flavor problems associated with the use of cheddar cheese
whey in the formulation of ice cream and other food products were
investigated. During spray drying of whey, which transforms bulky
liquid whey into an easily transportable and storable powder,
various degrees of off-flavor development may occur depending on
the care...
The thesis area is located southwest of Portland, Oregon, in the
Western Cascades. In the area are volcaniclastic rocks and lava flows
that range in composition from basaltic andesite to dacite. The dominant
volcaniclastic rock type is thin intracanyon ash-flow tuff. The
dominant lava flows are a thick sequence of...
During the Pleistocene, an andesitic volcano named Mount
Mazama grew to a probable elevation of 3000 meters in south-
central Oregon. Near the end of the Pleistocene, three diverse
magma types appeared in the eruptive products associated with Mount
Mazama: l)High-alumina basaltic andesite magma associated with an
early plateau and...
Coral reefs have become vulnerable to climate change, with mass bleaching events, the loss of symbiotic algae (Symbiodiniaceae), increasing in both frequency and severity. As climate change continues to threaten the persistence and existence of coral reefs around the world, the biggest question posed for coral reefs is “can they...
Year-round habitat use of marine predators provides knowledge of important marine areas throughout different life stages. Large-scale, environmental variability, both in space and time, causes changes in the behavior and distribution of marine predators that are important to quantify for conservation. In the Northern California Current System (NCCS), common murres...
This study used a nationally representative dataset of 21,260 kindergartners, Early Childhood Longitudinal Study, Kindergarten Class of 1998-1999 (National Center for Education Statistics, 2001a), and a conceptual framework of theories of cultural and social capital (Bourdieu, 1986) embedded in an ecological framework (Bronfenbrenner, 2005) to identify unobserved socio-cultural classes in...
Six standard coyote scent station index lines and one scentless control line were repeatedly sampled from May through October, 1974, on a 400 square mile study area in Central Oregon. The scent station index remained relatively constant at a mean value of 0.025 from May through mid-August; increased to a...
Under conditions of fixed N-limitation, as with most oligotrophic systems, the process of biological N₂ fixation (diazotrophy) is favored, provided the necessary trace elements and vitamins are sufficient. Despite the well understood contributions of N₂
fixation in oligotrophic regions, the nutritional and ecological controls of marine diazotrophs have not been...