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...