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
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....
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...
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...
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...
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...
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...