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...
Fusarium crown rot (FCR) is one of the most widespread root and
crown diseases of wheat in the Pacific Northwest (PNW) of the United
States. Our objectives were to characterize crown rot severity and
distribution throughout the PNW by conducting a survey of 210 fields
covering the diverse dryland wheat-producing...
Fusarium spp. frequent conifer nursery soils yet are rarely recovered from coniferous forest soils. Experiments were performed to determine what influence humic-rich organic amendments and volatiles from soil, ectomycorrhizal fungi and ectomycorrhizae have on the populations of several physiologic and taxonomic microbial groups potentially related to this phenomenon. A comparative...
Fusarium spp. are among the most important pathogens of Douglas-fir
(Pseudotsuga menziesii) seedlings in bareroot nurseries. Currently the most effective
disease control method is soil fumigation with methyl bromide. As methyl bromide is
phased out, however, other disease management strategies may become more important.
We explored two alternative approaches to...
Forty-seven isolates of Fusarium solani obtained from the roots of diseased and healthy conifer seedlings and forest nursery soil were tested for pathogenicity on young Douglas-fir germinants under controlled laboratory conditions. Isolate virulence varied widely; a few were highly virulent whereas many were classified as non-pathogenic. Isolates from the roots...
Mutation of repetitive DNA by repeat-induced point mutation (RIP) is a process that occurs in many filamentous fungi of the Ascomycota during the sexual cycle. Concurrently, direct DNA repeats are often deleted by homologous recombination at high frequency during the sexual cycle. Thus, the processes of RIP and deletion compete...
A necrosis at the tip of cones was observed on hop (Humulus lupulus), cultivar "Nugget", grown in Oregon in the early 1990's. Fusarium sambucinum and F. avenaceum were recovered from symptomatic cones in 1998 and preliminary inoculation experiments suggested both Fusarium species could cause hop cone necrosis. Studies were carried...
A total of 45 nondiseased containerized ponderosa pine seedlings from 10 seedlots were sampled at three different times during the growing season for root infection by Fusarium and Trichoderma at the USDA Forest Service Nursery in Coeur d'Alene, Idaho. More than 90 percent of the seedlings had roots infected with...
Sweet corn (Zea mays L.) yields in the Willamette Valley of Oregon have been declining since the early 1990’s. Studies were done to determine if there is a relationship between ear weight and several disease parameters including necrotic crowns or stalk nodes, nodal root rot, radicle root rot, and sub-crown...