Field study with 5 tall fescue genotypes treated at the vegetative
growth stage, with 0, 0.28, 0.56, and 0.84 kg/ha of mefluidide
was initiated in July, 1980. The regrowth of these plants were again
treated at the booting growth stage in April, 1981, with the same
rates of mefluidide as...
The objective of this study was to examine the variation among ammonia-oxidizing and denitrifying communities in soils of a natural Fennoscandian boreal forest and of a forest with a long history of fertilization with different levels of nitrogen (N), and to examine whether there are any changes in the microbial...
Cytokinins can be conjugated to N- and O-glucosides. While N-glucosylation generally leads to irretrievable loss of activity, O-glucosides are thought to play an important role in cytokinin storage and homeostasis since they can be hydrolyzed to the corresponding aglycones. The first zeatin O-glycosyltransferase genes isolated were ZOG1 and ZOX1 from...
In forest trees from temperate and boreal regions, cold acclimation is an important
adaptive trait that involves changes in gene expression and physiology. Genecological, quantitative genetic, and QTL studies have been used to study the genetics of cold acclimation in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), but the genes responsible for...
Riparian zone vegetation can influence terrestrial and aquatic food webs through variations in the amounts, timing, and nutritional content of leaf and other litter inputs. Differences in vegetation composition and density, as well as riparian topography, may modulate the strength and quality of these inputs. Changes in inputs to small...
The response of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) saplings to various levels of brush overtopping when growing on three north-facing sites in the Oregon Coast Range was investigated for two consecutive years. A fisheye (hemispherical) photographic technique combined with a digitizing computer system was used to determine the percentage of...
I conducted two separate studies, both related to the impacts of spring and fall prescribed fire on ponderosa pine (Pinus ponderosa Dougl. ex Loud.) forest soils in Eastern Oregon. The studies were either conducted at or linked to four stands of ponderosa pine, in the Malheur National Forest. Each stand...
Gene transfer via interspecific hybridization within Phaseolus has
been limited by abnormal hybrid development and the rapid loss of
hybridity in subsequent generations. The most advanced embryo
development occurs in P. vulgaris x P. coccineus where mature seeds
form. However, the reciprocal cross still results in abnormal embryos
unable to...
The Macrocheles glaber species group contains many
of the common mites which are associated with the dung
of domestic animals. Species in the glaber group have
been investigated for their use as biological control
agents of synanthropic flies.
Over 10,000 slide-mounted specimens of Macrocheles
in the OSU Acarology Collection and...
We identified and evaluated a phytoseiid predator as a biological control agent of multiple spider mites pests that occur in ornamental nurseries. When comparing species, Neoseiulus fallacis (Garman) had a wider prey range than Galendromus occidentalis (Nesbitt), a higher probability of overwintering than Neoseiulus califomicus McGregor and was equally or...
Breeding Port-Orford-cedar for resistance to Phytophthora lateralis, a causal agent of root disease, begins by screening, through artificial inoculation, phenotypically resistant trees selected from natural stands. The successful program selected tolerant or resistant POC parent trees for the purpose of disease management. Candidate resistant POCs were used in my dissertation...
Many investigators have suggested that current photosynthate
supply can limit adventitious root formation on leafy cuttings.
Accordingly, studies were undertaken to determine the effects of
altering photosynthesis and carbohydrate levels on adventitious root
formation by leafy cuttings of a number of different species.
Pea cuttings rooted at high CO₂ (1800...
Sinks, plant organs which depend on the import of assimilates
for growth, play a central role in determining assimilate distribution
patterns within the plant. The strawberry fruit is a strong
sink for dry matter and its effect on carbon partitioning and
assimilation in the plant as well as the mechanism...
Responses to two cycles of mass selection for heading date,
followed by selfing or intermating, were studied in two diverse
winter wheat (Triticum aestivum L. em. Thell) crosses. Selection
was bidirectional, resulting in early and late populations for
each mating system, cycle, and cross. The influence of mass
selection for...
Endogenous concentrations of indole-3-acetic acid (IAA) and cytokinins were compared to the tendency for plagiogravitropjc growth in rooted stein cuttings of Douglas-fir. A chromatographic method was developed for
the purification and quantitation of trace levels of IAA. Two elutions with reverse-phase high performance liquid
chromatography (HPLC) using a fluorescence detector...
Wild barley (Hordeum vulgare subsp. spontaneum) could be a source of useful genes for improving cultivated barley. The useful genes present in Hordeum vulgare subsp. spontaneum may be new alleles at described loci, or these may be entirely new genes in the sense that there is limited allelic variation at...
Epidermal RNA samples from FVB/N mice treated with PAH standards and
environmental PAH mixtures were harvested and purified using Trizol extraction and
RNeasy mini prep kit purification. Epidermal RNA integrity was low (RIN mean 3.5),
indicating significant RNA degradation and the need to modify handling, collection, and
processing of skin...
The present work is a study of three degenerate, linear parabolic
systems of equations, each of which represents a version of the so-called
double porosity model for underground fluid flows in natural fractured
rock. These systems of equations together with initial and boundary
conditions describe single-phase flows in fluids, slightly...
Porapak Q, Chromosorb 102, and Tenax GC, three porous
polymers commonly used as adsorbents in headspace analyses were
investigated. The retention times of various low-boiling compounds
relative to water were measured on the collection columns to determine
which compounds would be lost during the water removal step
employed after sampling...
Four studies were conducted. First, mountain big sagebrush communities were burned at Lava Beds National Monument, California, and The Crooked River National Grassland, Oregon. In two years at Lava Beds, basal cover of Idaho fescue in one community and Thur- ber's needlegrass in one of three communities did not recover....