The ability of N,N'-diphenylurea (DPU) to substitute for cytokininactive
adenine derivatives in promoting callus growth of Phaseolus lunatus
and Nicotiana tabacum has been examined. In general, DPU stimulated
callus growth of P. lunatus at high concentrations and the growth of
most callus tissues was irregular, while the response of tobacco...
The effects of five cytokinin antagonists on the growth
of cytokinin-autonomous lines of Phaseolus lunatus cv.
Kingston, Phaseolus vulgaris cv. Great Northern, and
Nicotiana tabacum cv. Wisconsin 38 callus tissues have been
compared. The antagonists tested included four N⁴-substituted 4-amino-2-methylthiopyrrolo[2,3-d]pyrimidines
bearing the following N⁴ side chains, 4-n-pentyl-
(ms²pnN⁴Prp), 4-n-hexyl- (ms²HxN⁴Prp),...
Experiments were performed to determine the nature of
maize influence on bean disease in additive-type
intercrops. Overall effects of intercrops on angular leaf
spot (caused by Phaeoisariopsis griseola) in Kenya
indicated >23% reductions (P<0.05) in area under the
disease progress curve (AUDPC) in two of three season-site
combinations. Fertilization tended...
The climate of the Pacific Northwest is in flux, and existing forest ecosystems are stressed and poised to shift in fundamental ways, with or without human intervention. This dissertation probes the nature of forest responses to environmental change through investigations of morphology and genetics of three species of alder co-occurring...
MicroRNAs (miRNAs) are an extensive class of noncoding genes that regulate gene expression through
posttranscriptional repression. Given the potential for large viral genomes to encode these transcripts, we
examined the human cytomegalovirus AD169 genome for miRNAs using a bioinformatics approach. We
identified 406 potential stem-loops, of which 110 were conserved...
Cyanobacterial harmful algae blooms (cyanoHABs) are a growing concern worldwide due to damage of ecosystems and threats to human health. Previous research indicates that plant humics from aquatic and wetland vascular plants are effective inhibitors of cyanobacterial metabolism and growth and may be useful as control agents for mitigating cyanoHABs....
An increased understanding of secondary metabolism in fungi is important for both biological and societal reasons. The ascomycete genus, Tolypocladium, is an ideal system to explore secondary metabolism characterization, ecology, evolution and regulation. The genus produces and has the genomic potential to produce a wide array of metabolites. Paired with...
The vegetation of the Oregon coast is characterized by a
variety of stages of plant succession which are repeated widely
throughout the sand dune area. During the years from 1960 to 1963
the gradation of upland sand dune succession was studied on 48 plots
within a 150 mile section of...
The scale of pest and disease dispersal is often larger than the scale of individual farms. Therefore, an individual grower’s response to pests and diseases can affect and is affected by their surrounding growing region. Individual growers are also not isolated, and engage in various forms of information gathering, sharing,...
Rhizopogon vesiculosus is a common ectomycorrhizal (EM) symbiont of Pseudotusga menziesii (Douglas-fir) in the coast range of the Pacific Northwest. The species has been studied for its systematics, genet size, population structure, and competitive ability in several field and experimental studies. This thesis seeks to provide a more thorough characterization...