The objectives of this study are to isolate and characterize pathogenic agrobacteria that cause crown gall in grapevines and test hot water dips as a method for eradicating the infectious bacteria . Crown gall is commonly found among Oregon vineyards and the causative agent, Agrobacterium vitis, is known to be...
Phytophthora infestans, the cause of the devastating late blight disease of potato and tomato, exhibits a clonal reproductive lifestyle in North America. Phenotypes such as fungicide sensitivity and host preference are conserved among individuals within clonal lineages, while substantial phenotypic differences can exist between lineages. Whole P. infestans genomes were...
Primula sect. Parryi comprises five species endemic to western North America: P. parryi, P. angustifolia, P. rusbyi, P. capillaris, and P. cusickiana with four varieties. This section, derived from a clade with representatives in Asia and Europe, exemplifies a phytogeographic pattern in which a widespread species is accompanied by multiple...
Convergent evolution is common throughout the tree of life, but the molecular mechanisms causing similar phenotypes to appear repeatedly are obscure. Yeasts have arisen in multiple fungal clades, but the genetic causes and consequences of their evolutionary origins are unknown. Here we show that the potential to develop yeast forms...
Plant growth stages are identified as distinct morphological landmarks in a continuous developmental process. The terms
describing these developmental stages record the morphological appearance of the plant at a specific point in its life cycle. The
widely differing morphology of plant species consequently gave rise to heterogeneous vocabularies describing growth...
The Arabidopsis Information Portal (AIP), a resource expected to provide access to all community data and combine outputs into
a single user-friendly interface, has emerged from community discussions over the last 23 months. These discussions began
during two closely linked workshops in early 2010 that established the International Arabidopsis Informatics...
Formal description of plant phenotypes and standardized annotation of gene expression and protein localization data require
uniform terminology that accurately describes plant anatomy and morphology. This facilitates cross species comparative
studies and quantitative comparison of phenotypes and expression patterns. A major drawback is variable terminology that is
used to describe...
Rice, maize, sorghum, wheat, barley and the other
major crop grasses from the family Poaceae
(Gramineae) are mankind’s most important source
of calories and contribute tens of billions of dollars
annually to the world economy (FAO 1999, http://www.fao.org; USDA 1997, http://www.usda.gov).
Continued improvement of Poaceae crops is necessary
in order...
Plants possess two myosin classes, VIII and XI. The myosins XI are implicated in organelle transport, filamentous actin
organization, and cell and plant growth. Due to the large size of myosin gene families, knowledge of these molecular motors
remains patchy. Using deep transcriptome sequencing and bioinformatics, we systematically investigated myosin...
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...
Montane forest vegetation as it occurs on the east flank of the
central Oregon Cascades has provided excellent conditions for a
"natural experiment" in the use of various methodologies in studying
vegetational distribution. This "experiment" has reflected on some
theory and practice for the discipline of plant synecology. Detailed
descriptions,...
Three growth forms of the genus Microseris, of the tribe
Cichorieae, family Compositae, were compared with respect to their
anatomical structure. The purpose of this study was to clarify lines
of evolutionary specialization in the genus. Two of the three species
studied, M. laciniata and M. borealis, are perennials, while...
At the time of the eruptions of Lassen Peak in 1914-1915, an
area of vegetation along the east slope of the mountain approximately
1 1/4 miles wide and four miles long was destroyed. Except for a
few surviving trees, all vegetation was destroyed.
A study of the revegetation of this...
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...
There is considerable variation among rose varieties in susceptibility
to mildew, and as a result of maturation, leaves of most
susceptible varieties become resistant to infection. The nature of
resistance has been sought in various studies involving environmental,
morphological, and physiological factors. An attempt was made in the
present investigation...
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...
Many initially healthy Pelargonium seedlings developed symptoms
of Verticillium wilt in an Oregon State University greenhouse
when they attained blooming age. The symptoms first appeared in
May as "edge burning," yellowing, and wilting of leaves. In late
summer, these seedlings which were the offspring of Verticillium
infected plants, became severely...
Three viruses were isolated from dahlias using a modification of
Yarwood's leaf-disc method of inoculation. Two of these isolates have
been reported previously in dahlias. In addition, a fourth virus was
isolated using a liquid-nitrogen transmission technique.
Dahlia virus isolate 1 possessed host range and thermal inactivation
properties similar to...
Longevity and germination of seed of western dwarfmistletoe (Arceuthobium campylopodum Engelm. f. campylopodum) of ponderosa
pine (Pinus ponderosa Laws.) was investigated to determine:
1) the influence of humidity and temperature on seed viability and
deterioration during storage; 2) the physiology of seed dormancy;
3) the composition of seed reserve food...
Contracting nucleolar vacuoles are a general and consistent
feature of somatic tobacco cells growing in microcultures. Nucleolar
vacuoles were studied in cells from callus tissues of two
single-cell clones, H-196 and H-239, of hybrid tobacco (Nicotiana
tabacum X N. glutinosa). Vacuoles periodically contracted either
completely or incompletely, apparently releasing a...
A comparative study was made of Pinus ponderosa Laws, and
Arceuthobium campylopodum Engelm. f . campylopodum to determine
(1) whether or not the parasite or parasitized tissues accumulate
abnormal concentrations of minerals, (2) whether or not there
was evidence of a blockage of mineral translocation in the phloem
because of...
Quercus garryana dominated plant communities are found in
the interior coastal valleys and on foothills from southeastern
Vancouver Island, British Columbia, south to San Francisco,
California. They occur as savannas, intermixed with a variety of
conifers, and in almost pure stands. The diversity of habitats
occupied by the species and...
This thesis reports a portion of a general ecological study of
a stream under conditions of controlled flow and low levels of organic
enrichment. It is concerned with the effects of experimental variations
of light intensity and concentration of soluble organic enrichment
imposed on seasonal variations of temperature and total...
The infectivity of plant viruses was suppressed by
inhibitory substances (IS) in the sap of Chenopodium. Various
methods were attempted to find an efficient method which would allow direct transmission of viruses from Chenopodium to other plants. Viruses used in these experiments were alfalfa mosaic
virus (AMV), tobacco mosaic virus...
Tissue differentiation of the primary root and its associated
laterals is reported. Secretory elements are the first of the primary
tissues to mature. They appear to be located between the precursory
phloem and pericycle in the primary root, but are more closely
associated with the pericycle in long lateral roots....
Recent investigations indicate that several latent viruses of
apples exist in common commercial apple stocks, but these viruses
and their relationships are incompletely understood. This thesis
describes investigations of crab apples as indicators of latent viruses
of apples.
Eighty-eight varieties and species of crab apples were tested
as indicators of...
A biosystematic investigation was undertaken in 15
species and three subspecies of the genus Aster, in western
North America. Previous studies had been based entirely on
external morphological features, and it was believed that
much could be learned about the natural affinities of the
taxa by exploring their cytological and...
Aphanizomenon flos-aquae from Upper Klamath Lake, Oregon
was introduced into culture in a precipitate -free medium developed
by modification of McLachlan's ASM medium. This medium ASMT
No. 8 contained no organic substances other than ethylendiaminetetraacetate
(EDTA) and Trishydroxymethylamino methane (Tris),
and was developed by modifying the concentrations of certain elements,...
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...
Arctostaphylos viscida Parry and A. canescens Eastw.,
two well-known and frequently encountered manzanitas in the
Siskiyou Mountains in southwestern Oregon, are shown to
hybridize and to produce an extensive series of morphological
intermediates. The hybridization occurs wherever populations
of these two species meet at contact zones of
serpentine and non-serpentine...
A study was undertaken to determine the reliability of the formation
of a line of demarcation between paired cultures of Fomes
cajanderi Karst. as an indicator of dissimilar compatibility genotypes.
The results were applied to an assay of the number and location of
compatibility genotypes in each of four glaze-damaged,...
Previous work on the rose mosaic virus has produced uncertainty
concerning the identity and properties of this virus. This work was
undertaken to help establish the true identity of the virus and to determine
some of its properties.
A mechanically transmissible virus associated with rose mosaic
virus disease of Rosa...
Fire has played a prominent role in the development and character of the ponderosa pine forests in western North American. Its
records are written in the scars of trees that have survived the fire.
Careful studies of these fire-scars may be used as a means of reconstructing
the fire history...
An investigation was undertaken to determine whether
potassium is indeed necessary for the in vivo synthesis of a
specific protein. The effects of univalent cations on the
inductive formation of nitrate reductase and on the level of
activity of representative non-adaptive enzyme are presented.
Cultures of Neurospora crassa were grown...
Sodium polypectate (SPP) was added to an ethanol-streptomycin
agar (ESA) medium to determine if it would provide a selective
substrate for the growth of Verticillium dahliae and for isolation of
the fungus from soil and plant tissues in the presence of saprophytic
fungi. Sodium polypectate improved greatly the formation and...
A study was conducted of the influence of various climatic and
soil factors on the development of onion pink root disease and of the
influences of temperature, light, pH, carbon and nitrogen sources,
and vitamins on the growth in vitro of an Oregon isolate of the pink
root fungus, Pyrenochaeta...
Manganese has been known to be essential for photosynthesis
for almost 30 years. Subsequent experimentation
indicated a definite function for manganese in oxygen evolution.
However, the mode of action of manganese and
further localization of its site of action have not been
determined.
Ten years ago it was demonstrated that...
Phages of crown gall bacteria were among the first to be
isolated and certain properties of these phages have been studied by
a number of investigators. However, several important characteristics
have not been studied in detail. The present investigation was
made in order to determine the major sources of phages...
An impounded estuary was employed to study primary productivity, community respiration, and community structure as they
related to seasonal and temporal succession, salinity, and water
temperature. Plankton metabolism was studied by means of the
light-and dark-bottle technique. Benthic community metabolism
was determined by using the "diurnal oxygen curve" method.
Four...
Twelve sites of uniform topography and soils were selected in
the Pinus ponderosa/Purshia tridentata/Festuca idahoensis Association.
These sites were located in the rain shadow on the east flank
of the Oregon Cascades. A fire history in the form of fire scars on
ponderosa pine was available for nine of these...
A study was conducted to determine the influence of DMSO
(dimethyl sulfoxide) on suberization and wound periderm formation
in cut potato tuber tissue, and to determine the effectiveness of
DMSO as a potato seedpiece treatment for prevention of seedpiece
decay in the field. The influences of tuber storage conditions,
varieties,...
This study concerns factors affecting production and survival
of ascospores of Elytroderma deformans (Weir) Darker, a needle
cast of ponderosa pine (Pinus ponderosa Laws.).
The results show that summer cooling and a reduction in host
vigor delays and diminishes the number of fertile hysterothecia
produced. Evidence is offered for classification...
The accumulation of dieldrin and its effects on species composition of benthic algal communities were studied in laboratory
streams. Effects of dieldrin on photosynthetic and respiratory
rates of the blue-green alga Phormidium retzii were determined using
a Gilson Differential Respirometer.
Dieldrin concentrations ranging from 0.05 to 7.0 ppb were
maintained...
Pine needle blight of Pinus ponderosa Laws. caused by
Elytroderma deformans (Weir) Darker is recognized by changes in
the needles, in the bark and in the development of the branches.
Anatomical studies of the host-parasite relation have been made previously
on young pine tissue up to four years of age...
Soil moisture depletion trends under five plant species growing
on the clear-cuts of the Marys Peak Watershed near Corvallis,
Oregon, were followed during the summers of 1963 and 1964. The
species were Holcus lanatus, Lotus crassifolius var. subglaber,
Gaultheria shallon, Berberis nervosa, and Acer circinatum; and
were dominant plants of...
Many species of the Fagaceae have been variously interpreted
on the basis, primarily of external morphological characteristics.
The objectives of this study are to elucidate generic and specific
characteristics of the wood of Fagaceae and to attempt to obtain evidence
regarding taxonomic relationships among some of the species
occurring in...
The effects of ultraviolet (UV) irradiation on photosynthesis and
various partial reactions involving the individual photoreactions of
photosynthesis were examined. These reactions included photo-reduction in adapted green algae, Hill reaction, cyclic photophosphorylation,
the 520 nm absorbance change and variable-yield fluorescence.
The reactions were measured in spinach chloroplasts and
isolated chloroplasts...
Crown gall infected and healthy Kalanchoe pinnata (Lam.)
Persoon plants were analyzed for soluble amino acids. Specifically
the amino acids in young leaf, mature leaf, stem, root, and gall
tissues were quantitatively measured. The plants were inoculated
with the bacterium, Agrobacterium tumefaciens (Smith and Townsend)
Conn., on one side of...
Partial reactions of photosynthesis were examined in the wild
type strain and six photosynthetic mutants (8, 11, 26, 40, 50, a') of
Scenedesmus obliquus, strain D₃. A reproducible procedure for the
isolation of active chloroplast fragments from Scenedesmus was
developed. Several chloroplast reactions were examined, as well
as two in...
Growth and replacement patterns of four successionally important
species occurring on Douglas fir clear-cuts were investigated
from September 1964 to June 1967. The study was carried out
on the Marys Peak watershed located near Corvallis, Oregon.
Species used in the study include Holcus lanatus, Senecio
jacobaea, Lotus crassifolius var. subglaber,...
Abundant conidial and sclerotial production occurs on iris
plants infected with Botrytis convoluta Whetzel and Drayton during
the cool moist months of the year. Experiments were designed to
study the survival and inoculum potential of conidia and sclerotia.
Basic nutritional requirements of the fungus in culture were also
studied.
Results...
The Artemisia ludoviciana polyploid complex is a highly polymorphic
assembledge of eight taxa in the Pacific Northwest, with a
chromosome base number of x=9. A cytogenetic analysis of this
complex was carried out to determine the sources of its variation,
the types of polyploidy present, and the genetic processes active...
Distribution of lichens was studied at seven coastal dune sites in
Oregon. Lichens were sampled in the dry stable, dry meadow,
meadow, rush meadow, marsh, shrub and forest deflation plain communities.
Observations were made of the standing water in the marsh
community. Quantitative measurements were made of the percent
organic...
The hop cyst nematode, Heterodera humuli Filipjev, 1934 was
first reported from Europe in 1894, however, very little is known
with respect to the biology and economic importance of this pest.
Abundant material from Oregon hop yards provided an excellent
opportunity to add additional details concerning the bionomics of this...
Verticillium dahliae Kleb. incites a vascular wilt disease of
mints. Susceptible Mentha piperita L. , resistant M. crispa L.,
and intermediate hybrid 148 were used to study 1) the site of differential
resistance and 2) the role of polygalacturonase (PG) in the
disease syndrome.
Many more V. dahliae propagules were...
Abundant conidial production occurs from colonized straws and
plants infected with Cercosporella herpotrichoides Fron during the
cool moist months of the growing season. Experiments were
designed to study the survival, inoculum potential and competitive
saprophytic ability of conidia in soil.
Laboratory results indicated that cool moist soil favors the
saprophytic...
Cambial activity in white spruce stems in Alaska was observed
from April, 1964 to September, 1965 in over 300 samples taken from
50- to 60-year-old natural stands. Mitotic index was used as a measure
of the rate of periclinal division of fusiform cells in the cambial
zone. Anticlinal divisions are...
Experiments were performed to determine whether a direct
correlation exists between the growth rates of tall and dwarf peas
grown either in the light or in the dark and endogenous gibberellin
(GA) content. Three separate but related experimental approaches
were utilized: (1) the determination of possible qualitative and /or
quantitative...
Shoot apex senescence is defined as the collective progressive
and deteriorative processes which ultimately terminate the functional
life of the shoot apex. Senescence of shoot apices of Pisum sativum
L. 'Alaska' as measured by cessation of stem elongation was delayed
by removal of flowers and by treatment with gibberellin A₃...
A disease of sweet cherry (Prunus avium L.) known as "cherry
rosette" has threatened production of cherries in Oregon. In 1961
this disease was observed in widely separated orchards. Rosette
occurred in isolated trees or in spreading patterns, often from
identified single trees or from one section of an orchard....
Ribonucleotide reductase from Rhizobium meliloti has been
partially purified and characterized. The enzymatic reduction of
ribonucleotides to deoxyribonucleotides is dependent upon B₁₂ coenzyme
and dihydrolipoate.
B₁₂ coenzyme was more effective than B₁₂ coenzyme analogues
in the reductase reaction. The affinity of the R. meliloti
reductase system for B₁₂ coenzyme was...
The physiologic specialization of nine isolates of stripe rust
(Puccinia striiformis West.) collected in the Pacific Northwest
was determined. The separation of races was based on the differential
susceptibility of the following wheat varieties: Cappelle
Desprez, Chinese 166, Dippes Triumph, Druchamp, Etoile de
Choisy, Flamingo, Gaines, Golden, Ibis, Leda, Michigan...
Twelve chemicals (Busan 72, Chloropicrin, Dacthal, Dexon,
Duter, EP 161, Lanstan, Methyl bromide, Phaltan, Vapam, Vidden D,
Vorlex) were tested to determine their effect on populations of certain
important soil-borne microorganisms including the onion pink root
fungus Pyrenochaeta terrestris. The soil used was from a field in
Malheur County, Oregon...
Three Oregon soil types (Chehalis silt loam (CSL), an alluvial
soil from the Willamette Valley; Ayre sandy loam (ASL), a volcanic
pumice soil from the Central high desert; and Klamath fine sandy
loam (KFSL), a basaltic mineral soil from the Klamath Basin) were
collected adjacent to fields which had been...
A saprozoic nematode, Diplogaster lheriteiri Maupas 1919,
was studied to determine its relationship to the plant pathogenic bacteria,
Agrobacterium tumefaciens (Smith and Townsend) Conn.,
Erwinia amylovora (Burrill) Winslow et al., Erwinia carotovora
(Jones) Holland, Pseudomonas phaseolicola (Burk. ) Dows.,
Xanthomonas campestris (Pam. ) Dows. and to a phage of A....
Verticillium wilt of hops in Oregon, caused by Verticillium
dahliae Kleb., was first reported in 1956. Later, V. albo-atrum
Reinke & Berth. was also isolated from infected hop plants, and thus
both species of the fungus were shown to be the causal agents of the
disease in Oregon.
The purpose...
Samples of benthic algae were collected from the Metolius River
of central Oregon at two-week intervals between April 15, 1967 and
March 9, 1968. Species of filamentous algae and diatoms present
were recorded for every sampling station on each sampling date.
Permanent mounts of diatom frustules were prepared.
This sampling...
The pathogenicity of A. flavus on alkali bee larvae was studied
using sample materials from three nesting sites of these soil
inhabiting bees along the Oregon-Washington state line. Soil
saprophytes of the biosphere of the alkali bee were also studied.
Field observations and direction of soil cores from bee beds...
A strain of Aphanizomenon flos-aquae Born. et Flah. has been
introduced into culture and maintained since August of 1964 in completely
defined media. It exhibits the planktonic, colonial flake form
found in nature, and both heterocysts and akinetes are present. The
color and size of the flake and general appearance...
Verticillium dahliae Kleb. causes a wilt disease of peppermint.
Attempts to control the disease by soil fumigation, crop rotation,
flaming of stubble, and deep plowing have met with only limited success.
Development of resistant varieties through conventional breeding
procedures is difficult because commercial peppermint is male-sterile.
Several strains of commercial...
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...
Raw and biologically stabilized Kraft mill effluents were introduced
into laboratory artificial streams at a ratio of 15 ml per liter
of water over a two year period. Effluent from the stabilization pond
of a second mill was introduced at concentrations of from 5 to 40 ml
per liter of...
Twenty sites of uniform topography and soil were select ed in the
montane forest found on the East flank of the Central Oregon Cascades.
These sites were located along a vegetational gradient composed of
five plant communities: Abies/Pachistima, Pinus/Ceanothus, Pinus
Arctostaphylos-Purshia, Pinus/Purshia/Festuca, and Juniperus
Festuca. An attempt was made to...
The purpose of this study was to investigate the effects of
logging on the productivity, structure and biomass of a periphyton
community developed in mountain streams. The three streams used
in this investigation were located in the coast range of Lincoln
County, Oregon. They were selected for similarity of habitat,...
The balsam woolly aphid (Adelges piceae Ratz.) feeds by inserting its stylets intra- and intercellularly into the cortex or outer phloem of the true firs. While feeding, the aphid injects into the bark an unknown stimulatory substance which affects the adjacent cortical parenchyma cells, the activity of the vascular cambium...
The fungus Phoma menthae Strasser causes black lesions and
cankers on stems and rhizomes of Mentha piperita L. The purpose
of this thesis was to: 1) study the production of polygalacturonase
(PG) and macerating enzymes (ME) by P. menthae in vivo and in
vitro, 2) study the effects of phenolic...
This thesis concerns the alteration of the course of selective
protein synthesis and morphogenesis in plants treated with growth
regulating chemicals. Treatment of 48-hour-old "Alaska" pea seedlings
(Pisum sativum L.) with 2, 4-D, IAA, NAA or picloram caused
inhibition of epicotyl and primary root elongation and proliferation of
massed lateral...
Alnus rubra (Bong. ) seedlings were grown in sand culture and
irrigated with nutrient solution containing CdCl₂
ranging from 5 μg to 100 mg per liter. Treatment of A. rubra seedlings for 4 weeks
with 50 and 100 mg CdCl₂
per liter of nitrogen-free nutrient solution
decreased in situ nitrogenase...
A cytogeographical study was made of populations of tetraploid
(n=18) and hexaploid (n=27) Achillea millefolium (Compositae-
Anthemideae) from the Pacific Coast states. There is a complex
distributional pattern, involving overlapping ranges, mixed populations,
migration of one form into areas occuplied by the other,
pentaploid hybrids, and septaploid and octoploid plants....
Developmental changes in the storage organ of Brassica
campestris L. were followed from the organization of the embryonic
radicle and hypocotyl to the mature storage organ. Three independent
primary meristems gave rise to the cortex, the stele, and the
root cap-epidermis. The primary development is typical of the
Cruciferae. Cambial...
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...
Root rot of ponderosa pine caused by Armillaria mellea was
studied in a pine forest that had been under management for 30 years
in Klickitat County, Washington. Information sources included
disease survey, detailed observation and description of specific
disease situations, and examination of roots in situ and removed.
Roughly circular...
Setaria lutescens (yellow foxtail) plants, grown from five seed
sources were compared in California. Seed sources were: Connecticut,
Iowa, Massachusetts, Pennsylvania and California. Morphological
and physiological differences between biotypes include: plant
size, growth habit, time required to mature and reproductive capa
city. Most significant is the prostrate habit of the...
Submarine volcanic eruptions can result in both real and apparent changes in marine algal communities, e.g., increases in phytoplankton biomass and/or growth rates that can cover thousands of square kilometers. Satellite ocean color monitoring detects these changes as increases in chlorophyll and particulate backscattering. Detailed, high resolution analysis is needed...