Molecular DNA markers have become widely used in all areas of genetic
research. The objectives of this thesis were to develop polymorphic markers in sunflower
and utilize the markers for genetic and candidate gene analyses. Amplified fragment
length polymorphism (AFLP) markers were used to estimate genetic similarities and
assess the...
Although the concept of breeding crops for organic agricultural systems has been around for decades, few studies have been reported for vegetable crops to quantify and compare how conventional and organic systems differ in their selection pressures on genotypes advancing through the breeding cycle; especially research utilizing modern sequencing capabilities....
Durum wheat cultivars for North-Eastern Oregon have to be competitive
in terms of their yield potential with soft white winter wheat cultivars and meet
strict quality requirements of the milling industry. Combining the high yield
potential of fall planted durum wheat cultivars which have an acceptable level of
winter hardiness...
A higher level of efficiency in the production of doubled-haploids must be achieved if
this procedure is to be beneficial in plant improvement. Of equal importance is the
development of protocols, which are not genotypic specific and result in progeny that represent
a random sample of gametes from the parental...
Podosphaera macularis, causal agent of hop powdery mildew, is known to produce cleistothecia (syn. chasmothecia) in eastern North America and Europe, but ascocarps are not reported from the Pacific Northwestern region of North America. Reasons for the apparent absence of cleistothecia in the Pacific Northwest are unknown. We established that...
A micropropagation system was developed for hazelnut cultivars and
rootstocks. Culture establishment was affected by explant source, explant collecting
season, and type of explant. The highest frequency of culture initiation and lowest
tissue oxidation and contamination were obtained from internodes with single axillary
buds from grafted greenhouse-grown plants early in...
This thesis consists of five chapters: a general introduction, two manuscripts, a collection of published lesson plans, and a general conclusion. The works collected herein are united by the common theme of practical applications in plant breeding. The first manuscript reports a study performed on five malting barley lines grown...
In the midst of double-digit growth in market demand for organic products, there is a lag in the growth of certified organic production in the United States. This thesis investigated the motivations and barriers farmers face when making the transition to organic agriculture. Three distinct organic farmer typologies were identified:...
The effects of erect leaf canopies on enhancing grain yield in wheat is not
understood. The main objective of this study was to understand the effect of leaf
angle on grain yield by comparing randomly derived-lines from crosses of erect
and droopy leaf spring wheats. Nine traits associated with canopy...
The success of a plant breeding program depends upon the availability of
useable genetic diversity. Such diversity may be enhanced depending on the type of
hybridization strategy employed. Segregating progenies resulting from F2
populations, a double cross, and a top cross were compared for the amount of
useable genetic diversity...
Meadowfoam (Limnanthes alba Bentham; Order: Brassicales; Family: Limnanthaceae) is a self-compatible, predominantly allogamous, insect pollinated species. Meadowfoam oil is a source of novel unsaturated very-long-chain (VLC) seed oils (C₂₀ and C₂₂) with low concentrations of saturated fatty acids (typically less than 2%) and outstanding oxidative stability. Here we report the...
We isolated and characterized the expression of two genes from Populus
trichocarpa that are homologous to the TERMINAL FLOWER 1 (TFL1) gene from
the model annual plant Arabidopsis. In Arabidopsis, overexpression of the TFL1
gene extends the vegetative growth phase, and the homozygous mutant tfl1 allele
causes early flowering and...
Historically, brewers have used dry-hopping (a cold extraction of nonvolatile and volatile chemicals from hops into fermenting or finished beer) to increase the microbial stability and shelf life of their beer. As hoppy beer styles have gained in popularity over the last decade (2007-2017), the objective of dry-hopping has turned...
Birdsfoot trefoil (Lotus corniculatus L.) is a popular perennial, non-bloating forage legume used for pasture, hay and silage throughout the temperate regions of Europe, Asia Minor, North Africa and North and South America. It is regarded as the most morphologically and biochemically variable species in the genus. Research investigating the...
Marker information in the new oilseed crop, meadowfoam, is limited. Molecular markers to facilitate meadowfoam breeding and cultivar improvement are not available. The knowledge of genetic relationships among recent germplasm is not known. The objectives of this study were (i) to gain an understanding of genetic diversity and relationship patterns...
Spike morphology characteristics and the free-threshing habit of wheat have been extensively investigated because of their evolutionary significance and practical importance. Several genetic systems that govern these traits have been reported. Some studies suggest polygenic inheritance while others have identified major genes. This study was conducted to identify and locate...
Italian ryegrass (Lolium perenne L. spp. multiflorum (Lam.) Husnot) is one of the most troublesome weeds with respect to herbicide resistance selection. Some reasons for this are the numerous documented cases of multiple and cross herbicide resistance and some of the biological characteristics of this species, such as wind cross-pollination...
Strawbreaker foot-rot is a major limiting factor to cost efficient winter wheat
production in the Pacific Northwest. Development of resistant cultivars has been
hindered by the lack of adequate levels of genetic resistance and screening techniques
which can consistently detect desired genotypes.
Studies were conducted to determine if the reported...
The level of polymorphisms of many biochemical and DNA markers are low in
cultivated sunflower (Helianthus annuus L.). The number of mapped public DNA
markers is limited. Molecular markers have not been developed for the most
important diseases of sunflower, such as downy mildew. The objectives of this
study were...
The cultivated sunflower (Helianthus annuus L., x=17) is one of the most important annual oilseed crops in the world. There are very few publicly shared sequence-based DNA markers and genetic maps in sunflower, even though molecular DNA markers and genetic maps have become widely used in all areas of genetic...
Wildtype sunflower typically produces 12-24% oleic acid (18:1) and 70-82%
linoleic acid (18:2). High-oleic sunflower, by contrast, produces up to 80-94% oleic
acid. The monounsaturated oleic acid has a greater oxidative stability than the
polyunsaturated linoleic acid, predominant in wildtype sunflower, and has greater
nutritional benefits than polyunsaturated and saturated...
Tomato [Lycopersicon esculentum Mill.] plants are chilling sensitive and do not
naturally accumulate glycinebetaine (GB), a metabolite that functions as a stress
protectant in plants. While GB can increase tolerance of tomato plants to salt and
drought stresses, its effect on chilling tolerance has not been examined. To evaluate
whether...
Attempts to develop dual-purpose durum wheat cultivars for both pasta and bread-making
have been unsuccessful. To better understand this limitation, thirty durum
genotypes, selected based on their diverse geographical origin, and five bread wheat
cultivars were compared as to their flour mixing properties, dough physical characteristics
and baking performance. The...
An organisms' genotype may not be reflected in its phenotype. For example, epistasis - the interaction of non-allelic genes can cause deviations from expected phenotypic ratios. The epistatic interaction between the hooded (Kap) and short-awned (lks2) loci in barley (Hordeum vulgare) precludes the localization of the Kap locus, based on...
Hemp is a dioecious, annual, flowering plant in the Cannabaceae family. It has been used for thousands of years to produce textiles, essential oils, and medicines. The overall purpose of these experiments was to propagate the cannabinoid-free cultivar, ‘I3’, and follow up by inducing polyploidy in the ‘I3’ hemp via...
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...
A major factor limiting the efficiency of plant improvement programs is the lack of knowledge as to which parental combinations to make when working with quantitatively inherited traits. The primary objective of this study was to provide information regarding the use of combining ability analysis to predict which cross combinations...
As DNA sequencing technologies continue to advance, resulting in increased throughput and decreased costs, both the number of researchers utilizing these technologies and the quantity of data outputted by a single sequencing experiment will, likewise, continue to increase. Currently, DNA sequence data can be generated at a much faster rate...
Naked (hull-less) barley has historically been grown for food, but interest in, and breeding efforts for, its use in malting and brewing have increased due to the potential benefits: reduced off-flavors, reduced spent grain, and higher malt extract. These benefits are offset by limiting factors such as high b-glucan and...
Common bean (Phaseolus vulgaris L.) comes in a huge assortment of fresh and dried varieties, including snap beans, kidney beans, and pinto beans. Together, these and other market classes provide a third of the daily dietary protein in some cultures, particularly in Africa, Asia, and developing nations in the Americas....
Water scarcity during summer becomes a serious problem in the Pacific Northwest, threatening forage production provided to livestock. Annual forages show great potential in handling drought because of their flexibility in seeding date and short growing season, and can shift the production to periods of feed shortage and fill the...
This work set out to examine the potential contribution of five aliphatic lactones, γ-nonalactone, γ-decalactone, γ-dodecalactone, δ-decalactone and δ-dodecalactone to stone fruit aroma in beer. This work consists of three related studies; lactone olfaction thresholds, additive/synergistic aroma effects and a gas-chromatography-mass-spectrophometry method of analysis. First was the determination of these...
The Asian noodle market is responsible for the increased volume of wheat
imported to that region in recent years. Soft white wheat produced in the Pacific
Northwest is mainly used for baked products, whereas an Australian wheat,
Australian Standard White, is preferred for noodles. To enter this market soft
white-wheat...
Pre-harvest sprouting in wheat costs farmers millions of dollars every year. Pre-harvest sprouting tolerance (PST) has minimized this problem, but improvement of PST is still necessary. Synthetic hexaploid wheats (synthetics) have been used as sources of
genes coding for many useful traits. Two studies evaluated the PST of a synthetic...
To identify novel host genetic resistance to eastern filbert blight, caused by the fungus Anisogramma anomala (Peck) E. Muller, ninety European hazelnut {Corylus avellana L.) varieties and interspecific hybrids (with C. americana Marsh, or C. colurna L.) were screened for response to the eastern filbert blight pathogen after inoculation in...
The advanced backcross-quatitative trait loci (AB-QTL) breeding method was employed on snap bean (OR 91G x PI433251B) and dry bean (M0162 x PI433251B) interspecific populations to transfer resistance QTL from resistant donor parent Phaseolus coccineus into P. vulgaris. For OR 91G x PI433251B, analyses produced nine linkage groups corresponding to...
A biosystematic investigation of Cryptogramma section
Cryptogramma in western North America has been directed towards
resolution of two separate taxonomic questions.
Results of this research support the hypothesis that a
previously undescribed diploid (2n = 30 II) taxon, C. cascadensis, is
present along with the common and widespread C. acrostichoides....
Cephalosporium stripe (Cephalosporium gramineum) is an important disease limiting adoption of conservation tillage practices in the Pacific Northwest. The disease can cause severe loss of grain yield and quality in winter wheat (Triticum aestivum L.). Modified cultural practices can reduce disease incidence, but are not always dependable because of variation...
White mold, caused by Sclerotinia sclerotiorum (Lib.) de Bary, results in severe losses in the production of common bean, Phaseolus vulgaris, especially snap bean varieties. Advanced backcross QTL analysis was used to identify quantitative trait loci for resistance to white mold in an interspecific cross of P. vulgaris and P....
Stripe rust (Puccinia striiformis f. sp. tritici) and Septoria tritici blotch (Zymoseptoria tritici) are a constant and significant threat to wheat production, significantly reducing wheat quality and yield. Wheat is responsible for 20% of the world’s human calorie intake, and wheat production must increase to supply the demand of the...
Wheat (Tritium aestivum) is an extremely important crop worldwide. It accounts for almost one quarter of the calories consumed each day by more than one third of the world’s population, and is grown over more land area than any other crop. Wheat breeding programs constantly strive to increase or maintain...
Green bean flavor has been studied since the 1960’s to better understand Blue Lake flavor in processed green beans in Oregon. Research by Stevens and colleagues showed that Blue Lake flavor could be reconstituted in a bland bean by adding 0.4ppm of 1-octen-3-ol and 1.6ppm of 3-hexen-1-ol. These two volatile...
When hops are added to beer, varying degrees of hoppy aroma persist in the finished beer as a result of a number of factors. Dry-hopping is a technique whereby hops are added to beer post-fermentation to leverage the maximum aroma potential of the hop essential oils while minimizing bitterness contribution...
Wheat (Triticum aestivum L.) is one of the major crops produced in the U.S. Pacific Northwest, a region known for its wheat production for international export. Wheat production in the region is threatened by diseases such as Cephalosporium stripe and stripe rust. Cephalosporium stripe is a vascular wilt disease of...
Imazamox-resistant wheat (Clearfield®) cultivars carry the Imi1 gene, which confers resistance to the imidazolinone (IMI) herbicide imazamox. Imazamox provides selective control of jointed goatgrass and other weeds in IMI-resistant wheat. Imi1 gene flow between IMI-resistant wheat and jointed goatgrass may occur via hybridization and backcross events. In 2009 and 2010,...