Phytophthora root rot decreases availability and quality of rhododendrons produced in the USA. Symptoms of Phytophthora root rot include root necrosis, leaf chlorosis, stunting, and permanent wilt. The purpose of this thesis was to better understand the impact of root damage, soil moisture, nitrogen fertilizer application, and pathogen species on...
BACKGROUND: Oregon produces 99% of the hazelnuts grown in the United States. The key pest threatening commercial hazelnut orchards in Oregon is Cydia latiferreana (Tortricidae), filbertworm moth (FBW). Currently, most growers control FBW with one to two applications of esfenvalerate (Asana XL), a broad spectrum pyrethroid. Pheromone mating disruption is...
Hibiscus and lilacs (Syringa spp.) are economically important nursery crops in the US that accounted for 4.5 million units ($30 million) and 2 million units ($20 million), respectively (USDA, 2016). To maintain and expand the market share of ornamental plants such as lilacs and Hibiscus, novel performance, floral ornamental value,...
Grape powdery mildew (GPM, causal agent Erysiphe necator) is the most economically important disease of grapevine in the Western U.S. Low levels of GPM infection on clusters (1-5%) can negatively affect wine sensory quality, so intensive fungicide programs are common. This may lead to problems like excessive fungicide use and...
The water status of grape vine throughout the growing season is a primary determinant of vine vigor and berry composition. The concentrations of volatile compounds and precursors in grape berries are highly influenced by viticultural practices. Imposing a water deficit on the vine during berry development is an important vineyard...
Hazelnut is one of the most important nuts in worldwide production and the European hazelnut (Corylus avellana L.) is the most economically important of the 11 recognized hazelnut species. Development of new cultivars is continuous, with emphasis on better nut quality, high yield and disease resistance. Hazelnuts are highly heterozygous,...
Strawberry is economically the most important berry crop grown worldwide and breeders are continuously striving to develop improved cultivars. So far, marker assisted breeding (MAB) in strawberry has been limited to the private sector. However, loci controlling some traits of economic importance such as perpetual flowering (PF) and soluble solids...
Strawberry is one of four crops included in the USDA-NIFA Specialty Crop Research Initiative-funded RosBREED project along with apple, peach, and cherry. Phenotyping strawberry for specific horticultural and commercial traits is important to identify associations with genotypic marker(s). This process is the first step in translating genomic knowledge into enhanced...
Cuphea is an herbaceous genus having species whose seed
storage lipids are predominantly medium-chain triglycerides (MCTs).
Cuphea lanceolate Ait, and Cuphea viscosissima Jacq. are central to
the breeding of Cuphea as a new commercial source of MCTs. The
objectives of this thesis were to develop a reliable method to
extract...
The occurrence of seed-producing wheat x jointed goatgrass hybrids in infested wheat fields suggests the possibility of gene flow between the two species. This study investigates 'Madsen' wheat x jointed goatgrass F₁ and reciprocal backcross derivatives produced in experimental field plantings. Electrophoresis of the high molecular weight (HMW) glutenin seed...
Single nucleotide polymorphisms (SNPs) are the most common DNA polymorphisms in plant and animal genomes. SNPs were identified in the allele sequences of up to 12 sunflower (Helianthus annuus L.) genotypes for a genome-wide sample of 81 loci originally mapped using restriction fragment length polymorphism (RFLP) markers. The RFLP loci...
Domesticated forms of wheat exhibit traits that have increased their adaptation
to cultivation by humans. Some of the most critical adaptive differences involve
changes to morphological features that make the crop easier to harvest like ear rachis
stiffness (brittle to non-brittle rachis) and the ease with which the seed is...
The easy picking characteristic, expressed as low pod detachment force (PDF),
offers a way to decrease pod damage in bush green beans mechanically harvested for
processing and fresh market, and makes hand picking easier and faster. This study was
undertaken to examine inheritance in a cross of two green bean...
Nuclear DNA flow cytometry was used to differentiate ploidy level and determine nuclear DNA content in Rubus. Nuclei suspensions were prepared from leaf discs of young leaves following published protocols with modifications that included: increasing the stain concentration, adding the stain after the RN ase treatment instead of adding it...
It is often perceived that late maturity of grape gives a more complex aroma
profile to Pinot noir wine, however, there is little understanding of the basic flavor
chemistry of grape maturity on wine aroma. The aroma contributing compounds in
Pinot noir were first identified by aroma extract dilution analysis...
Sclerotinia sclerotiorum (Lib.) de Bary is a necrotrophic pathogen capable of causing white mold, a severe disease in common bean. White mold is of particular concern to the Oregon snap bean processing industry, where processors allow less than
3% incidence in harvested shipments. Breeding for white mold resistance in beans...
The European hazelnut (Corylus avellana L.) is a tree nut crop that is important in Oregon, which produces 99% of the United States’ hazelnuts but only 5% of the world’s supply. In order to maintain this market share, farmers in Oregon need cultivars that produce high quality nuts, mature early,...