On a global scale, potato (Solanum tuberosum L.) plays an important role in tackling the threat of food insecurity due to its high yield and broad global acceptance. However, pathogens threaten potato production, causing direct yield loss and rendering potatoes tubers unmarketable. Breeding new cultivars that carry multiple resistances is...
Bacterial blight (Xanthomonas arboricola pv. corylina) (Xac) of hazelnut (Corylus avellana L.) was described first in Oregon in 1915 and is now recognized as a damaging disease of young hazelnut trees worldwide. Stressed hazelnut trees in conditions such as planting on marginal sites, and trees between 1 and 4-years-old are...
Hybridization, polyploidy, and apomixis have made phylogenetic estimation in Rubus challenging. I used target capture to sequence approximately 1000 low copy nuclear loci and the chloroplast genome for 94 accessions representing the genus Rubus and distributed worldwide. Species phylogenies were estimated using two coalescent based methods, ASTRAL-II and SVDQuartets, and...
Lilacs are a group of ornamental trees and shrubs in the Oleaceae family consisting of 22 to 30 species. There are six series within genus Syringa: Pubescentes, Villosae, Ligustrae, Ligustrina, Pinnatifoliae, and Syringa. Fertility and cross-compatibility among cultivars, species, and series have yet to be formally investigated. Over three years,...
Corylus avellana L. is a global commodity and a valuable crop for the U.S. Pacific Northwest. A tremendous amount of work has been put into the development of healthy disease free, high yielding and tasty hazelnuts for the in-shell and confectionary markets. Clonal propagation is required to provide nursery trees...
Higher grain yield is a key objective in barley (Hordeum vulgare. L) breeding.
Despite extensive research on the genetics of yield and its components, selection for
yield per se is still the most extensively employed because of negative relationships
among components, modest correlations between yield and any particular component,
and...
Cultivated meadowfoam (Limnanthes alba Benth.) is an annual oil seed crop native to southern Oregon. California and British Columbia. The genus Limnanthes is composed of nine species and divided into two sections, Inflexae and Reflexae. The seed oil of meadowfoam is a rich source of erucic acid and several novel...
Pectinmethylesterase (PME) activity in fresh cucumber
fruit was determined. The effects of several cationic
species, temperature, pH, and acetic acid on the activity
of cucumber PME was investigated. The efficacy of
blanching, infiltration with CaCl₂ or acetic acid, and
fermentation with 0 and 40 mM CaCl₂ on inhibition of
cucumber...
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 research is a series of five studies dealing
with various aspects of hazelnut quality:
1. Identification of kernel mold and its incidence among
hazelnut varieties.
2. Seasonal development and composition of kernels.
3. Hazelnut oil composition (fatty acids and
tocopherols) of seventeen varieties.
4. Hazelnut oil composition compared...