Seed piece to plant transmission of the potato late blight pathogen, Phytophthora infestans, occurred with isolates of the clonal lineages US-8 in Oregon and US-11 in Washington in field trials. Average transmission rate across potato cultivars was 0.5 and 2.4% with US-8, and 0.8 and 1.0% with US-11 in 1999 and 2000, respectively. Transmission rate with US-8 was 2.3% for Russet Burbank (RB) in 1999 and 1.7, 0.7, 4.3, 7.6 and 0.5% for Bannock, Bzura, Ranger, Russet Norkotah (RN), and Umatilla, respectively, in 2000. Transmission rate with US-11 in 1999 was 0.5, 4.9 and 1.4% for RB, RN, and Shepody, respectively, and 1.7% for RB in 2000. Seedborne inoculum of both clonal lineages significantly affected stand establishment and plant vigor. With US-8, final emergence, emergence rate, and aerial biomass of cvs Kennebec, RB, RN, and Shepody were significantly lower than Bzura in 1999, whereas in 2000, these same responses in Chieftain, Bannock, Ranger, and Shepody were significantly lower than Bzura, Umatilla and RN. With US-11, these same response variables were significantly lower in Kennebec, RN and Shepody compared to Bzura and RB in 1999, and were significantly lower in Bannock, Chieftain, Ranger and Shepody compared to RB and Umatilla in 2000. Plant growth responses of cvs RB and RN grown from seed pieces infected with US-8 or US-11 were evaluated in greenhouse trials. RN was equally susceptible to both clonal lineages whereas RB was more resistant than RN to seedborne inoculum of US-11. Compared to RN its final emergence was higher, emergence rate was faster, aerial biomass was greater, and seed piece decay was lower. US-8 was more aggressive than US-11 on RB. US-8 caused a greater reduction in final emergence, emergence rate, and aerial biomass, and a greater increase in seed piece decay. The two clonal lineages were similar in their aggressiveness on RN. This is the first report of cultivar*clonal lineage*inoculum density interactions for plant growth responses of potato grown from seed pieces infected with P. infestans. / Graduation date: 2002

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 F��� and reciprocal backcross derivatives produced in experimental field plantings. Electrophoresis of the high molecular weight (HMW) glutenin seed proteins, chromosome counts, and morphological studies were used to better understand the genetics of these hybrids, and to provide a baseline for evaluating hybrids collected in natural populations. The HMW glutenin profiles are a useful diagnostic tool because the banding patterns, in the 68-120 kDa molecular weight range, are species-unique (three bands for goatgrass, four bands for wheat) and can be used to trace parentage in the hybrid seed on the basis of band contribution. Experimental hybrids show considerable diversity in banding profiles (9 patterns of three to six bands). Diversity in number of different glutenin profiles and number of subunits per seed decreases in more advanced generations (BC��� and BC���S���). Chromosome counts confirm the direction of the crosses and vary as follows: 35 chromosomes for F���; 36 to 57 for BC���; 28 to 49 for BC���; and 33 to 52 for BC���S���. A chromosome number of 28 suggests that jointed goatgrass (2n=4x=28) was the recurrent backcross pollen donor, while numbers closer to 42 and above point to wheat (2n=6x=42) as the pollen donor. Partial female fertility was found in all generations, as well as full self-fertility in BC��� and BC���S��� plants. Analysis of the HMW glutenin profiles of the progeny seeds verifies that hybridization can go in either direction, with most banding patterns similar to either jointed goatgrass or wheat. The resulting potential for gene flow from wheat to jointed goatgrass calls for continued study of these hybrid derivatives. / Graduation date: 2001

Thesis (M.S.)--Oregon State University, 1983. / Typescript (photocopy). Includes bibliographical references (leaves 69-75). Also available on the World Wide Web.

The focus of this thesis is to explore the influence of market power possessed by seed input companies on rent distribution in an identity preserved production and marketing system. This thesis develops a theoretical model to estimate rent distribution between participants in an identity preserved production and marketing system under constrained production and the elicitation of a premium from market development activities in the presence of a range of seed ownership structures. The thesis employs an empirical model to examine rent distribution of two varieties involved in the Canadian Wheat Boards Identity Preserved Contract Program.<p> The theoretical model demonstrates that market development activities for an identity preserved production and marketing program had a diminished impact on farmers when the seed industry possessed a large degree of market power. The finding of the theoretical model were consistent with that of the empirical model, where the price of certified seed for varieties involved in the identity preserved production and marketing program were priced higher than conventional varieties. The difference in price was found to be greater than the premiums offered by the Identity Preserved Contract Program marketing and/or production contracts for Saskatchewan farmers that received average yields and average prices of grain.

To investigate vascular-plant phylogeny at deep levels of relationship, I collected and analyzed a large set of plastid-DNA data comprising multiple protein-coding genes and associated noncoding regions. I addressed questions relating to overall tracheophyte phylogeny, including relationships among the five living lineages of seed plants, and within two of the largest living gymnosperm clades (conifers and cycads). I also examined relationships within and among the major lineages of monilophytes (ferns and relatives), including their relationship to the remaining vascular plants. Overall, I recovered three well-supported lineages of vascular plants: lycophytes, monilophytes, and seed plants. I inferred strong support for most of the phylogenetic backbones of cycads and conifers. My results suggest that the cycad family Stangeriaceae (Stangeria and Bowenia) is not monophyletic, and that Stangeria is instead more closely related to Zamia and Ceratozamia. Within the conifers, I found Pinaceae to be the sister-group of all other conifers, and I argue that two conifer genera, Cephalotaxus and Phyllocladus (often treated as monogeneric families) should be recognized under Taxaceae and Podocarpaceae, respectively. Systematic error likely affects inference of the placement of Gnetales within seed-plant phylogeny. As a result, the question of the relationships among the five living seed-plant groups still remains largely unresolved, even though removal of the most rapidly evolving characters appears to reduce systematic error. Phylogenetic analyses that included these rapidly evolving characters often led to the misinference of the “Gnetales-sister” hypothesis (Gnetales as the sister-group of all other seed plants), especially when maximum parsimony was the inference method. Filtering of rapidly evolving characters had little effect on inference of higher-order relationships within conifers and monilophytes, and generally resulted in reduced support for backbone relationships. Within the monilophytes, I found strong support for the majority of relationships along the backbone. These were generally congruent with other recent studies. Equisetaceae and Marattiaceae may be, respectively, the sister-groups of the remaining monilophytes and of the leptosporangiate ferns, but relationships among the major monilophyte lineages are sensitive to the outgroups used, and to long branches in lycophytes.

The focus of this thesis is to explore the influence of market power possessed by seed input companies on rent distribution in an identity preserved production and marketing system. This thesis develops a theoretical model to estimate rent distribution between participants in an identity preserved production and marketing system under constrained production and the elicitation of a premium from market development activities in the presence of a range of seed ownership structures. The thesis employs an empirical model to examine rent distribution of two varieties involved in the Canadian Wheat Boards Identity Preserved Contract Program.<p> The theoretical model demonstrates that market development activities for an identity preserved production and marketing program had a diminished impact on farmers when the seed industry possessed a large degree of market power. The finding of the theoretical model were consistent with that of the empirical model, where the price of certified seed for varieties involved in the identity preserved production and marketing program were priced higher than conventional varieties. The difference in price was found to be greater than the premiums offered by the Identity Preserved Contract Program marketing and/or production contracts for Saskatchewan farmers that received average yields and average prices of grain.

Ultra Wide Band (UWB) is a short-pulse electrical signal which is widely used for short distant wireless communication because its low path loss, good immunity to multipath propagation, and high data rate. The reason of using optical fiber as carrier is fiber can bust up the communication capacitance in long distance range because of high capacitance, low loss propagation. Thereby, the technique of UWB signal on fiber has become more and more important. In this work, a novel method using electro-absorption modulation with short termination for interface of optical fiber and generate UWB signal is proposed and demonstrated. The structure is simple.This method don¡¦t need employing any complicated frequency mixer, or complex systems. This work need to generate optical pulse with high energy, which is feded into the EAM. The signal can generate electrical pulse and build electrical field on EAM in the same time. The optical pulse is modulated by the electrical field on EAM. Using this way, we can generate UWB optical signal.

Modules for cotton storage and transport should be constructed with a shape that will resist collecting water to maintain the quality of seed cotton during storage. Meeting this specification requires knowledge of the relationship between the applied compressive force, deformation, and time for seed cotton. Several factors were tested to determine their effects on the height and density of seed cotton during compression, creep loading, and recovery. Models were used to describe these processes. These results were used to develop an algorithm capable of providing information on module shape to the module builder operator. The initial loading density did not affect the compressed density, but a slight effect was observed in the recovered density, due to the weight of the seed cotton. Picker harvested cotton was compressed to a greater density than stripper harvested cotton, but expanded more during recovery, resulting in similar final densities. Multiple compressions increased the density, but this increase was not physically significant after the third compression. Higher moisture content increased the density seed cotton could be compressed to slightly. Viscoelastic behavior was observed; however, the effect on density was small. Both the compression and creep curves were described using mathematical models. A compression model using an asymptotic true strain measure yielded high R2 values; however, some aspect of this process remained unexplained and the equation was limited in its predictive ability. Creep behavior was described using a modified Burgers model. This model was more accurate than the creep model, although a definite trend existed in the creep model residuals. A feedback algorithm was developed based on the observation that the compressed density was primarily dependent on the mass of seed cotton and not the initial density. By measuring the compressed depth of cotton in a module and the hydraulic pressure of the tramper foot cylinder, the resulting shape of the module can be predicted. Improved loading of the module builder is necessary to produce a desirably shaped module. More seed cotton needs to be placed in the center of the module, resulting in a surface that slopes down towards the outer edges.

Thesis (M.S.)--University of Hawaii at Manoa, 2005. / Includes bibliographical references (leaves 128-137).

Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 95-99). Also available on the Internet.