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Pre-Breeding to Improve Yield and Disease Resistance of Hard Red Winter WheatBarry, Dylan Mitchell January 2020 (has links)
Challenges to growing winter wheat in North Dakota include winter temperature and disease pressure. Fusarium head blight (FHB) is a devastating disease that necessitates breeding for resistance. In the NDSU breeding program FHB resistance genes are often associated with a decrease in performance. This study used single seed descent to advance lines while maintaining a near random population. Early generation (F4) selection focused heavily on yield and the presence of FHB resistance quantitative trait loci to develop winter wheat lines with FHB resistance and high yield.
Stripe rust is a fungal disease that is becoming increasingly problematic in North Dakota. To assess the available stripe rust resistance in the NDSU winter wheat germplasm, two sets of diverse breeding lines were used for stripe rust resistance phenotyping and genotyping by sequencing. The phenotype and genotype data were then used to locate resistance genes through genome wide association study.
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Analyses of Arabidopsis Yellow Stripe-Like (YSL) Family of Metal TransportersChu, Heng-Hsuan 01 February 2010 (has links)
Iron is one of the most important micronutrients used by living organisms. Iron is frequently a limiting nutrient for plant growth, and plants are a major source of iron for human nutrition. The most prominent symptom of iron deficiency in plants is interveinal chlorosis, or yellowing between the veins, which appears first in the youngest leaves. Iron deficiency anemia (IDA) is the number one human nutritional deficiency worldwide. In order to solve the problem of iron deficiency, it is desirable to breed plants that have increased iron in those parts that are consumed by humans. To do this, we must first understand the molecular basis of Fe uptake, transport, and storage in plants. In soil, iron is quickly oxidized to Fe(III), and Fe(III) is relatively insoluble, thus difficult for plants to obtain. Our lab has been working on metal ion homeostasis mechanisms in plants and the ultimate goal of our research is to understand the mechanisms by which plants maintain the correct levels of iron, zinc and copper in each cell and tissue. The Yellow Stripe-like (YSL) family of proteins has been identified based on sequence similarity to maize Yellow stripe 1 (YS1). YS1 transports Fe(III) that is complexed by phytosiderophores (PS), strong Fe(III) chelators of the mugineic acid family of compounds. Non-grass species of plants neither make nor use PS, yet YSL family members are found in non-grass species including Arabidopsis thaliana. YSLs in non-grasses have been hypothesized to transport metals that are complexed by nicotianamine (NA), an iron chelator that is structurally similar to PS and which is found in all higher plants. In this dissertation, Arabidopsis YSL1 and YSL3 are demonstrated to be important in iron transport and also responsible for loading Fe, Cu, and Zn from leaves into seeds. Arabidopsis YSL4 and YSL6 are demonstrated to be involved in iron transport and metal mobilization into seeds. The transport function of Arabidopsis YSL1 and YSL2 are shown be partially overlapping to the function of Arabidopsis YSL3 in vegetative structures, but distinct in reproductive organs. Arabidopsis YSL3 and YSL6 are shown to have distinct functions in planta.
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FR‐H3 : a new QTL to assist in the development of fall-sown barley with superior low temperature toleranceFisk, Scott P. 01 December 2011 (has links)
Fall-sown barley will be increasingly important in the era of climate change due to higher yield potential and efficient use of water resources. Resistance/tolerance to biotic and abiotic stresses will be critical. Low temperature is an abiotic stress of great importance. Resistance to barley stripe rust (incited by Puccinia striifomis f. sp. hordei) and scald (incited by Rhynchosporium secalis) will be important in higher rainfall areas. Simultaneous gene discovery and breeding will accelerate the development of agronomically relevant germplasm. The role of FR-H1 and FR-H2 in low temperature tolerance (LTT) has been well documented. However the question still remains: is LTT due only to FR-H1 and FR-H2 or are there other, undiscovered, determinants of this critical trait? We developed two doubled haploid mapping populations using two lines from the University of Nebraska (NE) with superior cold tolerance and one line from Oregon State University (OR) with good malting quality and disease resistance: NB3437f/OR71 (facultative x facultative) and NB713/OR71 (winter x facultative). Both were genotyped with a custom 384 oligonucleotide pool assay (OPA). QTL analyses were performed for LTT, vernalization sensitivity (VS), and resistance to barley stripe rust and scald. Disease resistance QTL were identified with favorable alleles from both NE and OR germplasm. The role of VRN-H2 in VS was confirmed and a novel alternative winter allele at VRN-H3 was discovered in the Nebraska germplasm. FR-H2 was identified as a determinant of LTT and a new QTL, FR-H3, was discovered on chromosome 1H that accounted for up to 48% of the phenotypic variation in field survival at St. Paul, Minnesota, USA. The discovery of FR-H3 is a significant advancement in barley LTT genetics and will assist in developing the next generation of fall-sown varieties. / Graduation date: 2012
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Genetics of resistance to leaf and stripe rust diseases in the spring wheat 'Amadina'Nyori, Peter Michael Bulli January 1900 (has links)
Doctor of Philosophy / Department of Agronomy / Allan K. Fritz / In this research, a recombinant inbred line (RIL) population derived from cross between a leaf rust- and stripe rust-susceptible spring wheat ‘Avocet S’ and a slow leaf- and stripe-rusting resistant spring wheat ‘Amadina’ was used to postulate and map leaf rust seedling resistance genes, identify quantitative trait loci (QTL) for slow-rusting resistance against leaf and stripe rust, and study slow leaf-rusting components, latent period and infection frequency. Two known Lr genes (Lr23, and Lr26) were identified to be present in ‘Amadina’ through gene postulation, pedigree, cytogenetic, and polymerase chain reaction analyses. One unknown gene associated with seedling resistance was also mapped on chromosome 1BL. In greenhouse experiment, it was estimated that at least five genes conditioning final disease severity (FS) and latent period (LP), and four genes conditioning infection frequency (IF), segregated in the population. Correlations between LP and FS, and LP and IF were moderately negative, and that between IF and FS was moderately positive, indicating inter-dependence of the traits. Two QTL on chromosomes 1BL and 6BL were associated with LP and FS, and three QTL on chromosomes 1BL, 6BL and 2DS were associated with IF. Segregation of the RIL population in field experiment indicated that there were at least four and three adult plant resistance (APR) genes involved in resistance for leaf and stripe rust. Six QTL on chromosomes 3AL, 4AL, 1BL, 5BL, and 7BL were associated with APR for leaf rust, and seven QTL on chromosome 4AL, 5AL, 1BL, 2BL, 4BL, 5BL, 2DL, and 4D were associated with APR for stripe rust. Our results indicated that the major portion of genetic variability for slow-rusting resistance was additive gene action, and, to some extent, epistasis. In this research, we also explored the utility of remote sensing and geographic information systems (GIS) and analytical operations to discriminate leaf rust pustules from other parts of leaf and to accurately determine pustule size in ‘Amadina’ and ‘Avocet S’.
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Logistic regression models to predict stripe rust infections on wheat and yield response to foliar fungicide application on wheat in KansasEddy, Rachel January 1900 (has links)
Master of Science / Department of Plant Pathology / Erick D. DeWolf / Stripe rust, caused by Puccinia striiformis f. sp. tritici, historically has been a minor problem in the Great Plains. However, Kansas had significant losses due to stripe rust in 2001, 2003, and 2005. Recent research on the population of P. striiformis suggests changes in the fungal population may have been responsible for these epidemics. The objectives of this research were to determine conditions that are favorable for the infection of P. striiformis f. sp. tritici isolates from the current population and develop models to predict infection events. Two week old potted seedlings were inoculated with an isolate of P. striiformis and exposed to ambient weather conditions for 16 hours. Results of this bioassay were used to develop logistic regression models of infection. Models using hours at relative humidity >87%, leaf wetness, and mean relative humidity predicted infection with 93%, 80%, and 76% accuracy. Future research will use these results to determine weather patterns that influence the probability of stripe rust epidemics and to facilitate the development of regional prediction models for stripe rust.
Foliar diseases of wheat result in an average yield loss of 7.8% in Kansas. Although it is possible to reduce these losses with foliar fungicides, the yield increases resulting from these applications may not justify the additional costs. The objective of this research was to develop models that help producers identify factors associated with disease-related yield loss and the profitable use of foliar fungicides. Data were collected for two years at three locations in central Kansas to determine yield response to fungicide application on eight varieties with varying degrees of resistance. Logistic regression was used to model the probability of a yield response >4 bushels per acre based on disease resistance of a variety, historical disease risk, and in-season disease risk. The accuracy of the resulting prediction models ranged from 84% to 71%. A model combining in-season disease risk and variety resistance was most accurate. The prediction accuracy of the model was 79% when tested with an independent validation dataset. In the future, these models will serve as educational tools to help producers maximize profit and productivity.
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Ordre de rayure des cuprates supraconducteurs dans le modèle de HubbardMercure-Boissonnault, Pierre January 2015 (has links)
Ce mémoire contient l'essentiel de la recherche de Pierre Mercure-Boissonnault sur l'ordre de rayure dans les cuprates supraconducteurs. Cette recherche consistait à vérifier à l'aide du modèle de Hubbard et de méthodes numériques (VCA et CDMFT) si l'ordre de rayure est présent dans les plans cuivre-oxygène de ces matériaux et comment l'ordre de rayure interagit avec la supraconductivité. De plus, plusieurs amas différents sont utilisés dans le but de permettre l'observation de différentes formes d''ordre de rayure (centré sur les sites, centré sur les liens et diagonal). Finalement, les paramètres du modèle de Hubbard sont modifiés afin d'observer l'effet sur l'ordre de rayure par rapport à l'antiferromagnétisme.
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(Un)Perfect : Breaking the rules in textile printingFredin, Lisa January 2016 (has links)
This work explores the techniques of printing and preparation, in combination with technical mistakes. It aims to show how to use technical mistakes in different printing and preparation techniques as a design method to find accidental aesthetic expressions using the stripe as a tool to enhance and clarify the methods modification. The method confronts today’s textile industry by showing how these mistakes could develop into new expressions within textile design when fast -fashion is no longer an obligation. The stripe is a common shape, and is explored to clarify the method ans show how different techniques can change the stripes in various ways. This resulted in to three pieces each representing a technique; one transfer printed, one digital printed and one with the starting point in screen print. They present examples of how more time for developing mistakes in textile design can lead to development of the common shape of a stripe, broaden the technical limitations, and give a value to mistakes in the textile industry. By taking the method further more mistakes could be developed, and how to produce the developed designs in the industry could be investigated.
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Real-Time Part Position SensingGordon, Steven J., Seering, Warren P. 01 May 1988 (has links)
A light stripe vision system is used to measure the location of polyhedral features of parts from a single frame of video camera output. Issues such as accuracy in locating the line segments of intersection in the image and combining redundant information from multiple measurements and multiple sources are addressed. In 2.5 seconds, a prototype sensor was capable of locating a two inch cube to an accuracy (one standard deviation) of .002 inches (.055 mm) in translation and .1 degrees (.0015 radians) in rotation. When integrated with a manipulator, the system was capable of performing high precision assembly tasks.
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QTL mapping of pre-harvest sprouting and stripe rust resistance in wheat cultivars Danby and TigerShao, Mingqin January 1900 (has links)
Doctor of Philosophy / Department of Agronomy / Guihua Bai / Guorong Zhang / Wheat yield and quality is influenced by many abiotic and biotic environmental factors. Pre-harvest sprouting (PHS) occurs when physiologically matured spikes are exposed to wet field conditions before harvest, which results in seed germination and causes significant losses in yield and end-use quality. Wheat stripe rust is one of the most important biotic factors reducing grain yield and quality. To investigate the genetic basis of the resistance to PHS and stripe rust in hard white winter wheat cultivars Danby and Tiger and develop molecular markers for marker- assisted breeding, a double haploid (DH) population, derived from those two cultivars, was genotyped with simple sequence repeats (SSR) markers and simple nucleotide polymorphism (SNP) markers. This DH population was assessed for resistance to PHS and stripe rust in both greenhouse and field experiments. For PHS, one major resistant quantitative trait locus (QTL) was consistently detected on the short arm of chromosome 3A in all three experiments conducted and explained 21.6% to 41.0% of the phenotypic variation (PVE). This QTL is corresponding to a previously cloned gene, TaPHS1. A SNP in the promoter of TaPHS1 co- segregated with PHS resistance in this mapping population. Meanwhile, two other QTLs, Qphs.hwwg-3B.1 and Qphs.hwwg-5A.1, were consistently detected on the chromosome arms 3BS and 5AL in two experiments. These two QTLs showed significant additive effects with TaPHS1 in improving PHS resistance. For stripe rust, three major QTLs were consistently detected in four out of six environments for infection type (IT) or disease severity (DS). Two of them, QYr.hwwg-2AS1 and QYr.hwwg-4BL1, contributed by the Danby allele explained up to 28.4% of PVE for IT and 60.5% of PVE for DS. The third QTL, QYr.hwwg-3BS1, contributed by the Tiger allele, had PVE values up to 14.7% for IT and 22.9% for DS. QYr.hwwg-2AS1 and QYr.hwwg- 4BL1 are likely the same resistance genes reported previously on chromosome arms 2AS and 4BL. However, QYr.hwwg-3BS1 might be different from the reported gene cluster near the distal end of 3BS where Yr57, Yr4, Yr30 and Sr2 were located. Significant additive effects on reducing IT and DS were observed among these three major QTLs. In order to pyramid multiple QTLs in breeding, user-friendly Kompetitive allele specific PCR (KASP) markers were successfully developed for several QTLs identified in this study. The QTLs and their interactions found in this
study together with those novel flanking KASP markers developed will be useful not only for understanding genetic mechanisms of PHS and stripe rust resistance but also for marker- assisted breeding to improve wheat resistance to PHS and stripe rust by gene pyramiding.
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Creating realistic hair in Autodesk MayaLudwigsson, Jonas January 2013 (has links)
This thesis work focuses on how to create realistic looking hair using only the vanilla version of Autodesk Maya. It describes two approaches, the widely used polygon-stripe based technique and the Maya built-in nHair. It also evaluates these two approaches in terms of ease of implementation, production speed and quality of final results. The conclusion is that nHair has the potential to produce realistic looking hair but contains various bugs and is not optimized at the current stage, while the polygon-stripe based approach is robust and flexible but the realism of rendering results is heavily dependent upon the skill level of artists.
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