Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 18 of 18 for “"Polyploids"”.
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Navigating through the uncertainty of genotyping-by-sequencing data in polyploids
… genomics studies in non-model species, including polyploids. Variant and genotype calling methods have been established for autopolyploids but for a species with a complex genome, such as sugarcane, the level of uncertainty within GBS data increases making trait mapping difficult. Furthermore, …
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Molecular, cytogenetic, anatomical, and morphological variations associated with polyploids of prairie cordgrass
… and ploidy level. Genetic diversity in polyploids has resulted in variation in the number of silver stained NORs (AgNORs) on chromosomes at metaphase. The distribution patterns of AgNORs in metaphase cells of tetra- and octoploids appears to reflect changes in ploidy. Two populations of …
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Assessing the impact of genotype calling methodologies on genome wide association studies in polyploids and evaluating key yield traits of Miscanthus sacchariflorus
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2025-05-01
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Micropropagation of Begonia and a study of genome stability in Begonia rex
… treatment have been cultured and prove stable. Polyploids produced as variants from irradiation treatment have been subcultured but prove unstable. Media for the induction and proliferation of callus are outlined. The influence of callus subculture and aging on the stability of the B. rex genome …
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The Role of Polyploidy in Phenotypic and Genomic Evolution in the Shy Monkeyflower, <i>Mimulus sookensis<i>
… does chromosome pairing during meiosis in allopolyploids affect the magnitude of genetic variation?, (2) How does the genome of polyploids evolve following formation, and what genetic mechanisms govern this evolution?, and (3) How does genetic and genomic evolution in polyploids affect …
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Understanding How Whole Genome Duplication in Plants Impacts Herbivore-plant Interactions
… In particular, studies of herbivory on polyploids have primarily focused on established polyploid plant populations. Although this approach has yielded exciting results that suggest WGD affects insect herbivores feeding on polyploids, this approach also confounds the effects of WGD and …
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The Effects of Whole Genome Duplication on Functional Traits and Interactions With Arbuscular Mycorrhizal Fungi
… plants have shown that early generation polyploids, or "neopolyploids", should experience high extinction rates due to a population demographic disadvantage. A major gap in understanding why established polyploids are so prevalent despite theoretically high extinction rates is that we …
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The Effects Of Whole Genome Duplication On Functional Traits And Interactions With Arbuscular Mycorrhizal Fungi
… plants have shown that early generation polyploids, or “neopolyploids”, should experience high extinction rates due to a population demographic disadvantage. A major gap in understanding why established polyploids are so prevalent despite theoretically high extinction rates is that we …
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The biosystematics of pteridophytes: aspects of morphology and reproductive biology of some epiphytic ferns
… reproduced by intergametophytic mating whereas polyploids reproduced by either intragametophytic selfing or intergametophytic mating;Genetic load, antheridiogen, clone-formation and perennial habit are complexly interwoven determinants of reproductive mode. Genetic load both results from and …
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Control of gene expression by cell size
… Specifically, whether the enlarged cell size of polyploids causes differential gene regulation has not been investigated. In this thesis, I present the evidence for a size-sensing mechanism that alters gene expression in yeast. My results indicate a causal relationship between cell size and gene …
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The evolution and prevalence of reproductive assurance in the genus Lachenalia
… reproductive assurance, including intraspecific polyploids, vegetative reproduction and self-compatibility. Of the 27 study species, 20 were found to be self-compatible and four were capable of autonomous self-pollination. Pollinator-dependent species were found to have more attractive floral …
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Systematics and Biogeography of South American Tripsacum
… more common in the Indian subcontinent and polyploids increasing outward, suggesting a migration of the Andropogoneae out of this assumed center of origin. Since Tripsacum is absent from the Old World, the progenitor of this genus probably migrated to the New World (central Mexico) across …
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Polyploidy in Saccharomyces cerevisiae leads to the loss of cell cycle control in stationary phase
… in Saccharomyces cerevisiae. These newly formed polyploids do not grow abnormally during exponential growth. Furthermore, they are not increased or decreased in their sensitivity to a variety of stresses including oxidative stress, high osmolarity, salt stress, toxic ions, and growth at high …
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Analysis of phytochrome signaling pathways in Zea mays
… contain only three members, phyA-phyC, although polyploids may have multiple homeologs of each. Studies in Arabidopsis have shown that phytochromes primarily transduce light signals via interaction with PIFs (phytochrome interacting factors), a sub-family of bHLH proteins. The recent whole genome …
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Molecular Systematics of <i>Isoëtes</i> (Isoëtaceae) in Eastern North America
… through allopatric speciation, and fertile allopolyploids derived from whole genome duplication following primary hybridization. Phylogenies inferred from whole chloroplast genome DNA sequences using maximum-likelihood and Bayesian inference were fully resolved with high support. Ancestral state …
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Molecular evolution following allopolyploidization in Gossypium
… unique ways in which natural selection acts on polyploids and furthers our understanding of why polyploidy may be such an important and widespread evolutionary phenomenon in plants.
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Cytology, Mode of Reproduction, and Forage Quality of Selected Species of Brachiaria Griseb. (Chromosome Numbers, Fiber Structure, Pachytene Analysis, Apomixis)
… tropics. Most of the species investigated are polyploids of the basic chromosome number x = 9. Apomixis is the predominant mode of reproduction within the genus. To define chromosome behavior during meiosis and mode of reproduction, a small but diverse Brachiaria collection was assembled. …