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 20 of 45 for “"Petal"”.
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Petal cell shape and flower-pollinator interaction in Nicotiana
Petal epidermal cell shape has been shown to affect pollination success in flowering plants. Conical epidermal cells may increase grip for insect pollinators and enhance flower colouration compared to non-conical cells. Nicotiana (Solanaceae) presents a diverse range of petal cell shapes. …
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Mechanisms of bullseye boundary formation in Hibiscus trionum petal patterning
… cell fate specification is achieved across the petal epidermis remains obscure. Hibiscus trionum is an emerging model system producing flowers with a striking bullseye pattern on the adaxial petal epidermis. Cells in the proximal region are flat, elongated with cuticular striations and …
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Flavonoid diversification in Hibiscus and its impact on petal pattern evolution
… through distinct pigmentation patterns on their petals. While their ecological significance is known, the developmental and evolutionary origins of these patterns remain less understood. In Hibiscus trionum, a new model system, bullseye patterns are formed by flavonoid pigments including …
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FACTORS INFLUENCING A PETAL-BASED FORECASTING SYSTEM FOR SCLEROTINIA STEM ROT OF CANOLA
… relationship between the percentage of canola petals infested with Sclerotinia sclerotiorum and the incidence of sclerotinia stem rot: canopy density; diurnal and other weather mediated fluctuations in petal infestation; and long-term changes in infestation during flowering. Disease incidence …
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Pollinator behaviour and the evolutionary genetics of petal surface texture in the Solanaceae
Conical cells in the petal epidermis are a common trait across the angiosperms, and influence pollinator behaviour and pollination success. This work explores two key aspects of conical cell evolution: firstly, why conical cells are so prevalent across many diverse species, and secondly, why some …
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Population structure and the molecular genetics of petal spot pigmentation in Gorteria diffusa
Petal spots are aggregations of pigmented cells in distinct regions of the petal and are known to function in pollinator attraction across multiple systems. They occur within many plant lineages, but petal spots of the South African daisy species Gorteria diffusa are unusually complex. These …
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'Let There Be One': P.D. East, The Petal Paper and the Civil Rights Movement in Mississippi
… the few depictions of his life and work in The Petal Paper that exist, scholarly or otherwise, are brief and cursory, with the only extended study devoted solely to him containing many inaccuracies, particularly regarding his early life. In addition to establishing the facts of East’s early …
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Understanding the development, evolution, and function of bullseye pigmentation patterns in Hibiscus trionum
… important biotic and abiotic functions. These petal patterns are created by spatial differences in pigmentation, cell shape and texture of the adaxial petal epidermis. The mechanisms controlling formation and evolution of these patterns, and their exact role in plant-animal communication are …
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Mechanisms controlling cell shape patterning in petals
… often exhibit various patterns on their petals. These patterns allow entomophilous plants to attract pollinators and also help them deal with abiotic stress such as UV-levels and water loss. While previous research largely focused on pigmentation patterns, structural patterns created by …
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Polarity establishment and signalling mechanisms controlling patterning in Hibiscus Trionum petals
… and pigments combine with each other to pattern petals surfaces and these patterns can mediate plant-animal communication. Hibiscus trionum flowers produce a striking bullseye pattern by specifying cells with different pigmentation, shape, and texture in different regions of the adaxial petal …
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Evolution and Genetics of Floral Color Polymorphisms in Clarkia gracilis ssp. sonomensis and Erythronium umbilicatum
… are produced in the basal region of the petal. I demonstrated that the cup pigmentation is controlled by an R2R3-MYB transcription factor using transcriptome analysis, gene expression assays and cosegregation examination. I also found that petal pigmentation requires at least four …
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On the molecular pathways supporting the development of structurally coloured cuticle in Hibiscus trionum
… of the proximal adaxial part of Hibiscus trionum petals revealed the presence of structural colours. They are mainly characterised by the specific reflection of blue and UV-light in an angle dependant manner (also known as iridescence). Further observations of the cuticle showed the presence of …
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Role of KNOX genes in the evolution and development of floral nectar spurs
… from an abaxial bulge formed on the ventral petal relatively late in petal morphogenesis. However, spur development is progenetically curtailed in the short-spurred orchid D. viridis. In each case spur development involves class 1 KNOTTED1-like homeobox (KNOX) proteins. KNOX gene expression …
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Fantasia Nirvana
… East Asia. The piece mainly has two themes: the petal, and a shower of flower petals. The composer chooses to represent her vision about the Sutra.
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'n Ondersoek na die invloed van 8-hidroksikinoliensulfaat en n-6-bensielaminopurien op enkele aspekte van veroudering by angelierblomme
… of the individual free amino acids in senescing petal tissue was examined as well. The rate of 14co2 production from a-alanine-u- 14c solution applied in presence of the preservatives, during incubation of petal and receptacle tissue, was determined. This was done to elucidate the effect of these …
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Grip, slip, petals, and pollinators: Linking the biomechanics, behaviour and ecology of interactions between bees and plants
The ability to grip on petal surfaces is of crucial importance for the interactions between bees and flowers. In this thesis, I explore the biomechanics of attachment and morphological diversity of bee attachment devices, linking this to the behavioural ecology of bee interactions with flowers. …
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A revision of the South African species of Holothrix Rich. ex Lindl. (Orchidaceae)
… species is illustrated by a drawing of sepal, petal and lip. Those species available in liquid preservative have the whole flower drawn as well, while those where a live plant could be obtained are illustrated in full, with a drawing of the whole plant, leaves, column and pollinia. In those …
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Experimental investigation of tearing fracture in sheets under quasi-static loading
… accurate, quasi-static method of recreating the petalling phase of blast and projectile failure in metal sheets, based on a modified trousers- type test. By using the trousers-type fracture test the overall plastic bending kinematics of the fractured petal is preserved, as well as the mixed mode …
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Planetesimal Belts in Misaligned Wide Stellar Binaries
… of 88◦. It found that the EKM imprinted a petal shaped structure on the narrow discs due to the disc particles librating between a fixed set of values for the longitude of pericentre which depend only on the initial inclination. As the evolution of the wide disc is the superposition of the …
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