Dissertations / Theses: 'Plant growth and development'

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Wennersten, Fredrik. "STC-Plant Growth and Development, utvärdering av ett läromedel." Thesis, Linköping University, Department of Educational Science (IUV), 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1496.

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Denna uppsats är skriven höstterminen 1997, då ett nytt läromedel började utvärderas i Linköping. Den svenska skolan har sedan en tid haft bristande natur- och teknikundervisning i de lägre årskurserna. Den Kungliga Vetenskapsakademien gav vissa av Linköpings skolor uppdraget att i lärarlag arbeta med ett nytt material, för att kunna se dess fördelar och brister. Materialet heter Science and Technology for Children (STC) och är framtaget av den amerikanska organisationen National Science Resource Center. Sedan utvärderingen av STC har läromedlet bytt namn till NTA (Natur och Teknik för Alla).

Den Kungliga Vetenskapsakademien bad också ett antal lärarkandidater på Linköpings lärarhögskola att hjälpa till med utvärderingen. I denna uppsats behandlas ett av de tre teman som utvärderas i Linköping, nämligen Plant growth and Development, ett tema där man får följa en växts hela livscykel.

Uppsatsen är en studie av de utvärderande lärarlagens arbete. En enkät har delats ut för att kartlägga lärarnas attityder till läromedlet. Vissa åsikter har registrerats vid personliga samtal. Syftet är att se om lärarna tycker att STC är något för den svenska skolan, och om användandet av STC kan motiveras av läroplanen, Lpo94.

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Hay, Elizabeth Irene. "Somatic embryo development and phenotypic variation in an abscisic acid-independent line of Larix x eurolepis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0028/NQ32748.pdf.

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Knecht, Billberger Magnus F. "Plant growth - stoichiometry and competition : theory development in ecosystem ecology /." Uppsala : Dept. of Ecology and Environmental Research, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/200624.pdf.

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Miller, Paul Robert. "Non photosynthetic interactions of bentazone with plant growth and development." Thesis, Nottingham Trent University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327849.

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Khattak, Abdul Mateen. "Development of spectral filters for the regulation of plant growth." Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287598.

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Chatham, Catherine J. "The growth, development and modification of barley seed crops." Thesis, University of Nottingham, 1985. http://eprints.nottingham.ac.uk/13745/.

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A series of field and growth room experiments on winter barley (Hordeum vulgare) L. syn. H. sativum Jessen) were undertaken between 1980 and 1983 at the University of Nottingham School of Agriculture, Sutton Bonington. The aim of this study was to attempt to elucidate those factors which influence the suitability of harvested grain for use as seed. Density, nitrogen fertilizer (both rate and timing) and plant growth regulator applications were used to modify crop growth and development with a view to enhancing the suitability of the grain for seed purposes. It has been shown that the final grain yield and yield components could be manipulated by the judicious use of the inputs examined. However yield component modification was dependent upon the variety used. Consistent increases in seed yield as a result of the husbandry inputs were not always detectable but where alterations to crop growth and development did occur this occasionally resulted in a reduction in total grain yield. None of the PGRs applied significantly or consistently influenced the suitability of the grain for seed purposes. All nitrogen trials were conducted on Index 0 nitrogen sites. However the residual nitrogen may have differed between sites and seasons so confounding the effects of nitrogen treatments. Alterations of both nitrogen rate and timing can be used to modify crop growth patterns. Alteration of sowing density resulted in a change in the grain yield components. Increased sowing density resulted in an increase in total ear number with a concomitant reduction in mean grain number per year. As grain yield was shown to be correlated with grain number per unit area the modification of these two components by sowing density did not necessarily influence final grain yield because of yield component compensation. The seed industry is still divided in its attitude to the desirability or necessity of size graded seeds. However if more emphasis is placed on the production of cereal seed crops the work reported here will help to clarify the possible outcome of desirable modifications to the growth and development of the winter barley crop for seed.

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Bhattacharya, Anjanabha. "Genetic manipulation of plant growth and development by regulating gibberellin biosynethesis." Thesis, University of Nottingham, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491006.

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Gibberellins (GAs) are endogenous plant hormones that control key aspects of growth and development such as seed germination, shoot growth, flower induction and development, and fruit expansion. Chemical growth regulators that modify GA biosynthesis are used extensively in horticulture to modify plant stature, increasing production costs, manpower and associated environmental risks. An alternative strategy is genetic manipulation of GA metabolism in plants to induce similar phenotypic changes.

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Dudley, Penelope. "The role of the mitochondrial HSP70 in plant growth and development." Thesis, University of Sussex, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340855.

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Smith, Hayley L. "Optimisation of light spectral quality to improve plant growth and development." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/44338/.

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The many advantages of light-emitting diode (LED) grow lamps in terms of programmability and energy efficiency make them an attractive replacement for old lighting systems. However, when replacing conventional broad-waveband ‘white’ lighting with narrow-waveband LED lighting it is important to ensure that the system is able to produce plants of an equal or higher quality and yield. In order to choose suitable light ‘recipes’, i.e. combinations of wavelengths for optimal plant growth, we must first understand how light quality affects plant growth and development. The following work explores the role of each part of the light spectrum, both in natural sunlight in canopy environments in the field and glasshouse, and in an artificial light environment in controlled environment growth rooms. It was determined that, blue, green, red and far-red wavebands are all instrumental in the provision of positional signals to the leaf which enable optimisation of plant physiology to light conditions, especially in the canopy environment. A new hypothesis for the role of the blue:green light ratio in whole-canopy water use efficiency is presented. Wavelength-specific effects were observed in hypocotyl elongation, leaf expansion, photosynthetic stoichiometry and absorption of different wavelengths, root architecture, photosynthetic capacity, whole-plant morphology (in terms of biomass partitioning between leaves, stems and roots) and fresh weight yield of stems and leaves. In the glasshouse, it was determined that monochromatic red LED lighting is a suitable alternative for conventional high-pressure sodium light, as it boosted leaf photosynthetic capacity as well as leaf area, fresh and dry weight yield, and was the most efficient light source in terms of ‘crop per watt’. Finally, further applications of the work such as those for commercial horticulture and farming in closed plant production systems are presented, and it is concluded that LED lighting is likely to have a crucial role in the future of global food security.

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Blancaflor, Elison B., Aruna Kilaru, Jantana Keereetaweep, Bibi Rafeiza Khan, Lionel Faure, and Kent D. Chapman. "N-Acylethanolamines: Lipid Metabolites with Functions in Plant Growth and Development." Digital Commons @ East Tennessee State University, 2014. https://doi.org/10.1111/tpj.12427.

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Twenty years ago, N‐acylethanolamines (NAEs) were considered by many lipid chemists to be biological ‘artifacts’ of tissue damage, and were, at best, thought to be minor lipohilic constituents of various organisms. However, that changed dramatically in 1993, when anandamide, an NAE of arachidonic acid (N‐arachidonylethanolamine), was shown to bind to the human cannabinoid receptor (CB1) and activate intracellular signal cascades in mammalian neurons. Now NAEs of various types have been identified in diverse multicellular organisms, in which they display profound biological effects. Although targets of NAEs are still being uncovered, and probably vary among eukaryotic species, there appears to be remarkable conservation of the machinery that metabolizes these bioactive fatty acid conjugates of ethanolamine. This review focuses on the metabolism and functions of NAEs in higher plants, with specific reference to the formation, hydrolysis and oxidation of these potent lipid mediators. The discussion centers mostly on early seedling growth and development, for which NAE metabolism has received the most attention, but also considers other areas of plant development in which NAE metabolism has been implicated. Where appropriate, we indicate cross‐kingdom conservation in NAE metabolic pathways and metabolites, and suggest areas where opportunities for further investigation appear most pressing.

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Weener, Randy L. "A strategy to plant churches throughout the city of Wyoming, Michigan." Theological Research Exchange Network (TREN) Access this title online, 2008. http://www.tren.com.

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Guan, Ming. "Steroids in plant development : effects and possible role of brassinosteroids and estrogens." Thesis, University of Exeter, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328469.

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Spring, Gregory Mark. "The development and application of a field technique for exposing plant communities to elevated concentrations of carbon dioxide." Thesis, University of Sheffield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264747.

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Darwiche, Amal O., and Peter F. Ffolliott. "Effects of Plant Growth Regulators, Nitrogen Fertilization, and Irrigation on Eldarica Pine Seedlings." Arizona-Nevada Academy of Science, 1990. http://hdl.handle.net/10150/296436.

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From the Proceedings of the 1990 Meetings of the Arizona Section - American Water Resources Association and the Hydrology Section - Arizona-Nevada Academy of Science - April 21, 1990, Arizona State University, Tempe, Arizona
Effects of applications of cytokinin-like and gibberellic growth regulators, nitrogen fertilizer, and irrigation on the development of containerized eldarica pine (Pinus brutia var. eldarica) seedlings was studied in a greenhouse for 13 weeks. All concentrations of growth regulators reduced nitrogen content of needles and dry weight of shoots; importantly, medium and high concentrations also adversely affected root collar diameter growth and shoot elongation. Nitrogen fertilization alone was not significant in its effect on seedling development, due probably to the nitrogen-rich nature of the potting medium. It is suggested that contentration is a critical factor when applying growth regulators, as phytotoxicity of seedlings can result at high rates.

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Alvey, Elizabeth. "Investigating the role of DELLAs in the regulation of plant growth and development." Thesis, University of East Anglia, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.445513.

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Jaddoa, K. A. "Effects of chemical growth regulators on plant development and grain yield in barley." Thesis, University of Reading, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370622.

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Carew, James. "Factors affecting vegetative growth and reproductive development in the primocane fruiting raspberry cv. Autumn bliss." Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271195.

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Sandmann, Martin. "Fundamentals for modeling of micro climate, plant growth and plant quality development in field vegetable production below plastic covers." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2015. http://dx.doi.org/10.18452/17200.

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Folienmanagement ist von wirtschaftlicher Bedeutung im Freiland-Gemüsebau im Frühjahr. Aber die Prognose des optimalen Zeitpunktes der Abnahme von Plastik-Abdeckungen vom Bestand ist mit den bereits verfügbaren Mitteln zu ungenau, um die heutigen Anforderungen an die Produktionssicherheit zu erfüllen. Der bislang verwendete empirische Ansatz benötigt aktuelle Referenzmessungen unter den Abdeckungen, welche kostspielig sind. Das Ziel dieser Arbeit war es, die Grundlagen eines mechanistischeren Modellansatzes zu entwickeln, welcher auf dem physikalischen und biologischen Verständnis von Energiehaushalt, Pflanzenwachstum und den Prozessen der Qualitätsentwicklung unter den Abdeckungen beruht, um die zukünftige Produktionssicherheit zu verbessern. Entsprechende Feldversuche wurden durchgeführt, um Daten zum Pflanzenwachstum und Mikroklima unter und über der Abdeckung zu erhalten und neue sowie etablierte Untermodelle zu parametrisieren. Weiterhin wurden Laborversuche zum Verständnis z.B. der optischen Eigenschaften der Abdeckungen, Blätter und des Bodens ausgeführt. Außerdem wurde eine neue Methode zur Bestimmung des Blattflächenindex bei Kopfsalat und Kohlrabi geprüft und für die effiziente Erhebung der Pflanzendaten etabliert (Sandmann et al. 2013). Im Ergebnis können nun verschiedene Prozesse der Gemüseproduktion unter Abdeckungen besser verstanden und mit hinreichender Genauigkeit mathematisch beschrieben werden, z.B. Strahlungshaushalt (Graefe & Sandmann 2014) und Blattflächenwachstum. Die meisten Ziele der Arbeit wurden erreicht. Weitere Arbeit ist vor allem notwendig für die Modellierung der Lufttemperatur unter der Abdeckung und die Entwicklung eines mechanistischen Ansatzes zur Beschreibung der Pflanzenqualität. Hier konnte die Pflanzenqualität wegen der subjektiv beeinflussten Daten nur über einen empirischen Ansatz modelliert werden. Die übliche Erfassung der Pflanzenqualität sollte überdacht werden, um zukünftig möglichst objektive Werte zu erhalten.
Plastic film management is economically of importance for vegetable growing in the field in early spring, but the prediction of the best moment of removal of plastics from the crops is currently too imprecise to fulfill contemporary requirements in production safety. The broadly used approach for prediction is of empirical nature and is depending on current reference data from below covers, which are expensive to gather. The aim of this thesis was to develop the scientific foundations for a more mechanistic model approach, based on the physical and biological understanding of the energy balance, plant growth and plant quality formation process below plastic covers in order to increase future production safety. Field trials at three sites, with two species and several cover materials and removal strategies were carried out to gain data from plants and microclimate beneath and above covers for parameterization of new and established submodels. Additionally, laboratory experiments were performed to understand e.g. the optical properties of plastics, leaves and soil. Furthermore, a new method for determining leaf area index in lettuce and kohlrabi was adopted and established for a more efficient plant data collection (Sandmann et al. 2013). As a result, several processes of vegetable production using plastic covers are now better understood and can be described mathematically and sufficiently precise, e.g. the short wave radiation budget (Graefe & Sandmann 2014) and leaf area growth. Most, but not all aims of the thesis could be achieved. Further work will be necessary according to modeling of air temperature below the covers, leaf gas exchange and the development of a mechanistic approach for plant quality formation. Here, plant quality could only be modelled via an empirical approach, due to subjectively influenced data. Common plant quality data acquisition should be reconsidered to yield as much as possible objective values in the future.

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O'Berry, Nathan Brook. "Individual Experiments to Evaluate the Effects of Plant Population and Planting Date, Cultivar and Plant Growth Regulator Application, and Herbicide and Plant Growth Regulator Application on Cotton (Gossypium hirsutum L.) Growth and Development, Yield, and Fiber Quality." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/33882.

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Cotton (Gossypium hirsutum L.) growth and development, lint yield, and fiber quality are influenced by many management decisions. Three field experiments examining the interaction of plant population and planting date, and cultivar or herbicide and plant growth regulator application on these parameters were conducted in Virginia during 2005 and 2006 and in North Carolina, South Carolina, and Louisiana during specific years. Experiment I: Plant Population and Planting Date Lint yields were highest with populations of 8.9 and 12.8 plants mÂ¯Â² compared to 5.3 plants mÂ¯Â² in Virginia and North Carolina, while in Louisiana the highest yields resulted from populations of 5.8 and 9.5 plants mÂ¯Â² compared to 17.1 plants mÂ¯Â². Earlier planted (1 May) cotton produced higher yields relative to later planted (21 May) cotton in Louisiana, while yield was not influenced by planting date in Virginia and North Carolina. The impact of plant population and planting date on cotton appeared to be influenced significantly by heat unit accumulation. Experiment II: Cultivar and Mepiquat Pentaborate Application Mepiquat pentaborate (MPB) application consistently decreased plant height, HNR, and enhanced maturity for all cultivars, compared to untreated cotton. A trend of decreasing yield with increasing MPB application in Virginia was observed. These data suggests that cotton response to MPB application is influenced by cultivar maturity or fruiting interval. Experiment III: Trifloxysulfuron-sodium and Mepiquat Chloride Application Trifloxysulfuron-sodium (TFS) did not influence vegetative growth, maturity, or yield in comparison to untreated cotton. Mepiquat chloride (MC) application reduced vegetative growth and enhanced maturity in most years. The results of this experiment demonstrate that TFS application does not have the same effects on plant growth as MC application.
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Shearman, Julia. "The regulation of respiration on plant growth and development of Fallopia japonica, Japanese knotweed." Thesis, University of Sussex, 2016. http://sro.sussex.ac.uk/id/eprint/62040/.

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Fallopia japonica, or Japanese knotweed is a rhizomatous perennial herb native to East Asia; most notably Japan, China and Korea. Upon discovery of this species and subsequent import to Europe in the 1840's, it was considered an esteemed ornamental plant – winning the medal for the ‘most interesting new plant of the year' in 1847. F. japonica soon became known as a menace rather than a champion, when it began to spread throughout its new environment, spreading to gardens and nurseries and regenerating from discarded plant fragments. The species ability to cause environmental damage has earnt it a place in the ‘top 100 world's worst most invasive alien species' list. Commercially available herbicides have proven have little effect on F. japonica, and to be successful require many repeat applications. The plant can grow up to 10 cm per day during the early budding and shoot stage and can easily dominate an environment when left unchecked. A key objective of this research was to determine the biochemical pathways of energy generation particularly during the rapid phase of growth with the longer term goal of identifying potential inhibitors of this process which may have commercial opportunities. Very little research is available regarding the biochemistry of growth of F. japonica, thus detailed protocols were required to be established and optimised prior to biochemical investigations. Mitochondrial isolations and following respiratory activity measurements were performed on F. japonica prepared from naturalised plants. Such mitochondrial samples were found to have a very low respiratory rates when compared to mitochondria isolated from other species such as Arum maculatum. This was confirmed following an analysis of the respiratory complexes via electrophoresis, which revealed that all complexes were of low abundance in comparison with other plant species. Transmission electron microscopy also revealed that the numbers and volumes of mitochondria in budding tissue were considerably fewer and larger than those observed in other rapidly expanding plant tissues - providing further confirmation of the respiratory measurements. In an attempt to overcome the small yield associated with mitochondrial isolations, research is also presented on the generation, optimisation and characterisation of suspension cultures from F. japonica explants. Suspension cultures were shown to have almost identical characteristics in terms of mitochondrial protein complement and respiratory capacity as observed in bud and shoot isolations. Preliminary mass spectroscopy data indicated a large proportion of ATP synthase subunits were present in the isolated mitochondrial fractions from leaf, bud, shoot and suspension cultures. Glycolytic analysis of fractions isolated from suspension cultures were also undertaken the outcome of which are discussed in terms of the energy generation pathways within F. japonica and the implications of how such pathways may be controlled.

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Machin, Franklin Qasim. "Development of a system for high throughput screening of agrochemicals affecting plant growth behaviour." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31117.

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Why don’t crop plants grow as fast as they should? In optimal conditions, elite crop varieties routinely outperform those grown in the average field. The vast majority of this reduction in growth activity is due to abiotic stresses such as drought, heat, and nutrient limitation. Abiotic stress reduces plant growth by triggering a reduction of meristem size and causing premature differentiation of proliferating cells. Differentiated cells are no longer able to divide, and smaller meristems have a reduced capacity to restore growth when the abiotic stress passes. We have designed and evaluated a novel high-throughput screening system to identify compounds able to reduce or prevent this premature differentiation in order to retain modest growth capacity in stressful conditions and enable rapid recovery from stress. Such chemicals can be applied to crop plants using existing agricultural methods, and because there is no need for genetic modification, it is widely applicable to many different crop species. Using the novel technique of flow sorting followed by protoplast culture, we have developed a high-throughput automated confocal imaging method to screen chemicals for their effects upon cell differentiation. Meristem protoplasts isolated from the root tips of pROW1:GFP Arabidopsis plants were monitored for differentiation when exposed to different chemicals. To evaluate this system, a library of biologically active small molecules provided by Syngenta was screened against protoplasts and whole plants. Several compounds were identified with the ability to improve Arabidopsis root growth in in vitro growth conditions. Two subsets of these chemicals were identified: a subset of chemicals that improved stress tolerance through modulation of post-meristem differentiation, and a subset of chemicals that improve growth rate by increasing rates of cell division in the root apical meristem. This screening system is able to detect the subset of chemicals that was shown to affect postmeristem differentiation, but not the other subset. No false positives were detected. These results suggest that this single-cell screening system is a powerful, high-throughput method suitable for the detection of molecules for use in crop protection.

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Holmlund, Mattias. "The role of the BLADE-ON-PETIOLE genes in the regulation of plant growth and development /." Umeå : Dept. of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 2008. http://epsilon.slu.se/200869.pdf.

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Spalholz, Hans. "Development of Short Term Storage Techniques for Grafted Vegetable Seedlings." Thesis, The University of Arizona, 2013. http://hdl.handle.net/10150/293734.

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Vegetable grafting confers soil-borne disease resistance through the use of selected rootstocks. Additional costs associated with grafted vegetable seedling propagation limit grower access to this technology. The use of low temperature storage in grafted seedling production reduces labor costs and allows propagators to meet the seasonal and narrow-window demand of growers. For the first part of the experiment 22 genotypes of Solanaceae or Cucurbitaceae seedlings were evaluated in low temperature storage conditions (5 or 12°C). Seedling performance was better in 12°C storage than in 5°C storage. For the second part of the experiment watermelon, the most low-temperature sensitive species found in our first study, was grafted onto two different commercial rootstocks or on to other watermelon seedlings and stored at 12°C for two and four weeks. Both 'Strong Tosa' and 'Emphasis' rootstocks conferred chilling tolerance during storage to watermelon scions, allowing storage of grafted plants for two weeks.

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Hernández, Ricardo. "Growth and Development of Greenhouse Vegetable Seedlings Under Supplemental LED Lighting." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/306916.

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The greenhouse industry is interested in light emitting diodes (LEDs) as a light source supplement to solar light to improve plant growth and development. Before LEDs can be adopted as supplemental light for greenhouse crops, plant responses to LED spectral quality need to be investigated. Tomato and cucumber seedlings were grown under different supplemental blue and red photon flux ratios (B:R ratios) under high (16-19 mol m⁻² d⁻¹) and low (5-9 mol m⁻² d⁻¹) solar daily light integrals (DLIs). The supplemental daily light integral was 3.6 mol m⁻² d⁻¹. A treatment without supplemental light served as a control. Both tomato and cucumber seedlings had increased growth rate and improved morphology when grown under the supplemental LED light compared to the control. However, no significant differences were observed for any growth and morphological parameters measured in this study between the different B:R ratios for both cucumber and tomato transplants under high DLI conditions. Cucumber seedlings showed a tendency to decrease dry mass, leaf number and leaf area under low DLI conditions with increasing B:R ratio. Tomato seedlings did not show any differences between the different B:R ratios under low DLI conditions. Seedlings growth and morphology under supplemental LED light were compared to those under supplemental high pressure sodium (HPS) light. Cucumber seedlings under supplemental HPS light had greater shoot dry mass than those under the supplemental red LED light. Tomato shoot dry mass showed no differences between the HPS and red LED supplemental light treatments. Cucumber seedlings were also grown under supplemental LED pulsed lighting and supplemental LED continuous lighting. Cucumber seedlings showed no differences in shoot dry mass and net photosynthetic rate between the treatments. Collectively, these studies concluded that red LED is preferred for supplemental lighting and the increase of blue light does not offer any benefits unless the efficiency of blue LEDs largely exceeds the red LEDs. The results of this research can be used for fixture development by LED manufactures and as a decision making tool for the adoption of supplemental LED lighting by greenhouse growers.

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Patel, Jigarkumar J. "The Role of Polyamine Uptake Transporters on Growth and Development of Arabidopsis Thaliana." Bowling Green State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1429280174.

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Tibbitts, Spencer A. "Effect of Silicon on Wheat Growth and Development in Drought and Salinity Stress." DigitalCommons@USU, 2018. https://digitalcommons.usu.edu/etd/6925.

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Silicon is a major component of most soils, and is found in significant concentration in plant tissue. Plants vary widely in the amount of silicon they take up, with some plants excluding it, and others using transporters to move the silicon from the soil into their roots. Early plant physiology studies were unable to determine conclusively whether silicon was essential to plant growth, but for some plants, most notably rice, it has proved to be important enough to justify fertilizing silicon deficient fields. Researchers at the USU Crop Physiology Lab tested the effect of silicon on wheat growth and seed yield components. One study was grown in buckets of peat moss, with half the buckets being stressed with low water. The other study was grown in hydroponic tubs, with half the tubs being stressed with high levels of salt. The results from these studies showed that silicon does increase wheat seed yield and vegetative mass. Wheat with low levels of silicon exhibited twisting of the awns and decreased roughness of leaf surfaces. Silicon also improved water efficiency of drought stressed plants, and affected the concentration of many micro- and macro-nutrients in leaf tissue.

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Ajayi, Oyeyemi Olugbenga. "Three Beta-Glucuronosyltransferase Genes Involved in Arabinogalactan-Protein Biosynthesis and Their Roles in Growth and Development of Arabidopsis." Ohio University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1625497309408518.

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Ajayi, Oyeyemi Olugbenga. "Three Beta-Glucuronosyltransferase Genes Involved in Arabinogalactan-Protein Biosynthesis and Their Roles in Growth and Development of Arabidopsis." Ohio University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1625497309408518.

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Borgen, Birgit Hafeld. "Functional analysis of plant idioblasts (Myrosin cells) and their role in defense, development and growth." Doctoral thesis, Norwegian University of Science and Technology, Department of Biology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-476.

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Glucosinolates are natural plant products known as flavor compounds, cancerpreventing agents, and biopesticides. There is a strong interest in controlling the level of glucosinolates to improve flavor and nutritional qualities of food crops and to study the physiological role of glucosinolates in plants. The role of the myrosinaseglucosinolate system in plant defense-related reactions of Cruciferae is accepted. As metabolism of glucosinolates in healthy intact plants has been reported, this indicates that products produced by hydrolysis of glucosinolates may also be important in the growth and development of the plant.

The main focus in this thesis has been to study the effect of preventing glucosinolate hydrolysis by removal of the hydrolyzing enzyme, myrosinase. By the use of the Myr1.Bn1 promoter, we have made myrosinase free seeds of Brassica napus by controlled cell death (genetic ablation) of myrosin cells. The glucosinolate substrates were mainly unaffected by this ablation supporting their localization in non-myrosin cells and a cellular separation of enzyme and substrate. GC and GC-MS analysis confirmed that seeds with ablated myrosin cells had lost the ability to produce isothiocyanates. The effects of genetically ablating myrosin cells were tested for two other components in this complex enzyme system. The epithiospecifier protein (ESP) had lost the expression of one of its isoforms (39 kDa ESP) by the ablation indicating a cellular co-localization with myrosinase in myrosin cells for this specific isoform.

The expression of myrosinase binding proteins (MBPs) was not severely affected supporting localization to non-myrosin cells in the B. napus seed. Plants grown from seeds with ablated myrosin cells (MINELESS) showed a bushy phenotype and morphological abnormalities in flower and silique. Seed maturation was delayed and seed production reduced. Parallel experiments performed in our lab with Arabidopsis thaliana produced similar results. The tissues affected were consistent with the expression pattern directed by the myrosinase gene promoter used.

Ablating myrosinase proteins affected the behavior of the specialist cabbage aphid Brevicoryne brassicae and the generalist peach potato aphid Myzus persicae. When seedlings of MINELESS and wild type were challenged by these aphid species, a difference in preference was observed. B. brassicae preferred wild type seedlings with high levels of myrosinase proteins, while M. persicae preferred MINELESS seedlings with a reduced level of myrosinase compared to wild type. Statistical analysis revealed that the MINELESS seedlings were more susceptible to attacks by aphids, regardless of aphid species. Furthermore, the number of aphids established on the seedling influenced the myrosinase activity and the height of the plant. Thus, by ablating myrosinase proteins, new insights into the functions of the myrosinase-glucosinolate system have been elucidated. This complex system seems important not only in the defense against pests, but also show potential to influence the growth and development of the plant.

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30

Fowler, James H. "Effect of plant arrangement and density on growth development and yield of two potato varieties." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257946.

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31

Randall, Ricardo. "Exploring the roles of CYCD3s and AINTEGUMENTA in the control of plant growth and development." Thesis, Cardiff University, 2014. http://orca.cf.ac.uk/68397/.

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Regulation of higher plant growth and development involves the control of cell growth and division, since plant cells are immobile. A key point of plant cell cycle control is the G1 to S transition, which is promoted by CyclinD/CDK complexes. Several subgroups of D-type cyclins exist in higher plants, and the genes encoding these proteins appear to be under environmental and developmental regulation. In Arabidopsis, the CYCD3 subgroup consists of three members. The roles that these genes play in growth and development are explored, and the interaction between these genes and other factors controlling plant growth and development are investigated. A role for CYCD3;1 and its putative regulator ANT in root auxiliary meristem development is shown. However, whilst ant and cycd3;1 mutants shared some phenotypes, such as increased petal cell size, reduced leaf cell number and reduced root thickness, double mutants exhibited additive phenotypes, suggesting that there is not a strong regulation of CYCD3;1 by ANT. Supporting this, a physical interaction between ANT and a putative ANT-binding site from the CYCD3;1 promoter was not detected, and evidence of CYCD3;1 transcription regulation by ANT was weak. Supporting an alternative hypothesis, evidence of coregulation of ANT and CYCD3;1 by cytokinins in roots is provided. The expression of these genes in roots required cytokinins and appeared to be correlated. Roles for all three CYCD3s and the ERECTA (ER) kinase in the regulation of primary vascular tissue development are described, and genetic evidence of a link between CYCD3s and ER is provided. These genes appear to be required for cell division events in the procambium lineage. Furthermore, ER was also found to regulate secondary growth. Thus five novel regulators of root development have been identified, and important knowledge regarding mechanisms of lateral aerial organ size control has been gained.

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32

Charton, Lennart [Verfasser]. "Elucidate the important role of peroxisomal transport proteins for plant growth and development / Lennart Charton." Düsseldorf : Universitäts- und Landesbibliothek der Heinrich-Heine-Universität Düsseldorf, 2021. http://d-nb.info/1237104912/34.

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33

Sand, Laura Marie. "Effects of plant growth regulators and temperature on floral induction and development of Exacum Styer Group." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/7296.

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Plants of Exacum Styer Group, interspecific hybrids from five Sri Lankan taxa from the Gentian family, have significant horticultural potential as flowering potted plants, bedding plants and cut flowers. However, a better understanding of the requirements for floral induction and flower development is needed before commercialization. Experiments examining the impact of plant growth regulators (PGRs) on floral induction and subsequent plant development consisted of seven treatments: ethephon (500 and 1000 PPM), daminozide (2500 and 3500 PPM), gibberellin (GA₄₊₇ at 10 and 15 PPM), and a control of water plus surfactant. Analysis of data collected on weeks to anthesis resulted in a significant interaction between treatment and genotype indicating that genotypes did not behave uniformly across treatments. Overall, the effect of PGR treatments on flowering of E. Styer Group is impacted more by genotype than by chemical with late flowering genotypes less affected by chemical than earlier flowering genotypes. Nonetheless, daminozide effectively reduced stem length without dramatic negative impact on flowering and can be considered safe for commercial production. Experiments to evaluate the effect of temperature on floral induction and subsequent plant development consisted of four temperature treatments over two seasons (one treatment repeated in both seasons). The two most extreme treatments prevented flowering for some or all genotypes (35° C DT/31° C NT and 16° C DT/12° C NT, respectively). Intermediate treatments (23° C DT/19° C NT and 30° C/26° C NT) were optimal for fastest flowering depending on genotype. As with the response to PGR treatments, significant genotypic variation was observed in response to temperature indicating production schemes must be developed empirically for each individual genotype. However, the optimal temperature for fast flowering and attractive plant conformation is likely between 21° and 28° C average daily temperature for most E. Styer Group genotypes and should be used as a starting point for future studies. In addition, a cultivar series of E. Styer Group should be selected based on common production responses, not based on genetic relationships.

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Ng, Kok Leong. "The role pf plant growth substances in photoperiod-controlled Phaseolus vulgaris L. (Savi) flower bud development." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386349.

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Schnaubelt, Daniel. "The roles of glutathione in the control of plant growth, development and signalling in Arabidopsis thaliana." Thesis, University of Leeds, 2013. http://etheses.whiterose.ac.uk/6864/.

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Reduced glutathione (GSH) is an abundant low molecular weight thiol that fulfils multiple functions in plants, many of which remain poorly characterised. The following studies were undertaken in order to characterise the roles of GSH in growth, development and signalling in Arabidopsis thaliana. In the first experiments, a phenomics approach was used to investigate the effects of GSH deficiency on growth and stress tolerance using mutants that are either defective either in GSH synthesis (cad2-1, pad2-1 and rax1-1) or the export of -glutamylcysteine and GSH from the chloroplast (clt1clt2clt3). Whereas the clt1clt2clt3 mutant had a greater rosette area than the wild-type under low light growth conditions, the GSH deficient mutants were significantly smaller. Moreover, lateral root densities were significantly decreased in GSH deficient and clt1clt2clt3 mutants. The redox potentials of the nucleus and cytosol in the root cells of the wild-type seedlings measured using roGFP were over -300mV. However, in roots grown in the presence of the GSH synthesis inhibitor buthionine sulfoximine (BSO), the redox potentials of the nucleus and cytosol increased to approximately -260mV. Low GSH-responsive genes were identified by transcript profiling analysis of the GSH-deficient root meristemless 1-1 (rml1-1) mutant. These included a large number of transcription factors, proteins involved in cell division, redox regulation and auxin signalling. Many transcripts modified by low GSH influence plant growth and development, and explain the altered root development observed the low GSH mutants. These results demonstrate that low GSH leads to significant increases in the redox states of the nucleus and cytosol and results in specific responses in gene expression that are distinct from those observed under oxidative stress. Moreover, the findings suggest that the cytosolic/nuclear GSH pool is important in the control of root development and that low GSH per se does not enhance overall sensitivity to abiotic stresses.

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Hope, Frank. "The development of a micro-computerised plant establishment and growth model for use with landscape taxa." Thesis, University of Bath, 1990. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.581869.

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This study investigates the feasibility of a micro- computer based plant establishment and growth model, which can be used as a means of storing and manipulating information relating to the cultivation of decorative landscape taxa in England and Wales. The work includes four experiments in establishment husbandry, which investigate the feasibility of field work to provide information on specific ornamental husbandry practices. The study investigates computerised plant establishment and growth modelling in relation to climatic and site requirements, and the production of a micro-computer programme to enable the formulation of accurate predictions of plant performance. The work highlights the requirements of modern landscape management and has brought together environmental data essential for the formulation of accurate establishment and growth predictions. The computer model demonstrates the potential for such a predictive approach to selecting landscape plants. All data are formatted for inclusion in a practical working landscape based model, including the ability to predict the suitability of taxa for climatic, site and specific intolerances. viii

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Hooten, Thomas M. "Ammonium and Nitrate Effects on Growth, Development and Nutrient Uptake of Hydroponic Wheat." DigitalCommons@USU, 1998. https://digitalcommons.usu.edu/etd/6748.

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The long-term effects of low and high NH4+/ NO3- uptake ratios in a system with rigorous control of pH and nitrogen concentration are poorly understood. In two replicate studies, two cultivars of wheat (Triticum aestivum) were grown to maturity with three NH4+/ NO3- ratios in hydroponic solution: 0/100, 25/75, and 85/15%. Nitrogen was controlled at ample levels throughout the 70-d life cycle and pH was controlled at 5.8 ± 0.2. An equimolar ratio of NH4+ to Cl- was used to facilitate charge balance. Nitrogen consumption and transpiration were measured daily. Flag leaves were analyzed at 10-d intervals for total nitrogen, NO3--N, and essential elements. Essential nutrient elements in the biomass and seeds were measured at harvest. Yield components , nitrogen recovery, and nitrogen assimilation were calculated. There was no difference between the NO3- only (0/100) and the low NH4+ (25/75) treatments . The high NH4+ treatment (85/15) did not reduce vegetative biomass, but decreased seed yield and harvest index by 20%. The decrease was associated with a 23% reduction in seed number head-1. The high NH4+ treatment increased percent root mass by 50% and percent sterile heads by 800%, but increased assimilated N in the seeds by 30% and in the biomass by 130%. Supplemental additions of K were effective in preventing the reduction of K concentration in the wheat tissues typically caused by high NH4+, but the high NH4+ treatment decreased the concentrations of Ca, Mn, and Zn, and increased the concentrations of S, P, Fe, and B in the wheat tissue . The uptake of Mg and Cu was similar among all three treatments. Chloride concentrations in the flag leaves increased from 0.8% in the NO3- only treatment to 2.0% in the two NH4+ treatments. This research indicates that hydroponic wheat can be grown to maturity with high levels of NH4+ with a small reduction in grain yield.

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Harrison, Judith. "The effect of plant growth regulators on the growth and development of Rht and uniculm lines of spring wheat (Triticum aestivum L.)." Thesis, Bangor University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386668.

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39

O'Toole, William M. (William Michael). "A basic cell/small group training course for an intentional church plant in Platte County, Missouri." Online full text .pdf document, available to Fuller patrons only, 2004. http://www.tren.com.

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Ministry research project (D. Min.)--Midwestern Baptist Theological Seminary, 2004.
Submitted in partial fulfillment of the requirements for the Doctor of Ministry Degree. Includes bibliographical references (leaves 94-96).

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Carson, Deborah L. (Deborah Lee). "Gene discovery and expression analysis in sugarcane leaf and culm." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52860.

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Dissertation (PhD) -- University of Stellenbosch, 2002.
ENGLISH ABSTRACT: Sugarcane (Saccharum spp. hybrids) is a commercial crop plant capable of storing up to 20% sucrose on a fresh mass basis in the culm. Knowledge about gene expression during sugarcane growth and maturation is limited. The aim of this study was to assess whether an Expressed Sequence Tag (EST)-based approach towards analysis of sugarcane would reveal new information about gene expression and metabolic processes associated with sugarcane growth and development. The specific objectives were two-fold: firstly, to develop an EST database for sugarcane and secondly, to identify and analyse genes that are expressed in different sugarcane tissue types and developmental stages, with a specific focus on leaf and culm. An EST database for sugarcane was initiated to obtain information on sugarcane gene sequences. A total cDNA library was constructed from sugarcane immature leaf (leaf roll: meristematic region) tissue and 250 clones randomly selected and subjected to single-pass DNA sequence analysis. Sugarcane ESTs were identified by sequence similarity searches against gene sequences in international databases. Of the 250 leaf roll clones, 26% exhibited similarity to known plant genes, 50% to non-plant genes while 24% represented new gene sequences. Analysis of the identified clones indicated sequence similarity to a broad diversity of genes. A significant proportion of genes identified in the leaf roll were involved in processes related to protein synthesis and protein modification, as would be expected in meristematic tissues. Submission of 495 sugarcane gene sequences to the dbEST database represented the first sugarcane ESTs released into the public domain. Two subtracted cDNA libraries were constructed by reciprocal subtractive hybridisation between sugarcane immature and maturing internodal tissue. To explore gene expression during sugarcane culm maturation, partial sequence analysis of random clones from maturing culm total and subtracted cDNA libraries was performed. Database comparisons revealed that of the 337 cDNA sequences analysed, 167 showed sequence homology to gene products in the protein databases while 111 matched uncharacterised plant ESTs only. The remaining cDNAs showed no database match and could represent novel genes. The majority of ESTs corresponded to a variety of genes associated with general cellular metabolism. ESTs homologous to various stress response genes were also well represented. Analysis of ESTs from the subtracted library identified genes that may be preferentially expressed during culm maturation. The expression patterns of sugarcane genes were examined in different tissue sources and developmental stages to identify differentially expressed genes. cDNA arrays containing 1000 random clones from immature leaf and maturing culm cDNA libraries were hybridised with poly (At RNA from immature leaf, mature leaf, immature culm and maturing culm. All cDNAs examined hybridised to all four probes, but differences in signal intensity were observed for individual cDNAs between hybridisation events. No cDNAs displaying tissue- or developmental-stage specific expression were detected. Comparisons between hybridisation patterns identified 61 cDNAs that were more abundantly expressed in immature and mature leaf than the culm. Likewise, 25 cDNAs preferentially expressed in immature and maturing culm were detected. ESTs established for the differentially expressed cDNAs revealed sequence homology to a diverse collection of genes in both the leaf and the culm. These included genes associated with general cellular metabolism, transport, regulation and a variety of stress responses. None of the differentially expressed genes identified in the culm were homologous to genes known to be associated with sucrose accumulation. To examme differences at the level of gene transcription between low sucroseaccumulating and high sucrose-accumulating tissues, subtracted cDNA libraries were utilised. To isolate cDNAs differentially expressed during culm maturation, cDNA arrays containing 400 random clones (200 from each library) were screened with total cDNA probes prepared from immature and maturing culm poly (At RNA. Results indicated that 36% and 30% of the total number of cDNAs analysed were preferentially expressed in the immature and maturing culm, respectively. Northern analysis of selected clones confirmed culm developmental stage-preferential expression for most of the clones tested. ESTs generated for the 132 differentially expressed clones isolated exhibited homology to genes associated with cell wall metabolism, carbohydrate metabolism, stress responses and regulation, where the specific ESTs identified in the immature and maturing culm were distinct from each other. No developmentally regulated ESTs directly associated with sucrose metabolism were detected. These results suggest that growth and maturation of the sugarcane culm is associated with the expression of genes for a wide variety of metabolic processes. In addition, genes encoding enzymes directly involved with sucrose accumulation do not appear to be abundantly expressed in the culm.
AFRIKAANSE OPSOMMING: Kommersiële suikerriet variëteite (Saccharum spp. hibriede) is in staat om tot 20% sukrose op 'n vars massa basis in die stingel op te berg. Kennis oor geenuitdrukking tydens groei en rypwording is beperk. Die doel van die huidige studie was om vas te stelof 'n grootskaalse karatersisering van die geenvolgordes wat uitgedruk word "Expressed Sequence Tag (EST)-based approach" tot nuwe inligting aangaande die aard en omvang van metabolisme tydens groei en ontwikkeling van suikerriet sal lei. 'n Tweeledige benadering is in hierdie studie gevolg. Eerstens is 'n data basis oor die gene wat uitgedruk word "EST" databasis opgestel. Tweedens is gene geïdentifiseer en gekarakteriseer wat spesifiek op verskillende stadiums van ontwikkeling en in spesifiek weefsel uitgedruk word. Vir die opstel van die EST-databasis is 250 klone uit 'n totale cDNA biblioteek vanaf RNA uit suikerrietblaarweefsel (blaarrol:meristematiese streek) op 'n lukraak basis gekies en aan 'n enkel eenrigting DNA volgorde analise onderwerp. Suikerrriet EST's is geïdentifiseer deur middel van homologie soektogte teen geenvolgordes in internasionale databasisse. Uit die 250 blaarrol klone het 26% ooreenkomste met bekende plant gene en, 50% met nie-plant gene getoon. Ongeveer 24% het nuwe geenvolgordes verteenwoordig. Analise van die geïdentifeseerde klone het ooreenkomste met 'n breë diversiteit van gene getoon. 'n Betekenisvolle gedeelte van gene wat in die blaarrol geïdentifiseer is, is by proteïensintese en proteïenmodifikasies betrokke. Dit is in ooreenstemming met wat van meristematiese weefsel verwag kan word. Die 495 suikerriet geenvolgordes wat in die internasionale dbEST databasis gestort is, is die eerste sodanige inligting in die publieke domein. Twee spesifieke cDNA biblioteke (subtraction libraries) wat volgordes spesifiek aan onvolwasse suikerriet en rypwordende internodale weefsel bevat is voorberei. Geenuitdrukking gedurende die rypwordingsproses van die suikerrietstingel is bestudeer deur geenvolgorde analises van onwillekeurige geselekteerde klone van die twee eDNA biblioteke te doen. Van die 337 geenvolgordes wat geanaliseer is het 167 homologie met bekende gene en net 111ooreenkomste met ongekarakteriseerde plant gene getoon. Die oorblywende geenvolgordes het geen ooreenkomste met bekende gene getoon nie en daar kan dus aanvaar word dat hulle nuwe gene verteenwoordig. Die meerderheid ESTs het ooreenkomste met verskeie gene wat met sellulêre metabolisme geassosieer word getoon. ESTs wat homoloog was aan verskeie spannings geassosieerde gene was ook goed verteenwoordig. Die analise het gene wat by voorkeur tydens stringelrypwording uitgedruk word geidentifiseer. Die geenuitdrukkingspatrone van suikerriet in weefsels van verskillende oorsprong en ontwikkelingstadia is ondersoek om differensieel uitgedrukte gene te identifiseer. Reekse wat 1000 lukrake eDNA klone van onvolwasse en rypwordende stingel eDNA biblioteke is met poli-(A)-RNA van onvolwasse blaar, volwasse blaar, onvolwasse stingel en volwasse stingel gehibridiseer. Al die eDNA klone wat ondersoek is het met al vier die peilers gehibridiseer. Die intensiteit van die seine het egter grootliks gevarieer. Die analise het gelei tot die identifisering van 61 eDNA klone wat teen hoër vlakke in onvolwasse en volwasse blaar as in die stingel uitgedruk word. Daar is ook 25 eDNA klone wat by voorkeur in onvolwasse en rypwordende stingel uitgedruk word gevind. Gene wat geassosieer word met gewone sel metabolisme, vervoer prosesse, regulering en verskeie spannings-geassosieerde reaksies, is in die twee groepe teenwoordig. Geeneen van die volgordes wat selektief uitgedruk word kan met gene wat direk met sukrose akkumulering verband hou geassosieer word nie. Ten einde eDNA klone wat differensieel tydens rypwording van die stingel uitgedruk word te isoleer, is 400 eDNA klone (200 van elke biblioteek) lukraak geselekteer en met totale eDNA peilers, wat uit onvolwasse en rypwordende stingel poli-(A)-RNA voorberei is, gesif. Resultate het aangetoon dat 36% en 30% van die totale getal eDNA klonewat geanaliseer is, by voorkeur in die onvolwasse en rypwordende stingel uitgedruk word. RNA kladanalises van geselekteerde klone het getoon dat die meeste ontwikkelingstadium spesifieke uirtdrukkingspatrone het. Daar is gevind dat 132 van die EST klone homologie met gene geassosieerd met selwand- en koolhidraatmetabolisme, spannings geassosieerde- en reguleringsreaksies, toon. Die spesifieke ESTs wat in die onvolwasse en rypwordende stingel geïdentifiseer is het van mekaar verskil. Nie een van die ESTs wat geïdentifiseer is kan direk met sukrose metabolisme geassosieer word nie. Hierdie werk toon baie duidelik aan dat groei en rypwording van die suikerrietstingel met die uitdrukking van gene geassosieerd is wat by 'n hele aantal metaboliese prosesse betrokke is. Die resultate toon ook dat die gene wat vir ensieme kodeer wat direk by sukrose akkumulering betrokke is, nie teen hoë vlakke in die stingel uitgedruk word nie.

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41

Spencer, Andrew. "The development of shooty teratomas in Mentha species by genetic manipulation and studies on their growth and terpene production in vitro." Thesis, University of East Anglia, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292258.

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42

Pomeranz, Marcelo Christian. "The Role of the AtTZF1 Tandem CCCH Zinc Finger Gene in Plant Growth, Development, and Stress Response." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1299525118.

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43

Wang, Hao-Ching. "Role of tobacco anionic peroxidase on plant growth and development and the effect on endogenous auxin production /." The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu148639447597754.

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44

Longest, Robert Joseph. "Tillage System Effects On Upland Cotton Yield and Development In Virginia." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/77423.

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Identifying the proper tillage system which provides the best agronomic benefits for cotton production in the coastal plain soils of Virginia was the basis for this research. Strip-tillage was evaluated from 2015-2016 on-farm to determine the effects of annual and biennial treatments on plant growth and lint yield, as well as measuring the impacts on soil compaction. Also, small plot tillage experiments were conducted from 2013-2016 assessing no-till, conventional tillage, minimum tillage, and strip-tillage as well as the subsequent effects of these systems on four cotton varieties. Biennial strip-tillage produced similar lint yields to annual strip-tillage at 3 of 4 locations, with only one location showing a significant difference in lint yield of 135 kg ha-1. Persistence of subsoil tillage within the row from the previous year was observed at some locations and plant heights were not different at all locations, although annual strip-tillage provided deeper potential rooting depths both early season and at harvest. In short term tillage systems, minimal penalties in plant growth and lint yield were observed in no-till verses the other systems, primarily associated with greater soil compaction, shorter plant heights, and lower yields. An overall 8% reduction in yield was found with no-till systems, with no significant differences in yield among tillage systems observed in any year. Varietal effects on plant growth and yield were observed annually, with FM 1944 GLB2 being the shortest plants, and DP 1321 B2RF having the tallest plants. No tillage by variety interaction was observed, supporting the idea that varieties respond similarly across tillage systems.
Master of Science

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45

O'Toole, William M. "A basic cell/small group training course for an intentional church plant in Platte County, Missouri." Theological Research Exchange Network (TREN), 2004. http://www.tren.com.

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Jian, Jia Wei, and 簡嘉維. "Effects of plant growth regulator on growth and development in Cymbidium sincence." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/46666827714549027314.

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碩士
國立宜蘭大學
園藝學系碩士班
100
Cymbidium science ‘Ruihua’,‘Gold Huashan’ and ‘Pacific Ocean’ was used in this study. The objective is to investigate the effects of different concentration of Paclobutrazol (PBZ) (0、25, 50, 100, 200 and 400 ppm)、6-BA (0, 500, 1000 and 2000 ppm) and chitosan (1 mL．L-1 and 2 mL．L-1), and plants were soaked, soil drench and foliar application of different treatments on plant growth and development. Cymbidium sicience 'Ruihua' applying different concentrations of soak treatments, plant had the most significant difference, the higher concentration, the less elongation, but there was not a significant response for Cymbidium sicience ‘Gold Huashan’. PBZ drench had a greater retarding activity on leaf elongation than spray. A 400 ppm PBZ drench three times resulted in the shortest plants , which had the lowest leaf elongation count（0.75 cm）. It was apparent that 400 ppm drench and spray treatments with PBZ decreased leaf elongation of Cymbidium sicience ‘Gold Huashan’ over the control , it was also observed that Cymbidium sicience ‘Pacific Ocean’ plants leaf elongation decreased with increasing concentration of PBZ drench, plant drenched with PBZ 400 ppm after 105 days, leaf elongation was inhibited 70％ than control, and plant were sprayed 400ppm PBZ after 49 days reduced leaf elongation only 26％, but there was no significant difference between control and sprayed with PBZ 50 ,100 and 200 ppm . Flower stalk was significantly decreased with increased dose of PBZ , On the contrary, increased flower diameter only at the highest drench concentration, but there was no difference at flower diameter and color. It was investigated the photosynthesis enhanced was accompanied by higher leaf temperature all year through, and the net photosynthetic rate was greatest at 200ppmPBZ. During the first 20weeks after treatment, PBZ acceleration of the net photosynthetic rate than those untreated plants, but decreased the activities of photosynthesis as well as control in November. Results showed 6-BA applied to the plants, there were no significant effects between mother’s pseudobulbs thickness and width, but the application of 6-BA led to a decreasing of shoot’s pseudobulbs width and thickness, especially when applied as a soil drench. Drench application of 6-BA at dose of 500 ppm resulted in significant increasing in the number of lateral shoots and plants had no visual differences in the structure of roots , plants were sprayed 1000 ppm PBZ had less lateral shoots than former. Plants treated with 500 ppm and 1000 ppm of BA were significant increasing the number of lateral shoots（2.3 and 1.8 shoots/pot） than control（1.2 shoots/pot）, it was also observed from the other different treatments（1.2 shoots/pot）. Additionally, plant drenched with 500 ppm 6-BA was more effective inducing on the mother’s pseudobulb latent buds (0.8 buds of per pseudobulb), but no effects of control and spray applications . Cymbidium sicience ‘Gold Huashan’ application of PBZ could cause suppressing latent buds inducing and led plants to a poor resistance from plant dieses , Combing 100 ppmPBZ, 500 ppm 6-BA and 2 mL．L-1 chitosan had been effective in promoting the resistance from diseases, and Cymbidium sicience ‘Pacific Ocean’ was applied 50 ppm PBZ, 500 ppm 6-BA and 2 mL．L-1 chitosan before latent buds emergence, the treatments have high net photosynthesis and best foliar variegation, suggesting that weekly application chitosan continued was most effective at pathogens control.

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Waduwara-Jayabahu, Chammika Ishari. "Significance of Methylthioadenosine Metabolism to Plant Growth and Development." Thesis, 2011. http://hdl.handle.net/10012/6517.

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Arabidopsis thaliana contains two genes annotated as methylthioadenosine nucleosidases (MTN): MTN1, At4g38800 and MTN2, At4g34840. This enzyme activity hydrolyzes the methylthioadenosine (MTA) produced by nicotianamine (NA), polyamine (PA), and ethylene biosynthesis to methylthioribose (MTR) within the Yang cycle. Comprehensive analysis of the mtn1-1mtn2-1 mutant line with 14 % residual MTN activity revealed a complex phenotype that includes male and female infertility and abnormal vascular development. Based on metabolite profiling, mtn1-1mtn2-1 has a reduced NA content, altered PA profiles with higher putrescine (Put) and lower spermidine (Spd) and spermine (Spm) levels, disrupted metal ion profiles, and abnormal auxin distribution. The modeling of Arabidopsis PA synthases developed by comparison with the crystal structures of human Spd and spermine synthases complexed with MTA suggests that Arabidopsis PA synthases are product inhibited by MTA. Thus, these pleiotropic mutant phenotypes possibly are the result of one metabolite directly inhibiting numerous pathways. By creating and analyzing a series of mutants and transgenic lines with moderate levels of MTN activity the complex phenotype of mtn1-1mtn2-1 was dissected in order to determine the fundamental trait associated with MTN deficiency. Two double mutants were identified by crossing single T-DNA mutants, and an artificial micro RNA (amiRNA) line was generated by transforming mtn1-1 with amiRNA specific to MTN2. The T-DNA double mutants, mtn1 4mtn2-1, and mtn1-1mtn2-5 had 98 % and 28 % MTN activity, respectively, whereas the amiRNA line has 16 % MTN activity. The growth, development, and metabolite analysis of these mutants revealed that their delayed bolting, correlated with an increased number of leaves, was the common trait observed across all lines. Xylem proliferation defects and increased number of vascular bundles per unit area were shared in all lines except mtn1 4mtn2-1. Based on these results, auxin distribution is proposed as the key target of the accumulated MTA that results from MTN deficiency. The infertility related to MTN-deficiency was restored by supplying 100 ??M of Spd to the mtn1-1mtn2-1 seedlings over 14 days. The data presented in this thesis reveals two potential links that work synergistically to recover fertility in this mtn1-1mtn2-1 line. Based on a detailed analysis of the female gynoecia morphology, transcript, hormone and metabolite profiles, it is proposed that the Spd partially reverses the mutant phenotypes through the recovery of auxin distribution and /or vascular development. Interestingly, the Spd effect seems to be transgenerational: they give rise to plants that are genotypically mtn1-1mtn2-1 but phenotypically WT over generations. Taken together, all of the results suggest that MTN-deficient mutants provide the potential for unraveling the molecular mechanism associated with nicotianamine, polyamines, auxin, and vascular development with respect to enhancing the efficiency of nutrient use and yields in plants.

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48

Qi, Ruhu. "Genetic manipulation of cell proliferation : effects on plant development and growth." Phd thesis, 2004. http://hdl.handle.net/1885/148689.

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49

Mohammed, Abdul R. "Effects of High Nighttime Temperature and Role of Plant Growth Regulators on Growth, Development and Physiology of Rice Plants." 2009. http://hdl.handle.net/1969.1/ETD-TAMU-2009-05-596.

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Seasonally high nighttime temperatures (HNT) along the United States Gulf Coast and in regions of similar climate, during the critical stages of development, could reduce rice yield and quality. To study the effects of HNT on plant physiology, a method for applying a controlled heating treatment to plant canopies was developed using overhead infrared heaters, which are relatively inexpensive and are accurate, precise and reliable in rapidly controlling the temperature. The apparatus successfully maintained air temperatures within the set points plus/minus 0.5 degrees C, and was used for all the experiments. Several experiments were conducted to determine the response of various physiological parameters during and following exposure of rice plants to HNT (32 degrees C) or ambient nighttime temperature (ANT) (27 degrees C) starting from 2000 h until 0600 h, and with or without plant growth regulator treatments. The plant growth regulator treatments included alpha-tocopherol (vitamin E), glycine betaine (GB), and salicylic acid (SA), which play different roles in inducing thermo-tolerance in plants. High nighttime temperature had no effect on plant height, number of tillers and panicles, or rice net leaf photosynthetic rates. However, HNT increased leaf respiration (dark respiration in the night) (21%) and decreased membrane thermo-stability (60%), pollen germination (20%), spikelet fertility (18% as a % of total spikelets), grain length (2%), and grain width (2%). The HNT also hastened plant development. The combinations of these effects decreased rice yield by 90%. Moreover, under HNT, there were decreases in leaf chlorophyll concentration (7%) and nitrogen concentration (18%). Application of GB and SA increased total antioxidant capacity of the rice plants by 17%, thereby decreasing the leaf respiration rates, increasing membrane thermo-stability, pollen germination, and spikelet fertility, thus increasing the yield. High nighttime temperature decreased leaf starch concentration (14%), grain total nonstructural carbohydrate (TNC) concentration (9%), and grain extractable invertase activity (20%). Vitamin E- or GB-treated plants had greater grain soluble-sugar concentrations, whereas SA-treated plants had greater leaf soluble-sugar concentrations and lower grain TNC concentrations. Invertase activity was shown to be not rate limiting or required for sucrose degradation for starch synthesis in grain of 'Cocodrie' rice under short-term high nighttime temperatures exposures during grain filling. In conclusion, HNT decreased rice yield by increasing plant respiration, rate of crop development, and decreasing membrane thermo-stability, pollen germination, spikelet fertility and grain dimensions. Exogenous application of GB and SA increased yields under HNT, possibly acting through increased antioxidant levels, which might have protected the membranes and enzymes against heat-induced ROS-mediated degradation.

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50

Chen, ChiaChih, and 陳家智. "Development of a Computer Controlled System for Plant Growth Chamber." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/58979298997800894726.

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碩士
國立臺灣大學
農業機械工程學系研究所
88
Growth chamber plays an important role in the research of plants. Most commercially available growth chambers can only control a few factors of the environment and have the inflexible human-machine interface. Even so, they are still expensive and have no data acquisition capability. The purpose of this research is to develop a computerized control and data acquisition system of a growth chamber. The system is developed using MS Visual Basic and capable of controlling temperature, humidity, light, and concentration of CO2. Besides the single-point setting, two-step setting, daily multi-step setting and long-duration-muti-step setting, the human-machine interface of the system also provides the acclimatization-curve setting. Users can setup the acclimatization curves in form of sine-wave or triangle-wave and adjust the amplitude of the curve easily. The system developed can greatly improve the performance of the commercially available growth chamber. Thus, making it highly marketable. More test runs are required to insure the stability of the system.

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Dissertations / Theses on the topic 'Plant growth and development'

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