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Assessing The Genetic Diversity Of The Genus Viburnum Using Simple Sequence Repeats, Deborah Dean

Doctoral Dissertations

The genus Viburnum was established in 1753 by Linnaeus and is the largest genus in the Adoxaceae and consists of approximately 160 species. Viburnum species are small trees which grow throughout the temperate regions of the Northern Hemisphere (Hoch, 1995). While this genus shares little variety in fruit and flower morphology, it is diverse in many other traits. As molecular studies advance, this large genus continues to undergo reclassification. Here three SSR libraries were constructed to discern additional molecular insight into this vast genus.

Microsatellite markers were developed to characterize Viburnum on several different levels. V. dilatatum is an introduced …

Pore Selectivity And Gating Of Arabidopsis Nodulin 26 Intrinsic Proteins And Roles In Boric Acid Transport In Reproductive Growth, Tian Li

Doctoral Dissertations

Plant nodulin-26 intrinsic proteins (NIPs) are members of the aquaporin superfamily that serve as multifunctional channels of uncharged metabolites and water. They share the same canonical hourglass fold as the aquaporin family. The aromatic arginine (ar/R) selectivity filter controls transport selectivity based on size, hydrophobicity, and hydrogen bonding with substrates. In Arabidopsis thaliana, NIP II subclass proteins contain a conserved ar/R “pore signature” that is composed of Alanine at the helix 2 position (H2), Valine/Isoleucine at the helix 5 position (H5), and an Alanine (LE1) and an invariant Arginine (LE2) at the two loop E positions. In this study, …

Evaluation Of Traits Associated With Breeding For Improved Biomass And Ethanol Yield In Switchgrass, Virginia Roseanna Sykes

Doctoral Dissertations

Switchgrass (Panicum virgatum L.) is a perennial, warm season grass that can be used as a biofuel. A greater understanding of the relationship of biomass yield and ethanol yield with disease susceptibility and morphological traits, estimation of the underlying genetic parameters of these traits, and the efficacy of selection at different maturity and under different production conditions could help breeders more effectively develop improved biofuel switchgrass cultivars. To examine these issues, three studies were performed. The first examined switchgrass leaves exhibiting low, medium, and high severity of rust symptoms, caused by infection with Puccinia emaculata. Results indicate P. …

Integration And Management Of Winter-Annual Cover Crops And Herbicides To Control Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri S. Wats), Matthew Scott Wiggins

Doctoral Dissertations

The main objective of this research was to evaluate the integration of high residue winter-annual cover crops with herbicides, both preemergence and postemergence, to control glyphosate-resistant Palmer amaranth. The results of these trials indicated that winter-annual cover crops improved early-season weed suppression. However, cover crops alone or as part of an integrated weed management system including only preemergence or only postemergence herbicides was not sufficient to control of glyphosate-resistant Palmer amaranth. Therefore, winter-annual cover crops should be used in conjunction with existing weed control tactics to achieve adequate glyphosate-resistant Palmer amaranth control, where applicable.

Alternative Strategies For Weed Control In Creeping Bentgrass, Matthew Thomas Elmore

Doctoral Dissertations

Creeping bentgrass (CBG) (Agrostis stolonifera L.) is the most widely used cool-season turfgrass species on golf course fairways and tees in the United States, but it is tolerant of few post-emergence herbicides. Commercial herbicide development is currently focused on providing superintendents with herbicides that pose minimal environmental impact and can be used effectively at lower application rates than older alternatives. However, few of these products are safe for use on CBG. Several projects were conducted to evaluate alternative strategies to increase CBG herbicide tolerance.

Plants naturally contain enzymatic systems that metabolize xenobiotics. The interspecies variability in these enzymes is …

Molecular Marker Assisted Backcross Development And Evaluation Of An Environmentally Friendly, Commercially Acceptable Low Seed Phytate Soybean, Jeffrey David Boehm Jr.

Masters Theses

Soybean [Glycine max (L). Merrill] is the world’s top oilseed crop. High protein soymeal is a primary soybean use and staple food of livestock and fish. The storage form of phosphorus (P) in the seed is phytic acid, or phytate [myo-inositol 1,2,3,4,5,6 hexakisphosphate] which binds and chelates key nutritional cations forming stable salts that are non-digestible. Livestock waste laden with phytate P is an environmental concern, and a source of nonpoint P pollution causing eutrophication and surface water quality deterioration. The primary objective of this research was the development of a commercially acceptable low phytate (LP) soybean …

Aminocyclopyrachlor Efficacy For Non-Cropland Weed Control, José Javier Vargas Almodóvar

Masters Theses

The production of chemicals for crop protection purposes evolved after World War II with the commercialization of the auxin herbicides 2,4-D and MCPA. Their utility and effectiveness created an interest for North American and European companies to develop and research thousands of agrochemicals available today.

Recently discovered and introduced to the market by DuPont Crop Protection, aminocyclopyrachlor is the first broad spectrum synthetic auxin herbicide in this chemical class, and is structurally similar to the auxin herbicides: aminopyralid, clopyralid and picloram. Aminocyclopyrachlor has activity on broadleaf weed species with limited activity on monocot species. Aminocyclopyrachlor is absorbed via plant roots …

The Effect Of Abscisic Acid On Tomato Calcium Partitioning And Fruit Quality, Thomas Casey Barickman

Doctoral Dissertations

Tomato (Solanum lycopersicum) is a widely employed plant model system for studying fruit metabolism, development and ripening. Various environmental stress factors, such as drought and high relative humidity, can cause calcium (Ca) deficiency and lead to physiological diseases such as blossom-end rot (BER) in tomato fruit. Recent studies demonstrate that abscisic acid (ABA) triggers whole-plant and fruit-specific mechanisms to increase fruit Ca uptake and prevent BER development. The objective of this study was to evaluate the effects of exogenous ABA applications during plant development on tomato carotenoid pigments, soluble sugars, organic acids, aromatic volatiles, carbohydrates, and mineral nutrient …

Increasing Nursery Crop Canopy Density: Implications For Sustainable Insect Pest Management, Whitney Michelle Yeary

Masters Theses

Consumers are attracted to woody ornamental plants that have symmetrical, dense canopies. In order to get the desired canopy density and symmetry, growers often manipulate growth by pruning or applying chemical plant growth regulators. Another method of acquiring a dense plant canopy is for growers to purchase in vitro-propagated liners instead of traditional cutting-propagated liners. This work analyzed the validity of all three methods on several woody ornamental species. Liners from Cutting-propagated (CP) and in vitro-propagated (IVP) sources were purchased and treatments of pruning and PGRs were applied. Pruning only increased the canopy density of rhododendron (Rhododendron L. ‘Roseum Elegans’) …

Evaluating The Performance Of Low-Lignin Transgenic Bioenergy Feedstocks In The Field, Holly Lauren Baxter

Masters Theses

Lignin in the cell walls of lignocellulosic biomass limits the accessibility of carbohydrates for breakdown into fermentable sugars and subsequently biofuels. The resistance of plant biomass to enzymatic or microbial deconstruction, known as biomass recalcitrance, can be overcome by reducing lignin content or modifying its composition through genetic modification of the lignin biosynthetic pathway. However, few studies to date have assessed the performance of low-lignin biofuel feedstocks under field conditions. Because lignin plays a vital role in several developmental and stress-related processes, characterization of these plants under the appropriate agronomic conditions is necessary to confirm that the improved biofuel-related traits …

Genetic Variation And Trait Associations For Forage Yield And Quality Among F1 Half-Sib Families Of Switchgrass, Matthew Eric Bobbitt

Masters Theses

Switchgrass (Panicum virgatum L.) is widely accepted as a forage crop throughout the United States. It is known for its performance on field sites that may be marginal for row crop production and as a warm season grass to fill gaps for cool season forages. With the increase of fuel and fertilizer costs, forage producers need higher yields and better quality than ever before. The objectives of this research were to: (i) compare four F₁ [first generation] half-sib populations for their potential of producing superior lines for forage production, (ii) assess the genetic variances for yield, and (iii) …

Evaluation Of Crumb Rubber Dynamics For Improving Athletic Field Quality, Kyley Hampton Dickson

Masters Theses

Crumb rubber (CR) is an amendment used to reduce surface hardness and increase wear-tolerance on athletic fields. Turf managers can topdress CR particles into highly trafficked portions of athletic fields; however, optimum particle size and topdressing depth combinations for use on bermudagrass (Cynodon spp) athletic fields have not been determined. Optimum CR particle size and depth to maximize performance of hybrid bermudagrass (C. dactylon (L.) Pers. x C. transvaalensis Burtt-Davy, 'Tifway') athletic field turf established on a Sequatchie silt loam soil was investigated at the University of Tennessee Center for Athletic Field Safety (Knoxville, TN) in 2011 and …

Genetic Variability For Biomass Yield, Yield Components, And Ethanol Yield Among Half-Sibs Of Switchgrass, Eifion Wyn Hughes

Masters Theses

For bioenergy crops to be an economical alternative to fossil fuels, rapid biological and technological advancements will need to occur. Some advancements can be accomplished by producing new switchgrass (Panicum virgatum L.) varieties with higher biomass and ethanol yields. The objective of this research was to quantify biomass and ethanol yield potential of four F₁ [F1] half-sib populations for future variety development as a bioenergy crop.

The four parental lines were PI 421999 (AR), PI 607837 (TX), PI 421552 (Cimarron), and Exp. # NSL-2001-1 (OK). Seed for one hundred and forty F₁ [F1] half-sib progeny were produced …

Evaluating Pollination Ecology Of The Endangered Pityopsis Ruthii (Small) Small (Asteraceae), Philip Anthony Moore

Masters Theses

Pityopsis ruthii (Small) Small, also known as Ruth’s golden aster, is a federally endangered herbaceous perennial, endemic to two river systems, the Hiwassee and the Ocoee, within the Cherokee National Forest, Polk County, Tennessee. There are approximately 13,000 individuals that may be at high risk of short-term extirpation (Thompson and Schwartz, 2006). Little is known of the basic reproduction and life history of P. ruthii. Clebesh and Sloan (1993), Cruzan (2001), Park (1998), and Wadl et al. (2014) found evidence that seed production and seed viability are highly variable. Clebesh and Sloan (1993) indicated that pollinator visitation was highly temporal …

Influence Of Aba On Calcium Binding In Tomato Fruit And Its Impact On Fruit Texture, Kendall Cressman

Chancellor’s Honors Program Projects

No abstract provided.

Effects Of Organically Enhanced Biofertilizer And Fertilizer Briquettes On Mineral Nutrition, Quality, And Yield Of Corn And Soil Health, John Heggie Winings

Masters Theses

Interest in alternate fertilizers has increased in recent years in order to improve crop nutrition and soil health. The efficacy of these fertilizers on corn (Zea mays L.) production and quality has been scarcely documented. Two alternative fertilizers, organically enhanced NPSFe Unity biofertilizer (Unity) manufactured from sterilized organic additives extracted from municipal wastewater biosolids and NPKZn briquettes (briquettes) produced by compacting solid fertilizers into a super-granule between 1-3 grams, were evaluated for nutrient concentrations, growth, quality, and yield of corn, residual soil nutrient levels, and soil microbial community structure relative to the conventional fertilizers ammonium sulfate and urea at …

Synthetic Turf Surface Temperature Reduction And Performance Characteristics As Affected By Calcined Clay Modified Infill, Eric Hall Reasor

Masters Theses

Synthetic turf research plots containing crumb rubber (CR) infill were established in Knoxville, TN in 2012 and 2013. Calcined clay (CC) was amended to CR in several ratios: a 50:50 (vol vol-1) blend; a 50:50 blend with a polymer coating on CC (50 CR:50 CCC); a 15 mm layer of CC under 15 mm of CR (CR over CC); and a 15 mm layer of CC over 15 mm of CR (CC over CR). A 100% CR and a 70:30 blend of CR to sand (70 CR:30 S) were included for comparison. Surface temperature was measured in the summer of …

The Role Of Phosphorylation In Myosin Driven Organelle Movements In Arabidopsis Thaliana, Peter Andrew Duden

Chancellor’s Honors Program Projects

No abstract provided.

Do Plants Play A Part In Student Satisfaction?, Amanda Diane Plante

Masters Theses

Environmental psychologists have found relationships between plants, nature and satisfaction. Student satisfaction is important across grade levels. Two studies were conducted to determine the effect of spending time with live plants on student satisfaction and academic performance. In the first study, a quasi-experimental nonequivalent control group design was used to determine how participation in garden labs would affect high school student satisfaction with school and academic performance. Ecology students in the variable group participated in ten gardening labs during the semester. During labs, students did hands-on gardening activities in the school greenhouse and garden. Students in the variable and control …