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Full-Text Articles in Life Sciences

Relative Soybean Response To Aminocyclopyrachlor, 2,4-D, Dicamba, And Aminopyralid, Trey I. Clark Dec 2021

Relative Soybean Response To Aminocyclopyrachlor, 2,4-D, Dicamba, And Aminopyralid, Trey I. Clark

Masters Theses

This research compared the visual symptomology of four auxin herbicides applied at three rates to simulate tank contamination on non-auxin tolerant soybeans. The herbicides examined were aminocyclopyrachlor (ACP), 2,4-D, dicamba, and aminopyralid. The standard labeled rates (SLR) used to base the application rates were 0.12 kg ae ha-1 for ACP and aminopyralid while dicamba and 2,4-D used 1.12 kg ae ha-1. These four herbicides exhibit similar symptoms on soybeans which is problematic when diagnosing soybean response. One goal of this project was to obtain high-quality images of the four herbicide’s effect on soybeans, with the hope of …


Molecular Markers Within And Beyond Viburnum: A Single Set Of Ssrs For An Immense Genus, Trinity Paige Hamm Dec 2021

Molecular Markers Within And Beyond Viburnum: A Single Set Of Ssrs For An Immense Genus, Trinity Paige Hamm

Masters Theses

Comprised of more than 160 species, Viburnum is the largest genus in the Viburnaceae (formerly Adoxaceae) alongside Adoxa and Sambucus. The native range of Viburnum species spans much of the Northern Hemisphere and extends into the mountains of South America and Southeastern Asia. Their wide geographic range has made Viburnum particularly interesting to phylogeographers and phylogeneticists. This diverse genus is also horticulturally valuable with varying traits such as fragrance, fruit color, and bud and inflorescence form. There is sufficient morphological diversity in the genus for there to be more than 70 species and intraspecific hybrids in cultivation, and in …


A Modular Cloning Toolbox For Chloroplast Metabolic Engineering, Alexander C. Pfotenhauer Aug 2021

A Modular Cloning Toolbox For Chloroplast Metabolic Engineering, Alexander C. Pfotenhauer

Masters Theses

Plant synthetic biology is a rapidly evolving field with new tools constantly emerging to drive innovation. Of particular interest is the application of synthetic biology to chloroplast biotechnology to generate plants capable of producing new metabolites, vaccines, biofuels, and high-value chemicals. Progress made in the assembly of large DNA molecules, composing multiple transcriptional units, has significantly aided in the ability to rapidly construct novel vectors for genetic engineering. In particular, Golden Gate assembly has provided a facile molecular tool for standardized assembly of synthetic genetic elements into larger DNA constructs. In this work a complete modular chloroplast cloning system (MoChlo) …


Utilizing Synthetic Biology To Engineer Novel Plant Transcriptional Regulators For Precise Control Of Autoluminescent Plants, Dominique K. Reuter Aug 2021

Utilizing Synthetic Biology To Engineer Novel Plant Transcriptional Regulators For Precise Control Of Autoluminescent Plants, Dominique K. Reuter

Masters Theses

Plant transcription factors provide an opportunity for precise control of gene regulation at the transcriptional level. This research focuses on the validation and optimization of the Q-system, a novel plant transcriptional regulator capable of multigene activation and suppression. The ultimate goal of these developments is for the utilization of transcriptional regulation to develop inducible, luminescent plants. To highlight the developments necessary for this achievement, this research examines the history and current state of autoluminescent plants, to determine how the convergence of the Q-system and fungal luminescence system could generate inducible autoluminescent plants. These inducible, autoluminescent plants could be utilized to …


Understanding The Genetic Diversity Of The Invasive Callery Pear, Pyrus Calleryana Decne. In Native And Introduced Ranges Of The U.S. Using Microsatellite Loci, Shiwani Sapkota Aug 2021

Understanding The Genetic Diversity Of The Invasive Callery Pear, Pyrus Calleryana Decne. In Native And Introduced Ranges Of The U.S. Using Microsatellite Loci, Shiwani Sapkota

Masters Theses

Pyrus calleryana Decne. (Callery pear) is a deciduous tree native to China, Japan, Korea, and Taiwan. In the early 1900s, this species was initially brought in the U.S. to assist with disease resistance to fire blight-causing bacteria Erwinia amylovora Burrill. via hybridization with P. communis L. Since then, many popular ornamental hybrid cultivars of P. calleryana have been developed. ‘Bradford’ is the most well-known P. calleryana cultivar in the U.S. Today, P. calleryana has become an extremely common invasive tree species that is naturalized across the eastern U.S. Knowledge on genetic diversity and population structure of P …


Supplementing East Tennessee Landscapes For Pollinators With Native Perennials, Amani Khalil Aug 2021

Supplementing East Tennessee Landscapes For Pollinators With Native Perennials, Amani Khalil

Masters Theses

Tennessee, home to the Great Smoky Mountains, is a biodiversity hotspot for many plant and animal species, yet it receives relatively few conservation dollars (Jenkins et al., 2015). As a biodiversity hotspot, this region may be home to many endemic species, but little is known about the abundance or diversity of insect pollinators. In order to both estimate pollinator communities in East Tennessee and pollinator forage preferences for native Tennessee plants, we established four plots, comprised of three plant families across five common land use types. Over two field seasons we collected nearly 7,300 insect specimens with a total sampling …


Determining Critical Fall Height For Bermudagrass Grown On Sand And Native Soil Root Zones, Taylor L. Williams May 2021

Determining Critical Fall Height For Bermudagrass Grown On Sand And Native Soil Root Zones, Taylor L. Williams

Masters Theses

Surface hardness is typically measured using a Clegg Impact Soil Tester (ASTM F355-D), but recent trends in sports turf are to use the F355-E missile as a potential alternative, because it may provide a more meaningful measurement. Forty traffic events were applied to ‘Tifway’ bermudagrass grown in an ASTM constructed sand root zone and a silt loam soil on the Center for Athletic Field Safety at the University of Tennessee. An F355-E was used to measure head injury criteria (HIC) for both root zones after every eight traffic events. Head injury criteria values were regressed to varying drop heights to …


Identifying Drought Tolerance Traits In Tennessee Soybean Genotypes: Recovery From Severe Water Deficit Stress, Samuel W. Purdom May 2021

Identifying Drought Tolerance Traits In Tennessee Soybean Genotypes: Recovery From Severe Water Deficit Stress, Samuel W. Purdom

Masters Theses

Ninety-four percent of U.S. grown soybeans are produced under rainfed conditions with intermittent droughts occurring late in the season during reproductive growth stages. Due to the temporary nature of drought, the ability of a crop to survive and recover effectively from water deficit stress is important for ensuring yield stability. In 2019 and 2020, two greenhouse experiments and two field studies were conducted to screen eleven soybean genotypes for transpiration response and recovery from water deficit stress and high vapor pressure deficit (VPD). In the first greenhouse study, soybean plants were grown in pots sealed to prevent evaporation and plants …


Examining The Maternal Investment Of The Calyptra And Its Influence On The Sporophyte Offspring, Alessandra Marie Cabrera Aromin May 2021

Examining The Maternal Investment Of The Calyptra And Its Influence On The Sporophyte Offspring, Alessandra Marie Cabrera Aromin

Masters Theses

Maternal care is a critical component of offspring survival, development, and fitness in many organisms. In early diverging lineages of plants (mosses, liverworts, and hornworts), offspring sporophytes are physically attached to and nutritionally dependent on the maternal gametophyte throughout their lifespan. Mosses have a unique structure that is a maternal cap of gametophyte tissue that covers the sporophyte apex during critical developmental stages. The calyptra has shown to positively impact sporophyte survival and fitness. My research examines the influence of calyptra size on sporophyte growth and development.


Modeling Emergence Of Annual Bluegrass (Poa Annua L.) In Hybrid Bermudagrass [C. Dactylon (L.) Pers. X C. Transvaalensis Burtt-Davy], Dallas Rose Taylor May 2021

Modeling Emergence Of Annual Bluegrass (Poa Annua L.) In Hybrid Bermudagrass [C. Dactylon (L.) Pers. X C. Transvaalensis Burtt-Davy], Dallas Rose Taylor

Masters Theses

Annual bluegrass (Poa annua L.; ABG) is a troublesome weed of turfgrass systems. A model to predict ABG emergence patterns could aid in timing measures to control ABG. Field research was initiated in January 2019 at the East Tennessee AgResearch & Education Center (ETREC) (Knoxville, TN) to better understand environmental conditions associated with ABG emergence. Plots (1 m2) included both hybrid bermudagrass [C. dactylon (L.) Pers. x C. transvaalensis Burtt-Davy, cv. ‘Tifway’, at a 1.5 cm cutting height] and bare soil. Emerged ABG inside a 1000 cm2 area in the center of each plot was …


Drought-Stress-Inducible Synthetic Promoters In Rice (Oryza Sativa), Paolo Montano Tagaloguin May 2021

Drought-Stress-Inducible Synthetic Promoters In Rice (Oryza Sativa), Paolo Montano Tagaloguin

Masters Theses

Drought can potentially affect the global rice supply. Recent climate modeling studies projected a more frequent and intense drought scenario, especially in top producing and exporting countries worldwide. Several drought-tolerant genes had been identified in recent years, and transgenic approaches had been employed to develop drought-tolerant rice. However, the constitutive expression of some drought-tolerant genes resulted in undesirable phenotypes and metabolic burden. The use of an inducible synthetic promoter is advantageous in preventing the possible pleiotropic effects from constitutively expressing a drought-tolerant gene. In this study, rationally designed synthetic promoters based on poplar (Populus trichocarpa) cis-motifs were …