Life Sciences Commons^™

Molecular Breeding Strategies For Improvement Of Complex Traits In Soybean, Christopher Joseph Smallwood

Doctoral Dissertations

Soybean [Glycine max (L.) Merrill] is the leading oilseed crop grown in the world. Yield, fatty acids, protein, and oil are commercially important soybean traits; thus evaluation of breeding strategies for improvement of these traits is merited. To accomplish this, a comparison of molecular and phenotypic breeding strategies from progeny row selections was performed. From this it was determined that molecular strategies consistently outperformed phenotypic selections (PS) in the progeny row stage for soybean yield, fatty acids, protein, and oil. For yield, Epistacy was the preferred selection method. For fatty acids, protein, and oil, the genomic selection (GS) strategies were …

Confirming Resistance To Prodiamine And Glyphosate In A Single Annual Bluegrass (Poa Annua L.) Biotype From Tennessee, Shane Matthew Breeden

Masters Theses

Annual bluegrass (Poa annua L.; POAAN) is a cool-season weed that commonly infests warm-season turfgrasses during winter dormancy. In spring 2012, poor POAAN control (<50%) was reported on golf course roughs in Alcoa, TN (35.75 °N, -83.88 °W) following treatment with a tank mixture of prodiamine (1120 g ha^-1[hectare]) and glyphosate (840 g ae ha^-1) during bermudagrass dormancy. The objective of this research was to determine if this POAAN biotype was resistant to prodiamine and glyphosate.

Using mature plants from the field, 81 of the 100 selections were not controlled by glyphosate and prodiamine; 96 of the 100 selections were not controlled by glyphosate, while 84 were unaffected by prodiamine. Only a single plant sampled was susceptible to both herbicides. …

Improving Management And Species Selection Of Warm-Season Forage Grasses For Southeast Production Systems, Christine Helen Gelley

Masters Theses

Beef producers need drought tolerant options when selecting forage grasses and also practical methods to estimate forage nutritive value, which this study aims to provide for warm-season grasses. The objective of the first experiment was to develop estimates of warm-season forage nutritive value and herbage mass based on harvest timing. The experiment was conducted from 2013 to 2015 at the University of Tennessee Plateau AgResearch and Education Center (PREC) in Crossville, TN. Four species were evaluated, each for two years: bermudagrass [Cynodon dactylon (L.) Pers. cv. Vaughn’s # 1], switchgrass [Panicum virgatum (L.) cv. Alamo], sorghum-sudangrass [Sorghum …

Potential Interaction Between Pre- And Post-Emergence Herbicides And The Efficacy Of Insecticide And Fungicide Seed Treatments In Cotton, Cory Joseph Vineyard

Masters Theses

An apparent reduction in the performance of neonicotinoid seed treatments in controlling thrips, especially in cotton, has been observed, which has coincided with the increased use of both pre- and post-emergence herbicides to control glyphosate-resistant weeds. The objective of this research was to evaluate the potential interactions of both pre- and post-emergence herbicides on the efficacy of insecticide and fungicide seed treatments in cotton

Aldicarb along with imidacloprid and thiamethoxam seed treatments reduced thrips numbers compared with non-treated seed. However, thiamethoxam did not provide effective control. Some pre-emergence herbicide treatments reduced plant health. While there was evidence that thrips injury …

Rare Occurrences Of Free-Living Bacteria Belonging To Sedimenticola From Subtidal Seagrass Beds Associated With The Lucinid Clam, Stewartia Floridana, Aaron M. Goemann

Masters Theses

Lucinid clams and their sulfur-oxidizing endosymbionts comprise two compartments of a three-stage, biogeochemical relationship among the clams, seagrasses, and microbial communities in marine sediments. A population of the lucinid clam, Stewartia floridana, was sampled from a subtidal seagrass bed at Bokeelia Island Seaport in Florida to test the hypotheses: (1) S. floridana, like other lucinids, are more abundant in seagrass beds than bare sediments; (2) S. floridana gill microbiomes are dominated by one bacterial operational taxonomic unit (OTU) at a sequence similarity threshold level of 97% (a common cutoff for species level taxonomy) from 16S rRNA genes; …

Interactions Among Insect Defoliation, Insecticide Treatments, And Growth Rate In American And Hybrid Chestnuts, Ashley Elizabeth Case

Masters Theses

The American chestnut, Castanea dentata, was once one of the most useful and abundant canopy trees in eastern North American forests. Over the last 200 years, the species has been decimated by two exotic pathogens, Phytophthora cinnamomi and Cryphonectria parasitica, killing millions of trees and reducing surviving Castanea dentata to short-lived sprouts. Cryphonectria parasitica-resistance breeding programs are currently producing advanced backcross generations, which are being compared with pure American chestnut in field tests of growth performance and Cryphonectria parasitica resistance. The Asiatic oak weevil, Cyrtepistomus castaneus, has been identified as a common defoliator of chestnut seedlings in these …

Long-Term Impacts Of Conservation Management Practices On Soil Carbon Storage, Stability, And Utilization Under Cotton Production In West Tennessee, Candace Brooke Wilson

Masters Theses

Biogeochemical cycling of soil carbon (C) is heavily influenced by conservation agricultural (CA) practices. This study examined SOC stability under three CA practices: reduced nitrogen (N) fertilizer application rate, cover cropping, and zero-tillage implemented for 31 years. Respiration rates measured from a 602-day incubation period were fitted to a double-pool first order exponential model of SOC decomposition. The active [respired] SOC pool showed distinct differences between applications of reduced (34N kg ha^-1 [-1]) and high fertilization rates (101N kg ha^-1) combined with tillage, and suggest that high fertilizer applications with conventional tillage allocated more C into a …

Cowpea Adaptability To Southeastern Organic Farming Systems: Forage Productivity And Charcoal Rot Susceptibility, Samantha Lindsey Hill

Masters Theses

Cowpea (Vigna unguiculata (L.) Walp.) is a warm-season, multi-purpose legume that is well-adapted to the southeastern USA and has many traits that make it an attractive forage or cover crop for integration into organic production systems, including high rates of nitrogen (N) fixation, phosphorus (P) use efficiency, regrowth ability, and high digestibility. Eight cowpea varieties were evaluated under organic management at two locations in summer 2014 for stand establishment, forage yield and quality, and weed biomass.

Charcoal rot [Macrophomina phaseolina (Tassi) Goid.] is a fungal disease that is economically important to many host plant species. High temperatures and …

Physiological Evaluation And Root Morphological Differences Associated With Novel Drought Tolerant Corn (Zea Mays L.) Hybrids, Austin Gentry Scott

Masters Theses

Corn hybrids designated “drought tolerant” (DT) from three commercial seed companies were evaluated in order to determine the benefit of DT technology in a mid-south environment that may receive adequate but often poorly timed rainfall. Field research was conducted in 2014 and 2015 at Milan, TN where hybrid response to stress was evaluated at two planting dates and in non-irrigated and irrigated environments and greenhouse research was conducted in Jackson, TN to evaluate early season drought to plant physiology and root structure.

In 2014 and 2015, the non-irrigated trials received enough rainfall to create a high yielding environment. Since the …

Developing Expressed Sequence Tag Libraries And The Discovery Of Simple Sequence Repeat Markers For Two Species Of Raspberry (Rubus L.), Jill M. Bushakra, Kim S. Lewers, Margaret E. Staton, Tetyana Zhebentyayeva, Christopher A. Saski

Entomology & Plant Pathology Publications and Other Works

Background

Due to a relatively high level of codominant inheritance and transferability within and among taxonomic groups, simple sequence repeat (SSR) markers are important elements in comparative mapping and delineation of genomic regions associated with traits of economic importance. Expressed sequence tags (ESTs) are a source of SSRs that can be used to develop markers to facilitate plant breeding and for more basic research across genera and higher plant orders.

Methods

Leaf and meristem tissue from ‘Heritage’ red raspberry (Rubus idaeus) and ‘Bristol’ black raspberry (R. occidentalis) were utilized for RNA extraction. After conversion to cDNA …

Substantial Genome Synteny Preservation Among Woody Angiosperm Species: Comparative Genomics Of Chinese Chestnut (Castanea Mollissima) And Plant Reference Genomes, Margaret Staton, Tetyana Zhebentyayeva, Bode Olukolu, Guang Chen Fang, Dana Nelson, John E. Carlson, Albert G. Abbott

Entomology & Plant Pathology Publications and Other Works

Background

Chinese chestnut (Castanea mollissima) has emerged as a model species for the Fagaceae family with extensive genomic resources including a physical map, a dense genetic map and quantitative trait loci (QTLs) for chestnut blight resistance. These resources enable comparative genomics analyses relative to model plants. We assessed the degree of conservation between the chestnut genome and other well annotated and assembled plant genomic sequences, focusing on the QTL regions of most interest to the chestnut breeding community.

Results

The integrated physical and genetic map of Chinese chestnut has been improved to now include 858 shared sequence-based markers. …

Sources Of Heat In Synthetic Turf Systems, Adam William Thoms

Doctoral Dissertations

With options for cooling synthetic turf limited, an outdoor experiment was conducted at the University of Tennessee Center for Athletic Field Safety (Knoxville, TN) to develop a model to predict maximum, minimum, and mean synthetic turf surface temperature using forecasted atmospheric conditions. Synthetic turf surface temperature varied due to both air temperature and solar radiation. Predictive models using these data accounted for 86, 95, and 94% of the variation in daily maximum, minimum, and mean synthetic turf surface temperature. Accuracy of these models for predicting daily mean and minimum synthetic turf surface temperature using 48 and 72-hour forecasted air temperature …

Evidence Of Late Quaternary Fires From Charcoal And Siliceous Aggregates In Lake Sediments In The Eastern U.S.A., Joanne P. Ballard

Doctoral Dissertations

The late-glacial transition to the Holocene, 15,000–11,600 cal yr BP, is an enigmatic period of dynamic global changes and a major extinction event in North America. Fire is an agent of disturbance that transforms the environment physically and chemically, and affects plant community composition. To improve understanding of the linkages between fire, vegetation, and climate over the late glacial and Holocene in the eastern U.S., I analyzed lake-sediment cores for charcoal and indicators of wood ash, and compared results to existing pollen records. A new microscopic charcoal record from Anderson Pond, Tennessee revealed high fire activity from 23,000–15,000 cal yr …

Calmodulin-Like Protein 38: A Component Of Ribonucleoprotein Particles During Hypoxic Stress Responses In Arabidopsis, Ansul Lokdarshi

Doctoral Dissertations

Waterlogging stress leads to a crisis in energy metabolism and the accumulation of toxic metabolites due to the hypoxic and/or anoxic environment associated with this condition. To respond and adapt to this situation, higher plants employ an integrated genetic program that leads to the induction of anaerobic response polypeptide genes that encode metabolic and signaling proteins involved in altering metabolic flow and other adaptive responses. The study presented here shows that the Arabidopsis thaliana calmodulin-like protein CML38 is calcium sensor protein that serves as a member of the core anaerobic response gene family and is involved in modulating the survival …

Cellular Localization And Metabolomic Analysis Of The Arabidopsis Thaliana Major Intrinsic Protein Nip2;1: A Root-Specific Lactic Acid Transporter Induced In Response To Hypoxic Stress, Taylor K. Fuller

Chancellor’s Honors Program Projects

No abstract provided.

Economic And Environmental Optimization In The Supply Of Switchgrass In Tennessee, Jia Zhong

Masters Theses

The low efficiency of collection, storage and transportation in the switchgrass supply chain has hindered the commercialization of a switchgrass-based biofuel industry, even given its ecological and environmental advantages in carbon sequestrate, soil quality, water use, and pollution pressure. Thus, designing a switchgrass-based supply chain balancing both environmental and economic performance is important to expedite the development of the cellulosic biofuel industry to meet the national energy plan.

The objectives of this study are to 1) determine economic cost and multiple environmental outcomes in feedstock supply chains and 2) identify the relation between the economic and environmental performances. The first …

Population Structure Of Late Blight (Phytophthora Infestans) In Colombia And Ecuador And Downy Mildew (Peronospora Farinosa F. Sp. Spinaciae) On Spinach In Arizona And California, Rebecca Marie Lyon

Masters Theses

In this study, Phytophthora infestans and Peronospora farinosa f. sp. spinaciae populations were analyzed using single nucleotide polymorphisms (SNPs). In Ecuador and Colombia, Phytophthora infestans causes significant damage to potato and tomato and the epidemiology is known to be highly clonal. Our objective was to measure population structure within the context of this clonal epidemiology using both synonymous and nonsynonymous markers. Candidate SNP sites were selected by comparing the draft genomes of the Ecuadorian isolates EC1-3527 and EC1-3626. Genotypes were assessed directly from infected tissue using a targeted sequencing approach. A total of 54 polymorphic sites were assessed in 93 …

Comparison Of Seed Yield, Oil And Phenotypic Traits Among Selected Parents And Crosses Of Niger, Victoria Grace Benelli

Masters Theses

Niger (Guizotia abyssinica (L.f) Cass.) is primarily marketed as favorite seed among American goldfinches (Carduelis tristis) as well as pine siskin, redpoll, house finches, and ground feeding birds like quail and dove. As a part of a balanced diet, it is crucial for these species to consume a higher percentage of fats than other bird species. Fourteen niger accessions of Indian, Ethiopian, and American origin were obtained from USDA/ ARS germplasm collection at Pullman, WA and planted in August 2012 at the East Tennessee Research & Education Center. Five of these accessions were crossed to form different …

Identification And Molecular Characterization Of The Switchgrass Ap2/Erf Transcription Factor Superfamily, And Overexpression Of Pverf001 For Improvement Of Biomass Characteristics For Biofuel, Wegi A. Wuddineh, Mitra Mazarei, Geoffrey B. Turner, Robert W. Sykes, Stephen R. Decker, Mark F. Davis, Neal Stewart

Plant Sciences Publications and Other Works

The APETALA2/ethylene response factor (AP2/ERF) superfamily of transcription factors (TFs) plays essential roles in the regulation of various growth and developmental programs including stress responses. Members of these TFs in other plant species have been implicated to play a role in the regulation of cell wall biosynthesis. Here, we identified a total of 207 AP2/ERF TF genes in the switchgrass genome and grouped into four gene families comprised of 25 AP2-, 121 ERF-, 55 DREB (dehydration responsive element binding)-, and 5 RAV (related to API3/VP) genes, as well as a singleton gene not fitting any of the above families. The …

Map Supplements For The Metallic Woodboring Beetles (Coleoptera: Buprestidae) Of Tennessee, William E. Klingeman Iii, Jason A. Hansen, Joshua P. Basham, Jason B. Oliver, Nadeer N. Youssef, Whitney Swink, Christine A. Nalepa, Donna C. Fare, J. Kevin Moulton

Plant Sciences Publications and Other Works

Following compilation of distribution records and seasonal flight activity information for 106 metallic wood-boring beetle (Coleoptera: Buprestidae) species for Tennessee, maps were updated to provide county-level collection notations for 10,543 published records and specimen collections made from 1934 to 2013. County collection tallies across the ecoregions in Tennessee are also presented. Maps for individual species highlight gaps in key geographic areas where specimens have not been collected and can be valuable for future biosurveillance, monitoring and management efforts for these economically and ecologically important insects.

Cassava (Manihot Esculenta Crantz) Tuber Quality As Measured By Starch And Cyanide (Hcn) Affected By Nitrogen, Phosphorus, And Potassium Fertilizer Rates, Ivan Bernardo Cuvaca, Neal Eash, Svetlana Zivanovic, Dayton Mcgregor Lambert, Forbes R. Walker, B. Rustrick

Biosystems Engineering and Soil Science Publications and Other Works

Cassava (Manihot esculenta Crantz) is an important subsistence crop for many poor rural families in Africa. Cassava contains cyanogenic glucosides (linamarin and lotaustralin) which liberate hydrogen cyanide (HCN) during tuber processing. Once liberated, HCN attaches to the processed tuber. Continuous consumption of processed tuber containing high HCN concentration coupled with low protein intake causes Konzo – a paralyzing disorder that impacts children and women of childbearing age. There are ways to reduce HCN concentration during tuber processing; however, this can also reduce the overall starch content in the cassava tuber. A study comprising twenty treatments consisting of different combinations of …

Enhancing The Sustainability Of Integrated Biofuel Feedstock Production Systems, Amanda Joy Ashworth

Doctoral Dissertations

As use of second-generation biofuel crops increases, so do questions about sustainability, particularly their potential to affect fossil energy consumption and greenhouse gas emissions. Nitrogen (N)-fixing legumes interseeded into switchgrass (Panicum virgatum L.) may be an alternative to inorganic fertilizer in forage-feedstock systems. Research herein is divided into four general experiments: I). N replacement and feedstock impacts from legume intercrops and biochar in switchgrass; II). N-fixation rates in intercrop systems; III). impacts of biofuel systems under enhanced climate change; and, IV). projected sustainability of regional switchgrass production. Approaches included: characterization of feedstock/forage quality traits based on legume, biochar and …

Influence Of Aminocyclopyrachlor Plus Metsulfuron On Seedhead Development And Forage Quality In Tall Fescue, Trevor Davis Israel

Doctoral Dissertations

This research quantified the level of seedhead suppression, injury, total ergot alkaloid changes, and forage quality changes in endophyte-infected tall fescue resulting from spring applications of aminocyclopyrachlor (ACP) plus metsulfuron (MET). Results indicated that ACP plus MET reduced tall fescue seedhead density 53 to 55% but also reduced yield 39 to 51% at spring harvest. ACP plus MET also reduced total ergot alkaloid concentration 28 to 34% and improved crude protein (CP) and relative forage quality (RFQ).

This research also determined the impact of ACP plus MET application timing and rate on tall fescue injury and weed control. Spring and …

Development And Evaluation Of A Cost Effective Plant Growth Media Moisture Sensor And Development Of An Aqueous Data Transmission System For Irrigation Purposes, Steven Michael Pickett

Masters Theses

The ability to accurately monitor and transit the moisture content of soilless growing media in the rooting zone is critical for plant-based research, production of high value crops, and other agricultural production. The focus of this study is the development and evaluation of a cost effective moisture sensor designed to measure the plant-available moisture content of growing media and the development of a aqueous data transmission method for relaying this information back to a central location. While there are currently many commercially available soil moisture sensors on the market, the aim of this research is not to develop a more …

Reaping The Benefits Of Conservation Tillage: Implications Of Increased Soil Organic Matter And Aggregation In Surface Soils, Kenna Elizabeth Rewcastle

Chancellor’s Honors Program Projects

No abstract provided.

Distribution Of Abc Transporter Genes Across The Plant Kingdom, Thomas Scott Lane

Masters Theses

The ATP-binding cassette (ABC) transporter gene superfamily is ubiquitous among extant organisms. ABC transporters act to transport compounds across cellular membranes and are involved in a diverse range of biological processes and functions including cancer resistance in humans, drug resistance among vertebrates, and herbicide resistance in weeds. This superfamily of genes appears to be larger and more diverse in the plant kingdom—yet, we know relatively less about ABC transporter function in plants compared with mammals and bacteria. Therefore, we undertook a plant kingdom-wide transcriptomic survey of ABC transporters to better understand their diversity.

We utilized sequence similarity-based informatics techniques to …

Diallel Analysis Of Biomass And Ethanol Yield In Leaves Versus Stems Of Lowland Switchgrass, Alexandria Christina Desantis

Masters Theses

Switchgrass (Panicum virgatum L.) is a warm season perennial grass used widely as a forage crop. This research seeks to address improving biomass yield and predicted ethanol yield through certain traits by the following objectives: (1) differences in average biomass and predicted ethanol yields from leaves versus stems, (2) genetic variance and heritability estimates of biomass and ethanol yield traits (3) general (GCA) and specific combining ability (SCA) among the five parents for biomass and ethanol yield, and (4) correlations between agronomic and morphological traits. Five parents with varying morphological traits were crossed in a diallel design, excluding selfs. …

Production, Purification, And X-Ray Crystallography Of The Potra Domains Of Pstoc75, Gabriela Jordan Little

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Plastids arose via endosymbiosis when a cyanobacterium was engulfed by a primitive eukaryote. The cyanobacterium was enslaved by the eukaryote, eventually giving rise to a new organelle, termed the plastid. The transition from a free-living cyanobacterium to a cell-dependent organelle demonstrates how the chloroplast ancestor underwent many changes in its physiology and biological processes. The majority of the DNA belonging to the cyanobacterium was scavenged by the nucleus of the host cell. This led to higher fidelity of genetic duplication, due to the proofreading abilities of the DNA polymerase of the host cell. This left the cell with the problem …

A Short-Term Assessment Of Carbon Dioxide Fluxes Under Contrasting Agricultural And Soil Management Practices In Zimbabwe, Deb O'Dell, Thomas J. Sauer, Bruce B. Hicks, Christian Thierfelder, Dayton M. Lambert, Joanne Logan, Neal S. Eash

Biosystems Engineering and Soil Science Publications and Other Works

Two of the biggest problems facing humankind are feeding an exponentially growing human population and preventing the accumulation of atmospheric greenhouse gases and its climate change consequences. Refined agricultural practices could address both of these problems. The research addressed here is an exploration of the efficacy of alternative agricultural practices in sequestering carbon (C). The study was conducted in Zimbabwe with the intent to (a) demonstrate the utility of micrometeorological methods for measuring carbon dioxide (CO2) exchange between the surface and the atmosphere in the short-term, and (b) to quantify differences in such exchange rates for a variety of agricultural …