Digital Commons Network^™

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 …

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 …

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 …