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Genetic Modification Of Switchgrass (Panicum Virgatum L.) For Improvement Of Plant Architecture, Biomass Productivity And Sugar Release Efficiency For Biofuel, Wegi Aberra Wuddineh

Doctoral Dissertations

Switchgrass (Panicum virgatum L.) is a leading candidate bioenergy crop for sustainable biofuel production. To ensure its economic viability, tremendous improvements in switchgrass biomass productivity and recalcitrance to enzymatic saccharification are needed. Genetic manipulation of lignin biosynthesis by targeting transcriptional regulators of higher level domains of lignin biosynthesis and other complex traits could alter several bioenergy-desirable traits at once. A three-pronged approach was made in the dissertation research to target one plant growth regulator and transcription factors to alter plant architecture and cell wall biosynthesis.

Gibberellin (GA) catabolic enzymes, GA 2-oxidases (GA2oxs), were utilized to alternatively modify the lignin …

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 …

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 …

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. …