Life Sciences Commons^™

Reproduction And Bioconfinement Of Mir156 Transgenic Switchgrass (Panicum Virgatum L.), Chelsea Renai Johnson

Masters Theses

Genetic engineering of switchgrass (Panicum virgatum L.), an emerging cellulosic bioenergy feedstock, has been performed to alter cell walls for improved biofuel conversion. However, gene flow from transgenic switchgrass presents regulatory issues that may prevent commercialization of the genetically engineered crop in the eastern United States. Depending on its expression level, microRNA156 (miR156) can reduce, delay or eliminate flowering, which may be useful to mitigate transgene flow. However, flowering transition is dependent upon both environmental and genetic cues. In this study of transgenic switchgrass, two low (T14 and T35) and two medium (T27 and T37) miR156 overexpressing ‘Alamo’ lines …

Uncovering Tasselsheath3. A Genomic And Phenotypic Analysis Of A Maize Floral Mutant., Thompson Zhang

Masters Theses

In the modern era, maize has become the most successful crop grown in the United States. According to the USDA over 90 million acres of land are planted to corn and 96.2% of the U.S feed grain production is made up of the cereal. Part of the success of maize is due to its floral architecture, and its pollination technique in which the flower opens, exposing stamens containing pollen into the air. A unique organ called the lodicule functions as a release mechanism, forcing the flower to open. Lodicules from grasses and eudicot petals are homologous, yet there is little …

Extractable And Non-Extractable Polyphenols From Apples: Potential Anti-Inflammatory Agents, Makenzi Gennette

Masters Theses

With diet being such a huge factor in the development of diseases, emerging research has supported that apple consumption is a promising candidate for disease prevention due to the high phenolic content it possesses. These polyphenols can be found in two forms: extractable polyphenols (EP) and non-extractable polyphenols (NEP). Polyphenols have been shown to have strong anti-inflammatory and anti-oxidant properties, but up until this point, most researchers focus on EP fractions, while NEP are neglected. After the EP extraction using acetone and acetic acid (99:1) from the Apple Boost powder, three additional extraction methods were conducted on the remaining powder …

The Impact Of Genetic And Environmental Factors On Phytonutrient Concentrations Within Leafy Specialty Crops In Controlled Environments, Rosalie M. Metallo

Masters Theses

Specialty leafy greens are excellent sources of antioxidants, vitamins, and minerals. Many of these metabolites are influenced by microclimate environmental conditions and genotype. The objective of this thesis was to measure the impacts of abiotic factors on plant growth and development along with nutritional content of specialty leafy greens in controlled environments. Chapter one looks at changes in biomass and nutritional content of different microgreen cultivars grown in a greenhouse over four growing seasons. Chapter two looks at the influence of light-emitting diode (LED) treatments on the growth and nutritional content of hydroponically grown kale. The morphology and nutritional content …

Investigation Of Cytochrome P450 Monooxygenases In S. Homoeocarpa For Chlorothalonil Biotransformation, Robert Green

Masters Theses

Sclerotinia homoeocarpa (F.T. Bennett) is one of the most economically important pathogens on high amenity cool-season turfgrasses where it causes dollar spot. Due to decades of over-reliance and repeated chemical treatments, S. homoeocarpa has developed resistance and insensitivity to multiple classes of fungicides. To understand the genetic mechanisms of fungicide resistance, the whole genomes of two strains with varying resistance levels to fungicides, were sequenced. In unpublished data (Sang et al.), a RNA-sequencing analysis revealed three CYP450s that were validated to play a functional role in S. homoeocarpa’s resistance against different fungicide classes. We also identified CYP450 metabolic action …

Foliar Mineral Accumulation Patterns Of Gypsophiles And Their Relatives From The Usa And Spain, Clare Muller

Masters Theses

Gypsum endemism in plants (gypsophily) is common on gypsum outcrops worldwide, but little is known about the functional ecology of Chihuahuan Desert gypsophiles. We investigated whether leaf chemistry of gypsophile lineages from the northern Chihuahuan Desert are similar to leaves of related non-endemic (gypsovag) species relative to their soil chemistry. We expected widely-distributed gypsophiles, hypothesized to be older lineages on gypsum, would have distinct leaf chemistry from narrowly-distributed, relatively younger lineages endemic to gypsum and gypsovags, reflecting adaptation to gypsum. We collected leaves from 23 gypsophiles and related non-endemic taxa growing on non-gypsum soils. Soils and leaves were analyzed for …

Evaluation Of Hall’S Panicgrass (Panicum Hallii Vasey) As A Model System For Genetic Modification Of Recalcitrance In Switchgrass (Panicum Virgatum (L.)), Joshua Nathaniel Grant

Masters Theses

While switchgrass (Panicum virgatum (L.)) has long been recognized as a viable bioenergy feedstock, it and other plants have cell walls with recalcitrance to processing. Recalcitrance is recognized as a major barrier to broad adoption of switchgrass and other feedstocks for cellulosic bioenergy. In an effort to reduce recalcitrance, transgenic plants have been generated with altered cell wall phenotypes such as reduced lignin. Unfortunately, stable transformation of switchgrass and other C4 grasses is time intensive, costly, and genetic analysis is further complicated by polyploid genomic structures. Unlike switchgrass, which can be tetraploid to octoploid, a closely related species, Hall’s …

Protein, Methionine, And Cysteine Upregulation In Phaseolus Vulgaris ‘Black Turtle Bean’ Seeds Through Sulfur Fertilization At V2 And R2 Stages Of Growth, Hannah Paige Barry

Masters Theses

The purpose of this research was to increase protein, methionine, and cysteine content in Phaseolus vulgaris L., common bean in relation to the inhibitory compound tannin. Previous research has shown that sulfur fertilization increases total protein, methionine and cysteine content in various crops, but always in tandem with inhibitory compound increases. If successful, the resulting bean seed will have a better nutrient profile for malnourished populations around the world.

Granular gypsum was applied at 0 kg S ha^-1 [kilograms of sulfur per hectare], 10 kg S ha^-1, 20 kg S ha^-1, 40 kg S ha …

Effect Of The Mutant Danbaekkong Or Stem Termination Alleles On Soybean Seed Protein Concentration, Amino Acid Composition, And Other Seed Quality And Agronomic Traits, Mia Justina Cunicelli

Masters Theses

Soybean [Glycine max (L.) Merr.] is the world’s leading source of vegetable oil and high quality protein meal. Increasing soybean protein concentration through selection while maintaining oil concentration and yield has been a constant goal for plant breeders, as there is a negative correlation between protein and oil and protein and yield. The objective of this study was to determine if marker assisted selection (MAS) for the Danbaekkong (Dan) protein allele influences agronomic and seed quality traits. A population of 24 F_8:10 [eighth filial generation advanced to the tenth filial generation] near isogenic lines (NILs) of soybean was …

Comparative Transcriptome Analysis Of Wild Tomato Species During Fruit Development, Altynay Zhanayeva

Masters Theses

Fleshy fruits in different species can display large variation in color. A link between fruit color and seed dispersal success is suggested by previous studies showing that high intensity of fruit color increases the visitation rate in seed-dispersing birds. Wild tomato species (Solanum spp.) are excellent model organisms for research on genetic basis of differential fruit color development during the ripening process. Despite polymorphism in fruit color, all tomato species have yellow flowers due to accumulation of carotenoid pigments, which suggests that the carotenoid pathway is intact. Thus, regulatory changes controlling enzymes activity during fruit maturation are likely …

Comparative Leaf Anatomy Of C3 And Cam Species In Oncidiinae (Maxillarieae, Orchidaceae), Samuel A. Eident

Masters Theses

The subtribe Oncidiinae is a diverse group of mostly epiphytic orchids within the tribe Maxillarieae, consisting of 55 genera and 1700 species. In this group, there have been many studies examining morphological and anatomical variation as well as metabolic pathways of carbon fixation, but most have not integrated morphological and anatomical variation with a physiological aspect of inquiry. The objective of my research was to establish a suite of anatomical characteristics that can be used to distinguish between C₃ and CAM species. Secondarily, I hoped to use that suite of characteristics in determining whether intermediate CAM species (those that …

Evaluation Of Ecto-Mycorrhizae As A Determinant Of Chestnut Growth And Stress Response, Pabitra Aryal

Masters Theses

Although agriculture focuses on row crops throughout much of the Midwest, chestnut (Castanea spp.) appears to be an agroforestry crop well suited as a sustainable alternative to row crops in areas prone to erosion. As ectomycorrhizal (ECM) colonization is often crucial for tree establishment and production, I addressed the importance of ECM colonization on chestnut performance by assessing 1) natural ECM colonization in an established chestnut orchard and 2) the effect of experimental ECM inoculation on seedling establishment and drought response in a greenhouse. In the established orchard, I selected 50 Chinese-American hybrid chestnuts (C. mollisima x C. dentata …