Plant Sciences Commons^™

Foliar Symptoms Of Acute Ozone Injury And Exposure Response Characteristics Of Select Native Perennials, Susan Denise Frey

Graduate Theses and Dissertations

Twenty seven perennial species native to the Eastern Temperate Forests Level I Ecoregion were exposed to an acute ozone (O3) treatment consisting of a target peak O3 concentration of 2.0 ppm for 30 minutes in a closed chamber environment, during the summer of 2010. Plants were evaluated for visible foliar injury symptoms and symptoms were described and photographically documented. Ten of the 27 species developed visible foliar injury in which interspecific and intraspecific response to O3 was observed. A severity index was used to compare response to acute ozone exposure for the ten species displaying visible foliar injury. Species showing …

Rice (Oryza Sativa) Response To Low Glyphosate Rates As Influenced By Cultivar, Growth Stage, And Imazethapyr Applications, Jason R. Meier

Graduate Theses and Dissertations

Off-target movement of glyphosate onto rice is a perennial concern when rice is grown in close proximity to glyphosate-tolernat crops. If differential tolerance to sub-lethal rates of glyphosate exists among rice (Oryza sativa) cultivars, these cultivars could be utilized in breeding programs or glyphosate-drift sensitive areas. Field and greenhouse experiments were conducted in 2006 and 2007 to examine differences among rice cultivars in response to sub-lethal rates of glyphosate, and to examine imidazolinone-tolerant rice response to imazethapyr and sub-lethal rates of glyphosate applied sequentially to determine the potential for either herbicide to predispose rice to greater injury. In the field …

Earthworms Of Arkansas And Contributions Of Earthworm Evolutionary Origin And Ecological Group To Nitrogen Cycling In A Model Soil And Tall Fescue System, Peter John Tomlinson

Graduate Theses and Dissertations

Evolutionary origin and ecological niche may impact how earthworm species affect N cycling. Tall fescue (Lolium arundinaceum (Schreb) S. J. Darbysh) infection with the toxic endophyte Neotyphodium coenophialum Glenn, Bacon & Hanlin (E+) may influence earthworm communities in soil compared to non-toxic endophyte (NE+) infected tall fescue. Conversely, different earthworms may contribute different amounts of N to E+ vs. NE+ tall fescue. A field survey was conducted from January 2007 to January 2008 to determine the impact of E+ and NE+ tall fescue, planting date, and seasonal variables, e.g. soil temperature and moisture, on earthworm species, abundances, and population …

Determination Of Poultry Litter's Nitrogen-Fertilizer Value For Winter Wheat Production, Brett Lee Gordon

Graduate Theses and Dissertations

Nitrogen (N) availability in poultry litter (PL) applied in the fall as a nutrient source for winter wheat (Triticum aestivum L.) has not been adequately characterized. Our objective was to determine a potentially available N (PAN) coefficient based on the inorganic-N fertilizer equivalence (FEQ) of fall-applied PL to winter wheat via field and laboratory research. Wheat grown at six site-years received 0, 84 and 168 kg N ha-1 as PL applied preplant and/or at-planting. The FEQ of PL-N was based on growth and yield responses of wheat fertilized with 22 to 191 kg N ha-1 applied in late winter as …

Characterization And Molecular Analysis Of University Of Arkansas Peach, Prunus Persica (L.) Batsch, Flesh Types And Development Of A Post-Harvest Evaluation Protocol For Arkansas Peach And Nectarine Genotypes, Paul James Sandefur

Graduate Theses and Dissertations

This study determined the effect of pre-cold storage treatment on P. persica genotypes, developed a protocol for the evaluation of breeding selection and cultivar storage performance, and provided information on post-harvest performance of these individuals. Additionally, characterization of the peach and nectarine flesh types, validation of endopolygalacturonase (endoPG) DNA markers, and investigation of endoPG marker allele combinations associated with the slow-melting-flesh (SMF) trait were done.

Fruit from 30 individuals were harvested at minimum- and well-mature states. After conditioning for 24 h at 20 ◦C, all 2010 fruit were exposed to 2 min of 1 ◦C 100 ppm chlorinated hydro-cooling, a …

Bryoecology In The American Southwest: Patterns Of Biodiversity And Responses To Global Change, John Carroll Brinda

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation combines investigation of the large-scale responses of bryophyte species diversity and distribution with small-scale physiological adaptations to global change. These two areas of inquiry are linked because one way to predict plant species responses to global change is to examine their distribution across current ecological gradients produced by factors such as latitude and elevation. By examining these biogeographic patterns one can identify those species that have a narrow tolerance and therefore are most sensitive to change. Selected bryophytes might then be used as indicator species in long-term monitoring programs. Where historical data exist, these can be used to …

The Role Of Albino3 And The Lipid Environment In Chloroplast Signal Recognition Particle Targeting, Nathan Lewis

Graduate Theses and Dissertations

Signal recognition particles (SRPs) in pro- and eukaryotes function in cotranslational targeting of nascent poplypeptides to an SRP receptor at the target membrane. A unique chloroplast SRP (cpSRP) functions post-translationally to direct light-harvesting chlorophyll-binding proteins (LHCPs) to the receptor cpFtsY at the thylakoid membrane for LHCP insertion in a process involving the integral membrane protein Albino3 (Alb3) and requiring GTP. Work here focuses on understanding cpSRP targeting events at the thylakoid membrane, specifically those involving Alb3 and the lipid environment.

We show an interaction between the novel cpSRP subunit cpSRP43 and the soluble, stromal-exposed C terminus of Albino3 (Alb3-Cterm). We …