Digital Commons Network^™

Seed Germination And Seed Bank Of Scutellaria Species, Jennifer O'Brien

Undergraduate Honors Theses

Florida skullcap, Scutellaria floridana Chapm. (Lamiaceae), is a federally threatened species found in the Florida Panhandle. Its habitat is a fire-prone, longleaf pine forest dominated by Aristida stricta Michx. var. beyrichiana (wiregrass). Other Scutellaria species used in the study are found in southeastern U.S., including two within the Florida Panhandle. The objective of this study was to compare several techniques to germinate seeds of Scutellaria incana, Scutellaria lateriflora, Scutellaria ovata ssp. ovata, and Scutellaria floridana, and to access the presence of a seed bank for S. floridana. For the germination study, Scutellaria later …

Seed Ecology Of Federally Threatened Pinguicula Ionantha (Godfrey's Butterwort), Jenna Annis

Undergraduate Honors Theses

Pinguicula ionantha G. (Lentibulariaceae) is a carnivorous plant occurring in historically fire-dependent bog habitats of longleaf pine savannas. The species is limited to 6 counties within the Florida Panhandle. The species is currently listed as federally threatened due largely to habitat loss. The objective of this research is to provide the appropriate Pinguicula ionantha germination and seed bank information that would aid in the deli sting of the species. Eleven collections of Pinguicula ionantha seeds were made from natural populations. All germination trials took place in a seed germination chamber. Treatments included stratification, liquid smoke solutions, plant growth regulators (PGR), …

Agricultural Development In The Northern Savannah Of Ghana, Tara N. Wood

Doctor of Plant Health Program: Dissertations and Student Research

Since declaring independence in 1957, the Republic of Ghana has become a stable constitutional democracy. Ghana’s economy has grown substantially over the past decade, yet remains primarily agrarian, accounting for 50% of the total employment and 25% of the country’s Gross Domestic Product. Smallholder rain-fed farming using rudimentary technologies dominates the agricultural sector accounting for 80% of total agricultural production. Approximately 90% of smallholder farms are less than two hectares in size, and produce a diversity of crops. The major crops cultivated in Ghana include numerous cereal, root and tuber, leguminous, fruit, vegetable and industrial crops. Maize is the most …

Herbaceous 2013, Julia I. Chapman, Amy L. Myers, Ryan W. Mcewan

Data Files: Drew Woods Permanent Plots

Herbaceous vegetation data collected in 2013 at Drew Woods State Nature Preserve in Darke County, OH. Data key is provided in a supplemental file.

The Role Of Oswrky71 And Its Interacting Proteins In Seed Germination And Early Growth Of Cereal Grains, Margaret Ja Shin

UNLV Theses, Dissertations, Professional Papers, and Capstones

During seed germination and early seedling growth, complex molecular and physiological events occur in rice (Oryza sativa) and other cereal grains. As the seed transitions to vegetative tissue, it responds to both favorable and unfavorable environmental conditions and is vulnerable to attack by predation and disease. Although seeds are relatively small and tender in size, extensive and sophisticated molecular networks enables the immobile seed to grow, survive and adapt in its environment. One of the networks I am interested in is in the crosstalk between the gibberellin (GA) and abscisic acid (ABA) signaling pathways. These pathways are interesting because they …

Identification Of Cytokinin-Responsive Genes Using Microarray Meta-Analysis And Rna-Seq In Arabidopsis, Apurva Bhargava, Ivory Clabaugh, Jenn P. To, Bridey B. Maxwell, Yi-Hsuan Chiang, G. Eric Schaller, Ann Loraine, Joseph J. Kieber

Dartmouth Scholarship

Cytokinins are N⁶-substituted adenine derivatives that play diverse roles in plant growth and development. We sought to define a robust set of genes regulated by cytokinin as well as to query the response of genes not represented on microarrays. To this end, we performed a meta-analysis of microarray data from a variety of cytokinin-treated samples and used RNA-seq to examine cytokinin-regulated gene expression in Arabidopsis (Arabidopsis thaliana). Microarray meta-analysis using 13 microarray experiments combined with empirically defined filtering criteria identified a set of 226 genes differentially regulated by cytokinin, a subset of which has previously been …

Citrus Tristeza Virus-Host Interactions, W. O. Dawson, S. M. Garnsey, Satyanarayana Tatineni, S. Y. Folimonova, S. J. Harper, S. Gowda

Department of Plant Pathology: Faculty Publications

Citrus tristeza virus (CTV) is a phloem-limited virus whose natural host range is restricted to citrus and related species. Although the virus has killed millions of trees, almost destroying whole industries, and continually limits production in many citrus growing areas, most isolates are mild or symptomless in most of their host range. There is little understanding of how the virus causes severe disease in some citrus and none in others. Movement and distribution of CTV differs considerably from that of well-studied viruses of herbaceous plants where movement occurs largely through adjacent cells. In contrast, CTV systemically infects plants mainly by …

Physiological Response Of Kentucky Bluegrass Under Salinity Stress, Lijun Wang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Salinity is a significant stress for plants world-wide. In agriculture, salts reduce germination, overall growth, yield, and sometimes death in crop plants. Salinity similarly affects turfgrass in our urban landscapes. Kentucky bluegrass (Poa pratensis L.) is the most widely used cool-season grass in the northern part of the United States, including the cool-arid West, but generally is a salt sensitive species. The overall objectives of this study were to study the physiological responses of Kentucky bluegrass to salt stress and to evaluate the genetic similarity among the cultivars used in the research.

Four Kentucky bluegrass entries, two salt-tolerant and …

Using Student-Produced Time-Lapse Plant Movies To Communicate Concepts In Plant Biology, Marcia Harrison-Pitaniello Phd

Biological Sciences Faculty Research

Why do students think plants are “boring”? One factor may be that they do not see plant movement in real (i.e., their) time. This attitude may negatively impact their understanding of plant biology. Time-lapse movies of plants allow students to see the sophistication of movements involved in both organ development and orientation.

The objective of this project was to develop simple methods to capture image sequences for lab analysis and for converting to movies. The technology for making time-lapse movies is now easily attainable and fairly inexpensive, allowing its use for skill levels from grade school through college undergraduates. In …

Genetic Diversity Of Seed Dormancy And Molecular Evolution Of Weedy Red Rice, Te Ming Tseng

Graduate Theses and Dissertations

Rice is the grain with the third-highest global production. In the US, Arkansas is the largest rice producing state; however, an estimated 62% of the rice fields in the state are infested with red rice, and can cause up to 80% yield reduction in rice. Among its weedy traits, seed dormancy plays an important role in its persistence, and helps red rice escape weed management techniques thereby increasing the red rice soil seedbank. Red rice also has the potential to hybridize among themselves and with cultivated rice, thus resulting in diverse phenotypes and genotypes. In this study we measured variation …

Evaluating Integrated Weed Management: Russian Knapweed Control With Goat Grazing And Aminopyralid, Clarke G. Alder

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Invasion of natural communities by introduced plants is considered one of the biggest threats to biodiversity. Weeds in rangelands cause an estimated loss of $2 billion per year in the United States. These costs include losses in forage quality and yield, grazing interference, animal poisoning, lowering land values, depleting soil water and resources available to native plants, increasing costs of managing livestock, and impacts on wildlife habitat and forage. Integrated weed management (IWM) is a way for land managers such as farmers, ranchers, and government agencies to control invasive weeds. IWM uses several different control methods working in conjunction to …

Effects Of Non-Surface-Disturbing Restoration Treatments On Native Grass Revegetation And Soil Seed Bank Composition In Cheatgrass-Invaded Sagebrush-Steppe Ecosystems, Alexandra D. Reinwald

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The sagebrush-steppe communities of the Great Basin have been dramatically transformed by the invasion of the non-native annual grass cheatgrass. In many areas of the Great Basin, this invasion has resulted in the loss of native plant species and ultimately the conversion to cheatgrass-dominated communities. As healthy sagebrush communities provide multiple ecosystem services such as diverse wildlife habitat, forage for cattle grazing, and water filtration, restoration of these communities is a high priority to landowners and land management agencies. Established perennial grasses can successfully compete with non-native annual grasses and increase the resistance of plant communities to invasion by non-native …

Studies On Nitrogen And Silicon Deficiency In Microalgal Lipid Production, Curtis Adams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Microalgae are single celled plants that inhabit aquatic and terrestrial environments across the planet. Many species are oleaginous, which means they are capable of producing oils, similar to many higher plants we are familiar with like canola, safflower and coconut. Different from higher plants, however, algae have simple structures that allow them to grow at very high rates. Due to these characteristics—oil production and rapid growth rates—algae are considered a promising future source of oil. Algal oils could be useful for production of food for people, feed for animals, biodiesel, detergents, and many other applications.

Algae have not been heavily …

Integrated Management Of Downy Brome (Bromus Tectorum L.) Infested Rangeland, Heather Elwood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Invasive weed species are a threat to the health and functionality of many rangeland systems. Downy brome (Bromus tectorum) is an invasive annual grass that affects the productivity of rangelands by decreasing the grazing capacity for livestock as well as altering the wildfire cycle and competing against more desirable vegetation for limited resources.

In 2006, an Invasive Plant Management Plan and Environmental Assessment was approved for Dinosaur National Monument, calling for prioritization of invasive species management on high value wildlife habitat, vector areas, and for species with a high ecological impact. The Cub Creek Watershed was identified as a priority …

Developing An Optimized Light Spectrum For Plant Growth And Development, Kevin Richard Cope

Undergraduate Honors Capstone Projects

Light-emitting diodes (LEDs) are a rapidly developing technology for plant growth lighting and have become a powerful tool for understanding the spectral effects of light on plants. Several studies have shown that some blue light is necessary for normal growth and development, but the effects of blue light appear to be species dependent and may interact with other wavelengths of light as well as photosynthetic photon flux (PPF). Here we report the photobiological effects of three types of white LEDs (warm, neutral and cool) on the growth and development of radish, soybean, and wheat. All species were grown at two …

Groundcover Management System And Nutrient Source Impact Physical Soil Quality Indicators In An Organically Managed Apple Orchard, Neal Mays

Graduate Theses and Dissertations

In March 2006, four groundcover management systems (GMS) and two nutrient sources (NS) were implemented for their ability to alter the soil physical condition of a newly established, organically managed apple (Malus x domestica Borkh.) orchard. Annual applications of municipal green compost (GC), shredded office paper (SP), wood chips (WC), and mow-blow (MB) grass mulch were utilized as GMS, and NS supplied to trees were from composted poultry litter (PL), a commercial organic fertilizer (CF), or an untreated control (NF) in a 4x3 factorial study. An established, conventionally-managed orchard was located adjacent to the organic research orchard on the same …

Transforming The South Carolina Botanical Garden, Amy Blackwell

All Dissertations

This dissertation addresses the question of how to transform a small to mid-sized public garden into a botanical garden capable of making a significant contribution to science. Botanical gardens have certain features that distinguish them from pleasure gardens and public parks. These include a scientific basis for collections, an emphasis on recording data on the plants in the collection, exchanging plant materials and data with other botanical gardens, and providing educational information to visitors. Gardens often have several missions, including conservation of rare and endangered species, botanical and ecological research, and involving the public through citizen science. I describe my …

Predicted Effects Of Climate Change On The Distribution Of The Invasive Grass Dichanthium Annulatum, Cynthia Isabel Garcia

Theses and Dissertations - UTB/UTPA

Kleberg bluestem (Dichanthium annulatum) is an invasive grass species native to Africa but now found in southern United States, Mexico, and other tropical and subtropical countries throughout the world. Using the modeling software MaxEnt, climatic variables from WorldClim, the Intergovernmental Panel on Climate Change (IPCC) scenario A1B, and two General Circulatory Models: the Canadian model (Canadian Centre for Climate Modelling and Analysis or CCCMA), and the Australian model (Commonwealth Scientific and Industrial Research Organisation or CSIRO), several models were developed to determine the possible implications of climatic change on the suitable habitat for D. annulatum, in the year 2050. Models …

Dark Green Color Index As A Method Of Real-Time In-Season Corn Nitrogen Measurement And Fertilization, Upton Siddons

Graduate Theses and Dissertations

Corn (Zea mays L.) requires higher rates of nitrogen fertilizer than any other major U.S. crop partly because N fertilizers are subject to loss through various mechanisms. Because of this, corn may suffer from inadequate nitrogen fertilization or producers may over-apply nitrogen to compensate for early-season nitrogen losses. A timely, accurate, and precise method for measuring in-season corn N status is needed to allow producers to keep nitrogen use efficiency high within a growing season.

Using appropriate software, hue, saturation, and brightness values of digital images can be combined in a dark green color index (DGCI) which is closely associated …

Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri) In Arkansas: Resistance Mechanisms And Management Strategies, Griff Michael Griffith

Graduate Theses and Dissertations

Since 2000, there have been thirteen weed species confirmed resistant (R) to glyphosate in the United States, six of those resistant species are present in Arkansas. The goal of this research was to confirm and to determine the level of resistance in two R Palmer amaranth biotypes from Mississippi (MC-R) and Lincoln (LC-R) Counties, Arkansas, and one susceptible (S) biotype from Clarendon County, South Carolina, which had never been exposed to glyphosate. Shikimic acid concentration over time was significantly greater in the S biotype than both the MC-R and LC-R biotypes. The lethal dose required to kill 50% (LD_{50 …}

Functional Characterization Of Type-B Response Regulators In The Arabidopsis Cytokinin Response, Kristine Hill, Dennis E. Mathews, Hyo Jung Kim, Ian H. Street, Sarah L. Wildes, Yi-Hsuan Chiang, Michael G. Mason, Jose M. Alonso, Joseph R. Ecker, Joseph K. Kieber, G. Eric Schaller

Dartmouth Scholarship

Cytokinins play critical roles in plant growth and development, with the transcriptional response to cytokinin being mediated by the type-B response regulators. In Arabidopsis (Arabidopsis thaliana), type-B response regulators (ARABIDOPSIS RESPONSE REGULATORS [ARRs]) form three subfamilies based on phylogenic analysis, with subfamily 1 having seven members and subfamilies 2 and 3 each having two members. Cytokinin responses are predominantly mediated by subfamily 1 members, with cytokinin-mediated effects on root growth and root meristem size correlating with type-B ARR expression levels. To determine which type-B ARRs can functionally substitute for the subfamily 1 members ARR1 or ARR12, we …

Diacylglycerol Acyltransferase Sequences And Related Methods, David Hildebrand, Runzhi Li, Tomoko Hatanaka

Plant and Soil Sciences Faculty Patents

Isolated nucleic acid and amino acid sequences encoding a diacylglycerol acyltransferase 2 (DGAT2) polypeptide are provided. Vectors and transgenic cells that include a nucleic acid sequence encoding a DGAT2 polypeptide are also described. Further provided are methods of producing an epoxy fatty acid by transforming a cell with a first isolated nucleic acid that encodes a diacylglycerol acyltransferase polypeptide and a second isolated nucleic acid that encodes an epoxygenase polypeptide, such that expression of the diacylglycerol acyltransferase polypeptide and the epoxygenase polypeptide increases an amount of epoxy fatty acid in the cell.

Botany Of Desire: Looking At The Rose Plant As A Manmade Tool Of Love, Taylor Aaserud

The Review: A Journal of Undergraduate Student Research

The use of roses as a symbol of emotion (specifically love) and as a result, a model of artificial selection, is rarely questioned. These plants share a rich history with multiple humanities around the world and have been a subject of genetic interest to see exactly what genes are being expressed that signal those beautiful desirable traits. To answer the question of “why” these plants have been a vector for human love for so long, I have analyzed 7 articles, one of them outlining the cause of the favored “double flower” mutation found in so many modern roses today. Upon …

Chemical Warfare Agents In Plants: Biodefensive Terpenes From Sagebrush, Belinda Stierman

College of Arts and Sciences Poster Presentations

To prevent being eaten, some plants create compounds that are toxic to herbivores, and herbivores respond by creating new ways to metabolize these toxins. For example, sagebrush produces bio-defensive terpenes to deter foraging by sage grouse. A recent investigation to characterize plant secondary metabolites (PSM's) in sagebrush resulted in a correlation between terpene concentration and nutritional content in local sagebrush to the habitat selection of sage grouse. This study identified many of the terpenes in sagebrush, but not all of them. A highly volatile and elusive terpene is suspected to be an important PSM that significantly affects sage grouse foraging. …

Response Of Nebraska Horseweed (Conyza Canadensis) Populations To Dicamba, Roberto Crespo, Mark L. Bernards, Greg Kruger, Donald Lee, Robert Wilson Jr.

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Dicamba-resistant soybeans are being developed to provide an additional herbicide mechanism-of-action for postemergence weed control in soybean. Numerous broadleaf species, including horseweed, have evolved resistance to glyphosate. It is anticipated that dicamba will be used by farmers as a primary tool to manage these weeds. Studying and understanding variability in horseweed response to dicamba will aid in developing appropriate risk management strategies to extend the utility of the dicamba-resistance technology. Horseweed plants from ten Nebraska populations were treated with one of nine doses of dicamba in greenhouse experiments. At 28 days after treatment (DAT) visual injury estimations were made and …

Crystallization And Structure Of A Plant Peptide Deformylase, David W. Rodgers, Robert L. Houtz, Lynnette M. A. Dirk, Mark Williams

Horticulture Faculty Patents

This invention relates to the crystal structure of a plant peptide deformylase polypeptide and methods of using the structure to design compounds that modulate the activity of the polypeptide.

Determination Of Lead Levels In Soil And Plant Uptake Studies, Amanda Lewis

The Review: A Journal of Undergraduate Student Research

In lieu of an abstract, below is the first paragraph of the paper.

Lead poisoning is a problem for many urban areas and Rochester is no exception. The large number of older homes and high traffic areas of a city as large as Rochester create a city with a high potential for lead poisoning. This paper presents research in which the soil from Rochester area homes was tested for lead content. The samples were digested using EPA Method 3050B section 7.5 and analyzed for lead by Flame Atomic Absorption Spectroscopy. The majority of the houses were found to have concentrations …

Agricultural Research Magazine, April 2013

Agricultural Research Magazine

Table of Contents

4 Irrigation Wastewater: Waste Not, Want Not

6 Two Approaches for Optimizing Water Productivity

8 Compounds in Whole-Grain Rice Varieties

10 New Discovery Makes Detecting Johne’s Disease Easier

12 House Fly Virus Stops Flies from Reproducing

14 Improved Vitamin B12 Test May Help Young and Old Alike

16 Rooting Out a Novel Stress Syndrome in Pigs

18 A Modeling Milestone for Soil Phosphorus Management

20 New Technologies for Studying Crops and Crop Diseases

23 Locations Featured in This Magazine Issue

New Technologies For Studying Crops And Crop Diseases, Dennis O’Brien

Agricultural Research Magazine

Agricultural Research Service scientists in New York and California have developed very different technologies that share a common thread. They offer scientists new, innovative ways to probe what happens when a crop is threatened by drought or disease.

Michelle Cilia and Stewart Gray, ARS scientists at the Robert W. Holley Center for Agriculture and Health in Ithaca, New York, and their colleagues at the University of Washington have found a way to map the structure of an elusive protein that gives certain plant viruses the ability to travel from plants to insects, through the insects, and back into plants.

Andrew …

House Fly Virus Stops, Christopher J. Geden, Sandra Avant

Agricultural Research Magazine

The house fly is often considered merely a nuisance. But these flies are capable of transmitting animal and human pathogens that can lead to foodborne diseases, including Escherichia coli, Salmonella, and Shigella bacteria.

Insecticides are important for control, but house flies are particularly good at developing resistance, and their larvae tend to stay deep enough within their gooey food to avoid exposure to sprays.

Scientists at the Agricultural Research Service’s Center for Medical, Agricultural, and Veterinary Entomology (CMAVE) in Gainesville, Florida, are looking at new methods that target adult flies. A promising biological control agent—salivary gland hypertrophy virus …