Life Sciences Commons^™

New Binary Ti Vectors With Co-Directional Replicons For Agrobacterium Tumefaciens-Mediated Transformation Of Higher Plants, Seokhyun Lee

LSU Doctoral Dissertations

Small, high-yielding binary Ti vectors of Agrobacterium tumefaciens were constructed. All four basic components of the vector, ColE1 replicon (715 bp) for Escherichia coli, VS1 replicon (2,659 bp) for A. tumefaciens, a bacterial kanamycin resistance gene (999 bp), and the T-DNA region (170 bp), were modified to reduce the vector size to 4,566 bp and to introduce a number of mutations to increase the copy number and other functionality. The transcriptional direction of VS1 replicon can be the same as that of ColE1 replicon (co-directional transcription), or opposite (head-on transcription) as in the case of widely used vectors (pPZP or …

Phase-Linking And The Perceived Motion During Off-Vertical Axis Rotation, Jan Holly, Scott Wood, Gin Mccollum

Mathematics and Statistics Faculty Publications and Presentations

Human off-vertical axis rotation (OVAR) in the dark typically produces perceived motion about a cone, the amplitude of which changes as a function of frequency. This perception is commonly attributed to the fact that both the OVAR and the conical motion have a gravity vector that rotates about the subject. Little-known, however, is that this rotating-gravity explanation for perceived conical motion is inconsistent with basic observations about self-motion perception: (a) that the perceived vertical moves toward alignment with the gravito-inertial acceleration (GIA) and (b) that perceived translation arises from perceived linear acceleration, as derived from the portion of the GIA …

Spring Seed Guide 2010: Nebraska Variety And Hybrid Tests -- Soybeans, Teshome Regassa, Robert N. Klein, Bruce Anderson, Charles A. Shapiro, Jim Krall

Department of Agronomy and Horticulture: Faculty Publications

NEBRASKA SOYBEAN VARIETY TESTS 2009

Crop Production Summary: The November 2009 estimated soybean yield for Nebraska was 52 bushels per acre from 4.800 million harvested acres. The total production of soybeans for the state was forecasted at 247 million bushels. These estimates are from the November National Agricultural Statistics Service.

Selecting Strawberry Cultivars For Winter Greenhouse Production, Ellen T. Paparozzi, Stacy A. Adams, George E. Meyer, M. Elizabeth Conley, Vicki L. Schlegel, Erin E. Blankenship, Paul E. Read

Department of Agronomy and Horticulture: Faculty Publications

Costs of transportation and food safety concerns have spawned an increase in public support of locally grown vegetables and fruit. With this in mind, a two-phase investigation was planned with the goal of combining low start up costs for sustainable greenhouse production with selection of strawberry cultivars that would provide the greatest number and largest size of berries. Additionally, berries from each cultivar will be analyzed for their beneficial nutraceutical properties to determine if there is a difference among cultivars.

Spring Grazing Impacts On The Vegetation Of Reed Canarygrass–Invaded Wetlands, Heidi Hilhouse, Susan J. Tunnell, James L. Stubbendieck

Department of Agronomy and Horticulture: Faculty Publications

The Rainwater Basin region in Nebraska is critically important stopover habitat for spring waterfowl migrations, but the ability of these sites to produce sufficient food for migrating waterfowl is endangered by the invasion of reed canarygrass (Phalaris arundinacea L.). This species produces thick litter layers and abundant aboveground biomass, reducing germination and seedling survival of the annual plant species responsible for much of the seed production in the area. Cattle grazing often is used as a management tool in the Rainwater Basin to slow or reverse reed canarygrass invasion and to improve growing conditions for more desirable plant species. …

Rna-Seq Atlas Of Glycine Max: A Guide To The Soybean Transcriptome, Andrew J. Severin, Jenna L. Woody, Yung-Tsi Bolon, Bindu Joseph, Brian W. Diers, Andrew Farmer, Gary J. Muehlbauer, Rex T. Nelson, David Grant, James E. Specht, Michelle A. Graham, Steven B. Cannon, Gregory D. May, Carroll P. Vance, Randy C. Shoemaker

Department of Agronomy and Horticulture: Faculty Publications

Background: Next generation sequencing is transforming our understanding of transcriptomes. It can determine the expression level of transcripts with a dynamic range of over six orders of magnitude from multiple tissues, developmental stages or conditions. Patterns of gene expression provide insight into functions of genes with unknown annotation.

Results: The RNA Seq-Atlas presented here provides a record of high-resolution gene expression in a set of fourteen diverse tissues. Hierarchical clustering of transcriptional profiles for these tissues suggests three clades with similar profiles: aerial, underground and seed tissues. We also investigate the relationship between gene structure and gene expression and find …

Efficient Methods Of Estimating Switchgrass Biomass Supplies, Marty R. Schmer, Robert B. Mitchell, Kenneth P. Vogel, Walter H. Schacht, David B. Marx

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum L.) is being developed as a biofuel feedstock for the United States. Efficient and accurate methods to estimate switchgrass biomass feedstock supply within a production area will be required by biorefineries. Our main objective was to determine the effectiveness of indirect methods for estimating biomass yields and composition of switchgrass fields. Indirect measurements were conducted in eastern Nebraska from 2003 to 2007 in which switchgrass biomass yields were manipulated using three nitrogen rates (0 kg N ha^-1, 60 kg N ha^-1, and 120 kg N ha^-1) and two harvest periods …

Fertilizer Rate Effects On Forage Yield Stability And Nutrient Uptake Of Midland Bermudagrass, John A. Guretzky, Maru K. Kering, Jagadeesh Mosali, Eddie Funderburg, Jon T. Biermacher

Department of Agronomy and Horticulture: Faculty Publications

Our objectives were to document effects of nitrogen (N), phosphorus (P), and potassium (K) fertilizer rates on forage yields and uptake of N, P, and K by Midland bermudagrass [Cynodon dactylon (L.) Pers.] on a Minco fine, sandy loam in southern Oklahoma. After six years of this long-term experiment, forage yield responses to fertilization were mixed and depended on year. Stability analysis indicated forage yields responded positively to N fertilization during favorable weather conditions but negatively during poor weather conditions. Application of 112 kg N ha⁻¹ provided the best yield stability and mean annual forage yield among treatments, …

Economic Potential Of Substituting Legumes For Synthetic Nitrogen In Warm Season Perennial Grasses Used For Stocker Cattle Grazing, Maru Kering, John Biermacher, Ryan Reuter, Twain Butler, Job D. Springer, James Rogers, John Blanton, Joe Bouton, John A. Guretzky

Department of Agronomy and Horticulture: Faculty Publications

Stocker cattle grazing warm season perennial grasses is an important economic activity in the southern Great Plains. Substantial increases in the price of nitrogen fertilizer is negatively affecting forage producers‟ profitability. Two alternative nitrogen management systems that use annual and perennial legumes have been developed for bermudagrass pastures. The goal of the study is to determine if the legumes systems are more profitable than the conventional practice of applying synthetic sources of nitrogen. Results of the two-year grazing study show that the legume systems could not compete economically with the common practice.

Evaluation Of The Intercom Model For Predicting Growth Of Forest Herbs, Zorica S. Popović, J. L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

The ecophysiological model INTERCOM was evaluated for its suitability in predicting the growth of perennial forest herbs. A field experiment was conducted to obtain data on photosynthesis and growth parameters of two spring flowering understorey geophytes. Results were used to parameterize the model and its performance was evaluated using the average normalized difference (AE) between predicted and observed biomass and the leaf area index. The model was assumed to provide accurate simulations if the AE was smaller than 0.4. Adjusting the photosynthetic intensity parameters in the model to reflect observed changes in photosynthesis throughout the growing period resulted in the …

Growth And Fitness Components Of Wild × Cultivated Sorghum Bicolor (Poaceae) Hybrids In Nebraska, Lilyrani Sahoo, Jared J. Schmidt, Jeffrey F. Pedersen, Donald Lee, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

• Premise of the study: Gene flow from crops to wild relatives has received considerable attention since the advent of genetically modified crops. Numerous researchers have found wild – crop hybrids to be nearly as fit as their wild parents, which suggests that crop genes may persist in wild populations. Components of the ecological fitness of cultivated sorghum, its wild relative, shattercane, and their hybrids have not been studied.

• Methods: To assess the potential for gene introgression into shattercane, we crossed cultivated sorghum to a single inbred shattercane line to produce F₁ hybrids and measured growth …

Increased Weed Diversity, Density And Above-Ground Biomass In Long-Term Organic Crop Rotations, Samuel E. Wortman, John L. Lindquist, Milton J. Haar, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

While weed management is consistently a top priority among farmers, there is also growing concern for the conservation of biodiversity. Maintaining diverse weed communities below bioeconomic thresholds may provide ecosystem services for the crop and the surrounding ecosystem. This study was conducted to determine if weed diversity, density and biomass differ within and among organic and conventional crop rotations. In 2007 and 2008, we sampled weed communities in four long-term crop rotations near Mead, Nebraska, United States using seedbank analyses (elutriation and greenhouse emergence) and above-ground biomass sampling. Two conventional crop rotations consisted of a corn (Zea mays) …

Chromium, Copper, And Arsenic Concentration And Speciation In Soil Adjacent To Chromated Copper Arsenate (Cca) Treated Lumber Along A Topohydrosequence, Donald Roy Schwer Iii

University of Kentucky Master's Theses

Arsenic (As), Chromium (Cr), and Copper (Cu) are ubiquitous in soils as a result of anthropogenic and geogenic processes. The fate of As, Cr, and Cu in the environment is largely governed by their speciation, which is influenced by soil physiochemical properties. This study investigated the influence of soil physiochemical properties and landscape position on As, Cr, and Cu concentration and speciation in soils adjacent to Chromated Copper Arsenate (CCA) treated lumber fence posts. Concentration gradients showed elevated total As and Cu adjacent to the three fence posts, which decreased with increasing distance from the posts. In addition, As and …

Creating An Interactive And Dichotomous Key To The World Subfamilies Of Braconidae, Kacie Jo Johansen

University of Kentucky Master's Theses

Members of Braconidae (Hymenoptera: Ichneumonoidea) are mostly parasitoids of other holometabolous insects. It is a large family with a little over 18,000 described species and many more to be described. Subfamily classification in this group has been unstable and resolution of phylogenetic history at the subfamily level has been problematic. Since 1993, no new keys to the subfamilies of Braconidae have been produced. Many taxonomic and phylogenetic changes have taken place since then, including a recent phylogeny proposing 47 subfamilies and representing the most robust and resolved analysis to date. A pressing need for new keys to the world subfamilies …

Distribution Of Eastern Hemlock, Tsuga Canadensis, In Eastern Kentucky And The Susceptibility To Invasion By The Hemlock Woolly Adelgid, Adelges Tsugae, Joshua Taylor Clark

University of Kentucky Master's Theses

The hemlock woolly adelgid, an invasive non-native insect, is threatening eastern hemlock in Kentucky. This study examined three techniques to map the distribution of eastern hemlock using decision trees, remote sensing, and species distribution modeling. Accuracy assessments showed that eastern hemlock was best modeled using a decision tree without incorporating satellite radiance. Using the distribution from the optimal model, risk maps for susceptibility to hemlock woolly adelgid infestation were created using two species distribution models. Environmental variables related to dispersal were used to build the models and their contributions to the models assessed. The models showed similar spatial distributions of …

How Does Background And Training Affect Dance Pedagogy In Higher Education?, Meredith Erin Sims

University of Kentucky Master's Theses

Dance faculty in higher education have various backgrounds and training ranging from professional dance careers to doctoral degrees in dance. This study sought to examine the ways background and training impact faculty members‟ pedagogical approach to a dance technique class in a higher education dance department. This study examined the pedagogical knowledge, content knowledge, and pedagogical content knowledge of participants through qualitative methods including interviews, observations, and document analysis. Six major themes emerged from the data: desire to teach, teaching focus, challenging students, planning and preparation, instructional methods, and assessment strategies.

Genetic Diversity, Structure, And Recolonization Patterns Of Kentucky Black Bears, John Tyler Hast

University of Kentucky Master's Theses

After nearly a century of absence, the black bear (Ursus americanus) reappeared in Kentucky during the late 20th century and has since increased in number. Recolonization of bears in the southeastern portion of the state was thought to have been caused by emigration of bears from adjacent states into the Commonwealth, while in the south-central area, bears originated, or natural recolonization may have been supplemented by the translocation of 14 individuals into the Big South Fork National River Recreation Area. To investigate the recolonization patterns of bears in Kentucky, I used 20 microsatellite loci to determine the genetic …

Exotic Invasive Plants In Kentucky, Yu Liang

University of Kentucky Master's Theses

Invasion of exotic species is a significant problem in natural ecosystems, reaching epidemic proportions and resulting in significant economic losses. However, insufficient knowledge of explicit spatial distribution of invasive species hinders our ability to prevent and/or mitigate future invasion. In this study, we demonstrate the use of existing voluntary data to survey invasive plant species in Kentucky. We also reconstructed the historical distribution of 16 exotic invasive plants typical to Kentucky using herbarium records. We found that Kentucky is facing a large threat from exotic invasive plants as they are reported throughout most counties. The distribution maps for four of …

Spiny Amaranth Control And Aminopyralid Persistence In Kentucky Pastures, Meghan Elizabeth Edwards

University of Kentucky Master's Theses

Spiny amaranth is a problematic weed of heavily grazed pastures in Kentucky and surrounding states. The first objective was to evaluate spiny amaranth control when herbicides are applied before and after emergence. Spiny amaranth seed collected in 2008 were seeded in rows in the fall (November) and the following spring (March) in fields located near Lexington and Princeton, KY. Treatments consisted of five application dates and five herbicides plus an untreated control arranged in a split-split plot design. The following parameters were measured: fresh weight, plant height and percent visual control. At both locations pendimethalin applied in November, March and …

Field Scale Bromide Tranport As A Function Of Precipitation Amount, Intensity And Application Time Delay, Vicente Vasquez

University of Kentucky Master's Theses

Rapid and deep transport of solutes in soils can potentially pollute groundwater resources. Field estimates of solute leaching depth based on randomized sampling provide extremely variable field average estimates that confound the treatment effects of the leaching study with the high spatial variation of soil hydraulic properties. The purpose of this study was to investigate the spatial scale of variation of solute (Bromide) leaching depth, and apply this scale of variation to study the leaching depth of Bromide as a function of a sinusoidal application of transport causing factors, i.e., rainfall amount, intensity and application time delay. Solute leaching depth …

Cover Crops And Tillage Systems For Organic Corn Production In Kentucky, Alfonso Suarez

University of Kentucky Master's Theses

Organic corn (Zea mays L.) producers generally use intensive tillage for weed control. No-till methods reduce soil erosion, conserve water, maintain soil structure and reduce CO₂ emissions. The objective of this study was test different cover crops, tillage systems, N sources and N rates for organic corn production. Two tillage systems (no-till and moldboard plow), two cover crops [hairy vetch (Vicia villosa) and rye (Secale cereale)] and two organic N sources [Louisville Green (LG) and Nature Safe (NF)] at four N rates (45, 90, 135, 180 kg N ha^-1) were evaluated …

Shelter Availability, Occupancy, And Residency In Size-Asymmetric Contests Between Rusty Crayfish, Orconectes Rusticus, Nathan M. Klar

University of Kentucky Master's Theses

Contest outcomes are usually determined by differences in resource holding potential, the social histories of the combatants, and perceptions of resource value. One understudied aspect of gaining an advantage is the residency effect. Prior occupancy of a particular place can affect the knowledge and motivation of the resident. There could be a tactical advantage in knowing the terrain or an increased willingness to fight to maintain control of a familiar area. In this study we evaluated the importance of shelter residency effects relative to size differences between rusty crayfish (Orconectes rusticus) as potential competitors for access to shelter. …

Two Year Response Of A Woody Biofuel Plantation To Intensive Management On A Reclaimed Surface Mine In Eastern Kentucky, Joshua Scott Brinks

University of Kentucky Master's Theses

The establishment of intensively managed woody energy crops on reclaimed surface mine lands provides an opportunity to diversify domestic biomass sources, while increasing the productivity and economic value of underutilized land. Our objective is to test the effect of fertilization and irrigation on the growth, survival, biomass accumulation, biomass allocation, leaf area, and nutrient dynamics of American sycamore (Platanus occidentalis L.) and black locust (Robinia pseudoacacia L.) planted on a reclaimed surface mine. In 2008, replicated plantings of sycamore and black locust were established on the Big Elk mine in eastern Kentucky. Treatments tested include annual granular fertilizer …

Biodiversity Assessment Of The Fishes Of Saba Bank Atoll, Netherlands Antilles, Jeffrey T. Williams, Kent E. Carpenter, James L. Van Tassell, Paul Hoetjes, Wes Toller, Peter Etnoyer, Michael Smith

Biological Sciences Faculty Publications

Biodiversity surveys were conducted on Saba Bank, Netherlands Antilles, to assess ichthyofaunal richness and to compare with published surveys of other Caribbean localities. The primary objective was to estimate the total species richness of the Saba Bank ichthyofauna. A variety of sampling techniques was utilized to survey the fish species of both the visually accessible megafauna and the camouflaged and small-sized species comprising the cryptic ichthyofauna. Based on results presented herein, the number of species known on Saba Bank is increased from 42 previously known species to 270 species. Expected species-accumulation curves demonstrate that the current estimate of species richness …

Development And Sensory Characteristics Of Salt Substitute Containing Bitterness-Masking Agents, Pamarin Waimaleongora-Ek

LSU Doctoral Dissertations

This study was conducted to develop a sodium-free salt substitute and assess its sensory characteristics. The efficacy of bitterness-masking agents, adenosine-5’-monophosphate (AMP) and L-arginine (Arg), were studied. However, the effectiveness of AMP in inhibiting bitterness of potassium chloride (KCl) was specifically investigated. The threshold values of KCl with and without AMP were determined using the method of limits and the signal detection method. AMP effectively decreased the bitterness imparted by KCl at a ratio of KCl to AMP of 15:1 when the method of limits was utilized. To enhance saltiness and inhibit bitterness, Arg was added to KCl/AMP solutions. The …

Morphological Differences Among Eyeless Amphipods In The Genus Stygobromus Dwelling In Different Subterranean Habitats, David C. Culver, John R. Holsinger, Mary C. Christman, Tanja Pipan

Biological Sciences Faculty Publications

The amphipod genus Stygobromus occurs in a variety of subterranean habitats in North America, including caves, phreatic (groundwater) lakes, and superficial subterranean habitats (seeps and epikarst). The habitats share the absence of light but differ in other features, such as pore size of the habitat, available food, and degree of seasonality. Measurements of body size, antennal size, and antennal segment number of type specimens were compared for 56 species occurring in the eastern United States. Except for differences in body size, differences among species in the four different habitats were not significant. Body size was related to relative pore size …

Conservation Status And Habitat Use Of The West Virginia Spring Salamander (Gyrinophilus Subterraneus) And Spring Salamander (G. Porphyriticus) In General Davis Cave, Greenbrier Co., West Virginia, Matthew L. Niemiller, Michael S. Osbourn, Dante B. Fenolio, Thomas K. Pauley, Brian T. Miller, John R. Holsinger

Biological Sciences Faculty Publications

The West Virginia Spring Salamander (Gyrinophilus subterraneus) is one of four obligate cave-dwelling species of plethodontid salamanders found east of the Mississippi River in the United States. This species is endemic to a single cave system; General Davis Cave, in Greenbrier Co., West Virginia, where it is syntopic with the closely-related Spring Salamander (G. porphyriticus). Accordingly, the West Virginia Spring Salamander is a species of critical conservation concern. Because of it's conservation status and lack of data regarding the ecology and life history, particularly about population trends, we present data on relative abundance of and habitat …

Effect Of The Heterotrophic Dinoflagellate Oxyrrhis Marina And The Copepod Acartia Tonsa On Vertical Carbon Flux In And Around Thin Layers Of The Phytoflagellate Isochrysis Galbana, A. B. Bochdansky, S. M. Bollens, G. C. Rollwagen-Bollens, A. H. Gibson

OES Faculty Publications

Dynamics of material and energy flow through food webs differ when resources are allocated in patches in comparison to situations in which the same resources are distributed evenly throughout the water column. Thin layers of plankton are special cases of such resource patches. While previous studies have predominantly focused on the response of organisms to these layers, we investigated how 2 types of grazers in turn affect thin layers. In an experimental study with tightly controlled environmental conditions, we monitored the redistribution of particulate organic (POC), dissolved organic (DOC) and inorganic (DIC) carbon from thin layers of Isochrysis galbana. …

Benthic Ecology From Space: Optics And Net Primary Production In Seagrass And Benthic Algae Across The Great Bahama Bank, Heidi M. Dierssen, Richard C. Zimmerman, Lisa A. Drake, David J. Burdige

OES Faculty Publications

Development of repeatable and quantitative tools are necessary for determining the abundance and distribution of different types of benthic habitats, detecting changes to these ecosystems, and determining their role in the global carbon cycle. Here we used ocean color remote sensing techniques to map different major groups of primary producers and estimate net primary productivity (NPP) across Great Bahama Bank (GBB). Field investigations on the northern portion of the GBB in 2004 revealed 3 dominant types of benthic primary producers: seagrass, benthic macroalgae, and microalgae attached to sediment. Laboratory measurements of NPP ranged from barely net autotrophic for grapestone sediment …

A Seasonal Study Of Dissolved Cobalt In The Ross Sea, Antarctica: Micronutrient Behavior, Absence Of Scavenging, And Relationships With Zd, Cd, And P., M. A. Saito, T. J. Goepfert, A. E. Noble, E. M. Bertrand, Peter N. Sedwick, Giacomo R. Ditullio

OES Faculty Publications

We report the distribution of cobalt (Co) in the Ross Sea polynya during austral summer 2005-2006 and the following austral spring 2006. The vertical distribution of total dissolved Co (dCo) was similar to soluble reactive phosphate (PO(4)(3-)), with dCo and PO(4)(3-) showing a significant correlation throughout the water column (r(2) = 0.87, 164 samples). A strong seasonal signal for dCo was observed, with most spring samples having concentrations ranging from similar to ~ 45-85 pM, whereas summer dCo values were depleted below these levels by biological activity. Surface transect data from the summer cruise revealed concentrations at the low range …