Digital Commons Network^™

The Effects Of Living Mulches On Organic, Reduced-Till Broccoli Growth And Management, Sarah Elizabeth Broughton

Masters Theses

Conservation tillage programs have been successfully implemented for many agronomic cropping systems, but adoption of reduced tillage for vegetable crops has been slow. As many conventionally managed conservation tillage programs rely on synthetic herbicides for clean cultivation, alternative methods must be devised to suppress weed pressure and reduce reliance on mechanical cultivation to aid in the development of reduced tillage programs for organic cropping system. Strip tillage is a reduced tillage method that is well suited to vegetable crop production, and the utilization of cover crops and living mulches between rows provides a viable weed management option for organic systems. …

An Improved Tissue Culture And Transformation System For Switchgrass (Panicum Virgatum L.), Jason Neil Burris

Masters Theses

Switchgrass (Panicum virgatum), a summer perennial grass native to North America, is currently being explored for its potential use in the production of biofuels. With these interests, genetic manipulation of switchgrass to produce plants that are easier to digest, have an increased resistance to diseases and stresses, and maintain viability longer in the field are required. Therefore, it was necessary to develop a reliable and efficient tissue culture system for the transformation of switchgrass. Current switchgrass tissue culture requires months for regeneration of transformants with relatively poor transformation efficiencies and are limited to derivatives of a single variety, Alamo. We …

Competitive Interactions Between Appalachian Hardwoods And Different Groundcovers On Reclaimed Mine Sites, Adam David Klobucar

Masters Theses

Coal mining is a significant industry in Appalachia. Herbaceous groundcovers are commonly planted to reduce soil erosion and protect water quality during mine reclamation, but many groundcovers may be too competitive to be compatible with trees. The objectives of this research were to investigate the performance of trees planted within different groundcovers and to measure how different groundcovers influence resource availability, specifically soil moisture and light

Two studies were performed; one in a greenhouse and the other on 3 mine sites in east Tennessee where seedlings were planted and grown in competition with different groundcovers. Growth, biomass, leaf area, and …

Control Of Glyphosate Resistant Horseweed (Conyza Canadensis) With Saflufenacil And Tank-Mixture Partners., Brock Steven Waggoner

Masters Theses

Field and labratory studies were conducted to determine the efficacy of saflufenacil alone and with mixture partners for burndown. Field studies were conducted in 2009 and 2010 to evaluate saflufenacil in mixtures with glyphosate, glufosinate, or paraquat for control of glyphosate-resistant (GR) horseweed prior to planting cotton. Saflufenacil and saflufenacil mixtures were applied 7 days before planting (DBP). Saflufenacil at 25 and 50 g ai ha-1 in mixture with all three non-selective herbicides provided similar GR horseweed control when compared to the current standard of glyphosate plus dicamba. Control of GR horseweed was also not different at the 25 and …

Translation Reinitiation And Development Are Compromised In Similar Ways By Mutations In Translation Initiation Factor Eif3h And The Ribosomal Protein Rpl24, Fujun Zhou, Bijoyita Roy, Albrecht G. Von Arnim

Plant Sciences Publications and Other Works

Background

Within the scanning model of translation initiation, reinitiation is a non-canonical mechanism that operates on mRNAs harboring upstream open reading frames. The h subunit of eukaryotic initiation factor 3 (eIF3) boosts translation reinitiation on the uORF-containing mRNA coding for the Arabidopsis bZip transcription factor, AtbZip11, among others. The RPL24B protein of the large ribosomal subunit, which is encoded by SHORT VALVE1, likewise fosters translation of uORF-containing mRNAs, for example mRNAs for auxin response transcription factors (ARFs).

Results

Here we tested the hypothesis that RPL24B and eIF3h affect translation reinitiation in a similar fashion. First, like eif3h mutants, rpl24b …

Steps Toward Butternut (Juglans Cinerea L.) Restoration, Sunshine L. Brosi

Doctoral Dissertations

Butternut (Juglans cinerea L.), a lesser-known relative of black walnut (Juglans nigra L.), is a native tree species beneficial for wildlife, valuable for timber, and part of the great diversity of species in the eastern forests of North America. Populations of butternut are being devastated by butternut canker disease, caused by the fungus Sirococcus clavigignenti-juglandacearum (V.M.G. Nair, Kostichka, & Kuntz), which is thought to be introduced to North America. The disease causes multiple branch and stem cankers that eventually girdle trees. Small population sizes, lack of sprouting, and shade intolerance exacerbates the disease and results in permanent losses of butternut …

Investigating Cold Hardiness And Management Practices Of Warm-Season Putting Green Species In The Transition Zone, John M. Kauffman

Doctoral Dissertations

Warm-season turf species are becoming increasingly popular for putting green use in the transition zone. Ultradwarf bermudagrass (Cynodon dactylon (L.)  C. transvaalensis Burtt-Davy) is the prevalent warm-season putting green species, but seashore paspalum (Paspalum vaginatum Swartz) and ‘Diamond’ zoysiagrass [Zoysia matrella (L.) Merr.] may also be grown in the transition zone. Warm-season species are susceptible to winter injury and may require different management regimes than cool-season species. Therefore, the objectives of this research were to assess the impacts of various management practices on warm-season putting green species and characterize the physiological basis for differences in freeze tolerance of various …

Spatiotemporal Dynamics In A Lower Montane Tropical Rainforest, Robert Michael Lawton

Doctoral Dissertations

Disturbance in a forest’s canopy, whether caused by treefall, limbfall, landslide, or fire determines not only the distribution of well-lit patches at any given time, but also the ways in which the forest changes over time. In this dissertation, I use a 25 year record of treefall gap formation find a novel and highly patterned process of forest disturbance and regeneration, providing a local mechanism by examining the factors that influence the likelihood of treefall. I then develop a stochastic cellular automaton for disturbance and regeneration based on the analysis of this long term data set and illustrate the potential …

Four Aspects Of Dogwood Pollination: Insect Visitation, A Novel Approach To Identify Pollen, Floral Volatile Emission, And Tracking Parentage, Paul Raymond Rhoades

Masters Theses

Part 1: Visitation of potential pollinators to Cornus florida and C. kousa flowers was assessed in East Tennessee in 2008 and 2009. Data regarding insect visitation rates to multiple trees per location were gathered throughout the flowering period. Diurnal and seasonal variations in visitation were recorded. Pollen coverage was assessed on portions of captured insect exoskeletons that were most likely to contact the stigma. Eleven families in four insect orders were collected from C. florida and 26 families in five orders from C. kousa. The most important pollinators in eastern Tennessee were bees in the Andrenidae and Halictidae. The most …

Effects Of No-Tillage On Crop Yields And Net Returns Across The United States, Dustin Kevin Toliver

Masters Theses

Farmers are always looking for ways to increase yields and profits and no-tillage may be a way to achieve this goal. However, a comprehensive study of the performance of no-tillage yields relative to conventional tillage yields and their net returns is lacking. This study evaluated the potential factors that influence differences in conventional tillage and no-tillage yields and net returns as explained by such factors as time, crop, precipitation, soil texture and geographic region. Data were collected from 442 paired tillage experiments growing corn, soybeans, cotton, oats, wheat and sorghum published in three refereed journals. Data were evaluated using a …

Drought Response Of Populus Transformed With Stress Response Transcription Factors, Alina S. Campbell

Masters Theses

The economic feasibility of producing biomass-based fuels requires high-yielding feedstocks to supply biomass to biorefineries. Populus trees are a potential biomass feedstock due to their high yield, but their high water requirement limits productivity under drought conditions.

The number of genes controlling drought tolerance, and the long generation time for perennial species, slows cultivar development. Accelerated domestication proposes using the sequenced Populus genome to quickly incorporate target traits into productive clones by transgenesis.

Six putative drought tolerance transcription factors: DREB2A, DREB2B, AtMYB, AREB1/ABF2, MYB, and NAC, had been previously identified and manipulated in eastern cottonwood (Populus deltoides). Three …

A Vegetation History From Emerald Pond, Great Abaco Island, The Bahamas, Based On Pollen Analysis, Ian Arthur Slayton

Masters Theses

Emerald Pond (26° 32' 12" N, 77° 06' 32" W) is a vertical-walled solution hole in the pine rocklands of Great Abaco Island, The Bahamas. In 2006, Sally Horn, Ken Orvis, and students recovered an 8.7 m-long sediment core from the center of the pond using a Colinvaux-Vohnout locking piston corer. AMS radiocarbon dates on macrofossils are in stratigraphic order and indicate that the sequence extends to ca. 8400 cal yr BP. Basal deposits consist of aeolian sands topped by a soil and then pond sediment, suggesting that the site began as a sheltered, dry hole during a Late Pleistocene …

Comparative Functional Genomic Study Of Substrate Specificity Evolution Of The Sabath Family Of Methyltransferases In Plants, Nan Zhao, Jean-Luc Ferrer, Xiaofeng Zhuang, Feng Chen

Plant Sciences Publications and Other Works

Background

The plant SABATH protein family is composed of a group of related small molecule methyltransferases (MTs) that catalyze the S-adenosyl-L-methionine dependent methylation of a variety of plant small molecular weight metabolites encompassing widely divergent structures. Some of these substrates are important plant hormones and signaling molecules, such as indole-3-acetic acid (IAA), jasmonic acid (JA) and salicylic acid (SA). Methylating these compounds may have important impacts on plant growth and development. In the previous paper, we presented Indole-3-acetic acid (IAA) methyltransferase (IAMT) as an evolutionarily ancient member of the SABATH family in higher plants. Whether the IAMT exists in less …

Serendipitous Discoveries In Microarray Analysis, Sally R. Ellingson, Charles A. Phillips, Randy Glenn, Douglas Swanson, Thomas Ha, Daniel Goldowitz, Michael A. Langston

Faculty Publications and Other Works -- EECS

Background

Scientists are capable of performing very large scale gene expression experiments with current microarray technologies. In order to find significance in the expression data, it is common to use clustering algorithms to group genes with similar expression patterns. Clusters will often contain related genes, such as co-regulated genes or genes in the same biological pathway. It is too expensive and time consuming to test all of the relationships found in large scale microarray experiments. There are many bioinformatics tools that can be used to infer the significance of microarray experiments and cluster analysis.

Materials and methods

In this project …

Volume 7, Number 2 (Spring/Summer 2010), Ut Institute Of Agriculture

Tennessee Land, Life and Science Magazine

Issue Highlights:

• Celebrating UT Extension and 4-H's Centennial
• A Veterinarian Alum Blogs on His Life, Work
• Workshops and Tours Promote Direct Farm Marketing

A High-Throughput Transient Gene Expression System For Switchgrass (Panicum Virgatum L.) Seedlings, Xinlu Chen, Raymie Equi, Holly Baxter, Kyle Berk, Jin Han, Sujata Agarwal, Janice Zale

Plant Sciences Publications and Other Works

Abstract

Background

Grasses are relatively recalcitrant to genetic transformation in comparison to certain dicotyledons, yet they constitute some of the most important biofuel crops. Genetic transformation of switchgrass (Panicum virgatum L.) has previously been reported after cocultivation of explants with Agrobacterium and biolistics of embryogenic calli. Experiments to increase transient gene expression in planta may lead to stable transformation methods with increased efficiency.

Results

A high-throughput Agrobacterium-mediated transient gene expression system has been developed for in planta inoculation of germinating switchgrass seedlings. Four different Agrobacterium strains were compared for their ability to infect switchgrass seedlings, and strain AGL1 …

Evaluation Of Genetic Diversity Of Flowering Dogwood (Cornus Florida L.) In The Eastern United States Using Microsatellites., Denita Hadziabdic

Doctoral Dissertations

Flowering dogwood (Cornus florida L.) populations have experienced severe declines caused by dogwood anthracnose in the past three decades. Mortality has ranged from 48 to 98%, raising the concern that genetic diversity of this native tree has been reduced significantly. Microsatellite data were used to evaluate the level and distribution of genetic variation throughout much of the native range of the tree. In the first conducted study, we found that genetic variation in areas affected by anthracnose was as high as or higher than areas without die-offs. We found evidence of four widespread, spatially contiguous genetic clusters. However, there was …

Effects Of Trinexapac-Ethyl And Winter Overseeding On The Morphological Characteristics And Traffic Tolerance Of Bermudagrass Cultivars, William D. Haselbauer

Masters Theses

Common bermudagrass [Cynodon dactylon (L.) Pers.] and hybrid bermudagrass [C. dactylon (L.) Pers. X C. transvaalensis Burtt-Davy] are some of the most common turfgrasses used on athletic fields. Subsequently, the traffic tolerance of commercially available cultivars and the effects of trinexapac-ethyl (TE) on bermudagrass athletic fields with or without perennial ryegrass are often limited. A two year study at the University of Tennessee was conducted under simulated athletic field traffic to evaluate the performance of bermudagrass cultivars as affected by TE and overseeding. Bermudagrass cultivars evaluated were Tifway, Riviera, Patriot, and Celebration. TE treatments consisted of an untreated …

Early Vessel Evolution And The Diversification Of Wood Function: Insights From The Malagasy Canellales, Patrick Joseph Hudson

Masters Theses

Xylem vessels have long been proposed as a key innovation for the ecological diversification of angiosperms by providing a breakthrough in hydraulic efficiency to support high rates of photosynthesis and growth. However, recent studies demonstrated that angiosperm woods with structurally ‘primitive’ vessels did not have greater whole stem hydraulic capacities as compared to vesselless angiosperms. As an alternative to the hydraulic superiority hypothesis, the heteroxylly hypothesis proposes that subtle hydraulic efficiencies of primitive vessels over tracheids enabled new directions of functional specialization in the wood. However, the functional properties of early heteroxyllous wood remain unknown. We selected the two species …

Comparative Ecophysiology Of American Chestnut Under Different Planting Treatments On Reclaimed Mine Sites, Christopher Ryan Miller

Masters Theses

American chestnut was once an abundant species that dominated the Eastern U.S. deciduous forests. Although this species is currently functionally extinct due to the chestnut blight, researchers are working on blight-resistant hybrids in hopes of restoring the species. As one potential vector for chestnut reintroduction and dispersal, the reclamation of mine sites are being considered. Recent research has found that reforestation efforts on these reclaimed mine sites provide productive tree growth while also complying with mine-reclamation laws. Understanding how American chestnut performs physiologically on mine sites will aid in the restoration of this species and reclamation of mine sites.

The …

Classification And Fertility Of Soils In The Big South Fork National River And Recreation Area Based On Landscape Position And Geology, Ryan H. Blair

Masters Theses

The Big South Fork National River and Recreation Area encompasses more than 50,585 hectares (125,000 acres) of the Cumberland Plateau along the border of Tennessee and Kentucky. Highly dissected and steep terrain have made accessibility to much of the park limited, thus little work has been done to investigate the formation of these soils. Seven native soil profiles were selected for chemical and physical analysis representing Pennsylvanian-aged acidic sandstone and shale geology and landforms. The objectives of this study included the characterization of selected native profiles by physical and chemical analysis, as well as classification using US Soil Taxonomy, to …

Sp277-O-Root Rots And Seedling Disease Of Beans And Peas, The University Of Tennessee Agricultural Extension Service

Insects, Pests, Plant Diseases and Weeds

Root rots, seed rots and damping off (death of seedlings before or after emergence) are major diseases of snap beans, lima beans and Southern peas. Seed rots and damping off are collectively referred to as seedling disease. These diseases cause poor stands and reduced plant growth and yield. The fungi that cause seedling disease and root rots can be found in most soils, but the occurrence of these diseases is unpredictable. When conditions are favorable for vigorous plant growth, root rot fungi do little damage. These fungi can survive in the soil for long periods and can be moved with …

W187-Pesticide Safety Education Program (Psep) Online - Users Guide For Pesticide Applicators, The University Of Tennessee Agricultural Extension Service

Insects, Pests, Plant Diseases and Weeds

The Private Applicator (PA) Initial Certification and Recertification Programs can now be completed online! The Tennessee Department of Agriculture is presently certifying PAs until October 21, 2011. The PA recertification program may be used between January 1 and October 21 of the third year of the three-year certification program. The CA CORE presentation may be presented only by the PSEP coordinator or Extension agents. It may not be viewed by CAs at their home or office computers.

All information needed for your successful use of this online program is given below.

Sp341-B-Sorghum Webworm In Grain Sorghum, The University Of Tennessee Agricultural Extension Service

Insects, Pests, Plant Diseases and Weeds

The sorghum webworm (Figure 1) is an occasional pest of sorghum in Tennessee. Grain sorghum that is planted in late June can become severely damaged by this insect. Heavy infestations of webworms may completely destroy a developing grain head.

Sp503-A-Squash Vine Borer, The University Of Tennessee Agricultural Extension Service

Insects, Pests, Plant Diseases and Weeds

No abstract provided.

Sp277-Y-Blossom-End Rot, The University Of Tennessee Agricultural Extension Service

Insects, Pests, Plant Diseases and Weeds

Blossom-end rot is a common problem of peppers, tomatoes and watermelons. It is most often seen in home gardens, but has been quite a factor in droughty years in commercial plantings of these crops.

Pb1636 Butterfly Gardening, The University Of Tennessee Agricultural Extension Service

Home Garden, Lawn, and Landscape

No abstract provided.

Pb1576 Selecting Fescues, The University Of Tennessee Agricultural Extension Service

Home Garden, Lawn, and Landscape

Four fescue species are maintained as lawngrasses in Tennessee. Originally from Europe, these perennial, cool-season lawngrasses are an integral part of many Tennessee landscapes. They grow best in deep, well-drained soils at air temperatures from 60 to 75 F. High temperatures and drought often slow their rate of growth during late spring and summer. Species and varieties may vary in color, leaf texture, stand density, disease resistance and tolerance of shade, high temperature and drought. Tall fescue (Festuca arundinacea) is adapted to a wide range of soil and climatic conditions. This medium- to coarse-textured lawngrass tolerates high temperatures, …

W220 Bamboo (Phyllostachys Spp.), The University Of Tennessee Agricultural Extension Service

Home Garden, Lawn, and Landscape

Bamboo species have nearly a worldwide distribution, with Europe and Antarctica the only continents that do not have native bamboo species. Taxonomically, bamboo is classified in the grass family (Poacea) and is represented by more than 1,000 species and 91 genera. Taken together, bamboo is recognized as the fastest-growing woody, evergreen, perennial plant.

Sp503-I-Identifying The Flathead Appletree Borer (Chrysobothris Femorata) And Other Buprestid Beetle Species In Tennessee, The University Of Tennessee Agricultural Extension Service

Home Garden, Lawn, and Landscape

The flatheaded appletree borer, Chrysobothris femorata (Olivier) (FHATB) is a well-documented, native pest of deciduous trees. It has a wide host range and is particularly problematic in commercial nurseries and urban landscapes, where it can cause rapid decline of economically important hosts. When infestations are high, FHATB has been known to attack healthy trees as well as those stressed by drought, plant disease, mechanical injury and other environmental factors. Its distribution is ubiquitous, covering the entire continental United States and extending into Canada.