Digital Commons Network^™

Disturbance Is An Important Driver Of Clonal Richness In Tropical Seagrasses, Kathryn M. Mcmahon, Richard D. Evans, Kor Jent Van Dijk, Udhi E. Hernawan, Gary A. Kendrick, Paul S. Lavery, Ryan J. Lowe, Marji L. Puotinen, Michelle Waycott

Research outputs 2014 to 2021

Clonality is common in many aquatic plant species, including seagrasses, where populations are maintained through a combination of asexual and sexual reproduction. One common measure used to describe the clonal structure of populations is clonal richness. Clonal richness is strongly dependent on the biological characteristics of the species, and how these interact with the environment but can also reflect evolutionary scale processes especially at the edge of species ranges. However, little is known about the spatial patterns and drivers of clonal richness in tropical seagrasses. This study assessed the spatial patterns of clonal richness in meadows of three tropical seagrass …

Improving Nitrogen Use Efficiency And Yield In Louisiana Sugarcane Production Systems, Daniel Ernesto Forestieri

LSU Master's Theses

Proper nitrogen (N) management is essential to optimize crop production. This study was conducted to evaluate different N fertilizer management strategies to improve N use efficiency and yield in sugarcane production in Louisiana. This research was initiated in 2013 at the Sugar Research Station in St. Gabriel, LA and was arranged in a randomized complete block design with four replications consisting of different N rates (0, 45, 90, and 135 kg N ha-1) and sources (urea-46% N, ammonium nitrate [AN]-34% N, and urea-ammonium-nitrate solution [UAN]-32% N dribbled and knifed-in) as treatments. Sensor readings were taken from different N response trials …

Effects Of Silicon And Nitrogen Fertilization On Growth, Yield, And Leaf Rust Disease Development In Wheat, Maryamossadat Shahrtash

LSU Master's Theses

There are so many people who have helped me throughout my graduate studies and for whom I am grateful. I would like to take this opportunity to first and foremost thank God for his always guidance throughout my life and giving me the wisdom and the patience I needed to finish my thesis. I would like to thank Dr. Brenda Tubana for taking me in and providing me with guidance and knowledge. I also would like to thank my committee members, Prof. Brian D. LeBlanc who guided me, encouraged me and provided me with knowledge about sustainable agriculture and Dr. …

The Roles Of Avr4 In Fungal Virulence,Cercosporin Biosynthesis And Its Potential Use In Host Induced Gene Silencing For Controlling Cercospora Leaf Blight Disease Of Soybeans, Josielle Santos Rezende

LSU Doctoral Dissertations

The AVR4 effector, secreted by Cladosporium fulvum, has been demonstrated to be involved in pathogen virulence. Recent studies further demonstrated that Avr4 is highly conserved among several Cercospora species, indicating a potential important role of this gene in fungal virulence. Therefore, investigation to determine whether this fungal effector gene is present in Cercospora cf. flagellaris (previously known as C. kikuchii), the causal agent of soybean cercospora leaf blight (CLB) disease, and whether it plays any role in CLB disease development, is of great interest. In the present study, the Avr4 gene from C. cf. flagellaris was cloned and mutants lacking …

Documentation Of Siderophore Activity, Metal Binding, And Its Effect On Symptomatology Of Cercospora Leaf Blight Caused In Soybean By Cercosporin From Cercospora Cf. Flagellaris, Brian Michael Ward

LSU Doctoral Dissertations

Cercospora leaf blight of soybean (Glycine max) is a serious problem in the mid-south of the United States and is present in most soybean-growing regions of the world. The causal organisms, Cercospora kikuchii, C. cf. flagellaris and C. cf. sigesbeckiae, utilize the photo-activated toxin cercosporin as the primary pathogenicity factor. The disease has historically been understood to progress from a purpling or bronzing of the leaves to a blight in which tissue dies. Previous literature showed possible binding of cercosporin to metals and previous work in our group showed possible use of minor element nutrition in the plant to reduce …

Evaluation Of The Microbial Quality Of Cantaloupe Fruit Produced On Raised Or Flat Beds Following A Flooding Event, Isaack Kikway

LSU Master's Theses

Floodwater can contain microbial contaminants such as plant and foodborne pathogens and can compromise the quality of fresh fruit and vegetables produced in Louisiana. The goal of this research was to determine the impact of flooding on microbial quality (foodborne and plant pathogens) of cantaloupe fruit produced on raised or flat beds. Cantaloupe fruit produced on 30 cm raised beds or flat ground, were flooded with a mixture of surface and well water spiked with three generic Escherichia coli strains (ATCC 23716, 25922, 11775). Mean baseline generic Escherichia coli and total coliform populations in flood water (mixture of spiked well …

The Effects Of Early Pruning On The Near-Ground Branch Density Of Four Live Fencing Species, Aric Devens

Dissertations, Master's Theses and Master's Reports

Crop losses in home gardens greatly impact the wellbeing of rural West African families. Herbivory by migratory or local livestock represents a significant source of crop loss. Live-fencing gardens with thorny hedges is a low-cost and sustainable strategy for reducing losses due to herbivory. However, guidance on the establishment of thorny hedges is inconsistent, poorly publicized, and often anecdotal. Therefore, this study evaluated the effects of three early pruning treatments on near-ground branch density of four thorny species: Vachellia nilotica, Senegalia laeta, Senegalia mellifera, and Prosopis juliflora. Physical measurements and photographic data indicated that after one growing season, V. …

Neutral And Adaptive Genetic Variation In North American Hardwood Tree Species, Sudhir Khodwekar

Dissertations, Master's Theses and Master's Reports

'Northern Hardwoods,’ are a characteristic composition of multiple tree species and a part of the rich and diverse northeastern forests. Hardwoods e.g. oaks (Quercus: Fagaceae and Sugar maple), serve as foundation species and offer ecological and economical gains to wildlife and humans. Most of the forest trees go through many biotic and abiotic stresses, for example climate change in their long life span. To overcome these threats and to adapt to changing conditions, tree species need to maintain variation especially in adaptive genes. Therefore, it is necessary to analyze genetic diversity within forest tree populations and take appropriate …

Determinants Of Integrated Soil Fertility Management Technologies Adoption By Smallholder Farmers In The Chinyanja Triangle Of Southern Africa, Powell Mponela, Lulseged Tamene, Gift Ndengu, Ruth Magreta, Job Kihara, Nelson Mango

All Peer-Reviewed Publications

Integrated Soil Fertility Management (ISFM) technologies have proven to be viable options for improving land productivity and increasing yield. However, adoption of the set of complementary technologies that are required in ISFM is quite variable and studies tend to focus on single technologies. In this study we used cluster analysis to group technologies and ordered probit to determine the probability of multiple technology adoption. The result show that usage of ISFM in the Chinyanja Triangle (Southern Africa) is grouped into 3 technological sets based on complementarities. The set of nutrient dense technologies of inorganic fertiliser, compost and animal manure (ISFMset3) …

Salvinia Molesta: An Assessment Of The Effects And Methods Of Eradication, Arti Lal

Master's Projects and Capstones

Salvinia molesta is an invasive aquatic fern. It is now the second worse aquatic invader in the world. Since the 1930s, it has invaded most tropical and some temperate countries. S. molesta plants grow vegetatively and can increase in size rapidly. S. molesta can form thick mats of up to 1-meter-thick. There are a number of ways these thick mats negatively affect the environment: 1) reduce light to benthic organisms, 2) reduce oxygen in the water column for other organisms, 3) accumulate as organic matter at the bottom of the water column, 4) decrease nutrients for other organisms, and 5) …

Association Mapping Of Seed Weight, Protein, And Sucrose Content; And Kinetics Of Edamame Under Infrared Treatment, Laura Melissa Lara Santisteban

Graduate Theses and Dissertations

Edamame is a specialty large-seeded soybean (Glycine max L. Merr.) harvested at an immature stage (R6) that has become the second largest consumed soyfood. Although United States is the largest soybean producer, majority of edamame is imported from Asia, highlighting the importance of developing new edamame varieties. Association mapping (AM) provides an alternative to bi-parental linkage mapping method to detect quantitative trait loci (QTL) adding higher resolution and broader germplasm information. Seed weight, sucrose, and protein are quantitative traits of value when selecting edamame lines. However molecular mechanisms controlling each of these traits are still inconclusive and have not been …

Residual Effects Of Nitrogen Fertilization On Soil Nitrogen Pools And Corn Growth, Meghan E. Moser

Open Access Theses

Given the dynamic nature of soil nitrogen (N), inorganic N fertilization to corn (Zea mays L.) has potential to alter N pool balance by creating an accumulation or depletion of soil N. Current corn N recommendations in the common corn-soybean rotation of Indiana strive to find the best N rate that maximizes producer profit. Increasing our understanding of soil N will inform producers if they should adjust fertilizer rates for corn to influence maintenance of organic N and Carbon. Our objective was to determine residual N effects from fertilized corn in a corn-soybean rotation by measuring (1) soil N …

Annual Forage Cropping-Systems For Midwestern Ruminant Livestock Production, John Ernest Mcmillan

Open Access Dissertations

Annual forage cropping systems are a vital aspect of livestock forage production. One area where this production system can be enhanced is the integration of novel annual forages into conventional cropping systems. Two separate projects were conducted to investigate alternative forage options in annual forage production. In the first discussed research trial, two sets of crops were sown following soft red winter wheat (Triticum aestivum L.) grain harvest, at two nitrogen application rates 56 and 112 kg ha-1 . The first set of crops were C4 summer annuals seeded within two weeks of wheat grain harvest and included, brown …

Managing Corn Residue And Double Cropped Forages In Crop And Livestock Systems, Kristen M. Ulmer

Department of Animal Science: Dissertations, Theses, and Student Research

Integrating crop and livestock systems leads to opportunities to utilize land resources; however, crop producers focus on grain yields and ground cover, while livestock producers see opportunity to graze corn residue or annual forages. After wheat harvest or corn silage harvest, above ground forage production for brassica mixes and oats is greater than forage oats or oat production after high moisture corn harvest. Grazing steers on forage crops after grain harvest provides moderate gains. While annual forages provide good quality forages, corn residue grazing and utilization is still a cost-effective feedstuff for cattle producers. In the short term, grain yields …

Forage News [2016-12], Department Of Plant And Soil Sciences, University Of Kentucky

Forage News

• Bale Grazing Can Spread Nutrients
• Quote of the Month: "Before Anything Else, Preparation is the Key to Success" ~ Alexander Graham Bell
• Novel Tall Fescue Renovation Workshop to be held in Lexington March 9th
• Financial Assistance for Establishing Novel Endophyte Tall Fescue on Pastures
• Heart of America Grazing Conference Coming Up!
• AFGC Tour of New Zealand 2016
• Featured Publication: Using Dry Lots to Conserve Pastures and Reduce Pollution Potential (ID-171)
• Dallisgrass Makes Rare Impact on KY Horse Farm
• Small Ruminant Grazing Conference

Reintroducing Environmental Change Drivers In Biodiversity-Ecosystem Functioning Research., Frederik De Laender, Jason R. Rohr, Roman Ashauer, Donald J Baird, Uta Berger, Nico Eisenhauer, Volker Grimm, Udo Hommen, Lorraine Maltby, Carlos J Meliàn

Integrative Biology Faculty and Staff Publications

For the past 20 years, research on biodiversity and ecosystem functioning (B-EF) has only implicitly considered the underlying role of environmental change. We illustrate that explicitly reintroducing environmental change drivers in B-EF research is needed to predict the functioning of ecosystems facing changes in biodiversity. Next we show how this reintroduction improves experimental control over community composition and structure, which helps to provide mechanistic insight on how multiple aspects of biodiversity relate to function and how biodiversity and function relate in food webs. We also highlight challenges for the proposed reintroduction and suggest analyses and experiments to better understand how …

Finding The Best Remaining Black Hills Montane Grasslands, The First Step In Conservation, Hollis Marriott, Don Faber-Langendoen, David J. Ode

The Prairie Naturalist

Black Hills Montane Grassland is a rare and endangered plant community endemic to the Black Hills of western South Dakota and northeastern Wyoming. It is restricted to higher elevations on the Limestone Plateau in the western part of the uplift. Early visitors to the Black Hills wrote glowing reports of flower-filled grasslands on the Limestone Plateau. Lieutenant Colonel George A. Custer and his soldiers reveled in lush grass, and decorated the headgear of their horses with flowers (Custer 1875). Expedition botanist A. B. Donaldson “estimated the number of flowers in bloom in Floral Valley at 50, while an equal number …

Reproductive Characteristics Of Landlocked Fall Chinook Salmon From Lake Oahe, South Dakota, Kelsen L. Young, Michael E. Barnes, Jeremy L. Kientz

The Prairie Naturalist

Lake Oahe, South Dakota, USA, landlocked fall Chinook salmon (Oncorhynchus tshawytscha) reproductive characteristics were examined over a 27 year period, from 1988 to 2015. Mean total lengths of spawning females ranged from 665 mm (1995) to 812 mm (2015) with considerable year-to-year variation. Post-spawn female weights varied, ranging from 2.02 kg (2000) to 5.55 kg (2015), with an overall mean of 3.04 kg. Fecundity peaked at 4,555 eggs per female in 2003, which was just 3 years after a low of 2,011 eggs per female in 2000. Relative fecundity based on female weight was greatest at 1,211 eggs/kg …

Heterodimers As The Structural Unit Of The T=1 Capsid Of The Fungal Double-Stranded Rna Rosellinia Necatrix Quadrivirus 1, Daniel Luque, Carlos P. Mata, Fernando González-Camacho, José M. González, Josué Gómez-Blanco, Carlos Alfonso, Germán Rivas, Wendy M. Havens, Satoko Kanematsu, Nobuhiro Suzuki, Said A. Ghabrial, Benes L. Trus, José R Castón

Plant Pathology Faculty Publications

Most double-stranded RNA (dsRNA) viruses are transcribed and replicated in a specialized icosahedral capsid with a T=1 lattice consisting of 60 asymmetric capsid protein (CP) dimers. These capsids help to organize the viral genome and replicative complex(es). They also act as molecular sieves that isolate the virus genome from host defense mechanisms and allow the passage of nucleotides and viral transcripts. Rosellinia necatrix quadrivirus 1 (RnQV1), the type species of the family Quadriviridae, is a dsRNA fungal virus with a multipartite genome consisting of four monocistronic segments (segments 1 to 4). dsRNA-2 and dsRNA-4 encode two CPs (P2 and …

The Coat Protein And Nia Protease Of Two Potyviridae Family Members Independently Confer Superinfection Exclusion, Satyanarayana Tatineni, Roy French

Department of Plant Pathology: Faculty Publications

Superinfection exclusion (SIE) is an antagonistic virus-virus interaction whereby initial infection by one virus prevents subsequent infection by closely related viruses. Although SIE has been described in diverse viruses infecting plants, humans, and animals, its mechanisms, including involvement of specific viral determinants, are just beginning to be elucidated. In this study, SIE determinants encoded by two economically important wheat viruses, Wheat streak mosaic virus (WSMV; genus Tritimovirus, family Potyviridae) and Triticum mosaic virus (TriMV; genus Poacevirus, family Potyviridae), were identified in gain-of-function experiments that used heterologous viruses to express individual virus-encoded proteins in wheat. Wheat plants infected …

Evaluation Of A Cool-Season Grass-White Clover Mixture For Low-Nitrogen Input Lawns, Gabriel Adam Macke

Open Access Theses

Turfgrass lawns require supplemental nitrogen (N) to maintain green color and seasonal shoot density. Improper lawn fertilization with excess N or phosphorus has the potential to contaminate both surface and groundwater. Thus, to reduce the reliance on supplemental N fertilization, alternative strategies or novel turf systems like grass-legume mixtures need explored. White clover ( Trifolium repens L.) is a stoloniferous legume that biologically fixes N from the atmosphere and adds N into the soil via mineralization. The objective of this field study was to evaluate the persistence and feasibility of a cool-season grass-clover lawn mixture. A lawn grass mixture with …

Forest Industry Byproducts Improve Soil Quality And Increase Pepper Growth In Three Soils Infested With Phythophthora Blight, Xiaojun Zhao

Open Access Theses

Phytophthora blight is a serious threat to the Midwest vegetable industry, because the oomycete pathogen responsible for this disease, Phytophthora capsici, has a wide host range, can spread quickly in fields, and produces resilient oospores that can survive in soil for years. Phytophthora capsici has become resistant to commonly used fungicides and resistant crop varieties are rare. Amending soil with complex organic substrates has potential to improve soil quality and suppress soil-borne pathogens including P. capsici. Indiana has a significant forest industry with many residual products that could be used as locally available amendments to meet this goal. …

Plant Community Composition And Structure Monitoring For Scotts Bluff National Monument, 2016 Data Report, Molly B. Davis, Daniel J. Swanson

United States National Park Service: Publications

Abstract

This report presents the results of vegetation monitoring efforts in 2016 at Scotts Bluff National Monument (SCBL) by the Northern Great Plains Inventory and Monitoring Network (NGPN) and Northern Great Plains Fire Ecology Program (NGPFire).

During the sixth full year of field work, crew members from NGPN visited eight long-term monitoring plots on May 23-25, 2016 to collect data on the plant communities at SCBL. This is part of a long-term monitoring effort to better understand the condition of the vegetation at SCBL. NGPN staff captured data relating to species richness, herb-layer height, abundance of individual native and non-native …

Plant Community Composition And Structure Monitoring For Agate Fossil Beds National Monument, 2016 Data Report, Aaron T. Rasor, Daniel J. Swanson

United States National Park Service: Publications

Abstract

This report presents the results of vegetation monitoring efforts in 2016 at Agate Fossil Beds National Monument (AGFO) by the Northern Great Plains Inventory and Monitoring Network (NGPN).

During the sixth full year of field work, crew members from NGPN visited six long-term plant community monitoring (PCM) plots and the Northern Great Plains Fire Effects Crew (NGPFire) visited nine fire plant community monitoring (FPCM) plots to collect data on the plant communities at AGFO. This effort is part of a long-term monitoring program established to better understand the condition of the mixed-grass prairie, riparian, and upland regions in AGFO. …

Determination Of Plant Architecture And Component Phenotyping Based On Time-Lapse Image Analysis, Srinidhi Bashyam

School of Computing: Dissertations, Theses, and Student Research

Plant breeding and the development of new food production depend on accurate measurement of different phenotypes (observable physical traits) of a plant. The plant phenotypes play a very important role in the agronomic production. The successful computation of plant phenotypes largely depends on the determination of the architecture of the plant, i.e., the arrangement of its parts (leaves, stems, flowers, etc.) relative to each other, and how the size, shape, and positions of those parts change over time. Researchers and breeders extract valuable information from these types of data to make an informed decision on which individuals to advance to …

Quantitative Trait Loci (Qtl) For Salt Tolerance In Soybean And Physiological Response To Salt Stress During Early Growth Stage, Cindy Massiel Lopez Ramirez

Graduate Theses and Dissertations

Soybean is a major cash crop used as a source of high–quality protein and oil. Salt stress is one of the main abiotic stresses causing significant yield losses in soybean, which is considered a moderately salt–sensitive crop. Breeding selection is a promising strategy to improve salt tolerance as soybean germplasm display wide variation in response to salinity stress. However, the physiological and genetic mechanisms for salt tolerance are not quite clear. The discovery of novel QTL/genes associated with salt tolerance facilitates the development of tolerant cultivars through marker-assisted selection (MAS). The objectives of this study were: 1) identify/confirm QTL associated …

Quantitative Trait Loci Mapping, Genome-Wide Association Analysis, And Gene Expression Of Salt Tolerance In Soybean, Ailan Zeng

Graduate Theses and Dissertations

Salt stress is a common abiotic stress causing yield reduction in soybean. There are differential responses, namely tolerance (excluder) and intolerance (includer), among soybean germplasm. However, the genetic and physiological mechanism for salt tolerance is not clear. Identification of novel QTL for salt tolerance and genes that are differentially expressed under salt stress would help elucidate the salt tolerance mechanism and facilitate the development of salt tolerant cultivars through marker assisted selection (MAS). The objectives of this study were to identify new QTL or genes responsible for salt tolerance using three approaches: QTL mapping, association analysis, and RNA sequencing (RNA-seq). …

Nuclear Factor [Erythroid-Derived 2]-Like 2’S (Nfe2l2) Gene Expression In Feed Efficiency And Oxidative Stress In Avian Muscle, Devin Wayne Cook

Graduate Theses and Dissertations

Oxidative stress may play a role in the phenotypic expression of feed efficiency (FE). The transcription factor NFE2L2 (nuclear factor erythroid-derived 2-like 2) coordinates antioxidant response to oxidative stress and its activity is tightly regulated in part by KEAP1 (Kelch like-ECH protein 1) and the E3 ligase CUL3 (Cullin3). Thus, one objective was to determine mRNA expression of NFE2L2, KEAP1, and CUL3 as well as three antioxidant targets [glutathione peroxidase (GPx-1), superoxide dismutase 1 (SOD1), and superoxide dismutase 2 (SOD2)] in breast muscle of immature pedigree broiler males (8 wk), immature Japanese quail males (4 wk) divergently selected for high …

Liming Characteristics Of A High-Calcium, Dry Flue Gas Desulfurization By-Product And Its Effects On Runoff Water Quality, Jason Richard Burgess-Conforti

Graduate Theses and Dissertations

In 2013, only 37% of the 32 million Mg of flue gas desulfurization (FGD) by-products generated in the United States were reused beneficially. If FGD by-products could be used as a beneficial soil amendment, millions of megagrams may be diverted away from surface impoundments and landfills. The purpose of this research was to identify the liming characteristics of a high-Ca dry FGD (DFGD) by-product in comparison to a Class-C fly ash (FA) and reagent-grade CaCO3, and to evaluate the effects of land application to a managed grassland on runoff, plant, and soil quality. Liming characteristics were determined by measuring the …

Characterization Of Ground Nozzles For Pesticide Applications, Ryan Henry

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

Pesticide applications are a common component of crop production systems in the United States (US). For row crop systems (e.g. corn, soybean, or wheat), pesticides are applied by ground, aerial, or chemigation methods. The exact method of pesticide delivery is not universally regulated/ prescribed in the US, and the equipment and application technique are largely defined by the individual applicator. A wide variety of choices and decisions must be made by applicators to result in a successful pesticide application. Examples of these choices include proper active ingredient(s), carrier volume and equipment (e.g. nozzle type, spacing, and operating pressure) selection while …