Digital Commons Network^™

Genetic Characterization Of Resitance To Frogeye Leaf Spot Of Soybean, Gabriel D. Munoz Herrera

LSU Master's Theses

Cercospora sojina is the causal agent of the fungal disease frogeye leaf spot (FLS) in soybeans. Management of this disease consists of foliar application of fungicides and the use of resistant cultivars. However, fungicide resistance has been detected in C. sojina populations and characterization of host resistance genes is relatively limited. To overcome the latter obstacle, we aimed to identify novel resistance genes using quantitative image analysis of the SoyNAM population. Two image analysis workflows using ImageJ and PlantCV were optimized and implemented to increase reproducibility and reduce subjectivity. The quantitative measurements included disease severity, lesion count, and average lesion …

Population Genomic Characterization Of Cercospora Janseana On Rice In The Southern United States, Jacob Searight

LSU Master's Theses

Cercospora janseana is the causative agent of narrow brown leaf spot (NBLS). Effort had been undertaken since the 1940’s to control this disease through resistance breeding in the Southern United States. However, a severe epidemic of NBLS in 2006 inspired renewed focus on managing this disease. One tool for managing this disease has been identified among resistant cultivars, the CRSP-2.1 resistance locus to NBLS. One thing limiting the investment and deployment of CRSP-2.1, and other unknown resistance genes, is the historical observation that resistance to NBLS rapidly breaks-down in the field. Together, the rapid breakdown of resistance to NBLS …

Paraquat-Resistant Italian Ryegrass (Lolium Multiflorum) Confirmed In Louisiana, Alphonse B. Coco Iii

LSU Master's Theses

Paraquat is the only herbicide labeled for postemergence control of Italian ryegrass in sugarcane. In 2017, sugarcane farmers in Louisiana reported Italian ryegrass control failures with paraquat applications. Seeds were collected from sugarcane fields in White Castle, St. Gabriel, and Bunkie, Louisiana where control was not achieved (reduced susceptibility). Additionally, Italian ryegrass seeds were collected from a sugarcane field in Welcome, LA with a history of paraquat use and with no reported control issues (susceptible population). A dose-response study was conducted at the Louisiana State University Agricultural Center’s Sugar Research Station in February 2021 and was repeated in November 2021. …

Role Of Cd38 In Pulmonary Host Defense Against Gram-Negative Pneumonia, Xiaoqian Shan

LSU Master's Theses

The Gram-negative bacterium, Klebsiella pneumoniae, is a major cause of hospital-acquired pneumonia in the U.S. In particular, the dramatic increase in carbapenem-resistant K. pneumoniae infections poses a serious threat to the public health both in the United States and worldwide. Clearance of bacteria in the lungs depends on effective pulmonary immune response. It may be possible to design improved therapies that augment host immune responses while attenuating excessive pulmonary inflammation through modulation of key innate immunity molecules during pneumonic infections. Cluster differentiation CD38 (CD38) has been detected on the surface of many immune cells or intracellular compartments, acting as …

Impact Of Rma’S Projected Price On Prevent Planting Claims, Nicolas Enrique Alvarez Mena

LSU Master's Theses

This research studies the presence of ex-post moral hazard in the prevent planting provision from the crop insurance program in cotton, corn, and soybeans for the Plains Region and Southeast Regions of the U.S. Three fixed effect models are developed using the proportion of prevent plant acres as the dependent variable, as well as weather, input price, expected harvest price and a break-even point for the independent variables. In addition, a fourth fixed effect (FE) model is introduced using the logit transformation and the same variables as in previous models. The results show the number of PP claims has been …

Searching For The Soldier Pheromone: Behavioral Effects Of Soldiers And Soldier-Produced Chemicals In The Formosan Subterranean Termite, Coptotermes Formosanus (Blattodea: Rhinotermitidae)), Joseph Mccarthy

LSU Master's Theses

The Formosan subterranean termite, Coptotermes formosanus, is a eusocial insect and an invasive urban pest. Colonies function through a division of labor among castes (i.e., queens and kings, workers, and soldiers). Though soldiers are energetically expensive to maintain, C. formosanus has a relatively large soldier caste (~10% of the colony). Soldiers are physically unable to collect food or build tunnels but are regularly found with foraging workers. In some species, soldiers influence the worker foraging behavior. In C. formosanus, aside from defense, the roles soldiers play remains unknown. In this study, we determined if soldiers influence …

Review Of Structural Color In The Genus Chrysochroa Dejean, 1833 (Coleoptera: Buprestidae), Able Chow

LSU Master's Theses

The jewel beetles, (Coleoptera: Buprestidae Leach, 1815), is the eighth most speciose coleopteran family, with the majority of its members possessing diverse bright, saturated structural coloration of multilayer origin. This study focuses on the genus Chrysochroa Dejean, 1833, which includes some of the most brilliantly and charismatically colored buprestid species. While members of Chrysochroa are prised by entomologists amateurs and professional and are well-represented in museum collections, the evolution and ecology of their structural color remain underexplored. Twenty-eight select taxa including exemplars from all 13 subgenera of Chrysochroa were investigated to provide an overview of the objective optical properties and …

Immunohistochemical Localization Of Kisspeptin And Its Receptor In The Equine Ovary, Bryce M. Gilbert

LSU Master's Theses

Kisspeptin is recognized for its role as the gatekeeper of reproduction in most mammalian species. However, its role in regulation of reproduction at the ovarian level is poorly understood in the horse. In this study, ovaries from follicular phase, luteal phase, anestrous period, and mares treated with ECP-sulpiride were subjected to immunohistochemistry to characterize kisspeptin-10 (Kp10) and its receptor (Kiss1r) protein expression throughout each reproductive stage and follicle type. Kisspeptin and receptor staining was detected in all follicle types (primordial, preantral, and antral) throughout all reproductive stages, as well as oocytes, corpora lutea, and ovulation fossa. The pattern of Kp10 …

Understanding Motivations Among Sustained Cooperative Extension Partners For Obesity Prevention In Rural Louisiana, Catherine R. Losavio

LSU Master's Theses

Louisiana consistently has one of the highest rates of obesity in the nation with higher concentrations of obesity in many rural parishes (i.e., counties). Due to over a century of visibility and engagement in rural communities, Cooperative Extension (Extension) is uniquely poised to reach remote rural communities disproportionately impacted by obesity. As Extension increases its use of community coalitions and implements its new National Framework for Health Equity and Well-Being, understanding motivations and communication preferences among long-term rural coalition partners for obesity prevention and health promotion has become essential for duplicating successful local-level policy, system, and environmental (PSE) changes. This …

Influence Of Hesperidin On The Physico-Chemical, Microbiological, And Sensory Characteristics Of Frozen Yogurt, Roberto Antonio Cedillos Hernández

LSU Master's Theses

Frozen yogurts contain yogurt culture bacteria which might impart health benefits to its consumers. Global frozen yogurt market sales are expected to grow 4.8% by 2028 which represents an important opportunity for the industry, consumers, and researchers. Polyphenols are metabolites found in plants which have antioxidant and anti-inflammatory properties and might prevent chronical diseases such as cancer, diabetes, and cardiovascular diseases. The objective of this study was to elucidate the effect of the polyphenol hesperidin on the physico-chemical, microbiological, and sensory characteristics of frozen yogurts. Hesperidin was incorporated in frozen yogurt at three concentrations (500, 250 and 125 mg/90g of …

Role Of Nucleobindin-2/Nesfatin-1 In The Regulation Of Energetic Status And Maternal Mouthbrooding In The Cichlid Fish, Astatotilapia Burtoni, Saachi Chugh

LSU Master's Theses

Feeding and energetics are fundamental processes in all species that must also be balanced with reproductive investment. The peptide hormone nesfatin-1 is encoded by the nucleobindin-2(nucb2) gene and has recently emerged as a key player involved in both feeding and reproduction across vertebrates. How nesfatin-1 might help regulate trade-offs between feeding and reproduction, however, are relatively unexplored. The female cichlid fish Astatotilapia burtoniis an ideal system to examine the role of nesfatin-1 in regulating metabolic and reproductive functions because this species cycles between a gravid feeding state while preparing to mate, followed by a forced starvation …

Characterizing Habitat Suitability For Gulf Sturgeon (Acipenser Oxyrinchus Desotoi) In Southern Louisiana, Jenna N. Brogdon

LSU Master's Theses

A generalized additive modeling (GAM) framework was used to characterize fish-habitat relationships and develop habitat suitability maps to predict spatiotemporal and ontogenetic shifts in Gulf sturgeon distribution within an impacted estuary in the northern Gulf of Mexico, Lake Pontchartrain. Gulf sturgeon (n = 103) were fitted with acoustic transmitters in the Pearl River during the early summer and fall from 2013 to 2018, and an array of acoustic receivers (n = 81) was used to monitor Gulf sturgeon habitat use and movement in the estuary from 2016 to 2019. Daily presence data from the telemetry array were paired with environmental …

Effects Of Pesticides On Red Rot Of Sugarcane, Kezia Cristina Da Silva Reis

LSU Master's Theses

Red rot disease of sugarcane, caused by Colletotrichum falcatum, can be an important constraint to crop production. In Louisiana, red rot primarily affects seed-cane and is more severe when billets (stalk sections) are planted rather than whole-stalks. At planting application of seed-treatment chemicals, particularly a combination of fungicide and thiamethoxam insecticide, has improved stand establishment and increased yields in billet plantings in Louisiana. However, information has been lacking on the effect of the treatments on disease development. Greenhouse experiments were conducted in 2020 and 2021 to evaluate stalk rot symptom severity and initial plant growth for billets dip-treated with …

Application Of Organic Fertilizers For Lawn Establishment And Maintenance In Louisiana, Matthew Lambert

LSU Master's Theses

Landscape contractors are increasingly interested in organic products for Louisiana's residential and commercial turfgrass areas. However, the use, motivations, and barriers to adopting organic practices in the commercial turfgrass and landscape industry are undocumented. A survey with Louisiana Turfgrass Association (LTA) members to gauge their perceptions on current and future use of organic products in Louisiana was performed; and a field trial was conducted to evaluate organic fertilizers during turfgrass establishment. Substantial majorities of turfgrass professionals are currently applying organic fertilizers and believe organic product use will increase due to consumer demands, potential governmental regulation, and the belief that they …

The Association Of Cuzd1 And Stat5 In Adipocytes, Zachary Wigger

LSU Master's Theses

Obesity is a metabolic disorder that has turned into a global epidemic over the past few decades. Adipocyte dysfunction brought on by obesity can lead to increased risk of metabolic diseases such as cardiovascular disease and type 2 diabetes mellitus (T2DM). Knowing how adipocytes function to regulate metabolic homeostasis is critical. CUZD1 (CUB and Zona Pellucida-like Domain-containing protein 1) has not been studied in the context of adipocyte biology but could play a role in several metabolic processes. CUZD1 has been suggested to be a biomarker for several inflammatory diseases and cancers but little functional data has been published. There …

Qualifying Factors That Predict Weight Loss Success Within Diet Interventions, Jordan Losavio

LSU Master's Theses

Evidence-based diet strategies lead to weight loss for some, while for others, the same diet approach could result in trivial weight loss or even in weight gain. This prompts the underlying research question: what factors predict that a given diet strategy will be efficacious for some, but not for others? This research was a secondary analysis of clinical weight loss studies to determine which factors influence an individual’s weight loss success for three diet intervention strategies: low-carbohydrate, low-fat, and low-calorie. A combination of physiological, psychological, behavioral, and dietary factors was evaluated for each diet study. Multiple linear regression and logistic …

Defining Toxicological Endpoints Of Aphis Gossypii Feeding, Flinn O'Hara

LSU Master's Theses

The cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a destructive agricultural pest, due to photosynthate removal and plant virus transmission. This project consisted of two main goals. First, we employed toxicity bioassays and electrical penetration graph (EPG) methodology to quantify changes to feeding behavior and toxicity of A. gossypii after exposure to commercialized aphicides. Commercialized aphicides containing flupyradifurone, sulfoxaflor, thiamethoxam, thiamethoxam + lambda cyhalothrin, and bifenthrin induced > 90% aphid mortality within 4 hours of exposure. This was supported by our EPG results that showed a significant reduction in the proportion of aphids that continued to probe on cotton 4 …

Wetland Soil Development Along Salinity And Hydrogeomorphic Gradients In Active And Inactive Deltaic Basins Of Coastal Louisiana, Amanda Fontenot

LSU Master's Theses

Coastal wetlands provide an abundance of ecosystem services that benefit society, such as essential habitat for commercial species, storm protection, nutrient cycling, and carbon storage. Louisiana faces rapid rates of relative sea level rise (natural subsidence and eustatic sea levels) that threaten wetland survival, which are amplified by a reduction of riverine sediment input. An important determining factor of marsh survival is the formation of wetland platform elevation, known as vertical accretion, which is determined by several processes including sediment deposition & erosion, below ground biomass (BGB) productivity, decomposition of organic matter, shallow & deep subsidence, and soil compaction. Feldspar …

Identifying The Components Of A Hemp (Cannabis Sativa L.) (Rosales: Cannabaceae) Integrated Pest Management Program In Louisiana, Nathan C. Arey

LSU Master's Theses

Hemp, Cannabis sativa (L.) (Rosales: Cannabaceae), is defined as a plant in the genus Cannabis with a delta-9 3 tetrahydrocannabinol (THC) concentration of not more than 0.3% on a dry weight basis. Domestic acreage of this crop has increased in response to the ratification of the Agricultural Act of 2014 and the Agricultural Improvement Act of 2018. In 2021, 21,915 hectares of hemp were planted in the United States with a production value of $712 million. There is a current lack of literature on insect related research in this reemerging crop system in the state of Louisiana. Therefore, this present …

Developmental Competence Of Oocytes Derived From Seasonally Anovulatory Mares Treated With Estradiol And Sulpiride, Michelle O. Vetter

LSU Master's Theses

Over the course of two years (2021-2022), two experiments were conducted during the nonbreeding seasons to evaluate the in vitro developmental potential of oocytes derived from seasonally anovulatory mares treated with ECP-sulpiride. The objective of experiments 1 and 2 were to compare pooled recovery and maturation rates of oocytes from mares treated with estradiol cypionate (ECP) and sulpiride with oocytes collected from naturally transitional mares (controls). Cleavage rates of oocytes subjected to intracytoplasmic sperm injection (ICSI) were compared only in experiment 2. In experiments 1 and 2, a total of 36 light horse and pony-cross anovulatory mares were used. Treatment …

Aphid Herbivory On Industrial Hemp, Cannabis Sativa L., And The Impact Of Plant-Soil Feedbacks On Hemp Performance In Louisiana, Alex Leede

LSU Master's Theses

Industrial hemp, Cannabis sativa L., is defined as having less than 0.3% delta-9-tetrahydrocannabinol by dry weight. It can be grown for fiber, food, oil, and cannabinoids. As a newly legalized crop, little research exists regarding the cultivation or pest management practices in Louisiana. The versatility of industrial hemp may allow for substantial future production in Louisiana. This project set out to understand the impact of previous crops on hemp performance and soil microbial communities. Soybean, Glycine max L. (Merr), grain sorghum, Sorghum bicolor (L.) Moench, and sweetpotato, Ipomeae batatas (L.) Lam, were selected as soil conditioning crops because they are …

Understanding The Horse Fly Species And Species Relations Of The Tabanus Nigrovittatus Complex Along Coastal Louisiana, Darrius M. Davis

LSU Master's Theses

The Dipteran family Tabanidae is among the most diverse families of insects that is comprised of approximately 144 genera with 4455 described species (Pape et al. 2011). Members of the family Tabanidae have been studied for well over 100 years in Louisiana. Hine (1906, 1907) conducted the first surveys of the members of the tabanid family and noted the presence of 14 species. Jones and Bradley (1923) supplemented Hine’s observations with their own inventory of horse flies across four parishes and found an additional 14 species that were not recorded by Hine. Subsequently, Tidwell (1970, 1973) conducted a survey of …

Soil Moisture Mediated Behavioral And Physiological Alterations Of Coptotermes Formosanus And Reticulitermes Flavipes (Blattodea: Rhinotermitidae), Steven J. Richardson

LSU Master's Theses

Substrate moisture is a critical environmental factor for the survival and behavior of subterranean termites (Blattodea: Rhinotermitidae). The invasive Formosan subterranean termite (Coptotermes formosanus) and the native eastern subterranean termite (Reticulitermes flavipes) co-occur in the southeastern United States, but C. formosanus is predominant in subtropical and R. flavipes is more common in temperate regions. The difference in their geographic distributions is largely attributed to their different behavioral and physiological ecology. While ample research has been done on foraging behavior of the two species, there was no empirical evidence for the effects of constant soil moisture on …

Screening Soybean Cultivars For Resistance To Aerial Blight Caused By Rhizoctonia Solani Ag1-Ia, Kensy D. Rodriguez-Herrera

LSU Master's Theses

Aerial blight, caused by the fungus Rhizoctonia solani AG1-IA, is an economically important soybean disease in the mid-South. The same pathogen also infects other crops commonly rotated with soybeans like rice, corn, and grain sorghum. Rhizoctonia solani AG1-IA is difficult to manage because of its soilborne nature and the production of long-term survival structures, sclerotia. Management has relied on fungicide applications during the season. Still, there is an increasing prevalence of resistance to commonly used strobilurin fungicides and an urgent need to identify soybean cultivars resistant to aerial blight. Since the patchy distribution of the pathogen complicates field cultivar screening, …

Cover Cropping: Sensor-Based Estimations Of Biomass Yield And Nutrient Uptake And Its Impact On Sugarcane Productivity, Hector H. Fajardo Duran

LSU Master's Theses

Sugarcane in Louisiana can be harvested for up to three years from one planting. Soil cultivation along sides of established beds is done for weed control and improve fertilizer use efficiency which increases the risk of soil degradation and yield decline. Planting cover crops (CC) is a soil conservation practice and an effective strategy to improve soil health and nutrient recycling. Limited work has been done on remote sensor-based evaluation of the potential nutrient benefits from cover crops and its effect on nutrient cycling on sugarcane systems. This study was conducted to evaluate the effect of two planting methods (broadcast …

Analysis Of Geographic Variability Of Fecal Microbiomes Of Fratercula Arctica And Cross-Comparison Of Fecal Microbiomes Of Different Avian Feeding Types, Eric Jose Ramon Martinez

LSU Master's Theses

Gastrointestinal (gut) microbiota have a multitude of effects on their host, from aiding in digestion, to facilitating nutrient uptake, detoxification, and interactions with the immune system. Multiple factors have been identified that influence the composition of vertebrate microbiomes; these include host genetics, environmental conditions, diet and age, sex, and geography. However, broad inferences about wild avian gut microbial diversity and function under natural conditions are limited. Most knowledge on avian microbiomes is derived from studies on domestic poultry. Information on non-model taxa may provide important contextual information about vertebrate host-microbiome interactions and aid in future management of vulnerable species. Here, …

A New Insight Into Fungal Cell Wall Architecture By Functional Genomics And Solid-State Nmr Along With Recent Advancements In Dynamic Nuclear Polarization For Analyzing Biomolecules, Arnab Chakraborty

LSU Master's Theses

This dissertation summarizes the findings related to the way by which supramolecular architecture of fungal cell wall changes with genetic mutation, dispensing genes responsible for biosynthesis of cell wall polysaccharides. This is necessary because without perfect picture of how supramolecular assembly changes with genetic mutation it is hard to assess new anti-fungal targets. Alongside this we have highlighted how recent advancement into Dynamic Nuclear Polarization (DNP) methods improved characterization of biomolecules both in case of labeled and unlabeled samples.

First study utilized Solid-state NMR (SSNMR) which is a non-destructive technique hence enabled us for the first time to deduce how …

Evaluating The Effect Of Coated Urea And Urea-Ammonium-Nitrate Solution On Cane Tonnage, Sugar Yield, And Leaf-Soil Nitrogen Content Under Louisiana Sugarcane Production System, Hector J. Mendoza Lagos

LSU Master's Theses

Nitrogen (N) is a crucial nutrient for proper plant growth and development. N deficiency results in poor tillering and thin, short internode stem production for sugarcane production, thus resulting in low cane tonnage. Therefore, proper N fertilizer management is essential for a sustainable sugarcane production system. This research was conducted at the LSU AgCenter Sugar Research Station in St. Gabriel, LA, from 2019 to 2020 at three Sites (Site 1, 2, and 3). The treatments consisted of different N rates (0, 45, 90, and 135 kg N ha^-1) and sources (urea-ammonium-nitrate solution [UAN]-32%, 30-day [Coated Urea 1], 45-day …

Development And Characterization Of Physicochemical Properties And Consumer Perception Of Gluten-Free Oat-Based Snack Bars Containing Orange Peel, Andrea R. Muela Negrete

LSU Master's Theses

Orange peel (OP) is a major byproduct from orange juice production, and is a good source of fiber and flavonoids, particularly nobiletin. Nobiletin has been reported to exhibit pharmacological activities including anti-inflammation and antioxidation. Incorporating orange peel into food products would harness economic benefit of this industrial byproduct and support a sustainable food chain. This study was performed to evaluate consumer perception of gluten-free oat-based snack bars (GFOSBs) containing orange peel.

In the first study three GFOSBs were formulated to contain 17%, 20%, and 23% orange peel by weight. Consumers (N=103) evaluated GFOSBs for sensory liking (9-point hedonic scale) and …

Examination Of Pre-Emergence Control Of Johnsongrass In Sugarcane Seedlings, Carleton Baucum

LSU Master's Theses

Sugarcane is susceptible to many diseases and insect pests; therefore, to maintain high sugar yield new varieties must be developed. Producing new varieties contributes to the overall crop success through enhanced yield, insect and/or disease resistance, cold tolerance, and ratooning ability. However, unlike conventional sugarcane, which is vegetatively propagated, new sugarcane varieties are produced from true seed. These seedlings are more susceptible to herbicidal injury and weed competition than conventional sugarcane. For sugarcane seedlings to succeed, weeds must be controlled therefore, the most effective herbicide program with regards to seedling safety must be implemented. The objectives of this research were …