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Predictive Promoter Activity In Soybean Using A Novel Cell-Suspension Culture And Transient Expression Analysis In Protoplasts, Mst Shamira Sultana

Masters Theses

Transient gene expression in plant protoplasts has been widely utilized for rapid functional screening of promoters. This project describes a novel soybean cell suspension culture and protoplast system for rapid and predictive analysis of promoter activity. Since recovery of transgenic lines is low in soybean stable transformation, high-throughput studies of promoter activity have intrinsic limitations. First, I describe a novel cell suspension culture system from leaf-derived callus. Once the cell culture is established, it is easy to maintain, sterile, and produces fast-growing cells amenable for protoplast production. Second, I describe an efficient and simple protoplast preparation procedure. The results revealed …

A Functional Developmental Genomics Analysis Of Rin4 And Exocyst Genes As They Relate To Glycine Max Defense To The Plant Parasitic Nematode Heterodera Glycines Infection, Keshav Sharma

Theses and Dissertations

The initial interaction of vesicle and the target membrane prior to their fusion is called vesicle tethering, a process mediated by an octameric protein complex called the exocyst. The exocyst connects vesicles and binds them to phosphatidylinositol 4, 5-biphosphate (PI (4,5) P2), located on the plasma membrane. The exocyst complex is located at the target site, helping to prepare the soluble N-ethylmaleimide-sensitive fusion protein attachment protein (SNAP) receptor (SNARE) for docking and subsequent release of vesicular contents after fusion. The importance of the exocyst in cellular processes is inevitable since it performs central roles in exocytosis thereby inducing SNARE-mediated membrane …

Influence Of Winter Annual Cover Crops And Insect Management Strategies On Insect Pests Of Mississippi Soybean, Daniel Adam Whalen

Theses and Dissertations

An increasing cultural practice in soybean, Glycine max (L.), production is the use of winter annual cover crops before planting. Species of grasses, legumes, and forbs are planted for many agronomic purposes during the fall months. In the spring, cover crops are killed and soybean planted into the residue. When the termination of the cover crops is delayed for longer lasting benefits, insect pest issues can arise. The movement of insect pests from cover crops to subsequent cash crops happens through a connection known as the “Green Bridge”. Pests found in cover crops such as the pea leaf weevil, Sitona …

Temperature Effects On Soybean Vegetative, Physiological, Reproductive Growth And Development, And Seed Yield And Quality, Firas Ahmed Alsajri

Theses and Dissertations

Temperature is a major factor affecting plant growth and development at all stages. The objectives of this study were to investigate the temperature effects on all aspects of soybean growth and development. Five experiments were conducted at a wide range of temperatures under optimum water and nutrient conditions at specific growth stages. Two cultivars, Asgrow AG5332 (AG) and Progeny P5333RY (PR) from MG V with different growth habits, were used. All studies except the seed germination were conducted in sunlit plant growth chambers under optimum water and nutrient conditions. The seed germination experiment was conducted in a temperature-controlled incubator. Germination …

Molecular Basis Of Pathogenesis And Host Determination In Cercospora Sojina: From Phenotypic To Genotypic Patterns, Wagner Calegari Fagundes

Graduate Theses and Dissertations

Frogeye leaf spot (FLS), caused by Cercospora sojina, is an important and recurrent disease of soybean in many production regions. Genetic resistance is potentially one of the most cost-effective and sustainable strategies to control FLS. However, C. sojina has already demonstrated the ability to overcome resistance conveyed by single R-genes (resistance genes) of soybeans, followed by the emergence of new physiological races. Although understanding population genomics and the virulence gene inventories in fungal plant pathogens is extremely important to improve disease control measures, studies regarding host specificity and pathogenesis in C. sojina are very limited. Therefore, the overarching goal of …

Epidemiological Studies Of Soybean Vein Necrosis Virus And Potential Resistance Mechanisms To Its Vector Neohydatothrips Variabilis (Beach), Jing Zhou

Graduate Theses and Dissertations

Soybean (Glycine max (L.) Merrill) is one the most important crops in global agriculture with annual production of over 260 million metric tons. As the dependence of a growing global population to soybean has increased, so does the importance of soybean diseases and pests. Over 200 pathogens attack soybean; among them, viruses pose a major threat to the soybean industries accounting for approximately 10% of the annual yield reduction caused by diseases in the past two decades. Soybean vein necrosis virus (SVNV) is a relatively newly discovered virus causing the homonymous disease. The widespread occurrence of the disease in major …

Linkage Mapping For Soybean (Glycine Max) Flood Tolerance, Wade Stiles Hummer

Graduate Theses and Dissertations

Flood tolerance in soybean (Glycine max) is not a well-characterized trait, yet flooding damage is second only to drought stress in terms of yield reduction. The objectives of this study were to determine genetic variation for flooding tolerance in two populations of soybean recombinant inbred lines (RILs) and to identify and confirm flood tolerant QTL. Population A (WHA) consisted of 111 RILs derived from the cross 5002T by 91210-350 and Population B (WHB) consisted of 79 RILs from the cross RA-452 by Osage. Experiments were conducted at the Rice Research and Extension Center (RREC) near Stuttgart, AR in 2015 and …

Evaluation Of Soybean Maturity Group And Planting Date In A Soybean-Rice Rotation On Overall Crop Productivity, Carrie Ortel

Graduate Theses and Dissertations

Little is known about the effects of soybean (Glycine max L.) management techniques on soil-nitrogen (N) credit development and its impact on the subsequent rice (Oryza sativa L.) crop’s success. This study was conducted to determine how soybean maturity group (MG) and planting date effect overall soybean productivity and its influence on the following rice crop. Various soybean planting dates (optimum and late) and MGs (3.5, 4.7, 5.4, and 5.6) were grown and followed in rotation with a rice crop. Six rates of pre-flood fertilizer-N (0, 44, 89, 134, 179, 224 kg N ha-1) were applied to the rice crop. …

Physiological Characterization Of The Soynam Parental Lines Under Field Conditions, Akshita Mishra

Graduate Theses and Dissertations

The narrow genetic pool of soybean (Glycine max L. Merr.) in North America can limit its future yield gains. Among the worldwide germplasm collection of 45,000 unique landraces, only 80 contribute 99% to the collective parentage of North American soybean cultivars. Among these 80 landraces, just 17 contribute to 86% of the collective parentage of the modern cultivars. The Soybean Nested Association Mapping population (SoyNAM) was therefore developed with the objective of diversifying the soybean gene pool. Forty diverse soybean genotypes from maturity groups (MG) 1 through 5 were crossed with a common MG 3 parent to develop 40 recombinant …

Soybean Response To Dicamba: Associated Injury Criteria And Development Of A Model To Predict Yield Loss, Matthew Ryan Foster

LSU Doctoral Dissertations

In research conducted using indeterminate soybean [Glycine max (L.) Merr.], fourteen injury criteria observed following dicamba at 0.6 to 280 g ae ha^-1 (1/1000 to ½ of 560 g ha^-1 use rate) were rated using a scale of 0= no injury, 1= slight, 2= slight to moderate, 3= moderate, 4= moderate to severe, and 5= severe. Greatest crop injury 15 d after treatment (DAT) was observed following dicamba applied at 0.6 to 4.4 g ha^-1 at V3/V4 for upper canopy pale leaf margins (3.8 to 4.2) and at R1/R2 for terminal leaf cupping (4.1 to 5.0) …

Breeding For Improved Oil Quality In High Yielding Soybean Lines Using Molecular Markers For Selecting Fad2-1a, Fad2-1b, Fad3a And Fad3c Mutant Alleles To Produce A High Oleic, Low Linolenic (Holl) Soybean., Alison Rose Willette

Masters Theses

Soybean oil is a major commodity in the US with practical uses for both food and industrial products. A declining market for soybean oil production caused by added restrictions on oil hydrogenation practices, has fueled improvements in oil industry standards. Typical soybean oil contains 8 to 12 g kg^-1 of linolenic acid which causes unfavorable odor and rapid rancidity which has been dealt with using hydrogenation in the past. Scientists have identified fatty acid desaturase genes which when mutated, produce oil that does not require hydrogenation. Breeders use single nucleotide polymorphism (SNP) analysis to select for soybean mutations containing …

Effects Of Cultural Practices On Soybean Nectar Production, Tyler Miles Smith

Theses and Dissertations

Experiments were conducted to determine the effects of cultural practices such as irrigation, planting date, and maturity group on soybean nectar production. Multiple interactions between different factors influences the amount of total sugar present in soybean flowers. Pod production was increased in later planted soybean, but later planting resulted in reduction in yield. Another study was conducted to explore the effects that variety selection had on soybean nectar production. Soybean nectar production was highly variable among varieties and was influenced further depending on their growing location. Later maturing varieties produced significantly more soybean pods. This increase in pod production was …

Evaluation Of Kudzu Bug As A Pest In Mississippi Soybean Production Systems, William Michael Mcright

Theses and Dissertations

The kudzu bug is an invasive species to the United States, and it has recently become a problem in the southern U.S. Experiments were conducted to examine the potential damage to vegetative stage soybean, with findings suggesting that kudzu bugs pose little threat to vegetative stage soybean in Mississippi soybean production systems. Foliar insecticides are an effective option for management of kudzu bug, however, neonicotinoid seed treatments are not recommended as an effective management strategy. Kudzu bug population densities of nymphs peaked in early August in soybean, and adult densities peaked in late September. This project was designed to develop …

Agronomic Practices And Irrigation Water Management Tools That Improve Water Use Efficiency In Mid-South Soybean Production Systems, Clinton Wilks Wood

Theses and Dissertations

The Mississippi River Valley Alluvial Aquifer (MRVAA) is declining precipitously due to irrigation withdrawal for row-crops. The development of scientific irrigation scheduling techniques and for soybean (Glycine max L.) will reduce withdrawal from the MRVAA. The objective of this research was to determine if soybean grain yield, irrigation water use efficiency (IWUE), and net return above irrigation cost could be optimized using a static irrigation threshold or if the irrigation threshold should be changed as a function of plant growth stage.

Impact Of Planting Strategies On Soybean (Glycine Max L.) Growth, Development And Yield, Shane Michael Carver

Theses and Dissertations

Soybean seed is one of the most costly inputs for soybean producers. Research was conducted in 2016 and 2017 in Mississippi to evaluate the impact of row spacing, planting date and seeding rate on soybean yield. Additional research was conducted to determine the optimal replant seeding rate, following a sub-optimal stand of soybean, to maximize soybean yield. These data suggest an early planting date, mid-April, at a seeding rate of 296,400 seeds ha-1, no matter the row spacing, resulted in the greatest soybean yield. No yield differences were observed for a replant seeding rate of 160,500 seeds ha-1 added to …

Evaluation Of Soybean Production Practices That Impact Yield Losses From Simulated Insect Defoliation, Benjamin Carroll Thrash

Theses and Dissertations

Soybean, Glycine max (L.) Merr., is planted across a vast amount of land in the Mid-Southern U.S. (Arkansas, Louisiana, Mississippi, and Tennessee), and yield responses to defoliation can vary. Experiments were conducted during 2015-2017 evaluating how soybean yield responds to multiple and continuous defoliation, as well as planting date and plant population. Multiple defoliation events were evaluated by defoliating soybean at varying levels at V3, V6, and both growth stages. There was no interaction between defoliation occurring at V3 and V6 growth stages, indicating that the impact of each defoliation event was independent of the other. The effect of continuous …

Genetic And Phytopathological Studies On Charcoal Rot Resistance In Soybean [Glycine Max (L) Merr.], Marcos Paulo Da Silva

Graduate Theses and Dissertations

Charcoal rot of soybean (Glycine max (L.), caused by Macrophomina phaseolina is a disease of economic significance in the United States. The identification and quantification of the resistance is difficult, and very little is known about the genetics and markers linked to the charcoal rot (CR) resistance genes. Current assay methods can be time consuming, and data may vary between tests. The objectives of this study were to 1) create a robust seed plate assay (SPA) for CR resistance by comparing results with cut-stem and CFUI assays; 2) correlate and compare field data disease assessments with SPA; 3) identify QTLs …

Global Dna Methylation Changes In Soybean As A Response To Soybean Cyst Nematode (Scn) Infection., Aditi Rambani

Doctoral Dissertations

Soybean cyst nematode (SCN, Heterodera glycines) is the most damaging pest in soybean production worldwide. The compatible interaction of SCN with susceptible soybean plants is mediated by differential expression of thousands of genes in the infected root cells, leading to the formation of a functional feeding site, the syncytium. During an incompatible interaction of SCN with resistant soybean, the developing syncytium degenerates leading to nematode death. The resistance to SCN in soybean is derived from two major loci, Rhg1 and Rhg4. In this study, the role of genome-wide DNA methylation in regulating gene expression during the compatible interaction was …

Dicamba Effects On Soybean (Glycine Max) Growth, Yield, And Offspring, Mark Spencer Mccown

Graduate Theses and Dissertations

Introduction of a new dicamba-resistant (Xtend) trait in soybean and cotton will increase dicamba herbicide use. Consequently, concern for injury to sensitive crops from off-target movement and tank contamination will likely increase. For soybean, foliar symptoms associated with dicamba damage do not necessarily reflect yield losses; hence, experiments were conducted to determine the effects of dicamba on soybean growth, yield, and offspring. Low rates of dicamba [1/64X (8.75 g ae ha-1) and 1/256X (2.18 g ae ha-1) of a normal 1X field rate (560 g ae ha-1)] were applied at two vegetative growth stages (V4, V6) and at each reproductive …

Evaluation Of Dicamba Off-Target Movement And Subsequent Effects On Soybean Offspring, Gordon Travis Jones

Graduate Theses and Dissertations

Commercial launch of cotton with resistance to dicamba, glyphosate, and glufosinate occurred in 2015 and launch of soybean with resistance to dicamba and glyphosate occurred in early 2016. It is likely that non-dicamba-resistant soybean will be planted in close proximity to dicamba-resistant soybean and cotton. Therefore, experiments were conducted to examine the distance dicamba moves during an application using commercial application equipment, as well as the effect the drift events have upon soybean offspring. Additional experiments were designed to investigate the effect glyphosate addition to dicamba has upon soybean growth and yield as well as possible effects on offspring. Lastly, …

Regulation Of Local Auxin Metabolism During Soybean Nodule Development, Suresh Damodaran

Electronic Theses and Dissertations

Legume-rhizobia symbiosis leads to the development of secondary root organs called nodules. Rhizobia bacteria housed inside nodules assimilate atmospheric nitrogen and convert them into plant usable forms thereby reducing the need for fertilizer application in crop legumes like soybean. Nodule development is a coordinated process orchestrated by multiple plant hormones. In soybean, the auxin responsive gene expression was detected in nodule primordia and in the periphery of mature nodules, primarily in nodule vasculature. Auxin hypersensitivity reduces nodule formation in soybean and also polar auxin transport inhibition at the site of nodule development is not crucial for determinate nodule formation. Therefore, …

Insecticidal Seed And In-Furrow Treatment Recommendations For Soybean And Sunflower, Brady Hauswedell

Electronic Theses and Dissertations

Throughout the 2016 and 2017 growing season, field research experiments were replicated across South Dakota. Many times seed treatments are used prophylactic, which is neither good for the producers or the environment. Producers will be able to reduce production costs, if they only use a seed treatment when necessary. The purpose of the first experiment was to determine the effects of seed treatments in combination with planting date and seeding rate on soybean yield. To determine the effects, two years of field data from four eastern South Dakota locations were compared. Within each year and location we compared two planting …

Impacts On Salmonid Rearing Performance With Use Of Dietary Bioprocessed Plant-Based Protein And Water Velocity, Jill Voorhees

Electronic Theses and Dissertations

The inclusion of bioprocessed soybean (Glycine max) meal was evaluated in five experiments using either Rainbow Trout (Oncorhynchus mykiss) or Brown Trout (Salmo trutta). In the first experiment, adult Erwin x Arlee strain Rainbow Trout were fed diets formulated so that bioprocessed soybean meal (BSM) replaced 0, 60, or 80% of the dietary fishmeal. There were no significant differences in gain, percent gain, feed conversion ratio, specific growth rate, intestinal morphology, relative fin lengths, or organosomatic indices. In the second experiment, juvenile Plymouth strain Brown Trout were fed diets formulated so that BSM replaced 0, 60, 80, or 100% of …

Ecophysiological Analysis Of Yield Determination In Soybean Of Different Relative Maturities, Maria Morrogh Bernard

Theses and Dissertations--Plant and Soil Sciences

Soybean yield differences are a combination of the genotype, environmental conditions, and management practices. Understanding how these factors interact through the analysis of the components involved in yield determination, provides a way to increase potential and actual yields in Kentucky.

Two irrigated experiments were conducted to quantify differences in the mechanisms of yield determination across soybean maturity groups (MG) 2 to 5 (Chapter 1), and to quantify management options (seeding rate and choice of MG cultivar) that increase yield potential of double crop soybean systems (Chapter 2).

Results showed that cultivars used different physiological strategies to achieve high yields, but …

Evaluation Of An Essential Oil Blend And A Novel Soybean Variety As Alternatives To Preventative Antibiotic Use In Monogastrics, Samantha Tauer

Electronic Theses and Dissertations

Increasing consumer pressure to minimize antibiotic use and the implementation of the Veterinary Feed Directive in 2017 has increased research on alternatives to preventative antibiotics. This thesis focuses on evaluation of Ralco’s Microfused™ Essential Oils (MEO) fed to broilers and soybean meal from low allergenicity soybeans fed to weaned pigs and their potential use as alternatives to antibiotics. Essential oils are known to have antimicrobial, antioxidant, antiparasitic, and digestive stimulant effects. Low allergenicity (LA) soybeans were bred to contain significantly lower concentrations of the following anti-nutritional factors and allergenic proteins: Kunitz trypsin inhibitor, soybean agglutinin (lectin), and P34 (Gly m …