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A Robust Agroinfiltration Method, Bryce N. Trull

Masters Theses

Stable transformation of soybean (Glycine max) is a markedly slow and laborious process. Thus, a tool that enables rapid evaluation of genetic elements in planta is critical to advance complex research and genetic engineering in soybean. To that end, a substantially robust agroinfiltration method was innovated in this work. Agroinfiltration is a technique that leverages Agrobacterium-mediated transient transformation to deliver genetic elements to the cells of whole plant tissues, usually leaves. Several factors were found to be relevant to successful soybean leaf agroinfiltration, including genotype, surfactant, developmental stage, and Agrobacterium culture medium. The research represents not only …

Characterization And Management Of Auxin-Resistant Palmer Amaranth In Tennessee, Delaney C. Foster

Doctoral Dissertations

Palmer amaranth has a long history of evolving resistance to herbicides to the point it has become a significant row crop production obstacle. Cotton and soybean growers were offered new technologies in 2016, expanding in-crop herbicide options to include dicamba or 2,4-D. Within three years of commercialization, dicamba use in these crops increased ten-fold and growers began to report Palmer amaranth escapes in west Tennessee auxin-tolerant production systems. A survey of Palmer amaranth escapes in dicamba and 2,4-D-tolerant cotton and soybean fields in Tennessee was conducted in the fall of 2021 with the objective of determining if poor control was …

Functional Analysis Of Soybean Proteinase Inhibitor Genes And Cyst Nematode-Inducible Synthetic Promoters For Insects And Nematode-Resistance In Plants, Mst Shamira Sultana

Doctoral Dissertations

Proteinase inhibitors (PIs) from legumes have the potential for use as protectants in response to pests and pathogens. Soybean (Glycine max) contains two trypsin inhibitors (TIs): Kunitz trypsin inhibitor (KTI) and Bowman-Birk inhibitor (BBI). In this study, the possible role of soybean TIs in plant defense against insects and nematodes was investigated. In addition to the three known TIs (KTI1, KTI2 and KTI3), novel inhibitors KTI5, KTI7, and BBI5 were identified in soybean. Their functional role was further examined by overexpression in soybean and Arabidopsis. In vitro enzyme inhibitory assays showed significant increase in trypsin and chymotrypsin inhibitory …

Evaluating The Ecological Relationships Among Beauveria Bassiana, Kudzu Bug And Kudzu, Kassie L. Hollabaugh

Masters Theses

When kudzu bug, Megacopta cribraria, was identified in the United States in 2009 as an invasive species, populations began to establish, increase, and spread throughout the southeastern region at intense rates. Kudzu bug invades urban structures, causing unpleasant scenes for homeowners, and reduces crop yield, such as soybean. Kudzu bug caused about $2.8 million in soybean yield loss and treatment in Tennessee in 2020. Although initial spread was rapid throughout the southeastern U.S., spatial modeling has shown populations of kudzu bug are declining and reducing risk of crop damage to growers. These local and regional declines in populations appear …

Relative Soybean Response To Aminocyclopyrachlor, 2,4-D, Dicamba, And Aminopyralid, Trey I. Clark

Masters Theses

This research compared the visual symptomology of four auxin herbicides applied at three rates to simulate tank contamination on non-auxin tolerant soybeans. The herbicides examined were aminocyclopyrachlor (ACP), 2,4-D, dicamba, and aminopyralid. The standard labeled rates (SLR) used to base the application rates were 0.12 kg ae ha^-1 for ACP and aminopyralid while dicamba and 2,4-D used 1.12 kg ae ha^-1. These four herbicides exhibit similar symptoms on soybeans which is problematic when diagnosing soybean response. One goal of this project was to obtain high-quality images of the four herbicide’s effect on soybeans, with the hope of …

Fungicide Sensitivity Screening Of Corynespora Cassiicola In Us Soybean And Cotton, Tyler Miles Smith

Doctoral Dissertations

Target spot, caused by the fungus Corynespora cassiicola, is a foliar disease of cotton and soybean. Target spot has become a disease of concern in soybean and cotton production systems. Data for fungicide sensitivity and understanding potential impact on yield is lacking for C. cassiicola. Fungicide resistance is also a concern in C. cassiicola with the increase in resistant pathogens in soybean. With the lack of knowledge about baseline fungicide sensitivity and the concern of fungicide resistance the objectives of this study were: (i) to evaluate fungicide products and mixes in small plot soybean and cotton trials, (ii) …

Identifying Drought Tolerance Traits In Tennessee Soybean Genotypes: Recovery From Severe Water Deficit Stress, Samuel W. Purdom

Masters Theses

Ninety-four percent of U.S. grown soybeans are produced under rainfed conditions with intermittent droughts occurring late in the season during reproductive growth stages. Due to the temporary nature of drought, the ability of a crop to survive and recover effectively from water deficit stress is important for ensuring yield stability. In 2019 and 2020, two greenhouse experiments and two field studies were conducted to screen eleven soybean genotypes for transpiration response and recovery from water deficit stress and high vapor pressure deficit (VPD). In the first greenhouse study, soybean plants were grown in pots sealed to prevent evaporation and plants …

Defining Bee Pollinator Community Composition In Tennessee Soybean, Andrew L. Lawson

Masters Theses

Two planting dates of various soybean varieties were planted in Jackson and Knoxville, TN during 2018 and 2019 with the overall intent of surveying the diversity bee (Hymenoptera) genera in these agroecosystems and also to assess the potential for using late maturing soybean as a food resource for bees during the dearth of floral resources that often occurs during the fall. We also investigated how manipulating planting dates and soybean variety selection affected the occurrence of insect pests that occurred in the soybean.

Both active (netting) and passive (bee bowls and blue-vane traps) sampling were used to collect the bees, …

Influence Of Traditional And Dual-Use Cropping On Arthropods And Slugs In Soybean In Tennessee, Matthew L. Longmire

Masters Theses

Soybean is the number one agricultural crop in Tennessee for both number of hectares planted and economic value. Soybean, used in various products, is marketed globally. In recent years, Tennessee soybean growers have shown an increased interest in the use of cover crops with soybean. A cover crop is planted before the cash crop and can minimize some weeds, diseases, insects, and other pests. Traditionally, cover crops are terminated in the spring before cash crop planting. Traditional methods of cover cropping provide many benefits but can also produce some undesired results. Dual-use cover cropping is a newer method of cover …

Quantitative Trait Loci Analysis Of A Ril Soybean Population To Determine Chromosomal Regions Governing Seed Protein, Oil, And Linolenic Acid Content, Ronald E. Moore

Masters Theses

180 RILs (recombinant inbred lines) segregating for protein, oil, and fatty acids were produced from a cross between TN12-4098 and TN13-4303. These lines were grown across three locations spread horizontally across Tennessee: Research Education Center at Milan (RECM), Highland Rim Research and Education Center (HRREC), and East Tennessee Research and Education Center (ETREC) in 2018 and 2019. 21 quantitative trait loci (QTLs) spanning 7 chromosomes were found using WinQTLCart2.5.

Mapping And Identification Of Qtl Associated With Soybean Seed Protein, Oil, And Yield In 5601t × U99-310255 Ril Population Using Snp Genotyping, Mia Justina Cunicelli

Doctoral Dissertations

Soybean [Glycine max (L.) Merr.] is the world’s leading source of vegetable oil and high quality protein meal. However, soybean protein and oil and protein and yield are negatively genetically correlated. Agronomic and seed quality traits of soybean lines are important because they lead to increased soybean value. Molecular markers have played and will continue to play a major role in the genetic characterization and improvement of soybeans. Quantitative trait loci (QTL) are regions within a genome that contain genes that influence particular quantitative traits. Identification of QTLs through phenotypic evaluation only is not possible; therefore, to locate, identify, and …

Understanding Soybean Root Microbiome Assembly Along Its Development From Both Plant And Soil Perspectives, Fang Liu

Doctoral Dissertations

Plants have evolved intimate partnerships with microorganisms to compensate for their sessile nature and to respond to changing biotic and abiotic environmental conditions. The plant-associated microbiome greatly expands plant functions and plasticity via improved nutrient availability/uptake, enhancing plant abiotic stress tolerance, and promoting plant defense. Understanding plant microbiome assembly is crucial for leveraging their versatile benefits to the plant host and advancing the next green movement in sustainable agriculture. In this study, we comprehensively characterized soybean root-associated microbiome assembly via the 16S rRNA gene and ITS2 (internal transcribed spacer) region amplicon sequencing. Using this technology, we examined different factors influencing …

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 …

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 …

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 …

Characteristics Of Four Agricultural Crops Established As Northern Bobwhite Brood Habitat, Denise A. Maidens, John P. Carroll

National Quail Symposium Proceedings

Small plots of agricultural crops are often planted in the Southeast for northern bobwhite (Colinus virginianus) management. Often these are viewed as primarily winter habitat, and assumed to provide summer habitat. We evaluated the macroinvertebrate and vegetative structure of millet, sorghum, wheat, and soybean plots on a cotton farm to assess their value as bobwhite brood habitat. During June and July 1999 and June, July, and August 2000, we studied 5 blocks, each planted with all 4 agricultural crops. We measured invertebrate abundance along a 15-meter transect in each plot using vacuum sampling and height/density of vegetation. Visual obstruction readings …

Incentive Payments For Planting Upland Bird Habitat Field Borders In Tennessee, Nathaniel Scott Bruce

Masters Theses

Crop yields along field perimeters that are adjacent to trees and other tall-herbaceous are known to have the lowest yields in a field. An alternative use of these areas that might be more profitable and sustainable is to remove the land from crop production and enroll these areas into the upland bird habitat (UBH) buffer program. However, the adoption of UBH buffers have been limited by producers, despite being eligible for receiving an incentive payment for adopting UBH buffers. Therefore, the objective of this thesis was to determine the breakeven incentive payment for corn [Zea mays L.] and soybean …

Effect Of The Mutant Danbaekkong Or Stem Termination Alleles On Soybean Seed Protein Concentration, Amino Acid Composition, And Other Seed Quality And Agronomic Traits, Mia Justina Cunicelli

Masters Theses

Soybean [Glycine max (L.) Merr.] is the world’s leading source of vegetable oil and high quality protein meal. Increasing soybean protein concentration through selection while maintaining oil concentration and yield has been a constant goal for plant breeders, as there is a negative correlation between protein and oil and protein and yield. The objective of this study was to determine if marker assisted selection (MAS) for the Danbaekkong (Dan) protein allele influences agronomic and seed quality traits. A population of 24 F_8:10 [eighth filial generation advanced to the tenth filial generation] near isogenic lines (NILs) of soybean was …

Optimizing Soybean (Glycine Max L.) Yield With Nitrogen And Sulfur Applications, Kacey A. Cannon

Masters Theses

Although soybean (Glycine max L.) yields have increased over the past decade, even greater improvement is in demand. Nontraditional practices such as applying nitrogen (N) to soybean for yield optimization, might be one way to meet this demand. Also, sulfur (S) is becoming a more important limiting nutrient in production due to higher yielding crops, lower S containing production inputs, and reduced supply from the environment. The N study involved two environments, irrigated and dryland, in Milan (35.9198° N, 88.7589° W) and Jackson (35.6145° N, 88.8139° W), TN in 2015 and 2016. Urea fertilizer treatments were 34, 67, and …

Evolution Of An Intron-Poor Cluster Of The Cipk Gene Family And Expression In Response To Drought Stress In Soybean, Kaikai Zhu, Fei Chen, Jinyi Liu, Xinlu Chen, Tarek Hewezi, Zong-Ming Cheng

Plant Sciences Publications and Other Works

Calcium ion is an intracellular messenger that plays a central role in signal transduction pathways. Calcineurin B-like proteins (CBLs) and CBL-interacting protein kinases (CIPKs) signal network have shown different functions in the Ca2+ signaling process. In this work, we identified the entire soybean (Glycine max) CIPK gene family, which comprised 52 genes and divided into four subgroups (I to IV) based on phylogeny. The gene structural analysis separated these 52 genes into an intron-rich clade and an intron-poor clade. Chromosomal location analysis resulted in the identification of 22 duplicated blocks and six tandem duplication events. Phylogenetic classification of …

Molecular Breeding Strategies For Improvement Of Complex Traits In Soybean, Christopher Joseph Smallwood

Doctoral Dissertations

Soybean [Glycine max (L.) Merrill] is the leading oilseed crop grown in the world. Yield, fatty acids, protein, and oil are commercially important soybean traits; thus evaluation of breeding strategies for improvement of these traits is merited. To accomplish this, a comparison of molecular and phenotypic breeding strategies from progeny row selections was performed. From this it was determined that molecular strategies consistently outperformed phenotypic selections (PS) in the progeny row stage for soybean yield, fatty acids, protein, and oil. For yield, Epistacy was the preferred selection method. For fatty acids, protein, and oil, the genomic selection (GS) strategies were …

Effects Of Leaflet Orientation And Root Morphology On Physiological Traits And Yield In Soybeans., Richard Dewayne Johnson

Doctoral Dissertations

Drought is the most important abiotic stress adversely affecting soybean (Glycine max (L.) Merr.) yield. Leaflet orientation has been shown to reduce leaflet temperatures and transpiration while root morphology has been related to slower wilting phenotypes. The objective of this study was to investigate effects of leaflet orientation and rooting morphology on whole plant transpiration, yield, water use efficiency, and other physiological traits in soybeans using grafting techniques, population lines, near-isogenic lines, and restrained leaf canopy experiments. Experiments were conducted in Knoxville, TN with additional yield trial plots at Springfield, Spring Hill, and Milan, TN. Data were collected on …

Comparison Of Roundup Ready And Conventional Soybean (Glycine Max L.) Weed Control Systems For Optimizing Yield And Economic Profitability, Brittany Lee Gaban

Masters Theses

Research was conducted in 2010, 2011 and 2012 at the East Tennessee Research and Education Center in Knoxville, TN, in order to compare differences in soybean yield among differing levels of weed control within Roundup Ready® [Glyphosate-resistant] (RR)and conventional soybean cultivars to gain a better understanding of the impact different intensities of weed control have on RR and conventional cropping systems. Results determined that after applying the weed control regimens, there was no significant difference (p

Glyphosate resistant weeds introduce new challenges and create a more costly weed control regimen, especially when using a RR based soybean cultivation operation. Therefore, …

Heritability And Genetic Gain Of Seed Protein, Oil, And Yield Among Ril Of Soybean, Benjamin T. Wiggins

Masters Theses

Soybean is a remarkable crop that is used in many aspects of our everyday lives. The seed protein is used primarily for livestock feed, though it is becoming more available as a meat substitute for human consumption. Soybean oil is used in many products such as plastics, foods, and industrial products. Seed yield is the major trait that is selected for in a breeding program. A population of 239 F₄ derived RIL from the cross of USG 5601T × U99-310255 was used to calculate heritability estimates by parent offspring regression and on an entry mean basis. This population was …

Rr12-03 Soybean Variety Performance Tests In Tennessee 2011, Fred Allen, Richard Johnson, Robert C. Williams Jr., Angela Thompson Mcclure, Melvin Newman, Pat Donald

Field & Commercial Crops

No abstract provided.

Two Studies Evaluating Input Use In Soybean And Cotton Production, Nathanael Mark Thompson

Masters Theses

Farmers are price takers for both inputs and outputs. Therefore, when the prices of inputs rise, as they have with many inputs used in agricultural production, optimal production practices may change. Two separate studies of the impacts of agricultural technology on input use in crop production were undertaken in this thesis. The first study evaluated economically optimal plant population considering seeding rate, maturity group, row spacing, and input-output prices in soybean production in the rolling uplands region of the upper Midsouthern United States. Data from field experiments at the University of Tennessee Research and Education Center at Milan, Tennessee during …

W202 Thrips, The University Of Tennessee Agricultural Extension Service

Field & Commercial Crops

No abstract provided.

W201 Threecornered Alfalfa Hopper, The University Of Tennessee Agricultural Extension Service

Field & Commercial Crops

No abstract provided.

W200 Stink Bugs, The University Of Tennessee Agricultural Extension Service

Field & Commercial Crops

No abstract provided.

W198 Green Cloverworm, The University Of Tennessee Agricultural Extension Service

Field & Commercial Crops

No abstract provided.