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Microscopic Characterization Of A Transposon-Induced Male-Sterile, Female-Sterile Mutant In Glycine Max L., Katherine A. Thilges Jan 2016

Microscopic Characterization Of A Transposon-Induced Male-Sterile, Female-Sterile Mutant In Glycine Max L., Katherine A. Thilges

Graduate Theses and Dissertations

A male-sterile, female-sterile mutant was identified in a transposon-tagging study in soybean (Glycine max L.). This mutant displayed abnormalities in both micro- and mega-sporogenesis, as well as gametogenesis. Vegetatively, the mutant showed no visible differences from the wild-type phenotype. Analyses of male meiotic chromosomes were done to better understand any issues that could occur to cause sterility. Wild-type and mutant anthers and ovules were cleared throughout their development, followed by confocal scanning laser microscopy to look for any abnormalities, and to determine the timing of abortion in both the male and female organs in the mutant. Additionally, scanning electron microscopy ...


Molecular Characterization Of Short And Long Term Iron Stress Responses In Soybean, Leorrie Ann Atencio Jan 2016

Molecular Characterization Of Short And Long Term Iron Stress Responses In Soybean, Leorrie Ann Atencio

Graduate Theses and Dissertations

Iron Deficiency Chlorosis (IDC) is a disease caused by lack of useable iron in the soil. Symptoms include stunting and interveinal chlorosis of the leaves, eventually leading to yield loss at the end of the season. IDC is particularly important in the upper Midwestern United States because soil conditions favor its development. With the use of next generation sequencing approaches, we characterized soybeans’ short and long-term response to iron stress. Our research takes advantage of two near isogenic lines that are 98% genetically identical but differ in their iron efficiency response. Clark plants are iron efficient, while Isoclark plants are ...


Soybean Vein Necrosis Virus: Impacts Of Infection On Yield Loss And Seed Quality And Expansion Of Plant Host Range, Melissa Irizarry Jan 2016

Soybean Vein Necrosis Virus: Impacts Of Infection On Yield Loss And Seed Quality And Expansion Of Plant Host Range, Melissa Irizarry

Graduate Theses and Dissertations

Soybean vein necrosis virus (SVNV) rapidly became a widespread soybean (Glycine max) virus within a few years of its initial confirmation in 2008. The economic impact of soybean vein necrosis (SVN) disease remains unknown. Soybean is a crop of global importance with nearly 4 billion bushels of soybeans produced in the United States in 2014. This study was designed to pursue two main questions; is there any yield loss or change in seed quality associated with SVN and are there horticultural or cover crop species that could be serving as sources of SVNV inoculum?

In order to determine if there ...


Rye Cover Crop Biomass, Nutrient Composition And Crop Management Practices To Enhance Corn Yield, Swetabh Patel Jan 2016

Rye Cover Crop Biomass, Nutrient Composition And Crop Management Practices To Enhance Corn Yield, Swetabh Patel

Graduate Theses and Dissertations

Winter cereal rye (Secale cereal L.), a commonly used cover crop in corn (Zea mays L.) systems has potential to scavenge soil NO3–N through a fibrous root system. The objective of this study was to quantify root and shoot biomass, C, and N partitioning in rye cover crop at the time of termination in spring. This was a one–year study conducted at a site with a no-till corn–soybean [Glycine max (L.) Merr.] rotation, rye drilled following grain crop harvest, and three N rates applied to corn (0, 135, and 225 kg N ha–1). Rye root biomass ...


Identification And Characterization Of Brown Stem Rot Resistance In Soybean, Chantal Elaine Mccabe Jan 2016

Identification And Characterization Of Brown Stem Rot Resistance In Soybean, Chantal Elaine Mccabe

Graduate Theses and Dissertations

Breeding for pathogen resistance is an important objective to improve and protect soybean yields. In 2010, 14.4% of total soybean yield was suppressed by diseases. Brown stem rot (BSR), caused by the fungus Phialophora gregata, reduces yield by as much as 38%. To date, three dominant BSR resistance genes have been identified: Rbs1, Rbs2, and Rbs3. The objectives of my research were 1) to determine if plant introductions contained novel BSR resistance genes, 2) to determine the correlation between P. gregata hyphae growth and foliar symptoms as well as characterize the response of the three BSR resistance genes to ...


Studies On Cover Crops And Sudden Death Syndrome Of Soybean, Renan Kobayashi-Leonel Jan 2016

Studies On Cover Crops And Sudden Death Syndrome Of Soybean, Renan Kobayashi-Leonel

Graduate Theses and Dissertations

Soybean sudden death syndrome (SDS), caused by Fusarium virguliforme, is a major soybean disease affecting soybean production in the United States. In search for more diversified cropping systems, the adoption of cover crops in the corn-soybean rotation is being encouraged. However, there is lack of information regarding the impact that cover cropping can have on SDS. On the one hand, it is possible that the improvements in soil health caused by cover crop can create an environment that is not favorable to the disease. On the other hand, F. virguliforme is able to colonize many plant species and, if a ...


Genome-Wide Association And Epistasis Studies Of Sclerotinia Sclerotiorum Resistance In Soybean, Tara Catherine Moellers Jan 2016

Genome-Wide Association And Epistasis Studies Of Sclerotinia Sclerotiorum Resistance In Soybean, Tara Catherine Moellers

Graduate Theses and Dissertations

Sclerotinia stem rot or white mold (WM) [Sclerotinia sclerotiorum (Lib.) de Bary] is an important fungal disease affecting soybean [Glycine max (L.) Merr.] and causes yield and quality losses. WM is prevalent in cool and moist environments, particularly in the soybean growing regions of Northern United States and Canada. Although sources of complete resistance have not yet been identified, several quantitative trait loci (QTL) for partial resistance have been reported but generally using bi-parental mapping populations. Genome-wide association (GWA) studies have been used to dissect complex disease resistance traits in plants and to identify the genes controlling the expression. WM ...


Modeling Long-Term Corn Yield Response To Nitrogen Rate And Crop Rotation, Laila A. Puntel, John E. Sawyer, Daniel Barker, Ranae N. Dietzel, Hanna Poffenbarger, Michael J. Castellano, Kenneth J. Moore, Peter Thorburn, Sotirios Archontoulis Jan 2016

Modeling Long-Term Corn Yield Response To Nitrogen Rate And Crop Rotation, Laila A. Puntel, John E. Sawyer, Daniel Barker, Ranae N. Dietzel, Hanna Poffenbarger, Michael J. Castellano, Kenneth J. Moore, Peter Thorburn, Sotirios Archontoulis

Agronomy Publications

Improved prediction of optimal N fertilizer rates for corn (Zea mays L.) can reduce N losses and increase profits. We tested the ability of the Agricultural Production Systems sIMulator (APSIM) to simulate corn and soybean (Glycine max L.) yields, the economic optimum N rate (EONR) using a 16-year field-experiment dataset from central Iowa, USA that included two crop sequences (continuous corn and soybean-corn) and five N fertilizer rates (0, 67, 134, 201, and 268 kg N ha-1) applied to corn. Our objectives were to: (a) quantify model prediction accuracy before and after calibration, and report calibration steps; (b) compare ...


Candidate Perennial Bioenergy Grasses Have A Higher Albedo Than Annual Row Crops, Jesse N. Miller, Andy Vanloocke, Nuria Gomez-Casanovas, Carl J. Bernacchi Jan 2016

Candidate Perennial Bioenergy Grasses Have A Higher Albedo Than Annual Row Crops, Jesse N. Miller, Andy Vanloocke, Nuria Gomez-Casanovas, Carl J. Bernacchi

Agronomy Publications

The production of perennial cellulosic feedstocks for bioenergy presents the potential to diversify regional economies and the national energy supply, while also serving as climate ‘regulators’ due to a number of biogeochemical and biogeophysical differences relative to row crops. Numerous observational and model-based approaches have investigated biogeochemical trade-offs, such as increased carbon sequestration and increased water use, associated with growing cellulosic feedstocks. A less understood aspect is the biogeophysical changes associated with the difference in albedo (a), which could alter the local energy balance and cause local to regional cooling several times larger than that associated with offsetting carbon. Here ...


Reduced Fitness Of Virulent Aphis Glycines (Hemiptera: Aphididae) Biotypes May Influence The Longevity Of Resistance Genes In Soybean, Adam J. Varenhorst, Michael T. Mccarville, Matthew E. O'Neal Sep 2015

Reduced Fitness Of Virulent Aphis Glycines (Hemiptera: Aphididae) Biotypes May Influence The Longevity Of Resistance Genes In Soybean, Adam J. Varenhorst, Michael T. Mccarville, Matthew E. O'Neal

Entomology Publications

Sustainable use of insect resistance in crops require insect resistance management plans that may include a refuge to limit the spread of virulence to this resistance. However, without a loss of fitness associated with virulence, a refuge may not prevent virulence from becoming fixed within a population of parthenogenetically reproducing insects like aphids. Aphid-resistance in soybeans (i.e., Rag genes) prevent outbreaks of soybean aphid (Aphis glycines), yet four biotypes defined by their capacity to survive on aphid-resistant soybeans (e.g., biotype-2 survives on Rag1 soybean) are found in North America. Although fitness costs are reported for biotype-3 on aphid ...


Survey Of Soybean Insect Pollinators: Community Identification And Sampling Method Analysis, K. A. Gill, M. E. O'Neal Jun 2015

Survey Of Soybean Insect Pollinators: Community Identification And Sampling Method Analysis, K. A. Gill, M. E. O'Neal

Entomology Publications

Soybean, Glycine max (L.) Merrill, flowers can be a source of nectar and pollen for honey bees, Apis mellifera L. (Hymenoptera: Apidae), wild social and solitary bees (Hymenoptera: Apoidea), and flower-visiting flies (Diptera). Our objectives were to describe the pollinator community in soybean fields, determine which sampling method is most appropriate for characterizing their abundance and diversity, and gain insight into which pollinator taxa may contact soybean pollen. We compared modified pan traps (i.e., bee bowls), yellow sticky traps, and sweep nets for trapping pollinators in Iowa soybean fields when soybeans were blooming (i.e., reproductive stages R1–R6 ...


Evaluation Of Spontaneous Generation Of Allelic Variation In Soybean In Response To Sexual Hybridization And Stress, Katherine Espinosa, Jessica Boelter, Susan Lolle, Marianne Hopkins, Susana Goggi, Reid G. Palmer, Devinder Sandhu Mar 2015

Evaluation Of Spontaneous Generation Of Allelic Variation In Soybean In Response To Sexual Hybridization And Stress, Katherine Espinosa, Jessica Boelter, Susan Lolle, Marianne Hopkins, Susana Goggi, Reid G. Palmer, Devinder Sandhu

Agronomy Publications

Intra-cultivar variation reported in pure lines of soybean has been hypothesized to result from genetic mechanisms contributing to de novo genetic variation. In this study we have detected allele switching by following segregation pattern of Aconitase-4 isozyme in sexual crosses and pure lines. In sexual crosses, one F2 plant showed switch at the Aconitase- 4 (Aco4) locus from the expected heterozygous genotype Aco4-ac to Aco4-ab. In the pure lines grown in a honeycomb planting design and treated with an accelerated aging test, multiple cases of allele switching were detected at the Aco4 locus. Both single and double switches were detected ...


Influence Of Bradyrhizobium Inoculation And Fungicide Treatment On Development And Yield Of Selected Pulse Crops; Nutritional Composition Of Pulse Legume Leaves And The Impact Of Leaf Removal On Yield, Rosemary Bulyaba Jan 2015

Influence Of Bradyrhizobium Inoculation And Fungicide Treatment On Development And Yield Of Selected Pulse Crops; Nutritional Composition Of Pulse Legume Leaves And The Impact Of Leaf Removal On Yield, Rosemary Bulyaba

Graduate Theses and Dissertations

Part 1

Declining soil fertility due to inadequate nitrogen in most soils limits farmers’ goals of increasing yield. There is environmental and agricultural benefit of reducing dependence on nitrogen fertilizer by emphasizing adaptation of favorable farming practices that minimize nitrogen fertilizer. Cowpea [Vigna unguiculata (L.) Walp.] and lablab (Lablab purpureus (L.)] are pulses with potential for grain, forage, and cover crops in the Midwest of United States, but little is known about their growth, development, and productivity potential in Iowa. We conducted a two-year field study to determine the influence of rhizobia inoculation and fungicide seed treatment of selected pulses ...


Local Vs. Systemic Modifications Of Soybean (Glycine Max) Defense Signals In Response To Soybean Aphid (Aphis Glycines Matsumura) Infestation, Khoi Nguyen Jan 2015

Local Vs. Systemic Modifications Of Soybean (Glycine Max) Defense Signals In Response To Soybean Aphid (Aphis Glycines Matsumura) Infestation, Khoi Nguyen

Graduate Theses and Dissertations

Soybean aphids, Aphis glycines, are a specialized phloem-feeding pest of soybeans. They are known to employ different mechanisms to bypass plant defenses and reduce soybean plant yields of up to 50% a year. Once attacked or sensing distress, soybeans induce the oxylipin pathway, a biosynthetic pathway that produces key plant hormones. Among these hormones is jasmonic acid (JA), which is produced from linolenic acid (18:3). Jasmonic acid can signal the production of protease inhibitors as one of the products that obstructs the attackers’ ability to digest protein. Previous studies show that levels of three key fatty acid precursors (palmitic ...


Phenotypic And Genetic Variation In An Apios Americana Breeding Collection; And Characterization Of The Hd-Zip Gene Family, Involved In Abiotic Stress Responses In Glycine Max, Vikas Belamkar Jan 2015

Phenotypic And Genetic Variation In An Apios Americana Breeding Collection; And Characterization Of The Hd-Zip Gene Family, Involved In Abiotic Stress Responses In Glycine Max, Vikas Belamkar

Graduate Theses and Dissertations

This dissertation has two main objectives: (1) morphological and genetic characterization of a little-studied edible legume native to North America, Apios americana; and (2) characterization of the soybean (Glycine max) homeodomain leucine zipper (HD-Zip) transcription factor family (involved in abiotic stress responses), and identification of candidate genes for dehydration and salt stress. In these projects, next generation sequencing (NGS) is evaluated as a tool for rapidly characterizing genetic variation (in Apios) and fine-scale genetic responses to abiotic stress (in soybean).

Apios, commonly called “potato bean,” is a nitrogen-fixing legume that is adapted to diverse climatic conditions of central and eastern ...


Plant Tissue Analysis To Assess Phosphorus And Potassium Nutritional Status Of Corn And Soybean In Iowa, Andrew John Stammer Jan 2015

Plant Tissue Analysis To Assess Phosphorus And Potassium Nutritional Status Of Corn And Soybean In Iowa, Andrew John Stammer

Graduate Theses and Dissertations

Interest in re-evaluating the value of tissue testing to assess P and K status in corn (Zea mays L.) and soybean (Glycine max L. Merr.) is increasing. The objective of this research was to study relationships between grain yield response to P and K and the concentration of these nutrients in plant tissue. Single-year and multi-year response trials were conducted in Iowa at 30 sites for P (32 sites-years with corn and 34 with soybean) and at 53 for K (67 sites years with corn and 52 with soybean) that encompassed 17 soil series. We sampled above-ground plant parts at ...


Aboveground Feeding By Soybean Aphid, Aphis Glycines, Affects Soybean Cyst Nematode, Heterodera Glycines, Reproduction Belowground, Michael T. Mccarville, David H. Soh, Gregory L. Tylka, Matthew E. O'Neal Jan 2014

Aboveground Feeding By Soybean Aphid, Aphis Glycines, Affects Soybean Cyst Nematode, Heterodera Glycines, Reproduction Belowground, Michael T. Mccarville, David H. Soh, Gregory L. Tylka, Matthew E. O'Neal

Entomology Publications

Heterodera glycines is a cyst nematode that causes significant lost soybean yield in the U.S. Recent studies observed the aphid Aphis glycines and H. glycines interacting via their shared host, soybean, Glycine max. A greenhouse experiment was conducted to discern the effect ofA. glycines feeding on H. glycines reproduction. An H. glycines-susceptible cultivar, Kenwood 94, and a resistant cultivar, Dekalb 27–52, were grown in H. glycines-infested soil for 30 and 60 d. Ten days after planting, plants were infested with either zero, five, or ten aphids. At 30 and 60 d, the number of H ...


Identification Of Candidate Genes Involved In Early Iron Deficiency Chlorosis Signaling In Soybean (Glycine Max) Roots And Leaves, Adrienne N. Moran-Lauter, Gregory Allan Peiffer, Tengfei Yin, Steven A. Whitham, Dianne Cook, Randy Shoemaker, Michelle Graham Jan 2014

Identification Of Candidate Genes Involved In Early Iron Deficiency Chlorosis Signaling In Soybean (Glycine Max) Roots And Leaves, Adrienne N. Moran-Lauter, Gregory Allan Peiffer, Tengfei Yin, Steven A. Whitham, Dianne Cook, Randy Shoemaker, Michelle Graham

Plant Pathology and Microbiology Publications

Background

Iron is an essential micronutrient for all living things, required in plants for photosynthesis, respiration and metabolism. A lack of bioavailable iron in soil leads to iron deficiency chlorosis (IDC), causing a reduction in photosynthesis and interveinal yellowing of leaves. Soybeans (Glycine max (L.) Merr.) grown in high pH soils often suffer from IDC, resulting in substantial yield losses. Iron efficient soybean cultivars maintain photosynthesis and have higher yields under IDC-promoting conditions than inefficient cultivars.

Results

To capture signaling between roots and leaves and identify genes acting early in the iron efficient cultivar Clark, we conducted a RNA-Seq study ...


Effects Of Ilevo® On Soybean Sudden Death Syndrome And Soybean Cyst Nematode, Edward R. Zaworski Jan 2014

Effects Of Ilevo® On Soybean Sudden Death Syndrome And Soybean Cyst Nematode, Edward R. Zaworski

Graduate Theses and Dissertations

Fusarium virguliforme, the causal agent of soybean sudden death syndrome (SDS), and Heterodera glycines, soybean cyst nematode (SCN), are two of the most important pathogens of soybean. Host resistance is currently the main management strategy for both pathogens, and there are few other options available for each pathogen. Seed treatments are now an option for farmers for use of pesticides in early plant development. Bayer CropScience recently registered a seed treatment, ILeVO® (fluopyram), with reported activity against both SDS and SCN. The research described in the following manuscript tested ILeVO® in different combinations with currently available seed treatment products for ...


Candidate Gene Identification For A Lethal Chlorophyll-Deficient Mutant In Soybean, Sam Reed, Taylor Atkinson, Carly Gorecki, Katherine Espinosa, Sarah Przybylski, Alcira Susana Goggi, Reid G. Palmer, Devinder Sandhu Jan 2014

Candidate Gene Identification For A Lethal Chlorophyll-Deficient Mutant In Soybean, Sam Reed, Taylor Atkinson, Carly Gorecki, Katherine Espinosa, Sarah Przybylski, Alcira Susana Goggi, Reid G. Palmer, Devinder Sandhu

Agronomy Publications

Chlorophyll-deficient mutants have been studied persistently to understand genetic mechanisms controlling metabolic pathways. A spontaneous chlorophyll-deficient lethal mutant was observed in self-pollinated progeny of a soybean cultivar “BSR 101”. Observed segregation patterns indicated single-gene recessive inheritance for this lethal-yellow mutant. The objectives of this investigation were to develop a genetic linkage map of the region containing the lethal-yellow (YL_PR350) gene and identify putative candidate genes for this locus. The YL_PR350 gene was mapped to chromosome 15 and is flanked by BARCSOYSSR_15_1591 and BARCSOYSSR_15_1597. This region physically spans ~153 kb and there are 14 predicted genes that lie in this region ...


Effects Of Rag1 On The Preference And Performance Of Soybean Defoliators, Robert F. Bruner, Erin W. Hodgson, Aaron J. Gassmann Dec 2013

Effects Of Rag1 On The Preference And Performance Of Soybean Defoliators, Robert F. Bruner, Erin W. Hodgson, Aaron J. Gassmann

Entomology Publications

The Rag1 gene confers antibiotic resistance to soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), and in 2010, varieties expressing Rag1 were released for commercial use in the United States. We do not know how Rag1 varieties will influence the broader community of defoliating insects that inhabit soybean fields. In 2010 and 2011, the preference and performance of pest insects that defoliate soybeans [Glycines max (L.) Merr] were tested using Rag1 and aphidsusceptible varieties. Three coleopterans and four lepidopterans were used: northern corn rootworm, Diabrotica barberi Smith & Lawrence (Coleoptera: Chrysomelidae); southern corn rootworm, Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae); bean leaf beetle, Ceratoma trifurcata ...


Investigation Of The Arabidopsis Nonhost Resistance Mechanism Against The Soybean Pathogen, Phytophthora Sojae, Rishi Sumit Jan 2013

Investigation Of The Arabidopsis Nonhost Resistance Mechanism Against The Soybean Pathogen, Phytophthora Sojae, Rishi Sumit

Graduate Theses and Dissertations

Nonhost resistance (NHR) provides immunity to all members of a plant species against all isolates of a microorganism that is pathogenic to other plant species. Three Arabidopsis thaliana PEN (penetration deficient) genes, PEN1, 2 and 3 have been shown to provide prehaustorial NHR against the barley pathogen Blumeria graminis f. sp. hordei. Arabidopsis pen1-1 mutant is penetrated by the hemibiotrophic oomycete pathogen, Phytophthora sojae that causes root and stem rot disease in soybean. The P. sojae susceptible (pss) 1 mutant is infected by both P. sojae and the hemibiotrophic fungal pathogen, Fusarium virguliforme that causes sudden death syndrome in soybean ...


A Virus-Induced Gene Silencing Method To Study Soybean Cyst Nematode Parasitism In Glycine Max, Pramod K. Kandoth, Robert Heinz, Gregory Yeckel, Nathan W. Gross, Parijat S. Juvale, John H. Hill, Steven A. Whitham, Thomas J. Baum, Melissa G. Mitchum Jan 2013

A Virus-Induced Gene Silencing Method To Study Soybean Cyst Nematode Parasitism In Glycine Max, Pramod K. Kandoth, Robert Heinz, Gregory Yeckel, Nathan W. Gross, Parijat S. Juvale, John H. Hill, Steven A. Whitham, Thomas J. Baum, Melissa G. Mitchum

Plant Pathology and Microbiology Publications

Background

Bean pod mottle virus (BPMV) based virus-induced gene silencing (VIGS) vectors have been developed and used in soybean for the functional analysis of genes involved in disease resistance to foliar pathogens. However, BPMV-VIGS protocols for studying genes involved in disease resistance or symbiotic associations with root microbes have not been developed.

Findings

Here we describe a BPMV-VIGS protocol suitable for reverse genetic studies in soybean roots. We use this method for analyzing soybean genes involved in resistance to soybean cyst nematode (SCN). A detailed SCN screening pipeline is described.

Conclusions

The VIGS method described here provides a new tool ...


Transcriptome Analyses And Virus Induced Gene Silencing Identify Genes In The Rpp4 -Mediated Asian Soybean Rust Resistance Pathway, Aguida A.M.P. Morales, Jamie A. O'Rourke, Martijn Van De Mortel, Katherine T. Scheider, Timothy J. Bancroft, Aluizio Borem, Rex T. Nelson, Daniel S. Nettleton, Thomas J. Baum, Randy C. Shoemaker, Reid D. Frederick, Ricardo V. Abdelnoor, Kerry F. Pedley, Steven A. Whitham, Michelle Graham Jan 2013

Transcriptome Analyses And Virus Induced Gene Silencing Identify Genes In The Rpp4 -Mediated Asian Soybean Rust Resistance Pathway, Aguida A.M.P. Morales, Jamie A. O'Rourke, Martijn Van De Mortel, Katherine T. Scheider, Timothy J. Bancroft, Aluizio Borem, Rex T. Nelson, Daniel S. Nettleton, Thomas J. Baum, Randy C. Shoemaker, Reid D. Frederick, Ricardo V. Abdelnoor, Kerry F. Pedley, Steven A. Whitham, Michelle Graham

Plant Pathology and Microbiology Publications

Rpp4 (Resistance to Phakopsora pachyrhizi 4) confers resistance to Phakopsora pachyrhizi Sydow, the causal agent of Asian soybean rust (ASR). By combining expression profiling and virus induced gene silencing (VIGS), we are developing a genetic framework for Rpp4-mediated resistance. We measured gene expression in mock-inoculated and P. pachyrhizi-infected leaves of resistant soybean accession PI459025B (Rpp4) and the susceptible cultivar (Williams 82) across a 12-day time course. Unexpectedly, two biphasic responses were identified. In the incompatible reaction, genes induced at 12 h after infection (hai) were not differentially expressed at 24 hai, but were induced at 72 hai. In contrast, genes ...


13c-Metabolic Flux Analysis Of Soybean Somatic Embryos For Identification Of Metabolic Control Points In Developing Seed, Quyen Xuan Truong Dec 2012

13c-Metabolic Flux Analysis Of Soybean Somatic Embryos For Identification Of Metabolic Control Points In Developing Seed, Quyen Xuan Truong

Graduate Theses and Dissertations

Of the world's major agronomic food crops soybeans rank highest in protein content (~40% Dwt) while also containing significant quantities of oil (~20% Dwt). Based on these unique characteristics soy has become a mainstay in world agriculture, providing a protein source for livestock and human nutrition (68% of global vegetable protein meal consumption in 2011) as well as a primary source of vegetable oil (28% of global vegetable oil consumption in 2011; http://www.soystats.com/2012). The value of soy is therefore found both in its oil and protein content and increasing the content of both is therefore ...


Variability In Soybean Agronomic Performance Traits In Response To 41 C Heat And High Relative Humidity Seed Stress, Ruth Ann Rolling Jan 2012

Variability In Soybean Agronomic Performance Traits In Response To 41 C Heat And High Relative Humidity Seed Stress, Ruth Ann Rolling

Graduate Theses and Dissertations

Incorporation of genetic diversity into soybean [Glycine max (L.) Merr.] cultivars can be used to increase yield and plant adaptation to stresses. Genetic variation has been found in commercial soybean cultivars, but using a seed stress to generate intra-cultivar variation has not been studied. The first objective of this study was to use seed stress in an attempt to generate variation in soybean agronomic traits of field stand, plant maturity, plant height, seed size, seed yield, seed protein content, seed oil content, seed standard germination and seed vigor. The second objective was to evaluate if changes in variation were heritable ...


Marker-Assisted Selection For Elevated Concentrations Of The Α′ Subunit Of Β-, Sheilah Emilie Oltmans-Deardorff Jan 2012

Marker-Assisted Selection For Elevated Concentrations Of The Α′ Subunit Of Β-, Sheilah Emilie Oltmans-Deardorff

Graduate Theses and Dissertations

Soybean [Glycine max (L.) Merr.] contains two major storage proteins, glycinin and β-conglycinin (BC). Glycinin accounts for approximately 40% and BC approximately 25% of total soybean seed protein (Nielsen et al., 1989). Glycinin is controlled by five genes coding for the acidic (A) and basic (B) subunits: Gy1, Gy2, Gy3, Gy4, and Gy5 (Cho et al., 1989; Nielsen et al., 1989). BC consists of gene families that encode the three major subunits α, α′, and β. The relative concentrations of the BC subunits are about 45% α, 35% α′, and 20% β (Maruyama et al., 1999). Soybean cultivars were discovered ...


Agronomic, Seed Traits And Oleate Stability Of Soybean Lines Containing The High-Oleate Transgene Dp-305423-1 And The Molecular Characterization Of The Genomic Region Flanking The High-Oleate Transgene, Jordan Dustin Spear Jan 2012

Agronomic, Seed Traits And Oleate Stability Of Soybean Lines Containing The High-Oleate Transgene Dp-305423-1 And The Molecular Characterization Of The Genomic Region Flanking The High-Oleate Transgene, Jordan Dustin Spear

Graduate Theses and Dissertations

To improve the oxidative stability of soybean [Glycine max (L.) Merr.] oil, it is desirable to increase the percentage of the monounsaturated fatty ester oleate. By altering the endogenous FAD2-1gene in soybean, oleate concentrations of greater than 750 g kg-1 can be obtained. From a commercial perspective, it is important to understand the influence of this genetic alteration on agronomic and seed traits, as well as the stability of the increased oleate concentration across a range of environments.

Objective one of my research was to evaluate the influence of the DP-305423-1 high-oleate (HO) transgene on agronomic and seed ...


The Genetics Of Fertility In Soybean, Reid G. Palmer, Devinder Sandhu, Harry T. Horner, Ram J. Singh Jan 2012

The Genetics Of Fertility In Soybean, Reid G. Palmer, Devinder Sandhu, Harry T. Horner, Ram J. Singh

Genetics, Development and Cell Biology Presentations, Posters and Proceedings

Male and female reproductive structures play an important role in seed development in plants. Abnormalities in male or female reproductive structures can lead to sterility. In soybean, Glycine max (L.) Merr., about 75 sterility mutants have been identified and most of them have been mapped to chromosomes. Mapping results have shown that some chromosomal regions are hotspots for fertility genes. Fine mapping of some of the male-sterile, female-fertile mutants and male-sterile, femalesterile mutants resulted in identification of candidate genes for fertility. Sequence comparisons further helped in locating a few putative candidates. A CACTA- like transposable element that is responsible for ...


Analysis Of Iron Transporters In The Soybean (Glycine Max (L.) Merr.) Genome, Dan Stribe Jan 2012

Analysis Of Iron Transporters In The Soybean (Glycine Max (L.) Merr.) Genome, Dan Stribe

Graduate Theses and Dissertations

Iron plays a significant role in numerous cellular functions. Improved uptake and efficiency of use can have strong positive effects on the health of plants, animals and humans. Major players in iron homeostasis are the Iron-Regulated Transporters (IRT). The purpose of this research is to identify putative Iron-Regulated Transporter genes in soybean, structurally characterize these genes and examine their relational phylogeny. Additionally, gene sequence data and gene expression patterns will be considered to differentiate each gene's potential role in iron homeostasis of soybean. In this study, we identified fourteen soybean gene models with significant predicted protein similarity to A ...