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- A mycotoxin that is detrimental to human and animal health. Previous studies discovered that expression of FST1 is required for FB1 production and wild-type level of virulence on maize seeds. FST1 encodes a putative protein with 12 transmembrane domains with sequence similarity to hexose transporters. However (1)
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The Role Of African Leafy Vegetables In Food Security, Marcia M. Croft
The Role Of African Leafy Vegetables In Food Security, Marcia M. Croft
Open Access Dissertations
African leafy vegetables (ALVs) are a diverse set of crops grown across sub-Saharan Africa. They have been a staple of traditional diets and contain many critical micronutrients but their importance has been largely ignored by researchers and policymakers at the expense of imported crops. Availability, accessibility, and utilization of ALVs are limited by factors across the supply chain. This research investigated seed systems, drought tolerance, hydroponic production, market barriers, consumer preference, and the impact of gender as related to ALVs. We found that ALVs play an important role in food security and that critical differences exist between formal and informal …
Annual Forage Cropping-Systems For Midwestern Ruminant Livestock Production, John Ernest Mcmillan
Annual Forage Cropping-Systems For Midwestern Ruminant Livestock Production, John Ernest Mcmillan
Open Access Dissertations
Annual forage cropping systems are a vital aspect of livestock forage production. One area where this production system can be enhanced is the integration of novel annual forages into conventional cropping systems. Two separate projects were conducted to investigate alternative forage options in annual forage production. In the first discussed research trial, two sets of crops were sown following soft red winter wheat (Triticum aestivum L.) grain harvest, at two nitrogen application rates 56 and 112 kg ha-1 . The first set of crops were C4 summer annuals seeded within two weeks of wheat grain harvest and included, brown …
Managing Bacterial Wilt, Caused By Erwinia Tracheiphila, On Muskmelon With Early Control Of Striped Cucumber Beetle ( Acalymma Vittatum (F)), And Through Varietal Selection, Ahmad Shah Mohammadi
Managing Bacterial Wilt, Caused By Erwinia Tracheiphila, On Muskmelon With Early Control Of Striped Cucumber Beetle ( Acalymma Vittatum (F)), And Through Varietal Selection, Ahmad Shah Mohammadi
Open Access Dissertations
Muskmelon (Cucumis melo L), is an important vegetable crop in the United States. It is grown throughout the US, and Indiana ranked 4th in production after California, Arizona and Georgia with 12.4 thousand metric tons and market value of $7.6 million in 2015. Bacterial wilt of cucurbits, which is caused by Erwinia tracheiphila (E. F. Smith), and vectored by striped cucumber beetle (Acalymma vittatum (F)), is one of the most serious diseases of muskmelon that influences muskmelon quality and yield. Many cultivars of muskmelon are grown around the United States, especially in the Midwest. Muskmelon cultivars differ in …
Improving And Elucidating Factors Regulating Black Walnut (Juglans Nigra L.) Clonal Propagation, Micah E. Stevens
Improving And Elucidating Factors Regulating Black Walnut (Juglans Nigra L.) Clonal Propagation, Micah E. Stevens
Open Access Dissertations
Black walnut (Juglans nigra L.) is a fine hardwood tree species native to the central hardwood region of the United States. High-quality black walnut timber is highly desirable. Traded in both regional and global markets, it has been used for veneer, and the manufacture of high-end products such as cabinets, furniture, and gunstocks. As a result of its high economic value, black walnut has been commercially cultivated for many years, and breeding programs have generated superior timber genotypes with improved marketable traits. Once elite genotypes were developed, it was quickly recognized that black walnut was recalcitrant to clonal propagation …
Evaluation Of A Cool-Season Grass-White Clover Mixture For Low-Nitrogen Input Lawns, Gabriel Adam Macke
Evaluation Of A Cool-Season Grass-White Clover Mixture For Low-Nitrogen Input Lawns, Gabriel Adam Macke
Open Access Theses
Turfgrass lawns require supplemental nitrogen (N) to maintain green color and seasonal shoot density. Improper lawn fertilization with excess N or phosphorus has the potential to contaminate both surface and groundwater. Thus, to reduce the reliance on supplemental N fertilization, alternative strategies or novel turf systems like grass-legume mixtures need explored. White clover ( Trifolium repens L.) is a stoloniferous legume that biologically fixes N from the atmosphere and adds N into the soil via mineralization. The objective of this field study was to evaluate the persistence and feasibility of a cool-season grass-clover lawn mixture. A lawn grass mixture with …
Residual Effects Of Nitrogen Fertilization On Soil Nitrogen Pools And Corn Growth, Meghan E. Moser
Residual Effects Of Nitrogen Fertilization On Soil Nitrogen Pools And Corn Growth, Meghan E. Moser
Open Access Theses
Given the dynamic nature of soil nitrogen (N), inorganic N fertilization to corn (Zea mays L.) has potential to alter N pool balance by creating an accumulation or depletion of soil N. Current corn N recommendations in the common corn-soybean rotation of Indiana strive to find the best N rate that maximizes producer profit. Increasing our understanding of soil N will inform producers if they should adjust fertilizer rates for corn to influence maintenance of organic N and Carbon. Our objective was to determine residual N effects from fertilized corn in a corn-soybean rotation by measuring (1) soil N …
Cereal Rye Cover Crop Effects On Soil Physical And Chemical Properties In Southeastern Indiana, Joseph D. Rorick
Cereal Rye Cover Crop Effects On Soil Physical And Chemical Properties In Southeastern Indiana, Joseph D. Rorick
Open Access Theses
Cover crops are growing in popularity in the Midwest, although questions remain about how to include them most effectively in a corn-soybean ( Zea mays L. - Glycine max L.) rotation. This study was conducted to determine the effects of cereal rye ( Secale cereale L.) on soil bulk density and water retention, soil organic carbon, soil nitrogen, and water stable aggregate mean weight diameter after four years of cover crop growth and the effects on soil moisture over a five year period. The study was conducted at the Southeast Purdue Agricultural Center (SEPAC) on silt loam soils. A 14 …
Forest Industry Byproducts Improve Soil Quality And Increase Pepper Growth In Three Soils Infested With Phythophthora Blight, Xiaojun Zhao
Forest Industry Byproducts Improve Soil Quality And Increase Pepper Growth In Three Soils Infested With Phythophthora Blight, Xiaojun Zhao
Open Access Theses
Phytophthora blight is a serious threat to the Midwest vegetable industry, because the oomycete pathogen responsible for this disease, Phytophthora capsici, has a wide host range, can spread quickly in fields, and produces resilient oospores that can survive in soil for years. Phytophthora capsici has become resistant to commonly used fungicides and resistant crop varieties are rare. Amending soil with complex organic substrates has potential to improve soil quality and suppress soil-borne pathogens including P. capsici. Indiana has a significant forest industry with many residual products that could be used as locally available amendments to meet this goal. …
Physiological Aspects Of Relative Changes In Nitrogen And Plant Density Stress Tolerances Over A 38-Year Period Of Us Maize Hybrid Introductions, Keru Chen
Open Access Dissertations
Incremental gains in grain yield of maize hybrids over the decades are the consequence of genotype, environment and management interactions. Historically, genetic improvements in newer hybrids have included longer active grain filling periods (achieved by advancing silking and extending functional stay green in maize leaves); stronger source and sink during grain filling; enhanced tolerance to higher density; and canopy architecture changes. Newer hybrids were known to accumulate more dry matter and nitrogen in the post-silking period, but achieving a more comprehensive knowledge of pre-silking and post-silking dynamics required further understanding of dry matter and nitrogen partitioning in individual organs, as …
The Biology And Management Of Palmer Amaranth (Amaranthus Palmeri S. Wats) In Indiana, Douglas J. Spaunhorst
The Biology And Management Of Palmer Amaranth (Amaranthus Palmeri S. Wats) In Indiana, Douglas J. Spaunhorst
Open Access Dissertations
Palmer amaranth is a pernicious summer annual weed that has evolved resistance to six herbicide sites of action in the U.S. and threatens agriculture production. In 2011, Palmer amaranth was identified in flood plains in two southern Indiana counties (Posey and Vanderburgh). Determining if Palmer amaranth can survive and reproduce in northern Indiana may provide insight if this weed will be problematic for northern row crop producers. The objectives of our research were to identify fields containing Palmer amaranth and determine the distribution of herbicide resistance traits in Indiana; determine the influence of tillage frequency and tillage intervals on Palmer …
Dynamic Regulation Of Dna Demethylation And Rna-Directed Dna Methylation In Arabidopsis, Kai Tang
Dynamic Regulation Of Dna Demethylation And Rna-Directed Dna Methylation In Arabidopsis, Kai Tang
Open Access Dissertations
DNA methylation is an important epigenetic mark present in many eukaryotes, and is involved in many crucial biological processes, such as gene imprinting, regulation of gene expression, and genome stability. Proper genomic DNA methylation patterns are achieved through the concerted action of DNA methylation and demethylation pathways. In the model plant species Arabidopsis thaliana, ROS1 (REPRESSOR OF SILENCING 1) is one of the DNA demethylases and the key component in the demethylation pathway. Dysfunction of ROS1 leads to increase in DNA methylation level at thousands of genomic loci. However, the features of ROS1 targets are not well understood. In the …
Genetic Study Of Carotenoids In Maize Grain (Zea Mays L.), Oscar Rafael Espejel Venado
Genetic Study Of Carotenoids In Maize Grain (Zea Mays L.), Oscar Rafael Espejel Venado
Open Access Theses
Pro-Vitamin A (proVA) carotenoids, which are converted into retinol (Vitamin A) in the human body, have been the subject of human nutrition studies and are a target for biofortification of staple crops. Historically, β-carotene has been the principal target for enhancing levels of proVA, yet there is recent interest in enhancing the proVA carotenoid β-cryptoxanthin. Studies have shown that β-cryptoxanthin has excellent bioavailability, and its use in maize may be nearly as effective as β-carotene in providing retinol. The primary aim of this study was to gain a better understanding of the genetic control of levels of β-cryptoxanthin, conversion of …
Understanding Plant Response To Stress Using Gene Model Quality Evaluation And Transcriptome Analysis, Karthik Ramaswamy Padmanabhan
Understanding Plant Response To Stress Using Gene Model Quality Evaluation And Transcriptome Analysis, Karthik Ramaswamy Padmanabhan
Open Access Dissertations
The overall aim of the project was to understand how plants reacted to environmental stress and evolved to overcome it. The land plants that we see today evolved from a green algal ancestor around 510 million years ago. Plants had to make significant changes to their cellular, morphological, regulatory and physiological processes during their adaptation to the terrestrial environment from an aquatic environment. The first part of the project was to find out how these changes were reflected on the protein makeup of the early land plants. The gene model sequence data of two early land plants, Physcomitrella patens (moss) …
Learning From Data: Plant Breeding Applications Of Machine Learning, Alencar Xavier
Learning From Data: Plant Breeding Applications Of Machine Learning, Alencar Xavier
Open Access Dissertations
Increasingly, new sources of data are being incorporated into plant breeding pipelines. Enormous amounts of data from field phenomics and genotyping technologies places data mining and analysis into a completely different level that is challenging from practical and theoretical standpoints. Intelligent decision-making relies on our capability of extracting from data useful information that may help us to achieve our goals more efficiently. Many plant breeders, agronomists and geneticists perform analyses without knowing relevant underlying assumptions, strengths or pitfalls of the employed methods. The study endeavors to assess statistical learning properties and plant breeding applications of supervised and unsupervised machine learning …
Physiological Bases And A Novel Genetic Determinant Of Water-Use Efficiency (Wue), Jie Yin
Physiological Bases And A Novel Genetic Determinant Of Water-Use Efficiency (Wue), Jie Yin
Open Access Dissertations
Water-use efficiency (WUE), the ratio of biomass to water loss, is a heritable but complex trait, the genetic basis of which is largely unknown. We utilized diverse accessions of the halophyte Eutrema salsugineum to ultimately identify a novel genetic determinant of WUE. E. salsugineum accessions from locations with low water availability, temperature, and radiation have lower transpirational water loss and greater biomass, resulting in higher WUE. High-WUE accessions also have lower stomatal density and index and larger thinner leaves than low-WUE accessions. We identified 14,808 single nucleotide polymorphisms (SNPs) between two accessions of E. salsugineum,Shandong (SH) and Yukon (YK), …
The Biology And Management Of Waterhemp In Indiana, Joseph M. Heneghan
The Biology And Management Of Waterhemp In Indiana, Joseph M. Heneghan
Open Access Theses
Waterhemp is a dioecious weed species indigenous to the Midwestern United states yet it has only recently become problematic in agronomic crop production in Indiana. Waterhemp is a small-seeded broadleaf which has increased in prevalence in conjunction with an increase in conservation tillage practices. Waterhemp germinates and emerges from the top 3 cm of soil and is known to exhibit extended periods of continual emergence, longer than most other summer annual weed species that are typically present in agronomic production settings. As a C4 species, waterhemp then grows rapidly and is capable of producing thousands of seeds, while effectively competing …
Mapping And Analyzing Energy Use And Efficiency In A Modified Hydroponic Shipping Container, Rachel E. Sparks
Mapping And Analyzing Energy Use And Efficiency In A Modified Hydroponic Shipping Container, Rachel E. Sparks
Open Access Theses
In urban centers today, vertical farming is becoming a popular alternative to conventional agriculture in an effort to increase local food production and improve urban food security by growing crops using hydroponic methods in controlled environment spaces. More specifically, one vertical method involves growing crops inside refurbished shipping containers, or a “farm-in-a-box” concept, which offers a flexible, mobile, and scalable means of year-round food production in a variety of climates. Despite benefits of producing food locally, some of the concerns associated with these vertical farming systems include high energy consumption from climate control and electric lighting systems as well as …
Manipulating Air And Root-Zone Temperature For Energy-Efficient Floriculture Crop Production, Madeline W. Olberg
Manipulating Air And Root-Zone Temperature For Energy-Efficient Floriculture Crop Production, Madeline W. Olberg
Open Access Theses
Given the high energy costs for greenhouse floriculture production, growers are constantly searching for more energy-efficient methods of production. For example, some growers will lower greenhouse air temperature set points or grow crops in unheated high tunnels (HTs) or outdoors in order to minimize or eliminate heating costs. Unfortunately, development can be delayed and morphology can be altered if the mean daily air temperature (MDT) is reduced. We proposed that reducing MDT in combination with root-zone heating (RZH) could be an energy-efficient method for producing high-quality floriculture crops without significant delays. Unheated HT and unprotected outdoor production are very low-cost …
Stenocarpella Maydis: Identification, Management, And Population Diversity, Martha P. Romero Luna
Stenocarpella Maydis: Identification, Management, And Population Diversity, Martha P. Romero Luna
Open Access Dissertations
Diplodia ear rot (DER) has been a persistent corn disease across the Midwest, and in recent years it has become an annual problem. The objectives of this study were to i) develop a molecular assay for the identification of Stenocarpella maydis, causal agent of DER, ii) evaluate the effect of crop rotation and tillage on DER severity, iii) determine the survival period of S. maydis in corn residue at different soil depths in a corn field, and iv) identify genetic diversity among S. maydis isolates collected from the Midwestern and Southern United States. The genus Stenocarpella contains two species, S. …
Functional And Structural Analysis Of Fst1 In Fusarium Verticillioides, Chenxing Niu
Functional And Structural Analysis Of Fst1 In Fusarium Verticillioides, Chenxing Niu
Open Access Dissertations
Fusarium verticillioides causes an important seed disease on maize and produces fumonisin B1 (FB1), a mycotoxin that is detrimental to human and animal health. Previous studies discovered that expression of FST1 is required for FB1 production and wild-type level of virulence on maize seeds. FST1 encodes a putative protein with 12 transmembrane domains with sequence similarity to hexose transporters. However, those studies have failed to prove its ability to transport glucose, fructose or mannose. I identified another three phenotypes associated with the lack of a functional FST1, which includes reduced hydrophobicity of hyphae, reduced macroconidia production, and increased sensitivity to …
Effect Of Volunteer Corn Density On Deoxynivalenol Production By Fusarium Graminearum In Hybrid Corn, Gaelle Florence Hollandbeck
Effect Of Volunteer Corn Density On Deoxynivalenol Production By Fusarium Graminearum In Hybrid Corn, Gaelle Florence Hollandbeck
Open Access Theses
Fusarium graminearum causes Gibberella ear rot in corn and produces mycotoxins such as deoxynivalenol (DON). Volunteer corn is a weed resulting from uncollected kernels from the previous harvest and is very difficult to control once established. An experiment was established in Porter County, IN from 2013 to 2015 to examine the impact of volunteer corn density on Gibberella ear rot severity and DON levels in hybrid corn. Five densities of volunteer corn were established within plots of each hybrid (0, 0.5, 2, 4, and 8 volunteer plants/m2). Disease severity and DON were assessed for both hybrid and volunteer ears collected …
The Effect Of Adjuvants On Apple Disease Management, Chelsi Patricia Abbott
The Effect Of Adjuvants On Apple Disease Management, Chelsi Patricia Abbott
Open Access Theses
The management of common apple diseases such as apple scab ( Venturia inaequalis) and bitter rot (Colletotrichum spp.) relies heavily on effective fungicide applications. However, the development of fungicide resistance to newer fungicides has resulted in management failures and significant economic losses. This has led to a greater reliance on captan, an older fungicide, because there is a low risk of pathogens developing resistance. Label restrictions limit growers to 18 kg of captan per season, which may not provide sufficient control of both apple scab and bitter rot in wet years. Consequently, apple growers are faced with two …
Effects Of Temperature And Pollinator Availability On Plant Reproductive Success In The Indiana Spring Ephemeral Community, Asya Robertshaw
Effects Of Temperature And Pollinator Availability On Plant Reproductive Success In The Indiana Spring Ephemeral Community, Asya Robertshaw
Open Access Dissertations
Temperature is a key driver of phenology in both plants and insects, and even small changes in temperature can impact the reproductive success of insect-pollinated plants by influencing access to pollinator services. While it is well-established that temperature variation directly impacts the flowering phenology of many plant species, the mechanisms by which it ultimately influences seed production via the pollinator community are not well understood. Climate change has the potential to disrupt the temporal synchrony between plants and their primary pollinators, especially if the two rely on different seasonal cues for the timing of their life history events. If the …
Genetic, Agronomic And Compositional Characterization Of Brown Midrib Sweet Sorghum Lignocellulosic Biomass For Ethanol Production, Luis A. Rivera Burgos
Genetic, Agronomic And Compositional Characterization Of Brown Midrib Sweet Sorghum Lignocellulosic Biomass For Ethanol Production, Luis A. Rivera Burgos
Open Access Dissertations
Sorghum is a promising bioenergy crop due to its unique phenotypic and genotypic attributes. Quality (low lignin and high stem sugar concentration) and quantity (biomass yield, plant height, plant maturity, etc.) biomass traits are key contributors to ethanol yield and production. In this study, a 236 sorghum recombinant inbred line (RIL) population was subjected to genetic, agronomic and compositional characterization for ethanol yield and production. We found that the sweet mutation enhances biomass quantity traits in the RILs which translates to higher ethanol production and biomass quality which improves ethanol yield. The variance components showed from moderate to high heritability …
Cover Crop And No-Till Effects On Soil Health Properties In Indiana, Sara Alford
Cover Crop And No-Till Effects On Soil Health Properties In Indiana, Sara Alford
Open Access Theses
A growing concern of soil health and long-term sustainability has increased interest in no-till and cover crops in the Midwest. Some of the challenges with no-till in the Midwest can be higher soil moisture and lower soil temperatures at cash crop planting in the spring, planter adjustment issues, and lack of immediate economic benefit. Cover crops also have some of the same issues along with extra cost of seed and termination, mismanagement of cover crops, and lack of knowledge on the benefits and costs. This project was begun in order to quantify the effects of no-till and cover crops on …
Genetic Analysis Of Tocochromanol Variation In Maize Using High-Density Linkage Mapping, Megan E. Fenton
Genetic Analysis Of Tocochromanol Variation In Maize Using High-Density Linkage Mapping, Megan E. Fenton
Open Access Theses
Vitamin E is an essential nutrient in the human diet and refers to eight distinct compounds that are collectively known as tocochromanols. Tocochromanols are grouped into two classes: tocotrienols and tocopherols. Tocochromanols are the major lipid-soluble antioxidants in maize (Zea mays L.) grain. Enhancing the tocochromanol content of maize derived foods through plant breeding has important nutritional and health implications. Chapter one is a literature review that provides a foundational understanding of the biosynthesis, function and genetic control of tocochromanols in plants, with specific attention to maize (Zea mays L.). Upon this foundation two research objectives were developed that work …
Eco-Evolutionary Factors Drive Herbivore-Induced Plant Volatiles, Which Intercept Plant Defense, Elizabeth K. Rowen
Eco-Evolutionary Factors Drive Herbivore-Induced Plant Volatiles, Which Intercept Plant Defense, Elizabeth K. Rowen
Open Access Theses
Herbivore-induced plant volatiles (HIPVs) mediate a wide variety of interactions in ecosystems. However, many volatile compounds are found across plant taxa, and some are exploited to attract natural enemies for biological control. Subtle changes in HIPV blends can produce profound changes in the behavior of predators, parasitoids and herbivores, and may also alter the defensive processes of neighboring plants. I investigated different ecological and evolutionary factors to understand how plant volatile emissions are affected by feeding guild, herbivore diet breadth and domestication. I meta-analyzed 109 studies and found that specialists induce more total volatiles than generalists. Domesticated species have stronger …
Growth Parameters Of 'Golden Delicious' Apple Trees (Malus X Domestica Borkh), Biying Shi
Growth Parameters Of 'Golden Delicious' Apple Trees (Malus X Domestica Borkh), Biying Shi
Open Access Theses
High yield and high quality of tree fruit result from appropriate orchard design and management practices. This requires an accurate knowledge of vegetative growth, branching, and flowering processes of fruit trees. Tree development knowledge is the fundamental information necessary to build functional-structural tree models, which have various applications in agriculture. To build such models, information is needed on the distributions of growth parameters, not merely means as are often reported. The objective of this study was to quantitatively analyze shoot development and examine the correlations between fruit quality and light distribution in apple trees. This study was conducted in 2014, …
Profiling Gene Expression During Early Gametophyte Development And Sex Determination In Ceratopteris Richardii, Nadia Atallah
Profiling Gene Expression During Early Gametophyte Development And Sex Determination In Ceratopteris Richardii, Nadia Atallah
Open Access Dissertations
In the fern Ceratopteris richardii, every spore has the potential to develop as either a male or hermaphroditic gametophyte. Gametophyte sex is determined by a GA-like pheromone (ACE) that is secreted by hermaphrodites approximately 6 days after spore inoculation and induces male development in other juvenile gametophytes. Our goal is to better understand the genetic and molecular mechanisms involved in sex determination and to identify sex determination genes in Ceratopteris. RNA-Seq was used to create de novotranscriptome assemblies from gametophytes grown, with or without ACE, during the time that their sex is determined, and from male gametophytes in early …
Genetic Analysis Of Nitrogen Remobilization And Kernel Compositon In Zea Mays L. And Sorghum Bicolor (L.) Moench, Raymond S Lindsey
Genetic Analysis Of Nitrogen Remobilization And Kernel Compositon In Zea Mays L. And Sorghum Bicolor (L.) Moench, Raymond S Lindsey
Open Access Dissertations
Genetic Analysis of Nitrogen Remobilization and Kernel Composition in Zea Mays L. and Sorghum Bicolor (L.) Moench. Major Professor: Mitchell Tuinstra. Modern maize (Zea mays L.) production relies heavily on nitrogen fertilization for high productivity. Over-application of nitrogen fertilizers in cropping systems can have detrimental economic and environmental effects. For this reason, improving Nitrogen Use Efficiency (NUE) is a major goal of breeders and producers. Nitrogen Utilization Efficiency (NUtE) is one component of NUE, and the most important component under N-limited conditions. In this study we examined the genetic controls of the timing and preferential canopy position of leaf N …