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Excess Nitric Oxide Alters Cellular Ph To Restrict Salicylic Acid Movement And Systemic Immunity, Fan Xia, Huazhen Liu, Keshun Yu, Xinyu Yuan, Aardra Kachroo, Pradeep Kachroo

Plant Pathology Faculty Publications

Plants carrying a mutation in S-nitrosoglutathione reductase 1 (GSNOR1) accumulate high nitric oxide (NO) and exhibit impaired immunity characterized by reduced pathogen-responsive salicylic acid (SA) accumulation and failure to activate normal SA signaling. We show that this reduced SA responsiveness in gsnor1 plants arises from impaired vascular-associated movement of SA, thereby compromising systemic acquired resistance (SAR). Elevated NO perturbs cellular pH homeostasis, acidifying the apoplast and alkalinizing the cytosol, which likely interferes with phloem-associated SA movement and renders gsnor1 plants unresponsive to foliar SA. In contrast, SA supplied via root drench restores SA signaling and SAR in gsnor1, …

Phylogeography, Fungal Host Specificity, And Fitness In The Corallorhiza Maculata Species Complex, Hana Thixton-Nolan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Mycoheterotrophic plants exploit fungi for most or all nutritional needs, providing a compelling system to address the evolutionary consequences of genome reduction, population-level variation, and germination requirements. I am using the widespread Corallorhiza maculata species complex to address questions of genomic variation, fungal host specificity, morphological variation, and germination requirements across the broad geographic range from Mexico to northern North America. This complex contains C. bulbosa, C. macrantha, and C. mertensiana, the latter with three varieties (maculata, occidentalis, and mexicana). These taxa vary in flowering time, floral morphology, and fungal associations. However, the degree …

[Review Of The Book A Conspectus Of The North American Isoetaceae, By D. F. Brunton, J. T. Kartesz, M. Nishino, And P. C. Sokoloff]., Lytton John Musselman

Biological Sciences Faculty Publications

Isoetes (Isoetaceae; Lycopodiopsida; quillworts) constitutes a highly successful, cosmopolitan genus with over 200 species. Isoetes is derived from isos Greek for equal and eter for year, referring to the typically long persisting leaves of the sole genus in this ancient plant family. The leaves resemble a ‘quill-of-feather,’ hence the common name ‘Quillworts,’ wort, from old Germanic wurti, meaning plant. In large measure due to its simple form, inconspicuous appearance and negligible economic value, it represents one of the least studied and least collected of all North American genera. Isoetes constitutes a taxonomically enigmatic group with numerous polyploid species that arose …

Land Use Influences Dissolved Organic Matter Composition In The U.S. Coastal Critical Zone Network, Aleksandar I. Goranov, Elizabeth V. Whitney, Brian R. Moyer, Katherine L. Tully, Patrick G. Hatcher, Yu-Ping Chhin

Chemistry & Biochemistry Faculty Publications

Coastal watersheds are highly productive biogeochemical systems supporting robust coastal fisheries and contributing significantly to the marine gross primary production flux. These ecosystems are comprised of civil infrastructure, farms, forests, and marshes, and their diversity is reflected in the quantity and quality of dissolved organic matter (DOM). Here, we assess the role of farming in influencing DOM from surface waters of six coastal tidal creeks adjacent to forest and farm sites in the US Critical Zone Network. Molecular fingerprinting using electrospray ionization - Fourier transform - ion cyclotron resonance - mass spectrometry revealed that farm-influenced DOM was enriched in nitrogen-, …

Rate Response Of Curlyleaf Pondweed And Native Plants To Flumioxazin In Minnesota Lakes, Pearl J. Jensen

All Graduate Theses, Dissertations, and Other Capstone Projects

Curlyleaf pondweed (Potamogeton crispus L.) is an invasive aquatic plant present across the United States that causes significant recreational issues, outcompetes native plant species, and depletes water quality. Before senescing in mid-summer, curlyleaf pondweed forms a large number of turions that can lay dormant in the sediment for several years. Typical herbicide management of this species occurs in early spring to target the plant before turion production occurs and while native plants are dormant. Flumioxazin has shown potential in curlyleaf pondweed management in small scale studies, but its effects have not been assessed in operational management. In this study, treatments …

Red Clover Isoflavones And Establishment In The Context Of Tall Fescue Toxicosis Mitigation In The Mid-South, Jonathan L. Stephens

Theses and Dissertations--Plant and Soil Sciences

Low levels of red clover (Trifolium pratense L.) have been shown to mitigate tall fescue (Lolium arundinaceum (Schreb.) toxicosis symptoms. This is because of the presence of plant-produced compounds known as isoflavones. Production of a red clover supplement on a commercial scale would require industrial-level processing of raw plant material into granules or pellets. The first study of this thesis evaluated the impact of drying temperature on bioavailability of isoflavones. Drying temperatures up to 104°C had minimal impact on isoflavone concentrations. Additionally, varietal differences in isoflavone concentrations were documented. The second study of this thesis evaluated optimal establishment …

Reconnecting The Body With Nature: Inspired By Advances In Biomimicry, Elyse M. Orosa

Williams Honors College, Honors Research Projects

Reconnecting the Body with Nature: Inspired by Advances in Biomimicry will visually address the symbiotic relationship between nature and humans. The drawing series is inspired by the growing design field of biomimicry and its technological and architectural innovations influenced by nature’s systems and physical adaptations. Just as nature is limited by human misuse, humans are physically and neurologically limited by the state of the environment, and with this, form and function of both nature and humans will be equally represented and explored throughout the body of work presented. Biomimicry can help solve environmental issues such as rising CO2 emissions and …

Climate Change Effects On Biomass And Greenhouse Gas Emissions Are Ameliorated By Nontoxic Endophytes In Southeastern Usa Transition Zone Tall Fescue Pastures, Rebecca Kay Mcgrail, Jonathan D. Moore, A. Elizabeth Carlisle, Jim A. Nelson, Rebecca L. Mcculley

Plant and Soil Sciences Faculty Publications

Background: The plant–microbe interaction between tall fescue and its endophyte Epichloë coenophiala can affect ecosystem responses to changing rainfall patterns and increasing temperatures. Endophyte-infected (E+) stands often exhibit improved stress tolerance and differing soil greenhouse gas (GHG) emissions compared to endophyte-free (E−) stands. However, it is unknown if mammalian nontoxic endophyte (NTE) strains introduced into some tall fescue cultivars confer differing stress tolerances or reduce soil GHG emissions.

Methods: We quantified the impact of fescue-NTE symbioses in Jesup and Texoma on biomass and GHG emissions in response to increased temperature (+3°C) and altered precipitation (50% lengthened interval between events) using …

Hydroponics In The Classroom: Cultivating Plants, Captivating Young People, Stacy A. Adams, Christian Stephenson, Theresa James, Kim Todd

Department of Agronomy and Horticulture: Faculty Publications

Few students take the initiative to pursue coursework beyond that required for progression to graduation. Limited are opportunities that connect educational content to industry application, potentially inspiring young people towards impactful careers. The United States government has emphasized the importance of STEM education to ensure national security and to maintain economic competitiveness globally. STEM education is not a defined discipline but an approach for building knowledge through application and engagement. Developing and managing a hydroponics prototype provides numerous opportunities for embedding STEM content into a fun and interactive project. This poster provides inspiration for constructing a simple deep water culture …

Assessment Of Soybean Response To Irrigation Variability In Eastern Nebraska Using The Aquacrop Model, Anmol Singh, Saleh Taghvaeian, Yufeng Ge, Derek M. Heeren, Frank Bai

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Soybean [Glycine max (L.) Merr.] is a major irrigated crop in eastern Nebraska, where recent expansions in irrigated agriculture and projected trends in irrigation demand necessitate thorough investigations of approaches that can optimize its irrigation management. In this study, the AquaCrop model was calibrated and validated using 19 variable irrigation treatments from a five-year field experiment. The model accurately simulated canopy cover, soil water content, and grain yield, with validation normalized root mean square error (nRMSE) of 12%, 7%, and 7%, respectively. The model was subsequently applied to estimate soybean yield and water requirement during a 15-year period (2010–2024) …

Kentucky Bluegrass (Poa Pratensis L.) As A Perennial Groundcover: Establishment And Weed Management In Corn, Kiera S. Searcy

Theses and Dissertations--Plant and Soil Sciences

Perennial groundcover (PGC) systems offer a cost-effective alternative to annual cover crops, by providing continuous soil cover, reducing soil erosion, and contributing to integrated weed management (IWM) in corn (Zea mays L.) production systems. Kentucky bluegrass (Poa pratensis L.) has been proposed as a perennial groundcover for corn due to its low growth habit and seasonal dormancy; however, successful adoption is limited by challenges associated with establishment-phase weed competition and compatibility with weed management programs during corn production. The objectives of this research were to (1) evaluate weed management strategies that support Kentucky bluegrass establishment and (2) assess …

Evaluating Spatial Variability Of Corn Yield Response To Phosphorus Fertilizer For Improved Precision Phosphorus Management, Jennifer Fridgen

Theses and Dissertations--Plant and Soil Sciences

Soil scientists did not develop soil test-based fertilizer recommendations to support precision nutrient management. Knowledge of crop responses to applied essential nutrients, such as phosphorus (P), and the processes governing these responses at high spatial resolution are necessary to improve precision agronomic recommendations. This dissertation investigates the limitations of current soil sampling methodologies and recommendation frameworks for crop response to fertilizer, with particular emphasis on P fertility in Kentucky (KY) corn production. The first study examined the relationship between the resolution of systematic grid sampling and the spatial structure of soil test variables (Mehlich-3 P (M3P), Mehlich-3 potassium (M3K), and …

Transcriptomic And Epigenetic Analysis Of Dormant Grape Buds During Chilling Fulfillment, Imasha Thilakarathna

Electronic Theses and Dissertations

No abstract provided.

The Effect Of Different Nutrient Concentrations For Hydroponically Grown Pothos, Keaton Roether

A with Honors Projects

An experiment where Pothos plants are grown in three different solutions of water, NPK diluted into water, tap water, and distilled water. Data is recorded for multiple weeks and is then compiled into a comprehensible lab report of a minimum of 1000 words with graphs and data.

Regenerative Farming Practices Effects On Invertebrates In Wheat Systems, Daniel J. Pecenka

Electronic Theses and Dissertations

The modern agricultural system is based upon the Green Revolutions principle of creating more food. However, this came at a cost of invertebrate declines through habitat loss, pollution, and the introduction of agrochemicals. Here I address knowledge gaps in biological inventory of invertebrates across north, northwestern, and central North America. These invertebrates were identified and given a size scale and a dietary guild. We also examined how regenerative and conventional agricultural practices can affect invertebrate populations within the same crop. We also examined whether regenerative management wheat fields fostered great invertebrate communities while limited pest presence. Invertebrate populations were negatively …

The Geminivirus Al2 Protein Interacts With Host Proteins Involved In The Plant Antiviral Response, Pheobean Atieno Odongo

Graduate Research Theses & Dissertations

Geminiviruses are economically important plant DNA viruses infecting a broad range of plant species and causing devastating crop diseases, resulting in up to 100% crop loss. As a result of these heavy losses on food and cash crops, these viruses represent a new threat to global food security and sustainability. In this research, I use Tomato golden mosaic virus (TGMV) to study host-virus relationships with an overall goal of developing sustainable and eco-friendly crop resistance. TGMV belongs to the Geminivirus subgroup, Begomovirus, that is characterized by a split genome consisting of two single-stranded circular DNAs. The TGMV genome encodes proteins …

Sex In Plants: Birth, Death, And Trying To Survive In Changing Climates, Elena M. Meyer

Theses and Dissertations

Plant mating systems are key determinants of fitness. Angiosperms exhibit a wide variety of reproductive strategies, including self-fertilization (or selfing), outcrossing, and mixed mating. It has been estimated that up to 43% of plant species are capable of selfing, and selfing has been hypothesized to provide reproductive assurance where opportunities for mating may be limited, such as in marginal environments. However, questions regarding the overall distribution of selfing rates across angiosperms, the maintenance of mixed mating in the face of inbreeding depression, and the impact of self-fertilization on diversification rates remain incompletely resolved. Here, we explore the dynamics of self-fertilization …

Feasibility Of Corn Stover For Biogas Production In Northwestern Illinois: A Case Study Of Jo Daviess And Carroll Counties, Anthony Amotoe-Bondzie

Masters Theses

The growing demand for renewable energy and sustainable waste management has intensified interest in agricultural residues such as bioenergy feedstocks. This study evaluated the feasibility of converting corn stover into biogas through anaerobic digestion (AD) in Jo Daviess and Carroll Counties, Illinois, with consideration of the Savanna Industrial Park as a potential centralized processing hub. Although corn stover represents one of the largest biomass resources in the United States, this research identifies a critical gap between theoretical availability and practically recoverable feedstock. Using a mixed-methods framework, the study integrates biomass quantification, methane yield modeling, economic analysis, and policy assessment. Results …

Evaluating Planting Methods For Native Seed Production And Exploring Granivory In The Northern Great Plains, Allison Dollen

Electronic Theses and Dissertations

Temperate grasslands have faced immense losses due to land use change in the last 150 years and less than half of the overall grasslands that once covered North America remain today. A portion of historic and remaining U.S. grasslands are located within the northern Great Plains (NGP) region which is home to over 1,600 species of native plants and provides many ecosystem services and economic benefits. Initiatives to restore grasslands and their ecosystem services are currently underway, but barriers such as limited native seed supply and granivory hinder restoration efforts. My first chapter addresses knowledge gaps in planting methods for …

Non-Native Seagrass, Halophila Stipulacea, Reaches Northern Caribbean, Elizabeth R. Whitman, Elizabeth W. Stoner, Stephanie K. Archer

Gulf and Caribbean Research

Halophila stipulacea, a seagrass native to the western Indian Ocean, has become an established invader throughout the western Atlantic, where it often outcompetes native seagrass species across diverse environmental conditions. Here, we report its presence in the northern Bahamas, ca. 2300 km northwest of the first Caribbean record in Grenada and 304 km northeast of the recent observation in Florida, USA. This range expansion represents the northernmost Caribbean record to date and highlights the species’ capacity for long-distance dispersal and continued spread within the region. Our observation underscores the need for coordinated monitoring efforts to track the trajectory of …

A Comparative Analysis Of The Ecophysiology Between The Invasive Macroalgae Starry Stonewort And The Native Macroalgae Chara To Predict Invasion Potential, Thomas J. Zellmer

All Graduate Theses, Dissertations, and Other Capstone Projects

Starry stonewort (Nitellopsis obtusa) is an invasive macroalga from Eurasia. Currently, starry stonewort’s invasive range consists of the upper Midwest and Great Lakes region, including the Mississippi River. Starry stonewort poses recreational and ecological problems by forming dense canopies that extend through the water column. Starry stonewort occupies a late-season niche space with dense biomass occurring in late July and persisting well into autumn. There is a lack of information on the ecophysiology of starry stonewort. In this study, two populations of starry stonewort, Minnesota and New York, were analyzed to compare regional differences in ecophysiology, along with chara (native …

Evaluating Donor Site Recovery Following Halodule Wrightii Harvest For Restoration In Northwest Florida, Katie M. Konchar, Becca A. Hatchell, Colin P. Shea, Bradley T. Furman, Kent Smith

Gulf and Caribbean Research

Bare‑root harvesting of Halodule wrightii is widely used to supply donor material for seagrass restoration, yet the capacity of donor meadows to recover in near‑temperate systems remains poorly documented. We evaluated donor‑site recovery following bare‑root harvesting in St. Andrew Bay, northwest Florida—an estuary at the northern extent of Tropical Atlantic Bioregion 2 where H. wrightii exhibits strong seasonal senescence and a shortened growing season. Thirty harvest impact sites were monitored for 388 days to quantify changes in shoot density, percent frequency, and sediment elevation relative to nearby reference conditions. Shoot density and percent frequency at harvested sites converged with reference …

Comparative Analysis Of Six New Chloroplast Genomes In Platanthera (Orchidaceae) Enhances Understanding Of Its Diversification, Lisa E. Wallace, Martin I. Batalla, Matthew Maisonave

Biological Sciences Faculty Publications

Platanthera is among the most diverse genera of orchids in north temperate regions, with high species diversity in Asia and North America. Despite many ecological studies in this group, little is known about its genomic diversity. Here, we report the newly annotated chloroplast genomes from six species in subgenus Limnorchis from North America and compare them with plastomes published for Platanthera species from Asia and Europe. We found that the plastomes of species in subg. Limnorchis are among the smallest reported for Platanthera thus far. While major structural differences were not detected in the newly sequenced species, ndh genes were …

Challenging And Diagnosing Structured Population Models By Testing Predictions From Stochastic Demography, Stephen P. Ellner, Robin E. Snyder, Daniel T. Blumstein, Dylan Z. Childs, Joshua C. Fowler, Christina M. Hernández, Julien G. A. Martin, María Paniw, Yngvild Vindenes

Biological Sciences Faculty Publications

1. Structured population models are parameterized to accurately project expected population sizes, stage/state distributions and population growth rates, but they also predict the variation in outcomes among individuals, such as the variance and skewness of lifetime reproductive output (LRO) and lifespan, the probability of never reproducing, and many other life-history metrics.

2. Testing such predictions about individual outcomes can be very useful model 'stress tests', because they depend on how components of the model (e.g. submodels for survival and fecundity) interact over multiple time steps, not just on the accuracy of the submodels. Because data on among-individual variation is rarely …

Behavioral And Electrophysiological Responses Of Fall Armyworm Larval Parasitoid Coccygidium Luteum To Maize And Companion Plant Volatiles, Emmanuel Peter, Sevgan Subramanian, Abdullahi Yusuf, Samira A. Mohamed, Baldwyn Torto, Emily A. Martin, Amanuel Tamiru

All Peer-Reviewed Publications

Companion cropping and biological control are among the best agronomic practices recommended for ecologically sustainable management of the invasive fall armyworm (FAW), Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae). Companion plants may suppress the FAW population by repelling the pest, disrupting host-plant location and recruiting biocontrol agents such as parasitoids. These interactions are primarily mediated by plant-derived volatile organic compounds (VOCs). Understanding parasitoids’ responses to VOCs emitted by companion plants enables selection of suitable cultivars to enhance biological control and design appropriate intercropping systems for effective FAW management. This study investigated behavioral and electrophysiological responses of a key FAW larval parasitoid, …

Insect Farming Innovations: A Pathway To Self-Reliance In Agrifood Systems In Africa, Zewdu Abro, Menale Kassie, Dennis Beesigamukama, Shaphan Yong Chia, Ermias Engida Legesse, Subramanian Sevgan, Julius Ecuru, Chrysantus M. Tanga

All Peer-Reviewed Publications

Insect farming as an innovative approach to transforming agrifood systems

Insect farming has emerged as a transformative and sustainable approach to addressing the interconnected challenges of food insecurity, environmental degradation, and economic vulnerability in Africa’s agrifood systems. By converting organic waste into high-value products (protein-rich feed, frass fertilizers, and bioactive compounds), insect farming offers an efficient circular economy solution that bridges nutrition, livelihoods, and ecological resilience (Lalander et al. 2025; Mei et al. 2024; Barragán-Fonseca et al. 2022; Xia et al. 2021; Van Huis 2020; Barragán-Fonseca et al. 2017; Van Huis and Oonincx 2017; Yi et al. 2014). Almost all …

Ecological Intensification Of Maize-Kale Systems In Kenya By Biofertilization And Push-Pull Management Shifts Nematode Communities, Agnes Kiriga, Johnnie Van Den Berg, Frank Chidawanyika, Solveig Haukeland, Bianca Greyvenstein, Dennis Beesigamukama, Chrysantus M. Tanga, Sevgan Subramanian, Daniel M. Mutyambai

All Peer-Reviewed Publications

Plant-parasitic nematodes (PPNs) pose a persistent threat to vegetable production in Kenya, contributing to reduced yields and soil degradation. The management of PPNs in vegetables in Kenya has largely remained unaddressed. The integration of ecological intensification strategies such as the vegetable integrated push-pull (VIPP) system and the use of black soldier fly frass fertilizer (BSFF) is gaining traction in sustainable agriculture. The aim of this study was to determine the effects of integrating VIPP and BSFF on nematode abundance and diversity in maize-kale cropping systems. Field trials were conducted in two different agroecological zones in Kenya. Field treatments involved plots …

Aquatic Invasive Species Survey And Treatment On Lake Umatilla And Lake Celilo 2024-2025 Report, Jacob Rose, Gabriel E. Campbell

Center for Lakes and Reservoirs Publications and Presentations

Flowering Rush (Butomus umbellatus) is an invasive aquatic plant in the Pacific Northwest that threatens salmon habitat. The Center for Lakes and Reservoirs staff surveyed for this and other aquatic species from 2024 and 2025 in the Columbia River in Lake Umatilla and Lake Celilo. This document summarizes their survey efforts including their protocols, data, and small-scale removal efforts.

Editorial: Sustainable Management Of Tuta Absoluta, Ahmad A. Omar, Inusa Jacob Ajene, Hafiz Muhammad Usman Aslam, Fathiya Mbarak Khamis

All Peer-Reviewed Publications

The tomato leafminer, Tuta absoluta (Meyrick), remains one of the most devastating global threats to tomato production. Its rapid invasion across continents, exceptional reproductive potential, cryptic foliar-mining behavior, and accelerated evolution of insecticide resistance have significantly complicated management efforts. The persistent failure of conventional chemical strategies underscores an urgent need for integrated solutions that combine molecular innovation, ecological engineering, and rigorous resistance monitoring. This editorial synthesizes key insights from recent contributions by Ullah et al., Bavithra et al., and Adams et al., which collectively outline a transformative, multi-dimensional framework for sustainable T. absoluta suppression.

Effects Of Temperature On The Life-History Traits Of Myzus Persicae And Its Efficiency In Transmitting Potato Virus Y (Pvy) In Potato Crops, Bonoukpoè M. Sokame, Henri E. Tonnang, Heidy Gamarra, Pablo Carhuapoma, Jan Kreuze, Leah R. Johnson, Ali Arab, Peter A. Armbruster, Oswaldo C. Villena

All Peer-Reviewed Publications

Aphids are highly sensitive to temperature changes and play a crucial role in transmitting plant viruses, accounting for the transmission of more than 50% of viruses that cause disease in crops. Among them, Myzus persicae is a major global pest, affecting over 400 plant species and transmitting more than 100 plant viruses, including potato virus Y (PVY), which poses a severe threat to potato crops. This study examines how temperature influences the life-history traits of M. persicae and its efficiency in transmitting PVY. Our research revealed that temperature significantly affects developmental duration, survival, and fecundity of M. persicae. The aphids …