Plant Biology Commons^™

Plant Physiological Responses To Environmental Change In A Marsh-Mangrove Ecotone, Matthew Sturchio

UNF Graduate Theses and Dissertations

Globally, photosynthesis (A) and autotrophic respiration (R) are the two largest physiological processes responsible for CO₂ flux. Coastal wetland ecosystems are responsible for some of the highest rates of C sequestration. Marsh grass and mangrove habitats responsible for this service are important in supporting biodiversity and preventing shoreline erosion, yet little is known about how this vegetation will respond physiologically to effects of climate and global change. In the first chapter a warming experiment was used to determine whether a C₄ marsh grass (Spartina alterniflora) and a C₃ mangrove (Avicennia …

Nitrogen Response Functions Targeted To Technology Extrapolation Domains In Ethiopia Using Ceres-Maize, Feyera Merga Liben, Charles S. Wortmann, Haishun Yang, Tsegaue Tadesse, Z. P. Stewart, D. Wegary, W. Mupangwa

Department of Agronomy and Horticulture: Faculty Publications

The profitability of fertilizer-N use can be optimized using N response functions specific to climate-based technology extrapolation domains (TED). Crop growth simulation can complement field research for targeting of response functions. The objective of this study was to target maize (Zea mays L.) N response functions to seven TED in Ethiopia through CERES-Maize simulation of continuous maize over 30 yr. The complete factorial set of treatments included seven levels of N in 25 kg ha⁻¹ increments under no-till (NT) and conventional tillage (CT) systems. The CERES-Maize simulated experiments were done for two or three sites per TED. Nitrogen …

Abrasive Weeding As A Vehicle For Precision Fertilizer Management In Organic Vegetable Production, Tran Kim Ngan Luong, Frank Forcella, Sharon Clay, Michael S. Douglass, Samuel E. Wortman

Department of Agronomy and Horticulture: Faculty Publications

Abrasive weeding is a nonchemical weed control tactic that uses small, gritty materials propelled with compressed air to destroy weed seedlings. Organic fertilizers have been used successfully as abrasive grits to control weeds, but the goal for this study was to explore the effects of fertilizer grit, application rates, and background soil fertility on weeds, plant available nitrogen (N) uptake, and crop yield. Field trials were conducted in organic ‘Carmen’ sweet red pepper (Capsicum annuum) and organic ‘Gypsy’ broccoli (Brassica oleracea var. italica) and treatments included organic fertilizer grit (8N–0.9P–3.3K vs. 3N–3.1P–3.3K), grit application rates (low …

Collapse, Reorganization, And Regime Identity: Breaking Down Past Management Paradigms In A Forest-Grassland Ecotone, Victoria M. Donovan, Caleb P. Roberts, Carissa L. Wonkka, Daniel R. Uden, David G. Angeler, Craig R. Allen, David A. Wedin, Rhae A. Drijber, Dirac Twidwell

Department of Agronomy and Horticulture: Faculty Publications

The identity of an ecological regime is central to modern resilience theory and our understanding of how systems collapse and reorganize following disturbance. However, resilience-based models used in ecosystem management have been criticized for their failure to integrate disturbance outcomes into regime identity. Assessments are needed to understand how well these classifications represent ecosystem responses that occur over management relevant time scales. We tracked post-wildfire forest and grassland dynamics 27 years after wildfire in eastern ponderosa pine savanna. We tested for differences between the assigned identity of a site (forest or grassland) versus classifications based on the site's disturbance history …

Wild Emmer Introgression Alters Root-To-Shoot Growth Dynamics In Durum Wheat In Response To Water Stress, Harel Bacher, Feiyu Zhu, Tian Gao, Kan Liu, Balpreet Dhatt, Tala Awada, Chi Zhang, Assaf Distelfeld, Hongfeng Yu, Zvi Peleg, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

Water deficit during the early vegetative growth stages of wheat (Triticum) can limit shoot growth and ultimately impact grain productivity. Introducing diversity in wheat cultivars to enhance the range of phenotypic responses to water limitations during vegetative growth can provide potential avenues for mitigating subsequent yield losses. We tested this hypothesis in an elite durum wheat background by introducing a series of introgressions from a wild emmer (Triticum turgidum ssp. dicoccoides) wheat. Wild emmer populations harbor rich phenotypic diversity for drought-adaptive traits. To determine the effect of these introgressions on vegetative growth under water-limited conditions, we used image-based phenotyping to …

Seed-Shattering Phenology At Soybean Harvest Of Economically Important Weeds In Multiple Regions Of The United States. Part 1: Broadleaf Species, Lauren M. Schwartz-Lazaro, Lovreet S. Shergill, Jeffrey A. Evans, Muthukumar V. Bagavathiannan, Shawn C. Beam, Mandy D. Bish, Jason A. Bond, Kevin W. Bradley, William S. Curran, Adam S. Davis, Wesley J. Everman, Michael L. Flessner, Steven C. Haring, Nicholas R. Jordan, Nicholas E. Korres, John L. Lindquist, Jason K. Norsworthy, Tameka L. Sanders, Larry E. Steckel, Mark J. Vangessel, Blake Young, Steven B. Mirsky

Department of Agronomy and Horticulture: Faculty Publications

Potential effectiveness of harvest weed seed control (HWSC) systems depends upon seed shatter of the target weed species at crop maturity, enabling its collection and processing at crop harvest. However, seed retention likely is influenced by agroecological and environmental factors. In 2016 and 2017, we assessed seed-shatter phenology in 13 economically important broadleaf weed species in soybean [Glycine max (L.) Merr.] from crop physiological maturity to 4 wk after physiological maturity at multiple sites spread across 14 states in the southern, northern, and mid-Atlantic United States. Greater proportions of seeds were retained by weeds in southern latitudes and shatter rate …

Guiding Principles For Using Satellite-Derived Maps In Rangeland Management, Brady W. Allred, Megan K. Creutzburg, John C. Carlson, Christopher J. Cole, Colin M. Dovichin, Michael C. Duniway, Matthew O. Jones, Jeremy D. Maestas, David E. Naugle, Travis W. Naumen, Gregory S. Okin, Matthew C. Reeves, Matthew Rigge, Shannon L. Savage, Dirac Twidwell, Daniel R. Uden, Bo Zhou

Department of Agronomy and Horticulture: Faculty Publications

No abstract provided.

Vision, Challenges And Opportunities For A Plant Cell Atlas, Plant Cell Atlas Consortium, Suryatapa Ghosh Jha, Marc Libault, David W. Ehrhardt, Seung Y. Rhee, 32 Other Scientists

Department of Agronomy and Horticulture: Faculty Publications

With growing populations and pressing environmental problems, future economies will be increasingly plant-based. Now is the time to reimagine plant science as a critical component of fundamental science, agriculture, environmental stewardship, energy, technology and healthcare. This effort requires a conceptual and technological framework to identify and map all cell types, and to comprehensively annotate the localization and organization of molecules at cellular and tissue levels. This framework, called the Plant Cell Atlas (PCA), will be critical for understanding and engineering plant development, physiology and environmental responses. A workshop was convened to discuss the purpose and utility of such an initiative, …

Intervention Of Climate-Smart Practices In Wheat Under Rice-Wheat Cropping System In Nepal, Janma Jaya Gairhe, Mandeep Adhikari, Deepak Ghimire, Arun Khatri-Chhetri, Dinesh Panday

Department of Agronomy and Horticulture: Faculty Publications

Besides a proper agronomic management followed by Nepalese farmers, wheat (Triticum aestivum L.) production has been severely affected by changing climate. There are many interventions, including climate-smart practices, to cope with this situation and possibly enhance crop and soil productivity. Field experiments were set up in a randomized complete block design with six treatments (TRT) with four replications in three locations (LOC) during wheat-growing seasons in Nepal from 2014 to 2016. Treatments included (i) Controlled Practice (CP), (ii) Improved Low (IL), (iii) Improved High (IH), (iv) Climate Smart Agriculture Low (CSAL), (v) Climate Smart Agriculture Medium (CSAM), and (vi) …

Effect Of Foliar Micronutrients (B, Mn, Fe, Zn) On Maize Grain Yield, Micronutrient Recovery, Uptake, And Partitioning, Zachary P. Stewart, Ellen T. Paparozzi, Charles S. Wortmann, Prakash Kumar Jha, Charles A. Shapiro

Department of Agronomy and Horticulture: Faculty Publications

Timing of micronutrient demand and acquisition by maize (Zea Mays L.) is nutrient spe‐ cific and associated with key vegetative and reproductive growth stages. The objective of this study was to determine the fate of foliar‐applied B, Fe, Mn, Zn, and Fe/Zn together, evaluate the effect of foliar micronutrients applied at multiple rates and growth stages on maize grain yield, and deter‐ mine their apparent nutrient recovery efficiency (ANR). Five Randomized Complete Block Design (RCBD) experiments were conducted in 2014 and 2015 at five locations across Nebraska. Total dry matter was collected at 5–6 stages, and separated into leaves, stalk, …

Genomic Resources In Plant Breeding For Sustainable Agriculture, Mahendar Thudi, Rajeev K. Varshney, James C. Schnable

Department of Agronomy and Horticulture: Faculty Publications

Climate change during the last 40 years has had a serious impact on agriculture and threatens global food and nutritional security. From over half a million plant species, cereals and legumes are the most important for food and nutritional security. Although systematic plant breeding has a relatively short history, con- ventional breeding coupled with advances in technology and crop management strategies has increased crop yields by 56 % globally between 1965− 85, referred to as the Green Revolution. Nevertheless, increased demand for food, feed, fiber, and fuel necessitates the need to break existing yield barriers in many crop plants. In …

Development Of Mping-Based Activation Tags For Crop Insertional Mutagenesis, Alexander Johnson, Edward Mcassey, Stephanie Diaz, Jacod Reagin, Priscilla S. Redd, Daymond R. Parrilla, Hanh Nguyen, Adrian Stec, Lauren A.L. Mcdaniel, Thomas E. Clemente, Robert M. Stupar, Wayne A. Parrott, C. Nathan Hancock

Department of Agronomy and Horticulture: Faculty Publications

Modern plant breeding increasingly relies on genomic information to guide crop im- provement. Although some genes are characterized, additional tools are needed to effectively identify and characterize genes associated with crop traits. To address this need, the mPing element from rice was modified to serve as an activation tag to in- duce expression of nearby genes. Embedding promoter sequences in mPing resulted in a decrease in overall transposition rate; however, this effect was negated by using a hyperactive version of mPing called mmPing20. Transgenic soybean events carrying mPing-based activation tags and the appropriate transposase expression cassettes showed evidence of transposition. …

Responses Of Soil Surface Greenhouse Gas Emissions To Nitrogen And Sulfur Fertilizer Rates To Brassica Carinata Grown As A Bio-Jet Fuel, Dwarika Bhattarai, Gandura O. Abagandura, Thandiwe Nleya, Sandeep Kumar

Department of Agronomy and Horticulture: Faculty Publications

Carinata (Brassica carinata A. Braun), a non-food oilseed crop and an alternative bio-jet fuel feedstock, has received attention for its potential as a low-input option for production in the semi-arid region of the Northern Great Plains of the United States. Research addressing the impacts of nitrogen (N) and sulfur (S) fertilizers on soils and greenhouse gas (GHG; CO2, N2O, and CH4) emissions from carinata production are limited. Thus, objective of this study was to evaluate the impact of different rates of N and S fertilizers applied to carinata on soil properties and GHG emissions. Field experiments were conducted in 2017 …

Household Smoke-Exposure Risks Associated With Cooking Fuels And Cooking Places In Tanzania: A Cross-Sectional Analysis Of Demographic And Health Survey Data, Mazbahul G. Ahamad, Fahian Tanin, Nawaraji Shrestha

Department of Agronomy and Horticulture: Faculty Publications

Household smoke-exposure risk (SER) can be defined through the assessment of cooking fuels (smoke and no smoke-producing) and cooking places (indoor and outdoor) related information, which represent different levels of household air pollution. This study aimed to explore the prevalence and geographical variations in smoke-exposure risks (SERs) associated with indoor and outdoor cooking practices and use of smoke-producing and non-smoke-producing cooking fuels in Tanzania. We further investigated the social and spatial features associated with household SERs. We defined an indicator variable, the household SER, using country-level, cross-sectional data on cooking fuels and cooking places obtained from the 2015–2016 Tanzania Demographic …

Officially Confirmed Covid-19 And Unreported Covid-19–Like Illness Death Counts: An Assessment Of Reporting Discrepancy In Bangladesh, Mazbahul G. Ahamad, Fahian Tanin, Byomkesh Talukder, Monir Ahmed

Department of Agronomy and Horticulture: Faculty Publications

Reporting discrepancies between officially confirmed COVID-19 death counts and unreported COVID- 19–like illness (CLI) death counts have been evident across the world, including Bangladesh. Publicly available data were used to explore the differences between confirmed COVID-19 death counts and deaths with possible COVID-19 symptoms between March 2, 2020 and August 22, 2020. Unreported CLI death counts totaled more than half of the confirmed COVID-19 death counts during the study period. However, the reporting authority did not consider CLI deaths, which might produce incomplete and unreliable COVID-19 data and respective mortality rates. All deaths with possible COVID-19 symptoms need to be …

Soil Erosion Modelling: A Global Review And Statistical Analysis, Pasquale Borrelli, Panos Panagos, Dinesh Panday, 64 More Co-Authors

Department of Agronomy and Horticulture: Faculty Publications

To gain a better understanding of the global application of soil erosion prediction models, we comprehensively reviewed relevant peer-reviewed research literature on soil-erosion modelling published between 1994 and 2017.We aimed to identify (i) the processes and models most frequently addressed in the literature, (ii) the regions within which models are primarily applied, (iii) the regions which remain unaddressed and why, and (iv) how frequently studies are conducted to validate/evaluate model outcomes relative to measured data. To perform this task, we combined the collective knowledge of 67 soil-erosion scientists from 25 countries. The resulting database, named ‘Global Applications of Soil Erosion …

Potential Amendments For Improving Productivity Of Low Carbon Semiarid Soil, Bijesh Maharjan, Dinesh Panday, Humberto Blanco-Canqui, Maysoon M. Mikha

Department of Agronomy and Horticulture: Faculty Publications

Applying soil amendments with high C content can potentially improve soil properties and increase crop yields. The objective of this 3-yr field study was to evaluate the effects of organic amendments on soil organic C (SOC), chemical properties, crop nutrient uptake, and crop yields in a low C sandy loam soil near Scottsbluff, NE. The field was planted to dry bean (Phaseolus vulgaris L.) in 2017, maize (Zea mays L.) in 2018, and sugar beet (Beta vulgaris L.) in 2019. Char at 22.3, 44.6, 66.9, 89.2, and 133.8 Mg ha^–1; biochar at 5.6 and 11.2 …

Loss Of Comt Activity Reduces Lateral Root Formation And Alters The Response To Water Limitation In Sorghum Brown Midrib (Bmr) 12 Mutant, Manny Saluja, Feiyu Zhu, Hongfeng Yu, Harkamal Walia, Scott E. Sattler

Department of Agronomy and Horticulture: Faculty Publications

Lignin is a key target for modifying lignocellulosic biomass for efficient biofuel production. Brown midrib 12 (bmr12) encodes the sorghum caffeic acid O-methyltransferase (COMT) and is one of the key enzymes in monolignol biosynthesis. Loss of function mutations in COMT reduces syringyl (S) lignin subunits and improves biofuel conversion rate. Although lignin plays an important role in maintaining cell wall integrity of xylem vessels, physiological and molecular consequences due to loss of COMT on root growth and adaptation to water deficit remain unexplored.

We addressed this gap by evaluating the root morphology, anatomy and transcriptome of bmr12 mutant. The mutant …

Improving Publicly Available Corn Nitrogen Rate Recommendation Tools With Soil And Weather Measurements, Curtis J. Ransom, Newell R. Kitchen, John E. Sawyer, James J. Camberato, Paul R. Carter, Richard Ferguson, Fabián G. Fernández, David W. Franzen, Carrie A.M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John F. Shanahan

Department of Agronomy and Horticulture: Faculty Publications

Improving corn (Zea mays L.) N fertilizer rate recommendation tools is necessary for improving farmers’ profits and minimizing N pollution. Research has repeatedly shown that weather and soil factors influence available N and crop N need. Adjusting available corn N recommendation tools with soil and weather measurements could improve farmers’ ability to manage N. The aim of this research was to improve publicly available N recommendation tools with site-specific soil and weather measurements. Information from49 site-years ofNresponse trials in theU.S. Midwest was used to evaluate 21 rate recommendation tools for a single (at-planting) and split (at-planting + sidedress) N …

Adaptation And Forage Productivity Of Cool-Season Grasses In The Central Usa, Kenneth P. Vogel, Robert B. Mitchell

Department of Agronomy and Horticulture: Faculty Publications

Cool-season grass species (18) and cultivars (85) were evaluated for use in seeded grasslands in the tallgrass prairie and shortgrass steppe ecoregions of the central United States at the test locations of Ithaca and Sidney, NE, respectively. Both native and introduced grasses were evaluated in sward trails. Significant differences existed among species and cultivars for all traits evaluated except for in vitro dry matter digestibility (IVDMD) among cultivars within species at Sidney. The grasses that had the best establishment, persistence, and forage yields in the Ithaca trial were introduced wheatgrass (Thinopyrum) and bromegrass (Bromus) species. At …

Sterol Biosynthesis In Four Green Algae: A Bioinformatic Analysis Of The Ergosterol Versus Phytosterol Decision Point, Adam Voshall, Nakeirah T.M. Christie, Suzanne L. Rose, Maya Khasin, James L. Van Etten, Jennifer E. Markham, Wayne R. Riekhof, Kenneth Nickerson

School of Biological Sciences: Faculty Publications

Animals and fungi produce cholesterol and ergosterol, respectively, while plants produce the phytosterols stigmasterol, campesterol, and bsitosterol in various combinations. The recent sequencing of many algal genomes allows the detailed reconstruction of the sterol metabolic pathways. Here, we characterized sterol synthesis in two sequenced Chlorella spp., the free-living C. sorokiniana, and symbiotic C. variabilis NC64A. Chlamydomonas reinhardtii was included as an internal control and Coccomyxa subellipsoidea as a plant-like outlier. We found that ergosterol was the major sterol produced by Chlorella spp. and C. reinhardtii, while C. subellipsoidea produced the three phytosterols found in plants. In silico analysis …

Root And Crown Rot Pathogens Found On Dry Beans Grown In Mozambique, Suzana Vanessa Ismael Fernandes, G. Godoy-Lutz, Celestina Nhagupana Jochua, Carlos A. Urrea, Kent M. Eskridge, James R, Steadman, Joshua Herr

Department of Plant Pathology: Faculty Publications

Dry edible beans are a vital food source in Mozambique, East Africa—one that alleviates hunger and malnutrition and adds value to the economy. In recent years, root/crown rot (RCR) pathogens have emerged as limiting constraints in dry bean production. Not much has been characterized concerning the causal agents of RCR in Mozambique. The purpose of this study was to identify the primary pathogen(s) associated with RCR dry bean samples collected at breeder nursery sites and farmer fields in Mozambique using molecular sequencing and culture-based methods. Sequencing revealed, not surprisingly, an increased diversity of fungal/oomycete operational taxonomic units when compared to …

Lichens And Biofilms: Common Collective Growth Imparts Similar Developmental Strategies, Erin C. Carr, Steven D. Harris, Joshua R. Herr, Wayne Riekhof

Department of Plant Pathology: Faculty Publications

Lichens are traditionally defined as a symbiotic relationship between fungi and algae and/or cyanobacteria. This union forms a unique structure called the thallus, which attaches to surfaces such as rocks and tree bark. Recent reports challenge the view that lichens are comprised of one fungus and one photobiont, and instead suggest that they are a consortium of microbes. Much of lichen biology remains unknown as most of our knowledge of lichens is limited to morphological characteristics with little to no functional analysis of lichen genes. However, lichens and biofilms share many similar physiological traits which when compared may assist in …