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Minimal Effects Of An Invasive Flowering Shrub On The Pollinator Community Of Native Forbs, Y Anny Chung, Laura A. Burkle, Tiffany M. Knight

Biology Faculty Research

Biological invasions can strongly influence species interactions such as pollination. Most of the documented effects of exotic plant species on plant-pollinator interactions have been observational studies using single pairs of native and exotic plants, and have focused on dominant exotic plant species. We know little about how exotic plants alter interactions in entire communities of plants and pollinators, especially at low to medium invader densities. In this study, we began to address these gaps by experimentally removing the flowers of a showy invasive shrub, Rosa multiflora, and evaluating its effects on the frequency, richness, and composition of bee visitors to …

Warming Reduces Tall Fescue Abundance But Stimulates Toxic Alkaloid Concentrations In Transition Zone Pastures Of The U.S., Rebecca L. Mcculley, Lowell P. Bush, Anna E. Carlisle, Huihua Ji, Jim A. Nelson

Plant and Soil Sciences Faculty Publications

Tall fescue pastures cover extensive acreage in the eastern half of the United States and contribute to important ecosystem services, including the provisioning of forage for grazing livestock. Yet little is known concerning how these pastures will respond to climate change. Tall fescue's ability to persist and provide forage under a warmer and wetter environment, as is predicted for much of this region as a result of climate change, will likely depend on a symbiotic relationship the plant can form with the fungal endophyte, Epichloë coenophiala. While this symbiosis can confer environmental stress tolerance to the plant, the endophyte …

The Exometabolome Of Clostridium Thermocellum Reveals Overflow Metabolism At High Cellulose Loading, Evert K. Holwerda, Philip G. Thorne, Daniel G. Olson, Daniel Amador-Noguez, Nancy L. Engle, Timothy J. Tschaplinski, Johannes P. Van Dijken, Lee R. Lynd

Dartmouth Scholarship

BackgroundClostridium thermocellum is a model thermophilic organism for the production of biofuels from lignocellulosic substrates. The majority of publications studying the physiology of this organism use substrate concentrations of ≤10 g/L. However, industrially relevant concentrations of substrate start at 100 g/L carbohydrate, which corresponds to approximately 150 g/L solids. To gain insight into the physiology of fermentation of high substrate concentrations, we studied the growth on, and utilization of high concentrations of crystalline cellulose varying from 50 to 100 g/L by C. thermocellum. .

South Loup River Valley Floristics: A Survey Of Selected Sites In Buffalo County, Nebraska, Steven J. Rothenberger, April M. Christman, Kevin Turek, Emmylou A. O'Brien

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Originating in the Nebraska Sand Hills, the South Loup River flows 30 km north of Kearney, Nebraska and traverses the northern edge of Buffalo County as it flows eastward to its confluence with the Middle Loup River in southwestern Howard County. Several diverse plant communities are associated with the South Loup Valley, including wet-meadows, wetland/oxbows, sand prairie, and riparian forest. Over a period of 6 years (2006-2012), we surveyed representative wet meadow, wetland, and sand prairie communities. We compiled an annotated vascular plant checklist that included 324 vascular plant species of which 11 were new county records. Three species of …

Genetic And Aggressiveness Variation Among Sclerotinia Sclerotiorum Dry Bean Isolates From Brazil Fields, Willian Luis Antonio Zancan, James R. Steadman, Rebecca Higgins, Rachana Jhala, Jose Da Cruz Machado

Department of Plant Pathology: Faculty Publications

Sclerotinia sclerotiorum, infection of bean fields, has increased in Brazil. Fungicides application is the control strategy used due to lack of cultivars with complete disease resistance. To guide the use of isolates in resistance screening 25 S. sclerotiorum isolates from Brazilian dry bean fields were characterized using microsatellite markers, mycelial compatibility groups (MCGs) and aggressiveness. Microsatellite primer pairs were used to identify polymorphisms among the S. sclerotiorum isolates and MCGs were determined from interaction of all isolates grown side by-side. Aggressiveness was derived from a straw test where fungal mycelium was placed over a cut bean stem and rated for …

Experimental Approaches To Study Plant Cell Walls During Plant-Microbe Interactions, Ye Xia, Carloalberto Petti, Mark A. Williams, Seth Debolt

Horticulture Faculty Publications

Plant cell walls provide physical strength, regulate the passage of bio-molecules, and act as the first barrier of defense against biotic and abiotic stress. In addition to providing structural integrity, plant cell walls serve an important function in connecting cells to their extracellular environment by sensing and transducing signals to activate cellular responses, such as those that occur during pathogen infection. This mini review will summarize current experimental approaches used to study cell wall functions during plant-pathogen interactions. Focus will be paid to cell imaging, spectroscopic analyses, and metabolic profiling techniques.

The Involvement Of J-Protein Atdjc17 In Root Development In Arabidopsis, Carloalberto Petti, Meera Nair, Seth Debolt

Horticulture Faculty Publications

In a screen for root hair morphogenesis mutants in Arabidopsis thaliana L. we identified a T-DNA insertion within a type III J-protein AtDjC17 caused altered root hair development and reduced hair length. Root hairs were observed to develop from trichoblast and atrichoblast cell files in both Atdjc17 and 35S::AtDJC17. Localization of gene expression in the root using transgenic plants expressing proAtDjC17::GUS revealed constitutive expression in stele cells. No AtDJC17 expression was observed in epidermal, endodermal, or cortical layers. To explore the contrast between gene expression in the stele and epidermal phenotype, hand cut transverse sections of Atdjc17 roots were …

Effects Of Genetic Modification Of Phosphoinositol Pathway On Light Signaling And Secondary Metabolism In Tomato Plants, Mohammad Alimohammadi

Theses and Dissertations

Inositol- (1,4,5) triphosphate (InsP3) is known as an important signaling factor and a regulator of plant responses to environmental and stress conditions. Overexpression of the InsP 5-ptase gene is found to enhance tolerance of transgenic tomato plants to abiotic stress and the induction of lycopene synthesis in InsP 5-ptase transgenic plants. Here, we demonstrated that the genetic reduction of InsP3 affected the overall phosphoinositol pathway, flavonoid metabolism, and light signaling in InsP 5-ptase transgenic plants. Transgenic plants that overexpress the InsP 5-ptase gene demonstrate an increase in the expression of major light signaling transcription factors (LeHY5, SIMYB12, LeELIP). We found …

Allopolyploidy, Diversification, And The Miocene Grassland Expansion, Matt Estep, Michael Mckain, Dilys Diaz, Jinshun Zhong, John Hodge, Trevor Hodkinson, Daniel Layton, Simon Malcomber, Rémy Pasquet, Elizabeth Kellogg

Biology Department Faculty Works

The role of polyploidy, particularly allopolyploidy, in plant diversification is a subject of debate. Whole-genome duplications precede the origins of many major clades (e.g., angiosperms, Brassicaceae, Poaceae), suggesting that polyploidy drives diversification. However, theoretical arguments and empirical studies suggest that polyploid lineages may actually have lower speciation rates and higher extinction rates than diploid lineages. We focus here on the grass tribe Andropogoneae, an economically and ecologically important group of C4 species with a high frequency of polyploids. A phylogeny was constructed for ca. 10% of the species of the clade, based on sequences of four concatenated low-copy nuclear loci. …

An Eriophyid Mite-Transmitted Plant Virus Contains Eight Genomic Rna Segments With Unusual Heterogeneity In The Nucleocapsid Protein, Satyanarayana Tatineni, Anthony J. Mcmechan, Everlyne N. Wosula, Stephen N. Wegulo, Robert A. Graybosch, Roy French, Gary L. Hein

Department of Plant Pathology: Faculty Publications

Eriophyid mite-transmitted, multipartite, negative-sense RNA plant viruses with membrane-bound spherical virions are classified in the genus Emaravirus. We report here that the eriophyid mite-transmitted Wheat mosaic virus (WMoV), an Emaravirus, contains eight genomic RNA segments, the most in a known negative-sense RNA plant virus. Remarkably, two RNA 3 consensus sequences, encoding the nucleocapsid protein, were found with 12.5% sequence divergence, while no heterogeneity was observed in the consensus sequences of additional genomic RNA segments. The RNA-dependent RNA polymerase, glycoprotein precursor, nucleocapsid, and P4 proteins of WMoV exhibited limited sequence homology with the orthologous proteins of other emaraviruses, while …

Arboretum Annual Report 2013-2014, Glenn Dreyer

Annual Reports

No abstract provided.

Economic Contribution Of Agriculture And Food To Arkansas' Gross Domestic Product 1997-2012, Leah English, Jennie Popp, Wayne Miller

AAES Research Reports and Research Bulletins

Agricultural production, processing, and retail industries are major contributors to the Arkansas economy in terms of GDP. Agriculture contributes to the economy through direct agricultural production, value-added processing, and agricultural retail activities, and it also plays an important role through its interactions with other sectors. The use of non-agricultural goods and services as inputs into the agricultural sector promotes diversified growth in Arkansas’ economy; thus agriculture remains a vital part of Arkansas’ economy. This report: 1) compares the relative size of the Agriculture and Food Sector in Arkansas with those of neighboring states, the Southeastern region of the United States, …

Tallgrass Prairie Center Newletter, Autumn 2014, University Of Northern Iowa. Tallgrass Prairie Center.

Tallgrass Prairie Center Newsletter

Inside This Issue:

-- The Tallgrass Prairie Center Goes to Washington (and Missouri, West Virginia, and Colorado)
-- 2015 Iowa Prairie Conference
-- ISAC Excellence in Action Award to UNI's Native Seed Distribution Program
-- What You Sow Is What Will Grow
-- The effect of summer floods on plant and wildlife diversity in managed prairie plantings: observations from a "natural experiment" in the Cedar River floodplain
-- Ecological Restoration Seminar
-- Friends of the Tallgrass Prairie Center
-- New Grad Student/Employees
-- Name that plant?

Spatial Variation In Carbon And Nitrogen In Cultivated Soils In Henan Province, China: Potential Effect On Crop Yield, Xuelin Zhang, Qun Wang, Frank S. Gilliam, Yilun Wang, Feina Cha, Chaohai Li

Biological Sciences Faculty Research

Improved management of soil carbon (C) and nitrogen (N) storage in agro-ecosystems represents an important strategy for ensuring food security and sustainable agricultural development in China. Accurate estimates of the distribution of soil C and N stores and their relationship to crop yield are crucial to developing appropriate cropland management policies. The current study examined the spatial variation of soil organic C (SOC), total soil N (TSN), and associated variables in the surface layer (0–40 cm) of soils from intensive agricultural systems in 19 counties within Henan Province, China, and compared these patterns with crop yield. Mean soil C and …

Overexpression Of Patatin-Related Phospholipase Aiiiβ Altered The Content And Composition Of Sphingolipids In Arabidopsis, Maoyin Li, Jennifer E. Markham, Xuemin Wang

Department of Biochemistry: Faculty Publications

In plants, fatty acids are primarily synthesized in plastids and then transported to the endoplasmic reticulum (ER) for synthesis of most of the complex membrane lipids, including glycerolipids and sphingolipids. The first step of sphingolipid synthesis, which uses a fatty acid and a serine as substrates, is critical for sphingolipid homeostasis; its disruption leads to an altered plant growth. Phospholipase As have been implicated in the trafficking of fatty acids from plastids to the ER. Previously, we found that overexpression of a patatin-related phospholipase, pPLAIIIβ, resulted in a smaller plant size and altered anisotropic cell expansion. Here, we determined the …

Assessing Positional Accuracy And Correcting Point Data For Digital Soil Mapping At Varying Scales, Minerva J. Dorantes

Open Access Theses

Accuracy, timeliness, and the effect of scale of soil maps are rarely assessed. The recent increase in the use of GIS technologies and modelling software in natural resources and land management, has increased the demand for soil information at a finer resolution worldwide. Most of the world's developing countries rely on soils information at a scale that is too coarse for practical planning, and have obstacles impeding collection of new data, such as civil war and a lack of collection resources. The United States has an exhaustive collection of soils data at a fine scale. However, its location information is …

Automatic Extraction Of Plots From Geo-Registered Uas Imagery Of Crop Fields With Complex Planting Schemes, Anthony A. Hearst

Open Access Theses

Complex planting schemes are common in experimental crop fields and can make it difficult to extract plots of interest from high-resolution imagery of the fields gathered by Unmanned Aircraft Systems (UAS). This prevents UAS imagery from being applied in High-Throughput Precision Phenotyping and other areas of agricultural research. If the imagery is accurately geo-registered, then it may be possible to extract plots from the imagery based on their map coordinates. To test this approach, a UAS was used to acquire visual imagery of 5 ha of soybean fields containing 6.0 m2 plots in a complex planting scheme. Sixteen artificial targets …

Defining Management Strategies To Maximize Net Soil Carbon And Nitrogen Retention In Turfgrass Systems, Quincy D. Law

Open Access Theses

Soil carbon (C) sequestration has been proposed as a method to reduce atmospheric carbon dioxide (CO2 ). Managed turf areas are both a source and a sink for greenhouse gases (GHGs) including CO 2 , methane (CH4 ), and nitrous oxide (N2 O), among others. Management practices, including turfgrass selection and mowing, influence the amount of C and N stored in the soil, as well as the direct and indirect GHG emissions. Thus, the objective of this research was to determine how turfgrass selection (both species and cultivar) and mowing practices (such as frequency and grass clipping management) influence the …

Analyzing The Importance Of Diversifying Beyond Tobacco For Small-Scale Farmers In Malawi, Mphatso Charity Mbulukwa

Open Access Theses

This thesis analyses potential agricultural alternatives to production and marketing of tobacco in Malawi. I study existing patterns of crop and income diversification and factors that limit crop diversification. I also provide an analysis of the current profitability of different important cash crop alternatives that are commonly grown among smallholder farmers and compare their profitability to that of tobacco.

Following a review and synthesis of available literature on alternatives to tobacco, analysis is presented that relies upon data collected in 2009 from 380 households in Kasungu and Machinga districts of Malawi. Simpsons Index of diversification was used to measure the …

Effect Of Post-Anthesis Fungicide Applications To Manage Fusarium Head Blight In Winter Wheat, Anna Noversoke

Open Access Theses

Fusarium head blight (FHB) of wheat, caused by the fungus Fusarium graminearum, is currently considered one of the most economically important diseases on wheat in the North Central United States. The fungus causes light-weight "tombstone" grains to form and produces the mycotoxin deoxynivalenol (DON), reducing the yield and quality of the grain. Currently, farmers rely heavily on the sterol demethylase Inhibitor (DMI) triazole fungicide Prosaro (Bayer CropScience) to protect their crop from this disease. The optimal fungicide application timing is traditionally believed to be early anthesis - Feekes Growth Stage (FGS) 10.5.1. However, environmental conditions and uneven flowering across a …

Creating Initial Digital Soil Properties Map Of Afghanistan, Shams R. Rahmani

Open Access Theses

Afghanistan is a country with a population of more than 31 million people and is located in south central Asia. The total arable land in the country is 12%, 5% is irrigated and the remaining 7% is rainfed. Due to the lack of available soil information, poor farming practices and land management planning severely affect the yield of agriculture products. In order to ensure sustainable agriculture and prevent land degradation problems, understanding spatial variability of soil is crucial. The overall objective of this research study was to use digital soil mapping techniques to identify the soil resources and generate a …

Liquid Swine Manure Application Timing And Instincttm Impacts On Net Soil Nitrogen Mineralization And Corn Yield, Min Xu

Open Access Theses

Nitrogen (N) is one of the most expensive variable input costs for corn production. Optimized manure management is essential to ensure maximum crop N utilization and to reduce the risk of N loss. A field study was conducted in central Indiana from 2011-2013 to assess liquid swine ( Sus scrofa L.) manure N availability when applied at different times or co-applied with InstinctTM , a microencapsulated form of nitrapyrin. Soil inorganic N contents, soil N mineralization, corn yield, grain N content, whole plant N concentrations of corn at the V6 growth stage, and ear leaf N concentrations of corn at …

Invasive Silver Carp (Hypophthalmichthys Moltrix) Protein Hydrolysates And Their Efficacy In Increasing Seedling Vigor And Reducing Seed Borne Pathogen Growth, Shanleigh Pauline Thomson

Open Access Theses

Silver carp are an invasive fish species introduced into the United States within the last forty years. Unable to be effectively eradicated or commercialized as a source of food, other methods must be developed to control and/or use these fish. Fish protein hydrolysates (FPH) are products derived from the proteins inherent within fish. Development of FPH from Silver carp for a variety of uses could aid in controlling their expanding population and provide organic produces with a seed treatment option which is not available to them currently.

In the first study, FPH were used as a seed vigor treatment for …

Population Differentiation, Dispersal Limitation, And Local Adaptation In The Gametophytic Fern Vittaria Appalachiana, Sally M. Stevens

Open Access Dissertations

Species' distributions are driven by a variety of abiotic and biotic factors. As these factors become altered by global climate change, species are believed to respond to these projected environmental changes in four different ways. One response is the shifting of the species' geographic range to higher latitudes and elevations, which will be unlikely for those species that have limited dispersal potential. Alternatively, organisms may tolerate the change, which will be unlikely for those organisms that are not phenotypically plastic. A third potential response is to adapt to the new environment via rapid evolution, an unlikely response for those organisms …

Identification And Characterization Of Signal Components In Early Aba Signaling In Arabidopsis, Yueh-Ju Hou

Open Access Dissertations

The phytohormone abscisic acid (ABA) regulates growth, development, and response to abiotic stress in plants. The core ABA signaling has three key components: ABA receptors PYRABACTIN RESISTANCE 1 and PYR1-Like protein (PYR1/PYLs), type 2C protein phosphatases (PP2Cs) and SNF1- related protein Kinase 2s (SnRK2s). In the presence of ABA, PYR1/PYLs bind to and inhibit PP2Cs, leading to the release of SnRK2s from suppression, to activate downstream events such as ABA-responsive gene expression. To identify new components in the ABA signaling pathway, we performed a yeast two-hybrid screen for PYLs and SnRK2s interactors. We identified two proteins that interact with PYLs …

Identification And Characterization Of Factors Involved In Dna Demethylation And Anti-Silencing In Arabidopsis, Zhaobo Lang

Open Access Dissertations

DNA methylation is a key epigenetic mark for transcriptional gene silencing in many eukaryotes. DNA methylation status can be dynamically controlled by methylation and active demethylation processes. Compared to the well-known mechanisms of DNA methylation, the mechanisms of DNA demethylation and its regulation are poorly understood. In order to better understand the DNA demethylation pathway, we developed two genetic screening systems in Arabidopsis to identify new components involved in the DNA demethylation. In the first system, which is based on 35S promoter driven SUC2 (sucrose transporter 2) transgene, a mutant (91-1) was isolated and map-based cloning identified the …

Combining And Mapping Qtl For Fusarium Head Blight (Fhb) Resistance In Wheat, Jin Sun

Open Access Dissertations

Fusarium head blight (FHB) has become one of the most damaging wheat diseases in humid and semi-humid regions around the world. Single gene resistance to FHB in wheat provides only partial resistance and also the disease severity is highly influenced by environment. Consequently multiple genes are required for effective resistance. Our hypothesis is that identifying DNA markers for type I resistance will be very beneficial for selection, and combining type I and type II FHB resistance will be more effective than either type alone. The objectives of this project are to 1) combine type I resistance from cultivars Goldfield, INW0412, …

Using Energy-Efficient Technologies To Produce Bedding Plants And Microgreens In Protected And Controlled Environments, Joshua R. Gerovac

Open Access Theses

Gerovac, Joshua R. M.S., Purdue University, December 2014. Using Energy-Efficient Technologies to Produce Bedding Plants and Microgreens in Protected and Controlled Environments. Major Professor: Roberto G. Lopez. Production of bedding plants in commercial greenhouses (GHs) located in northern latitudes begins in late winter and continues through late spring when low outdoor temperatures generally necessitate active heating to maintain temperatures suitable for growth and development. Meanwhile, year-round production of microgreens using multi-layer systems requires sole-source (SS) photosynthetic lighting for production. Energy used to provide active heating in commercial GHs or SS lighting in multi-layer systems is second only to labor as …

Biosafety: Evaluation And Regulation Of Genetically Modified (Gm) Crops In The United States, Richard E. Goodman

Department of Food Science and Technology: Faculty Publications

This review of the safety assessment of genetically modified (GM) crops is focused primarily on the process and progress in the United States (US). It reviews the development of the safety evaluation process from the Asilomar conference in 1975 considering issues relevant to recombinant DNA technology, to discussions between the US government, academic and industrial scientists between 1984 and 1994 when the first GM crops were being field tested and evaluated commercial release for food and feed production. International guidelines were also reviewed for consistency with the US system. The overall process includes consideration of information relating to history of …

Systematics And Evolution Of Leandra S.Str. (Melastomataceae, Miconieae), Marcelo Reginato

Dissertations, Theses, and Capstone Projects

Phylogenetic studies in the Melastomataceae have demonstrated the need of taxonomic rearrangements in the current classification. Melastomes are among the most diverse groups of plants and several cases of known artificial taxa are observed and awaiting further resolution. One example is the Leandra s.str. clade, which includes the majority of the taxa traditionally treated in the genus Leandra. Some attempts have been made to infer the relationships of Leandra s.str., but the sampling in these earlier studies was sparse and the resolution low inside the clade. The main objective here is to propose a comprehensive phylogenetic framework for this group …