Digital Commons Network^™

Notes: Oriental Bittersweet In Grasslands Near Eastern Bluebird Nest Boxes, Neal D. Mundahl

The Prairie Naturalist

Oriental bittersweet (Celastrus orbiculatus Thunb.; hereafter OB) is an invasive, woody vine that has been expanding its range westward in North America since its introduction from East Asia in the mid-1700s for horticultural purposes (Albright et al. 2009, United States Department of Agriculture [USDA] 2012). Although typically a woodland problem in the United States (McNab and Meeker 1987), OB can invade grassland habitats (Fike and Niering 1999), likely sprouting from seeds dropped by birds and mammals (McNab and Meeker 1987, Greenberg et al. 2001, Sarver et al. 2008) and often developing into large, shrub-like tangles of intertwining stems (Fike …

Manitoba Tall Grass Prairie Preserve: Providing Habitat For Protected And Provincially Rare Species, Christie L. Borkowsky

The Prairie Naturalist

The establishment of the Manitoba Tall Grass Prairie Preserve in 1989 secured some of the largest and highest quality parcels of tall grass prairie remaining in the province. Shortly after securement by either Nature Manitoba (formerly Manitoba Naturalists Society) or Manitoba Habitat Heritage Corporation, seasonal staff from the Critical Wildlife Habitat Program (CWHP) began inventory efforts to document the various floral and faunal species occurring on these acquisitions. With the addition of the Nature Conservancy of Canada to the Preserve partnership, the Preserve has grown in size to nearly 5,000 ha. The list of species identified on the Preserve has …

Potential Impacts Of Bison Wallows On A Restored Tallgrass Prairie Community, Kimran Miller, Johanna Foster, Kristen Nielsen, Mary O'Loughlin

The Prairie Naturalist

When bison (Bos bison) repeatedly roll on the ground, they denude vegetation and create wallows (semi-permanent bare areas) that alter the native prairie plant community. Responses to these wallow-related disturbances are not as well documented in restored prairies. From 1 June to 1 September 2010 and from 3 June to 6 August 2011, we examined potential responses at Neal Smith National Wildlife Refuge, a restored prairie with resident bison. We hypothesized that plants and beetles would vary along a disturbance gradient. Our predictions were: (1) near wallows, plants with weedy lifestyles would have highest cover and biomass compared …

A Floristic Survey Of Selected Sites In The Loup River Valley, Nance County, Nebraska, Diane M. Flynn, Steven J. Rothenberger

The Prairie Naturalist

The Loup River Valley of Nebraska contains natural, undisturbed wet meadows with significant plant diversity. Even though these sites are infrequent and are often intermixed with heavily grazed pastures or cultivated fields, they support numerous plant and animal species that do not occur elsewhere. We surveyed three study sites (an ungrazed wet meadow; a grazed wet meadow; and a riparian area) that totaled approximately 68.8 ha during the 2010 and 2011 growing seasons. We compiled an annotated vascular plants checklist for the study area that included 244 plant species of which about 49% (119) were new county records. The mean …

Keys To The Families Of Vascular Plants In Northwestern California, James P. Smith Jr, John O. Sawyer Jr

Botanical Studies

No abstract provided.

Biology, Ecology, And Control Of Doveweed (Murdannia Nudiflora [L.] Brenan), Jeffrey Atkinson

All Dissertations

Doveweed (Murdannia nudiflora [L.] Brenan) is a summer annual in the Southeastern United States with an expanding geographic range. The light green color and texture of doveweed is problematic for turfgrass managers as it contrasts with the color and texture of desirable turfgrasses. Limited research is available concerning the biology, ecology, and herbicide control options for doveweed. Therefore, experiments were conducted to improve the understanding of how environmental conditions effect doveweed germination, how cultural practices and environmental resource availability effect doveweed growth and development, to identify pre- and postemergence herbicides with efficacy for doveweed control, and to improve the understanding …

Evaluation Of A Mycorrhizal-Like Fungus, Piriformospora Indica, On Floriculture Crops, Allison Justice

All Dissertations

Piriformospora indica is a fungal endophyte, often called an arbuscular mycorrhizal-like fungus, that has been shown to provide benefits to plant symbionts by increasing nutrient uptake, biomass production, flower number, and disease resistance in a wide range of plant hosts. Research was carried out to investigate the ability of P. indica to improve plant production in floriculture crops. The first objective was to determine the optimal environmental conditions for growing P. indica in pure culture. Environmental conditions were optimized to produce the maximum chlamydospores for inoculum preparation (Chapter 1). These findings were used in the remaining chapters to prepare inocula …

Expression And Functional Characterization Of Mtp Genes From Arabidopsis Thaliana In Saccharomyces Cerevisiae, Yessica E. Cerino

Theses and Dissertations - UTB/UTPA

In this study the functional characterization and overexpression of Metal Tolerance Protein (MTP) cDNA were evaluated using a transgenic yeast (Saccharomyces cerevisiae) model system as a preliminary means for the characterization of metal tolerance conferred by putative Group III MTP genes from Arabidopsis thaliana. Metal disc assays for nickel, zinc, cobalt and cadmium treatments were performed to measure the tolerance imparted to yeast by the MTP cDNAs. Statistical analysis from zinc and cadmium assays showed AtMTP1 imparted the highest zinc tolerance in yeast, while AtMTPB1 imparted the highest cadmium and cobalt tolerance. However, AtMTPA2 and AtMTPB produced a decrease in …

Leaf Mechanical Strength Corresponds To Tissue Water Relations In Twelve Species Of California Ferns, Breahna M. Gillespie, Stephen D. Davis, Jarmila Pittermann

Biology

The dominant vegetation types in southern California’s coastal foothills are chaparral and costal sage scrub. Chaparral shrubs have mechanically strong evergreen leaves whereas coastal sage scrubs bear mechanical weak, facultative deciduous leaves. What about the ferns that live in the understory of these vegetation types, especially considering their adaptations to a summer dry, Mediterranean-type climate? We tested the hypothesis that some fern leaves are stronger than others and mechanically strong leaves are associated with greater dehydration tolerance. Twelve fern species were examined. Tissue water relations were assessed via pressure volume curves using Scholander-Hammel pressure chambers. We estimated osmotic potential at …

An Exploration Of Fern Genome Space, Paul G. Wolf, Emily B. Sessa, D. Blaine Marchant, Fay-Wei Li, Carl J. Rothfels, Erin M. Sigel, Mathew A. Gitzendanner, Clayton J. Visger, Jo Ann Banks, Douglas E. Soltis, Pamela S. Soltis, Kathleen M. Pryer, Joshua P. Der

An Exploration of Fern Genome Space

Ferns are one of the few remaining major clades of land plants for which a complete genome sequence is lacking. Knowledge of genome space in ferns will enable broad-scale comparative analyses of land plant genes and genomes, provide insights into genome evolution across green plants, and shed light on genetic and genomic features that characterize ferns, such as their high chromosome numbers and large genome sizes. As part of an initial exploration into fern genome space, we used a whole genome shotgun sequencing approach to obtain low-density coverage (1X to 2X) for six fern species from the Polypodiales (Ceratopteris …

Ammonia-Oxidizing Bacteria And Archaea Under Continuous Maize: The Influence Of Tillage, N Input And Aggregation On Abundance And Community Composition, Lauren Segal

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nitrification involves the oxidation of ammonium (NH₄⁺) and is an important component of the overall N cycle. Nitrification occurs in two steps; first by oxidizing ammonium to nitrite, and then to nitrate. The first step is often the rate limiting step. Until recently ammonia-oxidizing bacteria (AOB) were thought to be the sole contributors to this process; however, the discovery of crenarchaeota, ammonia-oxidizing archaea (AOA), in marine environments has led to further study of their role in nitrification. Current literature supports the dominance of AOA over AOB in terrestrial ecosystems; however, little is known about what drives their …

Relationship Between Dehydration Tolerance Of California Ferns And The Mechanical Strength Of Their Stipes, Helen I. Holmlund, Stephen D. Davis

Biology

In recent years, experts in plant physiology have begun to explore the functional traits of ferns, especially in regards to their tissue-water relations. However, to our knowledge, no scientist had yet examined the relationship between fern biomechanics and physiology. We examined the mechanical properties of fern stipes (stems) and attempted to relate those properties to ecological and physiological traits. Based on our knowledge of fern anatomy, we hypothesized that stipe mechanical strength would not correlate with water-stress resistance as it does in seed-bearing plants.

We assessed mechanical strength using Modulus of Elasticity (MOE) and tissue-water relations using pressure-volume curves. Water-stress …

Water Use And Water Tolerance In The Riparian Species American Sycamore (Plantanus Occidentalis L.) And How Its Physiology Compares To The Coexisting Black Willow (Salix Nigra Marshall), Eric Duncan

Dissertations, Theses and Capstone Projects (Full IR Collection)

This study set out to compare aspects of water use and tolerance to inundation and drought of two riparian tree species, Platanus occidentalis L. and Salix nigra Marshall. The main goal of the study was to better understand the two species and assess the suitability of P. occidentalis for use in riparian restoration. To accomplish this, potted individuals were subjected to treatments of drought, inundation, or control, under greenhouse conditions, and separately, in order to estimate water use in trees, season-long diurnal measurements of sap flux (using Granier type thermal dissipation probes) were determined in situ for trees growing in …

Cell Type-Dependent Rna Recombination Frequency In The Japanese Encephalitis Virus, Wei-Wei Chiang, Chingkai Chuang, Mei Chao, Wei-June Chen

Plant Pathology Faculty Publications

Japanese encephalitis virus (JEV) is one of approximately 70 flaviviruses, frequently causing symptoms involving the central nervous system. Mutations of its genomic RNA frequently occur during viral replication, which is believed to be a force contributing to viral evolution. Nevertheless, accumulating evidences show that some JEV strains may have actually arisen from RNA recombination between genetically different populations of the virus. We have demonstrated that RNA recombination in JEV occurs unequally in different cell types. In the present study, viral RNA fragments transfected into as well as viral RNAs synthesized in mosquito cells were shown not to be stable, especially …

Genome-Wide Determination Of Poly(A) Sites In Medicago Truncatula: Evolutionary Conservation Of Alternative Poly(A) Site Choice, Xiaohui Wu, Bobby Gaffney, Arthur G. Hunt, Qingshun Q. Li

Plant and Soil Sciences Faculty Publications

BACKGROUND: Alternative polyadenylation (APA) plays an important role in the post-transcriptional regulation of gene expression. Little is known about how APA sites may evolve in homologous genes in different plant species. To this end, comparative studies of APA sites in different organisms are needed. In this study, a collection of poly(A) sites in Medicago truncatula, a model system for legume plants, has been generated and compared with APA sites in Arabidopsis thaliana.

RESULTS: The poly(A) tags from a deep-sequencing protocol were mapped to the annotated M. truncatula genome, and the identified poly(A) sites used to update the annotations of 14,203 …

Selection On Crop-Derived Traits And Qtl In Sunflower (Helianthus Annuus) Crop-Wild Hybrids Under Water Stress, Birkin R. Owart, Jonathan Corbi, John M. Burke, Jennifer M. Dechaine

All Faculty Scholarship for the College of the Sciences

Locally relevant conditions, such as water stress in irrigated agricultural regions, should be considered when assessing the risk of crop allele introgression into wild populations following hybridization. Although research in cultivars has suggested that domestication traits may reduce fecundity under water stress as compared to wild-like phenotypes, this has not been investigated in crop-wild hybrids. In this study, we examine phenotypic selection acting on, as well as the genetic architecture of vegetative, reproductive, and physiological characteristics in an experimental population of sunflower crop-wild hybrids grown under wild-like low water conditions. Crop-derived petiole length and head diameter were favored in low …

The Role Of The Testa During Development And In Establishment Of Dormancy Of The Legume Seed, Petr Smýkal, Vanessa Vernoud, Matthew W. Blair, Aleš Soukup, Richard D. Thompson

Agricultural and Environmental Sciences Faculty Research

Timing of seed germination is one of the key steps in plant life cycles. It determines the beginning of plant growth in natural or agricultural ecosystems. In the wild, many seeds exhibit dormancy and will only germinate after exposure to certain environmental conditions. In contrast, crop seeds germinate as soon as they are imbibed usually at planting time. These domestication-triggered changes represent adaptations to cultivation and human harvesting. Germination is one of the common sets of traits recorded in different crops and termed the “domestication syndrome.” Moreover, legume seed imbibition has a crucial role in cooking properties. Different seed dormancy …

Transcriptome Analysis Of A Petal Anthocyanin Polymorphism In The Arctic Mustard, Parrya Nudicaulis, Timothy Butler, Cynthia Dick, Matthew L. Carlson, Justen B. Whittall

Biology

Angiosperms are renown for their diversity of flower colors. Often considered adaptations to pollinators, the most common underlying pigments, anthocyanins, are also involved in plants’ stress response. Although the anthocyanin biosynthetic pathway is well characterized across many angiosperms and is composed of a few candidate genes, the consequences of blocking this pathway and producing white flowers has not been investigated at the transcriptome scale. We take a transcriptome-wide approach to compare expression differences between purple and white petal buds in the arctic mustard, Parrya nudicaulis, to determine which genes’ expression are consistently correlated with flower color. Using mRNASeq and de …

Germination Season And Watering Regime, But Not Seed Morph, Affect Life History Traits In A Cold Desert Diaspore-Heteromorphic Annual, Juan J. Lu, Dun Y. Tan, Jerry M. Baskin, Carol C. Baskin

Biology Faculty Publications

Seed morph, abiotic conditions and time of germination can affect plant fitness, but few studies have tested their combined effects on plasticity of plant life history traits. Thus, we tested the hypothesis that seed morph, germination season and watering regime influence phenotypic expression of post-germination life history traits in the diaspore-heteromorphic cold desert winter annual/spring ephemeral Diptychocarpus strictus. The two seed morphs were sown in watered and non-watered plots in late summer, and plants derived from them were watered or not-watered throughout the study. Seed morph did not affect phenology, growth and morphology, survival, dry mass accumulation and allocation or …

Most Soil Trophic Guilds Increase Plant Growth: A Meta-Analytical Review, Andrew Kulmatiski, Andrew Anderson-Smith, Karen H. Beard, Stephen Doucette-Riise, Michael Mazzacavallo, Nicole E. Nolan, Ricardo A. Ramirez, John R. Stevens

Wildland Resources Faculty Publications

Trophic cascades are important drivers of plant and animal abundances in aquatic and aboveground systems, but in soils trophic cascades have been thought to be of limited importance due to omnivory and other factors. Here we use a meta-analysis of 215 studies with 1526 experiments that measured plant growth responses to additions or removals of soil organisms to test how different soil trophic levels affect plant growth. Consistent with the trophic cascade hypothesis, we found that herbivores and plant pathogens (henceforth pests) decreased plant growth and that predators of pests increased plant growth. The magnitude of this trophic cascade was …

[Accepted Article Manuscript Version (Postprint)] Auxin Input Pathway Disruptions Are Mitigated By Changes In Auxin Biosynthetic Gene Expression In Arabidopsis, Gretchen Spiess, Amanda Hausman, Peng Yu, Jerry Cohen, Rebekah Rampey, Bethany Zolman

Biology Department Faculty Works

Auxin is a phytohormone involved in cell elongation and division. Levels of indole-3-acetic acid (IAA), the primary auxin, are tightly regulated through biosynthesis, degradation, sequestration, and transport. IAA is sequestered in reversible processes by adding amino acids, polyol or simple alcohols, or sugars, forming IAA conjugates, or through a two-carbon elongation forming indole-3-butyric acid. These sequestered forms of IAA alter hormone activity. To gain a better understanding of how auxin homeostasis is maintained, we have generated Arabidopsis (Arabidopsis thaliana) mutants that combine disruptions in the pathways, converting IAA conjugates and indole-3-butyric acid to free IAA. These mutants show phenotypes indicative …

A Win-Win On Agricultural Lands: Creating Wildlife Habitat Through Agroforestry, Gary Bentrup

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

With increasing demands from society for limited resources, agroforestry will likely be one source of solutions as people find it increasingly necessary to achieve multiple social, economic, and ecological objectives on the same plot of land. Indications are that this is a growing field, so wildlife biologists of the future may want to consider incorporating agroforestry into their career development.

Management Of Root Knot Nematode (Meloidogyne Incognita ) In Indiana Soybeans, David Edgardo Perla Martinez

Open Access Theses

The aim of this project was to evaluate different strategies for management of Root Knot Nematode (RKN) on soybean and tomato in Indiana. Seed treatments were evaluated under field and greenhouse conditions, but no effect on RKN populations was observed. Soybean lines evaluated for resistance to RKN under greenhouse conditions showed that six lines may be resistant to RKN. Four different commercial mustard cover crops were evaluated for their bio-fumigant impact on RKN populations in the production of tomato. Euruca sativa, Cv. Nemat was a poor host of RKN. A positive impact on the vigor of the tomato plants followed …

Supplemental, End-Of-Day, And Sole-Source Lighting From Light-Emitting Diodes Influences Growth, Morphology, And Quality Of Annual Bedding Plant Seedlings, Wesley C. Randall

Open Access Theses

Annual bedding plants make up the largest sector of the U.S. floriculture industry. High-quality annual bedding plant seedlings are compact, fully rooted transplants with a large stem caliper and high root dry mass. However, production usually occurs in late winter or early spring when the daily light integral (DLI) is as low as 1 to 5 mol·m^–2·d ^–1 in northern latitudes. Therefore, supplemental lighting (SL) is often used to increase the DLI to a recommended 10 to 12 mol·m ^–2·d^–1. The objectives of this study were to: 1) quantify the effects of SL from three …

Abcb11 Functions With B1 And B19 To Regulate Rootward Auxin Transport, Jesica Elyse Reemmer

Open Access Theses

Auxin transport is essential for the architecture and development of erect plants. In a network of transporters directing auxin flows, ATP-Binding Cassette (ABC) transporters are a ubiquitous family of proteins that actively transport important substrates, including auxins, across the plasma membrane. ABCB1 and ABCB19 have been shown to account for the majority of rootward auxin transport, but residual fluxes to the root tip in Arabidopsis b1b19 double mutants implies the involvement of at least one additional auxin transporter in this process. Of specific interest, the severe dwarfism seen in abcb1abcb19 is strikingly reminiscent of that seen in mutants defective in …

Fact Or Fiction: Random Mating In Field Populations Of Western Corn Rootworm (Diabrotica Virgifera Virgifera Leconte) Emerging On Bt And Refuge Corn Plants, Steven Joel Smith

Open Access Theses

The western corn rootworm, or WCR, (Diabrotica virgifera virgifera LeConte) is the most significant pest of field corn (Zea mays) in the United States, and has recently expanded its range into Europe. Since 2004, hybrid corn containing Bt toxins targeting the corn rootworm complex have been heavily adopted and are now the primary control measure for this pest in North American corn production. ^ The evolution of resistance is an ongoing concern, and to ensure Bt products will retain their usefulness, insect resistance management (IRM) tactics using various refuge structures have been adopted. One of the key …

Refining Phylogenetic Hypotheses Using Chloroplast Genomics And Incomplete Data Sets In Lasthenia (Madieae, Asteraceae), Joseph Frederic Walker

Open Access Theses

The genus Lasthenia (Madieae, Asteraceae), consists of predominantly annual plant species that are largely endemic to the California Floristic Province of western North America and occupy a large range of habitat types. With high levels of morphological and ecological diversity, Lasthenia is a robust tool, capable of providing a natural non-model organism for answering a diverse array of ecological and evolutionary questions. Future studies would benefit greatly from a strong phylogenetic hypothesis and more molecular resources, such as the whole plastome sequence for a representative species in the genus. Over a decade ago there was a study that laid a …

Agronomic And Genetic Characterization Of Aluminum Tolerance In A Recombinant Inbred Population Of Sorghum [Sorghum Bicolor (L.) Moench], Amanda Christine Easterly

Open Access Theses

Acid soils are estimated to cover up to 30% of arable soils globally and lead to significant limitations on agricultural productivity, primarily through aluminum toxicity. In sorghum [Sorghum bicolor (L.) Moench], significant genetic variation exists for tolerance to phytotoxic species of aluminum; tolerance is conferred through the exudation of citrate at the root tip, binding aluminum in the soil rhizosphere. A gene in the multidrug and toxic compound extrusion (MATE) family is the primary tolerance locus in sorghum. The purpose of this research was to evaluate a recombinant inbred line (RIL) population of sorghum segregating for SbMATE to establish …

Managing Swine Manure In Double-Crop Soybean, Donald Joseph Graper

Open Access Theses

Animal production, especially swine (Sus scrofa domesticus ) and poultry, has increased in the United States prompting the need to manage the larger volume of manure beyond land applications to supply nitrogen (N) for corn (Zea mays ) production. Applying swine manure to soybean (Glycine max ) has been shown to increase grain yield due to N supply. The goal of this research was to determine if swine manure applications to double-crop soybean following wheat can limit manure N loading to the soil by extending management options, increase soybean biomass and grain production, and increase N removal …

Expression Of Chlorovirus Mt325 Aquaglyceroporin (Aqpv1) In Tobacco And Its Role In Mitigating Drought Stress, Saadia Bihmidine, Mingxia Cao, Ming Kang, Tala Awada, James L. Van Etten, David Dunigan, Thomas E. Clemente

James Van Etten Publications

Main conclusions A Chlorovirus aquaglyceroporin expressed in tobacco is localized to the plastid and plasma membranes. Transgenic events display improved response to water deficit. Necrosis in adult stage plants is observed.

Aquaglyceroporins are a subclass of the water channel aquaporin proteins (AQPs) that transport glycerol along with other small molecules transcellular in addition to water. In the studies communicated herein, we analyzed the expression of the aquaglyceroporin gene designated, aqpv1, from Chlorovirus MT325, in tobacco (Nicotiana tabacum), along with phenotypic changes induced by aqpv1 expression in planta. Interestingly, aqpv1 expression under control of either a constitutive or …