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Anther Appendages Of Incarvillea Trigger A Pollen-Dispensing Mechanism, Yi Han, Can Dai, Chun-Feng Yang, Qing-Feng Wang, Timothy J. Motley

Biological Sciences Faculty Publications

Background and Aims Anther appendages play diverse roles in anther dehiscence and pollen dispersal. This study aims to explore the pollen-dispensing mechanism triggered by special anther appendages in Incarvillea arguta.

Methods Field studies were conducted to record floral characteristics, pollinator visitations, and flower-pollinator interactions. Measurements of flowers and pollinators were analysed statistically. Pollen counts following a series of floral manipulations were used to evaluate pollen dispensing efficiency and function of the anther appendages.

Key Results Field observations determined that two species of Bombus (bumble-bees) were the primary pollinators of I. arguta with a mean visiting frequency of 1.42 visitations …

Contents, Discovery Editors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Letter From The Dean, Lalit R. Verma

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

15n Effects On Chlamydomonas Reinhardtii, Ryan Geraets, Brett Kollars

The Journal of Undergraduate Research

Non-radioactive isotopic labeling has become a regular technique for efficiently labeling a wide range of macromolecules. The overall goal for this project was to develop a method of globally measuring plant protein turnover rates. In order to do so, an isotopic labeled environment that does not induce stress had to be used. The objective of this particular segment of research was to develop a 15N-labeled Tris-Acetate-Phosphate (TAP) media in which Chlamydomonas reinhardtii can successfully grow without eliciting stressed physiological responses. Our results illustrate that we have successfully developed 15N-labeled TAP that does not stress Chlamydomonas reinhardtii.

Molecular, Genetic And Biochemical Characterization Of Oleic Acid- And Glycerol-Mediated Signaling In Plant Defense, Srivathsa C. Venugopal

Theses and Dissertations--Plant Pathology

Oleic acid (18:1) is one of the important monounsaturated fatty acids, which is synthesized upon desaturation of stearic acid and this reaction is catalyzed by the SSI2 encoded stearoyl-acyl-carrier-protein-desaturase. A mutation in SSI2 leads to constitutive activation of salicylic acid (SA)-mediated defense responses. Consequently, these plants accumulate high levels of SA and show enhanced resistance to bacterial and oomycete pathogens. Replenishing 18:1 levels in ssi2 plants, via a second site mutation in GLY1 encoded glycerol-3-phosphate (G3P) dehydrogenase, suppresses all the ssi2-triggered phenotypes. Study of mechanism(s) underlying gly1-mediated suppression of ssi2 phenotypes showed that 18:1 levels are regulated via …

Agricultural Systems: Agroecology And Rural Innovations For Development [Book Review], Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

To welcome yet another book on sustainable development, a reviewer must look for what is unique and what adds value to the volumes already published. In Agricultural Systems, editors Sieglinde Snapp and Barry Pound have assembled a collection of chapters that goes beyond the usual praise and criticism of the green revolution and the focus on economic development. Their book provides a first-hand story by people with lengthy experiences in the field, especially in Africa, who have developed and tested grassroots, participatory development approaches. The result is a valuable set of principles, strategies and case studies that paint a new …

Biogeography Of South-West Asian Bryophytes – With Special Emphasis On The Tropical Element, Harald Kürschner

Turkish Journal of Botany

The recent bryophyte flora of South-West Asia is heterogeneous and consists of 6 floral elements [(Sub)cosmopolitan taxa, northern taxa, xerotherm-Pangaean taxa, circum-Tethyan taxa, tropical taxa, and endemics of various origins] that are derived from the different Pangaean ancestral floral stocks. Analysis of the flora and vegetation indicates that there is a very strong tropical - and especially palaeotropical and Afromontane - influence in the bryophyte flora of the area. Altogether, more than 95 taxa, or nearly 10% of South-West Asia´s total known bryoflora, are of xero-tropical origin. They concentrate mainly in the escarpment mountains of the Arabian Peninsula and Socotra …

Conservation In Developing Countries, Shahina A. Ghazanfar

Turkish Journal of Botany

The Convention on Biological Diversity (CBD) set a number of targets to work towards by 2010 in order to aid conserve the world´s biodiversity. Several countries are now aiming at ex-situ and in-situ programmes for the protection and conservation of plant species through the Global Strategy for Plant Conservation targets (GSPC). Is it possible to achieve these targets in rapidly developing countries where the usage of land for urban expansion and agriculture to support basic human needs holds priority? How can conservation and development be sustainable? I take examples from a rapidly developing country in the Arabian Peninsula to show …

Agricultural Systems: Agroecology And Rural Innovations For Development, Edited By Sieglinde Snapp And Barry Pound [Book Review], Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

To welcome yet another book on sustainable development, a reviewer must look for what is unique and what adds value to the volumes already published. In Agricultural Systems, editors Sieglinde Snapp and Barry Pound have assembled a collection of chapters that goes beyond the usual praise and criticism of the green revolution and the focus on economic development. Their book provides a first-hand story by people with lengthy experiences in the field, especially in Africa, who have developed and tested grassroots, participatory development approaches. The result is a valuable set of principles, strategies and case studies that paint a new …

Quantitative Trait Locus Mapping For Seed Mineral Concentrations In Two Arabidopsis Thaliana Recombinant Inbred Populations, Brian M. Waters, Michael A. Grusak

Department of Agronomy and Horticulture: Faculty Publications

Biofortification of foods, achieved by increasing the concentrations of minerals such as iron (Fe) and zinc (Zn), is a goal of plant scientists. Understanding genes that influence seed mineral concentration in a model plant such as Arabidopsis could help in the development of nutritionally enhanced crop cultivars. Quantitative trait locus (QTL) mapping for seed concentrations of calcium (Ca), copper (Cu), Fe, potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), sulfur (S), and Zn was performed using two recombinant inbred line (RIL) populations, Columbia (Col) × Landsberg erecta (Ler) and Cape Verde Islands (Cvi) × Ler, grown …

State Of The River Report For The Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, And Contaminants 2008, Environmental Protection Board, City Of Jacksonville, University Of North Florida, Jacksonville University

State of the River Report

No abstract provided.

4th Lone Star Regional Native Plant Conference, David Creech, Greg Grant, James Kroll, Dawn Stover

Lone Star Regional Native Plant Conference

No abstract provided.

Good Vibrations? Structure And Function Of The Cloacal Tip Of Male Australian Maluridae, Melissah Rowe, Murray R. Bakst, Stephen Pruett-Jones

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

When females mate multiply, sperm competition can generate strong selection for traits that provide males with a fertilisation advantage. This study examined the cloacal tip, a unique morphological structure of males that appears to be associated with sperm competition in Australian Maluridae. Species in this group appear to experience a range of sperm competition intensities and exhibit a diversity of associated reproductive adaptations and behaviours. A prominent cloacal tip was present in the striated grasswren Amytornis striatus striatus, and superb Malurus cyaneus cyanochlamys, splendid M. splendens melanotus, red-backed M. melanocephalus and white winged fairy-wrens M. leucopterus leuconotus …

General Introduction To Areawide Pest Management, Robert M. Faust

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Welcome to the realm of areawide pest management (AWPM). This book represents one of the first comprehensive 'treatises' on the AWPM concept and approach, and should be of interest and use to many types of readers, from research scientists in government, university and industry to pest control advisors and extension personnel, growers, pest control and integrated pest management (IPM) practitioners, students, teachers, natural resource managers and others interested in environmentally sound pest control. There is a range of topics included in the subject area. The book is grouped into three parts. Chapters 2-8 discuss the foundation of areawide pest management; …

Establishing Inter-Agency, Multidisciplinary Areawide Pest Management Programmes, Robert M. Nowierski, Hendrik J. Meyer

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Pest management today usually comprises multiple complex tactics that transcend disciplines, geographical regions, climatic zones, production/management systems, production scales and economic strata. Solutions to priority problems involve research, education and extension professionals. But, equally important to project success are the users of the knowledge generated and the end-users of the 'products'. Setting a direction for the future goals, IPM has been an important activity for the 'community' of constituents who share concerns for future pest management.

Under the leadership of the USDA and land grant universities, a road map for IPM has been developed with extensive participation of diverse stakeholders. …

The Role Of Databases In Areawide Pest Management, Vasile Catana, Norman Elliott, Kris Giles, Mustafa Mirik, David Porter, Gary L. Hein, Frank Peairs, Jerry Michels

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The simplest definition of the term 'database' is given in Webster's dictionary as 'a comprehensive collection of related data organized for convenient access, generally in a computer' (Random House, 1996). This term appeared in the late 1960s because of the evolution of computer software and the need to distinguish the specialized computer systems for the storage and manipulation of data, called database management systems (DBMS) (Neufeld and Cornog, 1986). Today, the acronym 'DBMS' is universally understood within Information Technology (IT), just like the acronym 'Bt' for 'Bacillus thuringiensis' is in the field of biological pest control. …

Turkey Sperm Reside In The Tubular Glands In The Urodeum Following Artificial Insemination, M. R. Bakst, V. Akuffo

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

A turkey hen in egg production requires 48 h after the last insemination to maximize the number of sperm in the uterovaginal junction sperm-storage tubules. Where the sperm that continue to fill the oviductal spermstorage sites during this 48-h period reside remains unknown. Histological sections of the juncture of the vagina with the urodeum, the central compartment of the cloaca, revealed deep tubular glands containing periodic acid- Schiff-positive secretory material. When examined 36 h after the last artificial insemination, sperm were observed in the lumen of the tubular glands associated with the urodeum. We suggest that sperm reside in the …

Central And Peripheral Administration Of Kisspeptin Activates Gonadotropin But Not Somatotropin Secretion In Prepubertal Gilts, Clay A. Lents, Neely L. Heidorn, C. Richard Barb, J. Joe Ford

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

It is well established that kisspeptin signaling is necessary for the onset of puberty in laboratory animals. However, the role that kisspeptin may have in regulating puberty in large domestic animals is unknown.We tested the hypothesis that either central or peripheral infusion of kisspeptin would stimulate gonadotropin and GH secretion in prepubertal gilts. In experiment 1, prepubertal gilts were fitted with i.c.v. cannula and indwelling jugular catheters. Animals were randomly assigned to receive 0, 10, or 100 μg kisspeptin in saline. In experiment 2, prepubertal gilts, fitted with indwelling jugular catheters, randomly received 0, 1, 2.5, or 5 mg kisspeptin …

Parentage-Based Dna Traceback In Beef And Dairy Cattle, Mike Heaton

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Why is animal ID needed?

Ways to physically label individual cattle

Disputes arise even when animal identification systems are in place

The dispute

The resolution

DNA is the label never removed from beef

A chromosome has genes and other DNA

Genes are encoded by sequences of DNA

What are SNPs?

Properties of SNPs

Ways to use DNA for traceback

Sometimes parentage testing is the last resort for DNA-based traceback

Using SNP markers for parentage

Accurate sire determination requires many DNA markers

Comparing the calf to the sire: elimination

Comparing the calf to a possible sire

The ideal parentage SNP markers …

Improvement Of Perennial Forage Species As Feedstock For Bioenergy, William Anderson, Michael Casler, Brian S. Baldwin

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Both native and non-native forage species other than switchgrass are less commonly considered as potential lignocellulosic feedstocks for bioenergy in the United States. These species hold potential as bioenergy feedstocks because of the experience and infrastructure that is already in place for management and harvest, and in certain areas of the country they have greater yield potential than switchgrass or other feedstocks. The forage grasses consist of temperate cool-season (most commonly C3) grasses as well as tropical or sub-tropical warm-season (C4) grasses. Some legume species may also play a significant role in supplying useful bioenergy feedstocks. Most have been researched …

The Artiodactyl Apobec3 Innate Immune Repertoire Shows Evidence For A Multi-Functional Domain Organization That Existed In The Ancestor Of Placental Mammals, Rebecca Larue, Stefán Jónsson, Kevin Silverstein, Mathieu Lajoie, Denis Bertrand, Nadia El-Mabrouk, Isidro Hötzel, Valgerdur Andrésdóttir, Timothy Smith, Reuben Harris

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Background: APOBEC3 (A3) proteins deaminate DNA cytosines and block the replication of retroviruses and retrotransposons. Each A3 gene encodes a protein with one or two conserved zinccoordinating
motifs (Z1, Z2 or Z3). The presence of one A3 gene in mice (Z2–Z3) and seven in humans, A3A-H (Z1a, Z2a-Z1b, Z2b, Z2c-Z2d, Z2e-Z2f, Z2g-Z1c, Z3), suggests extraordinary evolutionary flexibility. To gain insights into the mechanism and timing of A3 gene expansion and into the functional modularity of these genes, we analyzed the genomic sequences, expressed cDNAs and activities of the full A3 repertoire of three artiodactyl lineages: sheep, cattle and pigs.
Results: …

Chapter 17. Nitrogen Management Modeling Techniques: Assessing Cropping Systems/Landscape Combinations, J. A. Delgado, M. J. Shaffer

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Nitrogen use efficiency (NUE) in production agriculture is often low, which results in losses of excess N to groundwater as NO₃-N, to gaseous emissions of NH₃ and N₂O, and to N losses in surface runoff and erosion. Best management practices (BMPs) are needed to improve efficiency levels while maintaining proper nutrition for crops. Field studies designed to investigate potential BMPs are both time consuming and costly, and cannot cover all scenarios. Application of simulation models with N cycling components in conjunction with associated field investigations offers methodology that can help identify BMPs that show promise …

Genotype By Environment Interaction Due To Heat Stress, J. Bohmanova, University Of Georgia Misztal, S. Tsuruta, H. D. Norman, T. J. Lawlor

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Heat stress was evaluated as a factor in differences between regional evaluations for milk yield in the United States. The national data set (NA) consisted of 56 million first-parity, test-day milk yields on 6 million Holsteins. The Northeastern subset (NE) included 12.5 million records on 1.3 million first-calved heifers from 8 states, and the Southeastern subset (SE) included 3.5 million records on 0.4 million heifers from 11 states. Climatic data were available from 202 public weather stations. Each herd was assigned to the nearest weather station. Average daily temperature-humidity index (meanTHI) 3 d before test date was used as an …

Genomic Analysis Of Fusarium Verticillioides, D. W. Brown, R. A.E. Butchko, R. H. Proctor

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Fusarium verticillioides (teleomorph Gibberella moniliformis) can be either an endophyte of maize, causing no visible disease, or a pathogen-causing disease of ears, stalks, roots and seedlings. At any stage, this fungus can synthesize fumonisins, a family of mycotoxins structurally similar to the sphingolipid sphinganine. Ingestion of fumonisin-contaminated maize has been associated with a number of animal diseases, including cancer in rodents, and exposure has been correlated with human oesophageal cancer in some regions of the world, and some evidence suggests that fumonisins are a risk factor for neural tube defects. A primary goal of the authors’ laboratory is to …

Soil Properties And Macro Cations Status Impacted By Long-Term Applied Poultry Litter, Zhongqi He, Irenus A. Tazisong, Zachary N. Senwo, Donglin Zhang

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Most ethnic populations worldwide consume poultry products. Whereas poultry litter (PL) is a traditionally inexpensive and effective fertilizer to improve soil quality and agricultural productivity, overapplication to soils has raised concerns because excess nutrients in runoff could accelerate the eutrophication of fresh bodies of water. A long-term field experiment of land application of PL to soils used for pasture growth has been maintained for nearly two decades in the Sand Mountain region of north Alabama, USA. In this work, several soil parameters impacted by the long-term applied litter were characterized. The findings clearly support previous general observations that long-term applied …

Tillage Erosion Coefficients For Selected Tillage Tools, Javier Mollinendo

Electronic Theses and Dissertations

Soil loss as a result of differential translocation of soil by tillage is widespread in regions with irregular topography. Tillage erosion models are based on field derived transport coefficients that are specific to the tillage tool being used. Variables like speed and depth of tillage can modify tillage erosion transport coefficients. Four treatments were established for this research: moldboard plow, chisel plow, tandem disk, and no-till drill. The primary research site was located in Rock County MN, 43° 39 '40.24 "N, and 96° 24' 17.25" W, with a fine-loamy, mixed, superactive, mesic Cumulic Endoaquolls (USDA, 2006). The objectives of this …

Microbial Community Structure Dynamics In Ohio River Sediments During Reductive Dechlorination Of Pcbs, Andres Enrique Nunez

University of Kentucky Doctoral Dissertations

The entire stretch of the Ohio River is under fish consumption advisories due to contamination with polychlorinated biphenyls (PCBs). In this study, natural attenuation and biostimulation of PCBs and microbial communities responsible for PCB transformations were investigated in Ohio River sediments.

Natural attenuation of PCBs was negligible in sediments, which was likely attributed to low temperature conditions during most of the year, as well as low amounts of available nitrogen, phosphorus, and organic carbon. Moreover, surface sediments were relatively oxidized, as indicated by the prevalence of aerobic bacteria such as beta- Proteobacteria, alpha-Proteobacteria, Sphingobacteria, and Nitrospira in 16S rRNA sediment …

Branching Of Fungal Hyphae: Regulation, Mechanisms And Comparison With Other Branching Systems, Steven D. Harris

Department of Plant Pathology: Faculty Publications

The ability of rapidly growing hyphae to generate new polarity axes that result in the formation of a branch represents one of the most important yet least understood aspects of fungal cell biology. Branching is central to the development of mycelial colonies and also appears to play a key role in fungal interactions with other organisms. This review presents a description of the two major patterns of hyphal branching, apical and lateral, and highlights the roles of internal and external factors in the induction of branch formation. In addition, potential mechanisms underlying branch site selection are outlined, and the possible …

When Does Nitrate Become A Risk For Humans?, David S. Powlson, Tom M. Addiscott, Nigel Benjamin, Kenneth G. Cassman, Theo M. De Kok, Hans Van Grinsven, Jean-Louis L'Hirondel, Alex A. Avery, Chris Van Kessel

Department of Agronomy and Horticulture: Faculty Publications

Is nitrate harmful to humans? Are the current limits for nitrate concentration in drinking water justified by science? There is substantial disagreement among scientists over the interpretation of evidence on the issue. There are two main health issues: the linkage between nitrate and (i) infant methaemoglobinaemia, also known as blue baby syndrome, and (ii) cancers of the digestive tract. The evidence for nitrate as a cause of these serious diseases remains controversial. On one hand there is evidence that shows there is no clear association between nitrate in drinking water and the two main health issues with which it has …

Genetic Background Impacts Soluble And Cell Wall-Bound Aromatics In Brown Midrib Mutants Of Sorghum, Nathan A. Palmer, Scott Sattler, Aaron J. Saathoff, Deanna Funnell, Jeffrey Pedersen, Gautam Sarath

Department of Agronomy and Horticulture: Faculty Publications

Sorghum (Sorghum bicolor (L.). Moench) BMR-6 and BMR-12 encode cinnamylalcohol dehydrogenase and caffeic acid-O-methyltransferase, respectively. We have evaluated the impact of two bmr alleles, bmr-6 and bmr-12, respectively, on soluble and wall-bound aromatics in near isogenic, wild-type (WT), bmr-6, bmr-12 and double-mutant (DM; bmr-6 and bmr-12) plants in two genetic backgrounds, RTx430 and Wheatland. Immunoblots confirmed that COMT protein was essentially absent in bmr-12 and DM plants, but was present in bmr-6 and WT plants. In contrast, although CAD activity was not detected in bmr-6 and DM plants, …