Digital Commons Network^™

Impacts Of Genetic Bottlenecks On Soybean Genome Diversity, D. L. Hyten, Qijian Song, Youlin Zhu, Ik-Young Choi, Randall L. Nelson, Jose M. Costa, James E. Specht, Randy C. Shoemaker, Perry B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

Soybean has undergone several genetic bottlenecks. These include domestication in Asia to produce numerous Asian landraces, introduction of relatively few landraces to North America, and then selective breeding over the past 75 years. It is presumed that these three human-mediated events have reduced genetic diversity. We sequenced 111 fragments from 102 genes in four soybean populations representing the populations before and after genetic bottlenecks. We show that soybean has lost many rare sequence variants and has undergone numerous allele frequency changes throughout its history. Although soybean genetic diversity has been eroded by human selection after domestication, it is notable that …

Ethylene Could Influence Ferric Reductase, Iron Transporter, And H+-Atpase Gene Expression By Affecting Fer (Or Fer-Like) Gene Activity, Carlos Lucera, Brian M. Waters, Francisco Javier Romera, María José García, María Morales, Esteban Alcántara, Rafael Pérez-Vicente

Department of Agronomy and Horticulture: Faculty Publications

In previous works, it has been shown, by using ethylene inhibitors and precursors, that ethylene could participate in the regulation of the enhanced ferric reductase activity of Fe-deficient Strategy I plants. However, it was not known whether ethylene regulates the ferric reductase gene expression or other aspects related to this activity. This paper is a study of the effects of ethylene inhibitors and precursors on the expression of the genes encoding the ferric reductases and iron transporters of Arabidopsis thaliana (FRO2 and IRT1) and Lycopersicon esculentum (= Solanum lycopersicum) (FRO1 and IRT1) plants. The effects …

Developing And Extending Sustainable Agriculture: A New Social Contract, Michele Schoeneberger, Gary Bentrup, Charles A. Francis, Richard Straight

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

Conclusions

Based on the practical community applications of woody buffe rs and multifuncti onal areas that grew from the ini tial concepts ofecobelts. we are convinced that this type of initiative is a viable option in establishing a positive interface between different types of human activities. The challenge becomes more real every day, as cities expand and both city-edge subdivisions and acreages create ever more interfaces between people with different and often con!1icting activities and basic values. There is a need to provide some logical and acceptable boundary between these people and their different lifestyles. It is also desirable to …

Estrogenic Activity In The Environment: Municipal Wastewater Effluent, River, Ponds, And Wetlands, Nancy W. Shappell

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

Estrogenic activity of regional water samples was evaluated. Samples obtained from wetlands and ponds involved in various agricultural land uses, from three river sites over four seasons, and from municipal wastewater effluent held in storage lagoons were evaluated. The estrogen- responsive cell line MCF-7 BOS was used in the E-screen assay to determine 17β-estradiol equivalents (E₂ Eq) of water samples extracted by solid-phase extraction. Estrogenic activity in surrounding wetlands and ponds from different land uses was not different, with 10^-12 M E2 Eq (0.3 ppt). Estrogenic activity of Red River samples was within the same range as wetland–pond …

Net Global Warming Potential And Greenhouse Gas Intensity In Irrigated Cropping Systems In Northeastern Colorado, Arvin R. Mosier, Ardell D. Halvorson, Curtis A. Reule, Xuejun J. Liu

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

The impact of management on global warming potential (GWP), crop production, and greenhouse gas intensity (GHGI) in irrigated agriculture is not well documented. A no-till (NT) cropping systems study initiated in 1999 to evaluate soil organic carbon (SOC) sequestration potential in irrigated agriculture was used in this study to make trace gas flux measurements for 3 yr to facilitate a complete greenhouse gas accounting of GWP and GHGI. Fluxes of CO₂, CH₄, and N₂O were measured using static, vented chambers, one to three times per week, year round, from April 2002 through October 2004 …

Nutrient Uptake Of Maize Affected By Nitrogen And Potassium Fertility In A Humid Subtropical Environment, H. Arnold Bruns, M. Wayne Ebelhar

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

Nitrogen (N) and potassium (K) fertility management of maize (Zea mays L.) in the humid subtropical Mississippi Delta may differ from a temperate climate because of its use in rotation with cotton (Gossypium hirsutum L.), soil temperatures rarely falling to 0 °C, and heavy winter rains that facilitate nutrient losses. An experiment to determine the [N] (concentration = [ ]), phosphorus [P], [K], calcium [Ca], magnesium [Mg], iron [Fe], manganese [Mn], zinc [Zn], and copper [Cu] and their total contents plant^-1 of maize grown in rotation with cotton, using N fertility levels of (134, 179, 224, 269, …

Effect Of Foliar Applied Plant Elicitors On Microbial And Nematode Populations In The Root Zone Of Potato, H. P. Collins, D. A. Navare, E. Riga, F. J. Pierce

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

Systemic acquired resistance (SAR) is a process whereby a plant that successfully
resists a pathogen becomes highly resistant to subsequent infection not only by the original pathogen but also by a wide variety of pathogens. Most SAR research has focused on resistance in leaves, so much less is known about the effectiveness of foliar applications of SAR compounds in the protection of plant roots and associated microorganisms in soil. This study was conducted to determine if foliar SAR-inducing applications (BTH or harpin) negatively impact the potato root system beneficial rhizosphere microbial populations and activity or influence pathogenic nematode populations. Foliar …

Un-Ionized Ammonia Exposure In Nile Tilapia: Toxicity, Stress Response, And Susceptibility To Streptococcus Agalactiae, Joyce J. Evans, David J. Park, Gregg C. Brill, Phillip H. Klesius

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

A series of experiments were conducted to determine the toxicity, behavior, blood glucose stress response, and disease susceptibility in Nile tilapia Oreochromis niloticus following un-ionized ammonia (UIA) exposure. The acute toxicity of un-ionized ammonia to Nile tilapia was measured in a 96-h static test. The median lethal concentration (LC50) was 1.46 mg/L UIA at 24 and 48 h postexposure, 1.33 mg/ L at 72 h postexposure, and 0.98 mg/L at 96 h postexposure. No mortalities were noted in unexposed (0 mg/ L) control fish or fish exposed to 0.5 mg/L UIA. However, 93–100% mortalities were observed within 24 h among …

International Shipping Of Fumonisins From Maize Extracts On C18 Sorbent, R. T. Riley, O. A. Torres, E. Palencia

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

Fumonisins are mycotoxins found in maize. In developing countries, the resources required for analysis are often lacking, and the shipping of maize between countries can be difficult since the importation of plant materials requires permits/ inspection to prevent the entry of pests that frequently infest maize. A simple, safe and legal method for shipping maize extracts to the USA was needed to conduct a survey of fumonisins in Central America. The objective was to develop a method for isolating and shipping maize extracts for fumonisin analysis so as to facilitate a survey of fumonisin exposure. The results indicate that fumonisins …

Improvements In Channel Catfish Growth After Two Generations Of Selection And Comparison Of Performance Traits Among Channel Catfish, Blue Catfish, And Hybrid Catfish Fingerlings In An Aquarium Rack System, Brian C. Small

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

A 9-week growth study was conducted to compare the fingerling performance of two genetic groups of channel catfish Ictalurus punctatus (United States Department of Agriculture [USDA] 103 and USDA303) with that of blue catfish I. furcatus and their hybrid in an aquarium rack system. Fish of approximately 20 g were randomly selected from multifamily populations and acclimated to the aquarium rack system for 2 weeks prior to the start of the 9-week study. Differences in growth indices, feed and protein efficiency, nitrogen retention, whole-body proximate composition, and plasma cortisol levels were determined at the completion of the study. The USDA303 …

Restoration Of Spermatogenesis And Male Fertility By Transplantation Of Dispersed Testicular Cells In The Chicken, Pavel Trefil, Alena Micáková, Jitka Mucksová, Jiń Hejnar, Martin Poplstein, Murray R. Bakst, Jirí Kalina, Jean-Pierre Brillard

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

Transplantation of male germ cells into sterilized recipients has been widely used in mammals for conventional breeding and transgenesis purposes. This study presents a workable approach for germ cell transplantation between male chickens. Testicular cells from adult and prepubertal donors were dispersed and transplanted by injection directly into the testes of recipient males sterilized by repeated gamma irradiation. We describe the repopulation of the recipient seminiferous epithelium up to the production of heterologous sperm in about 50% of transplanted males. In comparison to males transplanted with testicular cell preparations from adult donors, in which the first ejaculates with sperm were …

Human Emanations And Related Natural Compounds That Inhibit Mosquito Host-Finding Abilities, Ulrich R. Bernier, Daniel Kline, Kenneth H. Posey

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

One mechanism by which the action of semiochemicals can be classified is based on the behavioral impact within or external to the species of interest. As such, one can classify a chemical as one of the following^2,3:

1. Pheromone, if it results in response between insects of the same species
2. Kairomone, if it results in response in another species that benefits the species receiving the chemical cue
3. Allomone, if it results in response in another species that benefits the species releasing the chemical cue

However, the distinctions can be more specific by classification of chemical cues …

Laboratory Evaluation Of Avian Odors For Mosquito (Diptera: Culicidae) Attraction, S. A. Allan, Ulrich R. Bernier, D. L. Kline

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

Attraction of Culex quinquefasciatus Say, Culex tarsalis Coquillett, Culex nigripalpus Theobald, and Aedes aegypti (L.) to avian and other host odors was investigated in a dual-port olfactometer. Although attraction to a human arm was high for Ae. aegypti (>80%) and low for all Culex spp. (<25%), all species responded similarly to a chicken (55.3-73.6%). Responses of Ae. aegypti, Cx. quinquefasciatus, and Cx. nigripalpus to feathers were low (<20%) but greater than to controls. There was no difference in attraction of Cx. tarsalis to feathers or controls. Responses to CO₂ (5 ml/min) were low for all species (<15%) except Cx. tarsalis, which were moderate (24.5%). When feathers were combined with CO2, the resulting attraction was additive or lower than responses …

2006 Wildflower Of The Year: Spicebush, Lindera Benzoin, W. John Hayden

Biology Faculty Publications

Spicebush is a multistemmed deciduous shrub that grows to a height of one to three meters. Young stems are delicate and may be smooth or finely hairy. Leaves are alternate and simple, with an elliptic to obovate blade that tapers at both the base and apex and is bounded by a smooth margin. Examined closely, the margin will reveal a series of fine hairs that project directly out from the leaf edge. In size, leaves are neither remarkably large nor small; they range from one to six inches in length and up to about two and a half inches wide, …

Genetic And Hybridization Evidence Confirms That A Geographic Population Of Gonatocerus Morrilli (Hymenoptera: Mymaridae) From California Is A New Species: Egg Parasitoids Of The Glassy-Winged Sharpshooter Homalodisca Coagulata (Homoptera: Cicadellidae), Jesse H. De León, Walker A. Jones, Mamoudou Sétamou, David J. W. Morgan

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

We investigated the differentiation and reproductive isolation among different geographic populations of Gonatocerus morrilli, egg parasitoids of the glassy-winged sharpshooter (Homalodisca coagulata), to confirm previous observations that there may exist a cryptic species complex or a new species. Two mitochondrial genes [cytochrome oxidase subunits I (COI) and II (COII)] and the internal transcribed spacer region 2 (ITS2) of several individuals per population were sequenced. G. morrilli populations from Texas (TX), Florida (FL), California (CA), and an outgroup (G. ashmeadi) were analyzed. For comparison, a population from Argentina (G. annulicornis) morphologically similar to G. …

The Effects Of Light Reduction Treatments On Mobile Epifaunain An Amphibolis Griffithii (Black) Den Hartog Seagrass Ecosystem, Helen Barwick

Theses : Honours

One of the main anthropogenic disturbances to seagrass meadows in Australia is reduction in light availability, through nutrient enrichment or suspended sediments. Dredging can create suspended sediment plumes from the expulsion of particulates into the water column and in tum reduces light penetration to seagrass ecosystems. Preliminary investigations have demonstrated that light reduction for different intensities and durations results in reduced seagrass and epiphytic algae biomass. The main aim of this study was to determine the effects of different intensities and durations of light reduction on epifaunal assemblages in Amphibolis griffithii seagrass meadows in Jurien Bay, Western Australia. This was …

Canopy-Tree Influences Along A Soil Parent Material Gradient In Pinus-Ponderosa-Quercus Gambelii Forests, Northern Arizona, Scott R. Abella, Judith D. Springer

Public Policy and Leadership Faculty Research

ABELLA, S. R. (Public Lands Institute and School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-2040) AND J. D. SPRINGER (Ecological Restoration Institute, Northern Arizona University, Flagstaff, AZ 86011-5017). Canopy-tree influences along a soil parent material gradient in Pinus ponderosa- Quercus gambelii forests, northern Arizona. J. Torrey Bot. Soc. 135: 26–36. 2008.—The distribution of canopy trees can impose within-site patterns of soil properties and understory plant composition. At ten sites spanning a soil parent material gradient in northern Arizona Pinus ponderosa-Quercus gambelii forests, we compared soils and plant composition among five canopy types: openings, Pinus ponderosa …

On The Taxonomy Of Plantaginaceae Juss. Sensu Lato: Evidence From Sem Of The Seed Coat, Azza Ahmed Shehata, Mohamed Hesham A. Loutfy

Turkish Journal of Botany

SEM of the seed coat was studied in 41 taxa of the Plantaginaceae sensu lato. The study included 31 taxa of Plantago L. and 10 taxa that were formerly assigned to the Scrophulariaceae, representing the genera Antirrhinum L., Digitalis L., Linaria Mill. and Veronica L. The obtained data were analysed by the NT sys-PC program package using the UPGMA clustering method. The study showed that Veronica possessed certain affinities to Plantago species, thus giving extra support to earlier views that Plantaginaceae sensu stricto and Scrophulariaceae sensu lato are allied through Veronica. The study also favoured the paraphyly of Plantago subgenus …

Roles Of Intra-Fruit Oxygen And Carbon Dioxide In Controlling Pepper (Capsicum Annuum L.) Seed Development And Storage Reserve Deposition, J. Blasiak, Anxiu Kuang, Chakavak S. Farghangi, M. E. Musgrave

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Seeds developing within a locular space inside hollow fruit experience chronic exposure to a unique gaseous environment. Using two pepper cultivars, `Triton' (sweet) and `PI 140367' (hot), we investigated how the development of seeds is affected by the gases surrounding them. The atmospheric composition of the seed environment was characterized during development by analysis of samples withdrawn from the fruit locule with a gas-tight syringe. As seed weight plateaued during development, the seed environment reached its lowest O2 concentration (19%) and highest CO2 concentration (3%). We experimentally manipulated the seed environment by passing different humidified gas mixtures through the fruit …

Wayne E. Sabbe Arkansas Soil Fertility Studies 2005, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.

Effects Of Substrate And Temperature On Growth Of Aspergillus Flavus In Peanuts From Georgia, Premila Achar, Andres Sachez

Faculty Articles

We investigated the effects of different substrates (potato dextrose agar [PDA], nutrient agar [NA], and corn meal agar [CMA]) and temperatures on growth and aflatoxin production in Aspergillus flavus. Contaminated peanuts from retailers at different locations in Georgia were used throughout the experiment and 200 seeds were selected from each sample. PDA, NA, and CMA served as the substrate to express the mold from the contaminated seeds. Seeds were plated equidistantly on each of the media and incubated at 10° C, 27° C, 30° C, and 37° C, respectively. Seeds incubated on moist filter paper served as control. Neither growth …

Rules V. Standards For Patent Law In The Plant Sciences, Mark D. Janis

Articles by Maurer Faculty

This article argues that US patent jurisprudence as applied to the plant sciences is moving to a second stage that will be characterized by more by incremental calibration than by spectacular change. The article discusses two doctrines of patent scope that are likely to be implicated in calibrating the utility patent system for the plant sciences: enablement and experimental use. It considers how those doctrines may be refined to serve as calibration tools in the application of patent law to the plant sciences.

Lake Mead National Recreation Area Vegetation Monitoring And Management: Quarterly Progress Report, Period Ending December 31, 2005, Margaret N. Rees

Vegetation Monitoring

Executive Summary

• Required reports on sticky buckwheat (Eriogonum viscidulum) and threecorner milkvetch (Astragalus geyeri var. triquetrus) to be submitted through appropriate protocols by December 30, 2005
• Summary report on several other rare plants to be submitted through appropriate protocols by December 30, 2005
• Invasive perennial pepperweed (also called tall whitetop; Lepidium latifolium) documented and treated by Weed Sentry within Black Canyon, Lake Mojave

Performance Of A Sisal Fibre Fixed-Bed Anaerobic Digester For Biogas Production From Sisal Pulp Waste, A. Mshandete, A. K. Kivaisi, M. S. T. Rubindamayugi, L. Björnsson, B. Mattiasson

Tanzania Journal of Science

A single stage anaerobic digester employing a sisal fibre waste fixed bed was studied for biogas production from sisal pulp waste. The fibre was colonized by microorganisms involved in biogas production. The sisal pulp waste to be digested was fed from the top and was sprinkled intermittently with recirculating leachate from the material. Organic loading rates of 0.1-10 kg volatile solids (VS) m-3d-1 could be applied and methane yields in the range of 0.13-0.48 m3 CH4 kg-1 VS added were obtained. The average methane content in the biogas produced from sisal pulp waste was 55%, and the biogas production rate …

Center For Grassland Studies Newsletter, Winter 2005, Volume 11, No. 1

Center for Grassland Studies: Newsletters

Grass Seed Production Research in Nebraska Panhandle by David Baltensperger, Department of Agronomy and Horticulture, UNL

Can Perennial Grass Pastures be Profitable in the Great Plains by Rob Mitchell, Ken Vogel, and Gary Varvel, USDA-ARS, Lincoln, NE Terry Klopfenstein (Animal Science), Dick Clark (Agricultural Economics), and Bruce Anderson (Agronomy and Horticulture), UNL

Forum – Monitoring Rangeland Health for an Experiment in Public Land Ownership

2005 Nebraska Grazing Conference to be Aug. 8-9

PGM Program Swings into 2nd Semester

Dates for 7th Nebraska Ranch Practicum Set

Changing Natural Landscapes: Ecological and Human Dimensions

The Prairie Naturalist, Volume 37, No.4 December 2005

The Prairie Naturalist

AVIAN COMMUNITY RESPONSE TO CONSTRUCTION OF A NATURALISTIC GOLF COURSE IN TALL GRASS PRAIRIE IN KANSAS ▪ R. J. Robel, S. L. Bye, K. E. Kemp, and S. J. Thien

SECOND REPORT OF THE NORTH DAKOTA BIRD RECORDS COMMITTEE: 2002-2003 ▪ D. Svingen, and R. E. Martin

RECENT RECORDS OF FORMERLY EXTIRPATED CARNIVORES IN NEBRASKA ▪ J. D. Hoffman, and H. H. Genoways

PLAINS HARVEST MOUSE IN NORTH DAKOTA ▪ R. W. Seabloom, and T. L. Shaffer

Book Reviews

A Primer on Prairie Ecology ▪ M. A. Cunningham

Range Wars: Have Prairie Dogs Lost the Battle for the West? ▪ …

Loss Of Nitrate-Nitrogen By Runoff And Leaching For Agricultural Watersheds, M. A. Elrashidi, M. D. Mays, A. Fares, C. A. Seybold, J. L. Harder, S. D. Peaslee, Pam Vanneste

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

The loss of nutrients in runoff and leaching water from agricultural land is a major cause of poor water quality in the United States. Scientists (NRCS) developed a technique to estimate the impact of agricultural watersheds on natural water resources. The objectives were to apply the technique on Wagon Train (WT) watershed in Nebraska to predict: (i) loss of water by surface runoff and subsurface leaching, (ii) loss of nitrate-N from soils by runoff and leaching, and (iii) nitrate-N loading for WT reservoir. The annual loss of water was estimated at 4.32 million m³ for runoff and 0.98 million …

Comparison Of Glomalin And Humic Acid In Eight Native U.S. Soils, K. A. Nichols, S. F. Wright

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

Two important extractable fractions of soil organic matter (SOM) are humic acid (HA) and glomalin-related soil protein (glomalin). Optimizing the purity of each fraction is necessary to correlate fraction quantity and molecular characteristics with soil quality. Manipulation of extraction sequence and controlled precipitation of HA were used to evaluate co-extraction of HA and glomalin. Eight bulk soil samples (0 to 10 cm depth) were collected from four U.S. states (Colorado, Nebraska, Maryland, and Georgia). In Experiment 1, glomalin extraction (50 mM citrate, pH 8.0, at 121 'C) was followed by HA extraction (0.1 N NaOH at room temperature), and Experiment …

Emerging Research Techniques & New Instrumentation For Plant Biology, Bruce Bugbee

Techniques and Instruments

We have not achieved an efficient food production system in US Agriculture by manipulating only the environment.

Genetic engineering techniques now allow us to quickly develop new crop cultivars.

The Effect Of Nitrogen Fertilizer Application To Maize And Sorghum On The Bionomics Of Chilo Partellus (Lepidoptera: Crambidae) And The Performance Of Its Larval Parasitoid Cotesia Flavipes (Hymenoptera: Braconidae), N. Jiang, F. Schulthess

All Peer-Reviewed Publications

Laboratory and field trials were conducted to evaluate the effect of plant species (maize, sorghum), plant age (young, middle, old) and four different nitrogen fertilization levels (N0-N3) on the bionomics of the invasive crambid Chilo partellus and the performance of its braconid larval parasitoid Cotesia flavipes. Plant N varied significantly between N0 and N1-N3, but the differences among the latter were not significant. Intrinsic rates of increase and net-reproductive rates of C. partellus followed the same trends: they were lowest with N0 and similar among the other treatments. On maize only, mortality of C. partellus and parasitism by C. flavipes …