Agricultural Science Commons^™

Phenologymms: A Program To Simulate Crop Phenological Responses To Water Stress, Gregory S. Mcmaster, Da Edmunds, W.W. Wilhelm, D.C. Nielsen, P.V.V. Prasad, J.C. Ascough Ii

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

Crop phenology is fundamental for understanding crop growth and development, and increasingly influences many agricultural management practices. Water deficits are one environmental factor that can influence crop phenology through shortening or lengthening the developmental phase, yet the phenological responses to water deficits have rarely been quantified. The objective of this paper is to provide an overview of a decision support technology software tool, PhenologyMMS Vl.2, developed to simulate the phenology of various crops for varying levels of soil water. The program is intended to be simple to use, requires minimal information for calibration, and can be incorporated into other crop …

Determination Of Representative Elementary Areas For Soil Redoximorphic Features Identified By Digital Image Processing, T. Kevin O'Donnell, Keith W. Goyne, Randall J. Miles, Claire Baffaut, Stephen H. Anderson, Kenneth A. Sudduth

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

Photography has been a welcome tool in documenting and conveying qualitative soil information. When coupled with image analysis software, the usefulness of digital cameras can be increased to advance the field of micropedology. The determination of a representative elementary area (REA) still remains a critical information need for soil scientists so that field measurements are independent of sample size and account for spatial heterogeneity. An objective of this study was to define and determine an REA for Low Chroma and High Chroma soil redoximorphic features (SRFs) present in claypan soils of northeastern Missouri, USA using a digital camera and image …

Evaluation Of Two Mutants Of Mycobacterium Avium Subsp. Paratuberculosis As Candidates For A Live Attenuated Vaccine For Johne’S Disease, Kun Taek Park, Andrew J. Allen, John P. Bannantine, Keun Seok Seo, Mary J. Hamilton, Gaber S. Abdellrazeq, Heba M. Rihan, Amanda Grimm, William C. Davis

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

Control of Johne’s disease, caused by Mycobacterium avium subsp. paratuberculosis, has been difficult because of a lack of an effective vaccine. To address this problem we used targeted gene disruption to develop candidate mutants with impaired capacity to survive ex vivo and in vivo to test as a vaccine. We selected relA and pknG, genes known to be important virulence factors in Mycobacterium tuberculosis and Mycobacterium bovis, for initial studies. Deletion mutants were made in a wild type Map (K10) and its recombinant strain expressing the green fluorescent protein (K10-GFP). Comparison of survival in an ex vivo …

Improving In-Season Nitrogen Recommendations For Maize Using An Active Sensor, J. Schmidt, D. Beegle, Q. Q. Zhu, R. Sripada

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

An active crop canopy reflectance sensor could be used to increase N-use efficiency in maize (Zea mays L.), if temporal and spatial variability in soil N availability and plant demand are adequately accounted for with an in-season N application. Our objective was to evaluate the success of using an active canopy sensor for developing maize N recommendations. This study was conducted in 21 farmers’ fields from 2007 to 2009, representing the maize production regions of east central and southeastern Pennsylvania, USA. Four blocks at each site included seven sidedress N rates (0–280 kgNha⁻¹) and one at-planting N …

A Comparison Of Internal And External Lipids Of Nondiapausing And Diapause Initiation Phase Adult Colorado Potato Beetles, Leptinotarsa Decemlineata, George D. Yocum, James S. Buckner, Charlotte L. Fatland

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

The Colorado potato beetle, Leptinotarsa decemlineata, reared under diapause-inducing conditions will emerge fromthe soil as an adult and enter the diapause initiation phase, a periodwheremetabolic reserves are stockpiled before the beetles enter the nonfeeding diapause maintenance phase. Internal and external lipids were characterized during the diapause initiation phase (IP) and compared to the lipid profiles of nondiapausing adults. The primary internal lipids of both diapause IP and nondiapausing adults are triacylglycerols. Only trace amounts of internal lipids were detected in day 1 diapause IP adults. A dramatic increase in internal lipids was observed between day 7 and day 15 …

Oil Productivity And Composition Of Sunflower As A Function Of Hybrid And Planting Date, Valtcho D. Zheljazkov, Brady A. Vick, Brian S. Baldwin, Normie Buehring, Christine Coker, Tess Astatkie, Billy Johnson

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

Sunflower (Helianthus annuus L.) is a potential cash crop for the southeastern United States for production of cooking oil or biodiesel. Two years (2006 and 2007) of experiments were conducted at each of five locations in Mississippi to evaluate the effect of planting date (April 20, May 20, and June 20), and hybrid (DKF3875, DKF2990, DKF3510, DKF3901, PR63M80, PR62A91, PR63A21, PR63M91, and PR64H41) on seed yield, oil content, and oil composition of sunflower. Seed oil concentration varied from 25 to 47%. The oleic acid concentration in the oil was greater than 85% for DKF3510 and PR64H41, above 65% for …

Quality And Agronomic Effects Of Three High-Molecular-Weight Glutenin Subunit Transgenic Events In Winter Wheat, Robert A. Graybosch, Bradford Seabourn, Yuanhong R. Chen, Ann E. Blechl

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

Quality and agronomic effects of three transgenic high molecular weight glutenin subunit (HMW-GS) events were characterized in advanced generation breeding lines of hard winter wheat (Triticum aestivum L.) in three Nebraska crop years. Two or the transgenic events studied, Dy10-E and B52a-6, ovenexpress HMW-GS IDY10, while the third event, Dx5 +Dy10-H, overexpresses HMW-GS IDx5 and to a much lesser extent. IDY10. In addition, novel proteins possessing solubility characteristics defined as HMW-GS were present in Dx5+Dy10-H and B52a-6. Average grain yield of lines derived from the three transgenic events was statistically lower than that of a group of control cultivars …

Evaluation Of Propane Combustion Traps For The Collection Of Phlebotomus Papatasi (Scopoli) In Southern Israel, Daniel Kline, Gunter Miller, Jerome Hogsette

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

In this study, we evaluated the efficacy of eleven commercial models of propane combustion traps for catching male and female Phlebotomus papatasi. The traps differed in physical appearance, amount of carbon dioxide produced and released, type and location of capturing device, and the method by which the trap suction fans were powered. The traps tested were the Mosquito Magnet^™(MM)-Pro, MM-Liberty, MM-Liberty Plus, MM-Defender, SkeeterVac^®(SV)-35, SV-27, Mosquito Deleto™(MD)-2200, MD-2500, MT150-Power Trap, and two models of The Guardian Mosquito Traps (MK-01 and MK-12). All trap models except the SV-35, the SV-27, the MD-2500, and the MK-12 attracted …

Effect Of Coal Combustion By-Products On Phosphorus Runoff From A Coastal Plain Soil, Keisha N. Johnson, Arthur L. Allen, Peter J. A. Kleinman, Fawzy M. Hashem, Andrew N. Sharpley, William L. Stout

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

Coal combustion by-products can lower soil phosphorus (P) solubility, but few studies have assessed their effect on runoff P. A soil with elevated P content was amended with fluidized bed combustion ash, flue gas desulfurization gypsum, and anthracite refuse ash at rates of 0–40 g kg⁻¹ soil, and runoff from small plots was monitored over 3 years. In the first year, by-products lowered dissolved P in runoff by up to 47% below the untreated control; however, effects did not persist into the remaining years of the study. Total P losses were not significantly affected by coal combustion by-products, likely …

Antibody Recognition Of Porcine Circovirus Type 2 Capsid Protein Epitopes After Vaccination, Infection, And Disease, Benjamin R. Trible, Maureen Kerrigan, Nicholas Crossland, Megan Potter, Kay Faaberg, Richard Hesse, Raymond R. R. Rowland

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

Open reading frame 2 (ORF2) of porcine circovirus type 2 (PCV2) codes for the 233-amino-acid capsid protein (CP). Baculovirus-based vaccines that express only ORF2 are protective against clinical disease following experimental challenge or natural infection. The goal of this study was to identify regions in CP preferentially recognized by sera from experimentally infected and vaccinated pigs and to compare these responses to those of pigs diagnosed with porcine circovirus-associated disease (PCVAD), including porcine multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS). The approach was to react porcine sera with CP polypeptide fragments followed by finer mapping studies …

Conventional And Glyphosate-Resistant Maize Yields Across Plant Densities In Single- And Twin-Row Configurations, Kipling S. Balkcom, Jason L. Satterwhite, Francisco J. Arriaga, Andrew J. Price, Edzard Van Santen

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

Maize (Zea mays L.) produced in narrow rows can increase yields and accelerate canopy closure. Costly equipment modifications make narrow rows impractical, but a twin-row configuration may boost production with fewer equipment modifications. Four field experiments were conducted to measure weed biomass, leaf area index (LAI), and yield for a conventional (CN) and a glyphosate-resistant (GR) hybrid across three plant densities (low 4.0–4.4 plants m⁻²; medium 5.9–6.4 plants m⁻²; and high 7.9–8.4 plants m⁻²) and two row configurations (single vs. twin) in a conservation tillage system during the 2005 growing season. The experimental design …

Switchgrass Contains Two Cinnamyl Alcohol Dehydrogenases Involved In Lignin Formation, Aaron J. Saathoff, Christian M. Tobias, Scott E. Sattler, Eric J. Haas, Paul Twigg, Gautam Sarath

Department of Agronomy and Horticulture: Faculty Publications

Lignin content of switchgrass (Panicum virgatum L.), a bioenergy species, is a critical determinant of biomass quality since it can negatively impact conversion of biomass into liquid fuels via biochemical platforms. Cinnamyl alcohol dehydrogenase (CAD) is a key enzyme in lignin biosynthesis. Here, we have shown that cv. Kanlow switchgrass contains at least two closely related CAD genes (PviCAD1 and PviCAD2) that code for proteins containing highly conserved domains and residues that identify them as bona fide CADs. Both recombinant proteins displayed substrate kinetics consistent with their presumed role in cell wall lignification. Proteomic and immunoblotting detected …

The Composition And Origins Of Genomic Variation Among Individuals Of The Soybean Reference Cultivar Williams 82, William J. Haun, D. L. Hyten, Wayne W. Xu, Daniel J. Gerhardt, Thomas J. Albert, Todd Richmond, Jeffrey A. Jeddeloh, Gaofeng Jia, Nathan M. Springer, Carroll P. Vance, Robert M. Stupar

Department of Agronomy and Horticulture: Faculty Publications

Soybean (Glycine max) is a self-pollinating species that has relatively low nucleotide polymorphism rates compared with other crop species. Despite the low rate of nucleotide polymorphisms, a wide range of heritable phenotypic variation exists. There is even evidence for heritable phenotypic variation among individuals within some cultivars. Williams 82, the soybean cultivar used to produce the reference genome sequence, was derived from backcrossing a Phytophthora root rot resistance locus from the donor parent Kingwa into the recurrent parent Williams. To explore the genetic basis of intracultivar variation, we investigated the nucleotide, structural, and gene content variation of different …

Genome-Wide Association Analysis Identifies Candidate Genes Associated With Iron Deficiency Chlorosis In Soybean, Sujan Mamidi, Shireen Chikara, R. Jay Goos, D. L. Hyten, Deepti Annam, Samira Mafi Moghaddam, Rian K. Lee, P. B. Cregan, Phillip E. Mcclean

Department of Agronomy and Horticulture: Faculty Publications

Iron deficiency chlorosis (IDC) is a significant yield-limiting problem in several major soybean [Glycine max (L.) Merr.] production regions in the United States. Soybean plants display a variety of symptoms that range from a slight yellowing of the leaf to interveinal chlorosis, to stunted growth that reduces yield. The objective of this analysis was to employ single nucleotide polymorphism (SNP)-based genome-wide association mapping to uncover genomic regions associated with IDC tolerance. Two populations [2005 (n = 143) and 2006 (n = 141)] were evaluated in replicated, multilocation IDC trials. After controlling for population structure and individual relatedness, and selecting …

The Role Of Transition Metal Homeostasis In Plant Seed Development, Elsbeth L. Walker, Brian M. Waters

Department of Agronomy and Horticulture: Faculty Publications

Copyright © 2011 Elsevier Ltd. Used by permission.

Moving Magnesium In Plant Cells, Brian M. Waters

Department of Agronomy and Horticulture: Faculty Publications

Magnesium (Mg) is among the most abundant mineral elements in plants, yet the knowledge of which genes control its accumulation in specific tissues and organelles lags behind that of many other mineral elements. Only in recent years has identification of important molecular players begun to take shape. In this issue of New Phytologist, Conn et al. (pp. 583–594) shed additional light on two Mg transporters that play important roles in accumulation of Mg in leaf cell vacuoles. Using subcellular-level ion measurements on leaves, gene expression measurements after single-cell sampling, a genetic approach, and clever use of calcium (Ca) and …

Registration Of Seven Winter Wheat Germplasm Lines Carrying The Wsm1 Gene For Wheat Streak Mosaic Virus Resistance, Jasdeep S. Mutti, P. Stephen Baenziger, Robert A. Graybosch, Roy French, Kulvinder S. Gill

Department of Agronomy and Horticulture: Faculty Publications

Seven winter wheat (Triticum aestivum L.) germplasm lines carrying the Wsm1 gene conferring resistance to Wheat streak mosaic virus (WSMV)—Alliance-Wsm1 (Reg. No. GP-858, PI 653710), Arrowsmith-Wsm1 (Reg. No. GP-859, PI 653711), Goodstreak-Wsm1 (Reg. No. GP-860, PI 653712), Harry-Wsm1 (Reg. No. GP-861, PI 653713), Millennium-Wsm1 (Reg. No. GP-862, PI 653714), Wahoo-Wsm1 (Reg. No. GP-863, PI 653715), and Wesley-Wsm1 (Reg. No. GP-864, PI 653716)—were codeveloped by Washington State University, Pullman, WA; the University of Nebraska, Lincoln, NE; and the USDA-ARS. These seven different winter wheat cultivars were selected to provide more sources of effective …

Forage Nutritional Quality Evaluation Of Bahiagrass Selections During Autumn In Florida, Robert Myer, Ann Blount, Samuel Coleman, Jeffery Carter

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

Bahiagrass (Paspalum notatum Flugge) is the major pasture forage in the southern Gulf Coast, USA. A bahiagrass selection breeding program has been ongoing since 1960 at the Coastal Plain Experiment Station at Tifton, Georgia, USA, to increase forage yield in Pensacola (P. notatum var. sanese) bahiagrass. However, the impact of selecting for forage yield on forage nutritional quality is unknown. Forage quality was evaluated on four Pensacola derived selection cycles (C) of bahiagrass [C0 (Pensacola), C4, C9 (Tifton 9), and C23]. A total of 175 plants per cycle were grown. Forage from individual 1-year-old plants was harvested by …

Dehydration Of Pollock Skin Prior To Gelatin Production, Cindy K. Bower, Roberto J. Avena-Bustillos, Katie A. Hietala, Cristina Bilbao-Sainz, Carl W. Olsen, Tara H. Mchugh

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

Alaska pollock (Theragra chalcogramma) is the U.S.A.’s largest commercial fishery, with an annual catch of over 1 million tons. During pollock processing, the skins are discarded ormade into fish meal, despite their value for gelatin production. The absence of gelatin-processing facilities in Alaska necessitates drying of the skins before transport to decrease the moisture content, but conventional hot-air drying is expensive. This study evaluated a less energy-intensive technology, the use of desiccants for reducing water weight in pollock skins prior to shipment. To ensure that the functional properties of gelatin obtained from dried pollock skins were not affected …

Isolation And Characterisation Of The First Microsatellite Markers For Cyperus Rotundus, R. S. Arias, W. T. Molin, J. D. Ray, M. D. Peel, B. E. Scheffler

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

This is the first report of microsatellite markers for Cyperus rotundus. A total of 191 sequence-specific microsatellite markers were isolated and used to screen
12 accessions of C. rotundus and one accession of Cyperus esculentus collected from 10 different countries. Polymorphisms were observed in 49% of the markers tested, 22% of the markers were monomorphic and 29% had weak or no amplification. The best 57 markers are reported, and cluster analysis was used to analyse their resolving power. BLASTx screening of the contig sequences was also performed. Multiallelic loci over all samples ranged from 24% to 60%. The maximum …

Genetic Variability Among Isolates Of Fusarium Oxysporum From Sugar Beet, A. L. Hill, P. A. Reeves, R. L. Larson, A. L. Fenwick, L. E. Hanson, L. Panella

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

Fusarium yellows, caused by the soil-borne fungus Fusarium oxysporum f. sp. betae (Fob), can lead to significant yield losses in sugar beet. This fungus is variable in pathogenicity, morphology, host range and symptom production, and is not a well characterized pathogen on sugar beet. From 1998 to 2003, 86 isolates of F. oxysporum and 20 other Fusarium species from sugar beet, along with four F. oxysporum isolates from dry bean and five from spinach, were obtained from diseased plants and characterized for pathogenicity to sugar beet. A group of sugar beet Fusarium isolates from different geographic areas (including nonpathogenic and …

Pathogenicity And Molecular Characterization Of Emerging Porcine Reproductive And Respiratory Syndrome Virus In Vietnam In 2007, S. Metwally, F. Mohamed, K. Faaberg, T. Burrage, M. Prarat, K. Moran, A. Bracht, G. Mayr, M. Berninger, L. Koster, T. L. To, V. L. Nguyen, M. Reising, J. Landgraf, L. Cox, J. Lubroth, C. Carrillo

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

In 2007, Vietnam experienced swine disease outbreaks causing clinical signs similar to the ‘porcine high fever disease’ that occurred in China during 2006. Analysis of diagnostic samples from the disease outbreaks in Vietnam identified porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV-2). Additionally, Escherichia coli and Streptococcus equi subspecies zooepidemicus were cultured from lung and spleen, and Streptococcus suis from one spleen sample. Genetic characterization of the Vietnamese PRRSV isolates revealed that this virus belongs to the North American genotype (type 2) with a high nucleotide identity to the recently reported Chinese strains. Amino acid …

Performance Of Larval Florida Pompano Fed Nauplii Of The Calanoid Copepod Pseudodiaptomus Pelagicus, Eric J. Cassiano, Cortney L. Ohs, Charles R. Weirich, Nancy E. Breen, Andrew L. Rhyne

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

The Florida pompano Trachinotus carolinus is a highly prized marine fish species, the larviculture of which currently includes the feeding of live rotifers and nauplii of brine shrimp Artemia spp. However, no previous studies have evaluated the feeding of copepod nauplii. In this study, the growth and survival of Florida pompano larvae fed nauplii of the calanoid copepod Pseudodiaptomus pelagicus were compared with those of larvae fed the standard reference diet of enriched rotifers Brachionus plicatilis. Experiments were conducted during the first 7–9 d posthatch (DPH), a period preceding the provision of Artemia nauplii. Treatments included feeding only copepod …

Whole-Body And Muscle Protein Metabolism Are Not Affected By Acute Deviations From Habitual Protein Intake In Older Men: The Hormonal Regulators Of Muscle And Metabolism In Aging (Horma) Study, Kevin E. Yarasheski, Carmen Castaneda-Sceppa, Jiaxiu He, Miwa Kawakubo, Shalender Bhasin, Ellen F. Binder, E. Todd Schroeder, Ronenn Roubenoff, Stan P. Azen, Fred R. Sattler

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

Background:

Acute deviations in protein intake before the quantification of protein kinetics in older humans may explain the controversy over the effects of older age on muscle protein synthesis and proteolysis rates.

Objective:

We hypothesized that an acute decrease in protein intake from the habitual intake is associated with lower muscle protein synthesis and higher proteolysis rates, whereas an acute increase in protein intake from the habitual intake is associated with higher muscle protein synthesis and lower proteolysis rates.

Design:

In 112 community-dwelling healthy men aged 65–90 y, we quantified resting whole-body [1,2-¹³C₂]leucine kinetics, muscle mixed …

Relative Contributions Of Animal And Muscle Effects To Variation In Beef Lean Color Stability, D. A. King, S. D. Shackelford, T. L. Wheeler

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

Muscles from beef carcasses (n = 100) were selected from a commercial processor and aged for 14 d. Longissimus lumborum (LL), semimembranosus (SM), biceps femoris (BF), gluteus medius (GM), triceps brachii (TB), rectus femoris, vastus lateralis, adductor, semitendinosus, infraspinatus, teres major, biceps femoris ischiatic head, biceps femoris sirloin cap, and gracillus steaks were placed in display for 9 d. Instrumental color variables [lightness (L*), redness (a*), yellowness (b*), hue angle, chroma, and overall color change from d 0 (ΔE)] were determined on d 0, 1, 3, 6, and 9 of display. Muscle pH and myoglobin content were determined for LL, …

Fluid Fertilizer’S Role In Sustaining Soils Used For Bio-Energy Feedstock Production, John L. Kovar, Douglas L. Karlen

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

The use of corn (Zea mays L.) as a bio-energy feedstock has attracted the attention of many producers. Recently, the focus has shifted from grain-based to cellulose-based ethanol production. In addition to biological conversion of corn stover to ethanol, thermal conversion (pyrolysis) of stover is being explored. Regardless of post-harvest processing, the short- and long-term effects of both increasing grain yields and removing stover on soil nutrient cycling, physical properties, and biological activity must be understood to ensure that soil productivity and ecosystem services are maintained. Our objectives for 2010 were to evaluate: (i) the use of surface or …

2011 Across-Breed Epd Table, Larry Kuehn, Mark Thallman

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

The table of adjustment factors to be used to estimate across-breed expected progeny differences (AB-EPDs) for eighteen breeds was presented at the Beef Improvement Federation Annual Meeting in Bozeman, MT, on June 2 (see Table 1). Across-breed adjustment factors have been calculated for growth traits and maternal milk since 1993. Adjustment factors for carcass traits have been calculated since 2009; to be included, breeds must have carcass data in the U.S. Meat Animal Research Center (USMARC) database and report their carcass EPDs on an actual carcass basis using an age-adjusted endpoint. Bulls of different breeds can be compared on the …

Patterns Of Widespread Decline In North American Bumble Bees, Sidney A. Cameron, Jeffrey D. Lozier, James P. Strange, Jonathan B. Koch, Nils Cordes, Leellen F. Solter, Terry L. Griswold

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

Bumble bees (Bombus) are vitally important pollinators of wild plants and agricultural crops worldwide. Fragmentary observations, however, have suggested population declines in several North American species. Despite rising concern over these observations in the United States, highlighted in a recent National Academy of Sciences report, a national assessment of the geographic scope and possible causal factors of bumble bee decline is lacking. Here, we report results of a 3-y interdisciplinary study of changing distributions, population genetic structure, and levels of pathogen infection in bumble bee populations across the United States. We compare current and historical distributions of eight species, compiling …

Comparative Cryopreservation Of Avian Spermatozoa: Benefits Of Non-Permeating Osmoprotectants And Atp On Turkey And Crane Sperm Cryosurvival, Juan M. Blanco, Julie A. Long, George Gee, David E. Wildt, Ann M. Donoghue

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

A comparative approach was used to evaluate the cryosurvival of turkey and crane sperm frozen in a dimethylacetamide (DMA) cryodiluent supplemented with osmoprotectants and ATP. A range (6–26%) of DMA concentrations was used alone or in combination with ATP (30, 60 or 118mM) or one of the following osmoprotectants: (1) sucrose (turkey, 8.0%; crane, 5.0%); (2) 5.0% sucrose and 5.0% trehalose; or (3) betaine hydrochloride (0.1, 0.2 or 0.4 mM). The viability of thawed sperm was assessed using the nigrosin–eosin stain and sperm motility was determined using the hanging-drop technique. For semen frozen only with DMA, post-thaw sperm motility was …

Carbon Exchange By Establishing Biofuel Crops In Central Illinois, Marcelo Zeri, Kristina Anderson-Teixeira, George Hickman, Michael Masters, Evan Delucia, Carl J. Bernacchi

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

Perennial grass bio-fuels may contribute to long-term carbon sequestration in soils, thereby providing a broad range of environmental benefits. To quantify those benefits, the carbon balance was investigated over three perennial grass bio-fuel crops – miscanthus (Miscanthus×giganteus), switch-grass (Panicum virgatum) and a mixture of native prairie plants – and a row crop control (maize–maize–soy) in Central Illinois, USA, during the establishment phase of the perennial grasses (2008–2011). The eddy covariance technique was used to calculate fluxes of carbon dioxide and energy balance components, such as latent and sensible heat fluxes. Whereas maize attained the highest maximal …