Life Sciences Commons^™

Efficacy And Costs Of Controlling Eastern Redcedar, John Ortmann, James L. Stubbendieck, Robert A. Masters, George H. Pfeiffer, Thomas B. Bragg

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

(Juniperus virginiana L.) is reducing grassland productivity across much of the Great Plains. Control methods include broadcast prescribed fire, herbicides, cutting, and individual tree ignition. All methods have disadvantages when used alone. Fire can be ineffective against larger trees. Intensive methods can be too expensive for low-productivity grasslands. The objectives of this research were to determine the effects of broadcast prescribed fie alone as measured at 3 weeks after fire; to compare the effects of picloram herbicide application with or without fire, sawing with or without fire, and individual tree ignition with fire; and to compare all treatment costs. …

Productivity Of Well-Watered Panicum Virgatum Does Not Increase With Co2 Enrichment, Philip A. Fay, H. Wayne Polley, Virginia L. Jin, Michael J. Aspinwall

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

Aims Rising atmospheric CO₂ has been shown to increase aboveground net primary productivity (ANPP) in water-limited perennial grasslands, in part by reducing stomatal conductance and transpiration, thereby reducing depletion of soil moisture. However, the benefits of CO₂ enrichment for ANPP will vary with soil type and may be reduced if water limitation is low. Little is known about CO₂ effects on ANPP of Panicum virgatum, a perennial C₄ tallgrass and potential bioenergy crop. We hypothesized that if water limitation is minimized, (i) CO₂ enrichmentwould not increase P. virgatum ANPP because photosynthetic rates of this C …

Trait Convergence And Plasticity Among Native And Invasive Species In Resource-Poor Environments, Rebecca E. Drenovsky, Albina Khasanova, Jeremy J. James

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

Premise of study: Functional trait comparisons provide a framework with which to assess invasion and invasion resistance. However, recent studies have found evidence for both trait convergence and divergence among coexisting dominant native and invasive species. Few studies have assessed how multiple stresses constrain trait values and plasticity, and no study has included direct measurements of nutrient conservation traits, which are critical to plants growing in low-resource environments.

Methods: We evaluated how nutrient and water stresses affect growth and allocation, water potential and gas exchange, and nitrogen (N) allocation and use traits among a suite of six codominant species from …

Opportunities And Challenges From The Use Of Genomic Selection For Beef Cattle Breeding In Latin America, Hugo H. Montaldo, Eduardo Casas, José Bento Sterman Ferraz, Vicente E. Vega-Murillo, Sergio Iván Román-Ponce

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

In 2009, Latin American countries had approximately 401 million cattle (29% of the world’s total cattle population) and produced 8.2 million tonnes of beef, equivalent to 29% of the world’s total production (FAO, 2011). Beef in Latin American countries is produced under widely differing climates (ranging from tropical to temperate), resources available (vegetation, food), types of markets, and genetic backgrounds of the animals. The main production systems are classified as beef and dual-purpose cattle. The genetic backgrounds of animals vary from purebred European (Bos taurus taurus) or Zebu (Bos taurus indicus) to crossbreeds (Figures 1 and …

Separation Of Alcohol Soluble Sorghum Proteins Using Non-Porous Cation-Exchange Columns, Deidre L. Blackwell, Scott R. Bean

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

Kafirins, the storage proteins and major protein of the cereal grain sorghum, play an important nutritional role for millions of people in parts of Africa and Asia. Kafirins are non-water soluble, being soluble only in the presence of detergents or aqueous alcohol mixtures and are among the most hydrophobic of the cereal proteins. Limited M_w heterogeneity of kafirins reduces their resolution when separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Charge based separation techniques have been shown to have improved resolution of kafirins, but due to the nature of their solubility, ion-exchange (IE)-HPLC has not been widely used to …

Spillover Of Functionally Important Organisms Between Managed And Natural Habitats, Eleanor J. Blitzer, Carsten F. Dormann, Andrea Holzschuh, Alexandra-Maria Klein, Tatyana A. Rand, Teja Tscharntke

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

Land-use intensification has led to a landscape mosaic that juxtaposes human-managed and natural areas. In such human-dominated and heterogeneous landscapes, spillover across habitat types, especially in systems that differ in resource availability, may be an important ecological process structuring communities. While there is much evidence for spillover from natural habitats to managed areas, little attention has been given to flow in the opposite direction. This paper synthesizes studies published to date from five functionally important trophic groups, herbivores, pathogens, pollinators, predators, and seed dispersers, and discusses evidence for spillover from managed to natural systems in all five groups. For each …

Water Use And Yields Of No-Till Managed Dryland Grasspea And Yellow Pea Under Different Planting Configurations, F.J. Calderón, M.F. Vigil, D.C. Nielsen, J.G. Benjamin, D.J. Poss

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

Grasspea (GP) (Lathyrus sativus) is a drought-tolerant legume that can be grown for forage and grain. It has potential value to be used as a nitrogen-fixing crop in dryland rotations with non-legume grain crops. However, the agronomy of GP for the Central Great Plains region have not been investigated. The objective of this research was to compare the grain and biomass yield, as well as N accumulation of GP relative to field pea (FP) in two planting configurations. We carried out a 3-year field experiment to compare dryland GP with Admiral yellow field pea (Pisum sativum) …

Characterization Of Sorghum Grain And Evaluation Of Sorghum Flour In A Chinese Egg Noodle System, Liman Liu, Thomas J. Herald, Donghai Wang, Jeff D. Wilson, Scott R. Bean, Fadi M. Aramouni

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

Sorghum is a gluten free grain that has potential to be used as an alternative to wheat flour for the Celiac Sprue market. There are thousands of sorghum lines that have not been characterized for grain, flour or end product quality. The objective of the research was to gain an understanding among grain sorghum quality factors and Chinese egg noodles quality. Four sorghum hybrids were characterized and evaluated for kernel characteristics, proximate analysis, flour composition and end product in a Chinese egg noodle system. Kernel size and weight affected the flour particle size and the amount of starch damage. Flour …

Potential Causes And Consequences Of Decreased Body Size In Field Populations Of Coccinella Novemnotata, John Losey, Jordan Perlman, James Kopco, Samuel Ramsey, Louis Hesler, Edward Evans, Leslie Allee, Rebecca Smyth

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

Coccinella novemnotata, the nine-spotted lady beetle, was historically one of the most common lady beetles across the US and southern Canada. In the 1980s it became extremely rare and has remained rare. In 2008 adult C. novemnotata were collected from field populations in Oregon and South Dakota and initial observations suggested that these individuals seemed smaller than the mean size of the species historically. These observations led to a series of experiments to determine if there had been significant decrease in size and if any decrease found was due to a genetic change or to environmental factors. In the …

Animal Foraging As A Mechanism For Sediment Movement And Soil Nutrient Development: Evidence From The Semi-Arid Australian Woodlands And The Chihuahuan Desert, David J. Eldridge, Terry B. Koen, Aaron Killgore, Niki Huang, Walter G. Whitford

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

An emerging area of interest in geomorphology over the past two decades has been the effects of biota on ecosystemprocesses.We examinedthe roles of a rangeof vertebrates onsoildisturbance in twomarkedlydifferent environments, the semi-arid woodland of eastern Australia and a Chihuahuan Desert grassland–shrubland in the south-westernUnited States. Foraging pits of soil-disturbingvertebrates variedmarkedly fromsmall scratchings of heteromyid (mainly Dipodomys spp.) rodents (1.8×10⁻⁴m³) to deep (1.0×10⁻² m³) excavations of the burrowing bettong (Bettongia leuseur) and greater bilby (Macrotis lagotis). Vertebratesmoved substantial volumes of soil in both environments, and activity was highly temporally and …

Transcriptome And Gene Expression Analysis In Cold-Acclimated Guayule (Parthenium Argentatum) Rubber-Producing Tissue, Grisel Ponciano, Colleen M. Mcmahan, Wenshuang Xie, Gerard R. Lazo, Terry A. Coffelt, Jillian Collins-Silva, Aise Nural-Taban, Martin Gollery, David K. Shintani, Maureen C. Whalen

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

Natural rubber biosynthesis in guayule (Parthenium argentatum Gray) is associated with moderately cold night temperatures. To begin to dissect the molecular events triggered by cold temperatures that govern rubber synthesis induction in guayule, the transcriptome of bark tissue, where rubber is produced, was investigated. A total of 11,748 quality expressed sequence tags (ESTs) were obtained. The vast majority of ESTs encoded proteins that are similar to stress-related proteins, whereas those encoding rubber biosynthesis- related proteins comprised just over one percent of the ESTs. Sequence information derived from the ESTs was used to design primers for quantitative analysis of the …

Modifying Crops To Increase Cell Wall Digestibility, Hans-Joachim G. Jung, Deborah A. Samac, Gautam Sarath

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

Improving digestibility of roughage cell walls will improve ruminant animal performance and reduce loss of nutrients to the environment. The main digestibility impediment for dicotyledonous plants is highly lignified secondary cell walls, notably in stem secondary xylem, which become almost non-digestible. Digestibility of grasses is slowed severely by lignification of most tissues, but these cell walls remain largely digestible. Cell wall lignification creates an access barrier to potentially digestible wall material by rumen bacteria if cells have not been physically ruptured. Traditional breeding has focused on increasing total dry matter digestibility rather than cell wall digestibility, which has resulted in …

Post-Biological Control Invasion Trajectory For Melaleuca Quinquenervia In A Seasonally Inundated Wetland, Philip W. Tipping, Melissa R. Martin, Ryan Pierce, Ted D. Center, Paul R. Pratt, Min B. Rayamajhi

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

The recruitment and mortality of Melaleuca quinquenervia seedlings were evaluated over a 3-year period in a seasonally inundated wetland in the western Everglades region. The mean (±SE) density of seedlings/ saplingsm^-1 declined from 64.8 (±4.5) to 0.5 (±0.2) over the 3 years, a population reduction of 99.2%. Four distinct water regimes characterized this site: dry, dry to wet transition, flooded, and wet to dry transition. Seedling recruitment was highest in the dry to wet transition and lowest in the flooded water regime, while mortality was highest under flooded and dry water regimes. The mean estimate of population growth (λ) …

Analysis Of Off-Grid Hybrid Wind Turbine/Solar Pv Water Pumping Systems, Brian D. Vick, Byron A. Neal

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

While many remote water pumping systems exist (e.g. mechanical windmills, solar photovoltaic, wind-electric, diesel powered), few combine both the wind and solar energy resources to possibly improve the reliability and the performance of the system. In this paper, off-grid wind turbine (WT) and solar photovoltaic (PV) array water pumping systems were analyzed individually and combined as a hybrid system. The objectives were to determine: (1) advantages or disadvantages of using a hybrid system over using a WT or a solar PV array alone; (2) if the WT or solar PV array interfered with the output of the other; and (3) …

A Field Study Of Wind Erosion Following A Grass Fire On The Llano Estacado Of North America, J.E. Stout

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

Interactions between earth, wind, and fire have always played an important role in the formation and evolution of the level plains of the Llano Estacado of North America. The uppermost sediments of this vast region are aeolian deposits, formed by aeolian deposition into grassland vegetation. Grass cover enhances aeolian deposition by slowing near-surface winds and vegetation secures sediments once they are deposited. The benefits of grass cover, however, are lost when occasional fires remove protective vegetation fromfields. After a fire, the underlying soil surface becomes exposed and susceptible to wind erosion until the vegetative cover is re-established. The purpose of …

The Effect Of Soil Surface Litter Residue On Energy And Carbon Fluxes In A Deciduous Forest, T.B. Wilson, T.P. Meyers, J. Kochendorfer, M. C. Anderson, M. Heuer

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

The Atmosphere–Land Exchange Surface Energy (ALEX) balance model is an analytical formulation of the energy and mass transport within the soil and the vegetation canopy used for simulating energy, evapotranspiration, and CO2 fluxes in a wide range of vegetation environments. The objective of this study was to evaluate the ability of ALEX to simulate the effect of soil-surface leaf litter residue on soil heat conduction (G), sensible heat (H), evapotranspiration (ET) (or latent heat (LE) when expressed as rate of energy loss) and CO₂ fluxes in a deciduous forest. The model was evaluated in a deciduous forest in Oak …

Zebra Chip-Diseased Potato Tubers Are Characterized By Increased Levels Of Host Phenolics, Amino Acids, And Defense-Related Proteins, Christopher M. Wallis, Jianchi Chen, Edwin L. Civerolo

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

Little is known about specific host chemistry effects on zebra chip disease symptom development in potatoes (Solanum tuberosum). This research compared chemical profiles and defense-related enzyme levels between non-symptomatic and zebra chip-symptomatic potato tubers. Levels of phenolics, five amino acids, peroxidases, polyphenol oxidases, chitinases, and B-1,3-glucanases were greater in symptomatic tubers than non-symptomatic tubers, and many of these compounds also were positively correlated with zebra chip disease severity. 'Candidatus Liberibacter solanacearum’ was consistently present in symptomatic tubers. However, the lack of associations between titers and tuber chemistry suggests a complicated relationship between this bacterium and zebra chip …

Genomics Of Tropical Fruit Tree Crops, R. S. Arias, James W. Borrone, Cecile L. Tondo, David N. Kuhn, Brian M. Irish, Raymond J. Schnell

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

The genetic improvement of tropical fruit trees is limited when compared to progress achieved in temperate fruit trees and annual crops. Tropical fruit tree breeding programs require significant resources to develop new cultivars that are adapted to modern shipping and storage requirements. The use of molecular markers in tropical fruit tree breeding is greatly assisting in solving a number of difficult challenges for breeders such as the development of complex family structures for recombination mapping and for recurrent selection. A review of the literature on molecular markers development and new techniques for increasing single-nucleotide polymorphic markers is discussed. The development …

Registration Of ‘Byrd’ Wheat, Scott D. Haley, Jerry J. Johnson, Frank B. Peairs, John A. Stromberger, Emily E. Hudson, Scott A. Seifert, Rebecca A. Kottke, Victoria A. Valdez, Jeff B. Rudolph, Guihua Bai, Xianming Chen, Robert L. Bowden, Yue Jin, James A. Kolmer, Ming-Shun Chen, Bradford W. Seabourn

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

’Byrd’ (Reg. No. CV-1073, PI 664257) hard red winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released in August 2011 through a marketing agreement with the Colorado Wheat Research Foundation. In addition to researchers at Colorado State University (CSU), USDA-ARS researchers at Manhattan, KS, St. Paul, MN and Pullman, WA participated in its development. Byrd was selected from the cross ‘TAM 112’/CO970547- 7 made in 2002 at Fort Collins, CO. TAM 112 (PI 643143) is a hard red winter wheat cultivar released by Texas A&M University in 2005. CO970547-7 is an experimental line …

Pulling Together: Linking Unemployment Insurance And Supplemental Nutrition Assistance Program Administrative Data To Study Effects Of The Great Recession, Theresa Anderson, John A. Kirlin, Michael Wiseman

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

The SNAP-UI Data Linkage Project is an effort coordinated by the United States Department of Agriculture‘s Economic Research Service (ERS) to link state-level administrative data from the Supplemental Nutrition Assistance Program (SNAP) and Unemployment Insurance (UI) program to examine the concurrent and sequential patterns in use of these program before and during the Great Recession. The project focuses on calendar years 2006 through 2009 and utilizes data from seven states: California, Florida, Georgia, Illinois, Maryland, Michigan, and Texas. The project has illuminated various issues with administrative data linkage, which this paper characterizes as the ―”Three C’s" of administrative data: custody, …

Reduction Of Mosquito Biting Pressure By Timed-Release 0.3% Aerosolized Geraniol, Edita E. Revay, Amy Junnila, Daniel L. Kline, Rui-De Xue, Ulrich R. Bernier, Vasiliy D. Kravchenko, Zoya Yefremova, Günter Müller

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

We conducted a study to determine the degree of personal protection provided by the Terminix^® ALLCLEAR^® Mosquito Mister – Lantern Edition. This outdoor unit was operated to disperse an aerosolized aqueous 0.3% geraniol emulsion in timed-release intervals of 5.0, 7.5, and 10.0 min. Human volunteers participated in landing catch experiments to test the effect of geraniol sprayed at pre-set time intervals, at two distances: (1) 18 ft (5.49 m), the maximum effective distance claimed by the manufacturer, and (2) 9 ft (2.74 m), half the effective distance from the unit. When aerosolized geraniol was dispensed, reductions in biting …

Natural Product Studies Of U.S. Endangered Plants: Volatile Components Of Lindera Melissifolia (Lauraceae) Repel Mosquitoes And Ticks, Joonseok Oh, John J. Bowling, John F. Carroll, Betul Demirci, K. Hüsnü Can Baser, Theodor D. Leininger, Ulrich R. Bernier, Mark T. Hamann

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

The number of endangered plant species in the U.S. is significant, yet studies aimed towards utilizing these plants are limited. Ticks and mosquitoes are vectors of significant pathogenic diseases of humans. Repellents are critical means of personal protection against biting arthropods and disease transmission. The essential oil and solvent extracts from Lindera melissifolia (Walt.) Blume (Lauraceae) (pondberry) drupes were gathered and analyzed by GC and GC–MS. The essential oil obtained from this endangered plant showed a significant dose dependent repellency of ticks and a moderate mosquito repellent effect while the subsequent hexanes extract was completely ineffective. Fractional freezing enriched the …

Reproductive Potential Of Stable Flies (Diptera: Muscidae) Fed Cattle, Chicken, Or Horse Blood, Kristina M. Friesen, Gregory D. Johnson

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

Reproductive potential was assessed for stable fly cohorts fed cattle, chicken, or horse blood. Flies provided chicken blood oviposited20%moreeggs per day than did those fed cattle or horse blood. However, flies provided cattle or horse blood were fecund 50% longer. When both egg viability and number of eggs produced were considered, lifetime reproductive potential was almost twice as high for flies fed cattle or chicken blood than for flies fed horse blood. Maternal investment, which took egg production and volume into account, was higher in cohorts fed cattle blood (70 mm³) when compared with the other treatments (chicken …

First Report Of Strobilurin Resistance In Cercospora Beticola In Sugar Beet (Beta Vulgaris) In Michigan And Nebraska, Usa, W.W. Kirk, L.E. Hanson, G.D. Franc, W.L. Stump, E. Gachango, G. Clark, J. Stewart

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

Cercospora leaf spot (CLS) caused by Cercospora beticola Sacc. is the most important foliar disease of sugar beet (Beta vulgaris) worldwide (Jacobsen & Franc, 2009). CLS is controlled mainly with fungicides, including strobilurins (FRAC group 11). Resistance to strobilurins in C. beticola has not been reported in the field (Secor et al., 2010) but insensitive mutations have been artificially developed (Malandrakis et al., 2011). In 2011, fields from several areas in Michigan, USA treated with strobilurins had severe CLS and diminished control was also noted in small plot trials (Fig. 1). Individual leaf spot lesions were sampled from …

Efficacy Of Three Attractant Blends Tested In Combination With Carbon Dioxide Against Natural Populations Of Mosquitoes And Biting Flies At The Lower Suwannee Wildlife Refuge, Daniel L. Kline, Ulrich R. Bernier, Jerome A. Hogsette

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

Synthetic blends of chemicals identified previously from human skin emanations were evaluated against mosquito and biting fly populations at the Lower Suwannee Wildlife Refuge near Cedar Key, FL. Mosquito Magnet^TM-Experimental traps were baited with the Red (400 ml acetone:10 ml 1-hexen- 3-ol:10 ml 1-octen-3-ol), Blue (400 ml acetone:1 g/liter lactic acid:20 ml glycolic acid), or Green blend (400 ml acetone:1.5 g/liter lactic acid:20 ml dimethyl disulfide) plus CO₂ or with CO₂ alone (control). A relative index of efficacy was determined by dividing each mean blend trap catch by the mean control trap catch. Five mosquitoes (Aedes …

An Annotated Checklist Of The Horse Flies (Diptera: Tabanidae) Of Lebanon With Remarks On Ecology And Zoogeography: Pangoniinae And Chrysopsinae, Günter Müller, Theo Zeegers, Jerome Hogsette, Edita E. Revay, Vasiliy Kravchenko, Andrey Leshvanov, Yosef Schlein

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

Knowledge of the horse fly fauna (Diptera: Tabanidae) of Lebanon is fragmentary, while the local fauna of most neighboring countries has been fairly well researched. Within the framework of the 20-year project “The ecology and zoogeography of the Lepidoptera of the Near East,” we regularly collected biting flies in the whole region, including Lebanon. During this time we recorded 14 horse fly species for two subfamilies in Lebanon: four Pangoniinae and ten Chrysopsinae. Only a single species, Chrysops flavipes Meigen, 1804, was known previously in Lebanon, but the following four Pangoniinae: Pangonius haustellatus (Fabricius, 1781), Pangonius obscuratus Loew, 1859, Pangonius …

Nuisance Flies On Australian Cattle Feedlots: Immature Populations, Jerome Hogsette, R. Urech, P.E. Green, A. Skerman, M.M. Elson-Harris, R.L. Bright, G.W. Brown

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

Species composition, seasonality and distribution of immature fly populations on a southern Queensland feedlot during 2001–2003 were determined. Similar data were collected on feedlots in central New South Wales and central Queensland. The fly species recovered in the highest numbers were Musca domestica L. (Diptera: Muscidae), Stomoxys calcitrans L. (Diptera: Muscidae) and Physiphora clausa Macquart (Diptera: Ulidiidae). Houseflies were the dominant species at all feedlots. Houseflies preferred the warmer months from October to June, but stable flies preferred the cooler months and peaked in spring (September–November) and autumn (March–May). Larval abundance ratings recorded in the feedlot and numbers of larvae …

Soil Carbon Sequestration By Switchgrass And No-Till Maize Grown For Bioenergy, Ronald F. Follett, Kenneth P. Vogel, Gary E. Varvel, Robert B. Mitchell, John Kimble

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

Net benefits of bioenergy crops, including maize and perennial grasses such as switchgrass, are a function of several factors including the soil organic carbon (SOC) sequestered by these crops. Life cycle assessments (LCA) for bioenergy crops have been conducted using models in which SOC information is usually from the top 30 to 40 cm. Information on the effects of crop management practices on SOC has been limited so LCA models have largely not included any management practice effects. In the first 9 years of a long-term C sequestration study in eastern Nebraska, USA, switchgrass and maize with best management practices …

Germination And Emergence Tests For Predicting Switchgrass Field Establishment, Robert B. Mitchell, K. P. Vogel

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

The effect of switchgrass (Panicum virgatum L.) seed quality tests on field establishment has been addressed inadequately. Our objective was to evaluate the ability of seed quality tests to predict field establishment. Standard Association of Official Seed Analysts (AOSA) tests are based on the percentage of seeds in a seedlot that germinate under standard laboratory conditions, whereas the seedlot establishment tests (SETs) are based on the number of seeds that emerge per gram of seed using different germination or stress test conditions. The SET was determined using six laboratory tests and the results validated in three replicated field trials. …

Genome Sequencing Of Ovine Isolates Of Mycobacterium Avium Subspecies Paratuberculosis Offers Insights Into Host Association, John Bannantine, Chia-Wei Wu, Chungyi Hsu, Shiguo Zhou, David C. Schwartz, Darrell O. Bayles, Michael L. Paustian, David P. Alt, Srinand Sreevatsan, Vivek Kapur, Adel M. Talaat

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

Background: The genome of Mycobacterium avium subspecies paratuberculosis (MAP) is remarkably homogeneous among the genomes of bovine, human and wildlife isolates. However, previous work in our laboratories with the bovine K-10 strain has revealed substantial differences compared to sheep isolates. To systematically characterize all genomic differences that may be associated with the specific hosts, we sequenced the genomes of three U.S. sheep isolates and also obtained an optical map.

Results: Our analysis of one of the isolates, MAP S397, revealed a genome 4.8 Mb in size with 4,700 open reading frames (ORFs). Comparative analysis of the MAP S397 isolate showed …