Physical Sciences and Mathematics Commons^™

Classification Of The Waxy Condition Of Durum Wheat By Near Infrared Reflectance Spectroscopy Using Wavelets And A Genetic Algorithm, Barry K. Lavine, Nikhil Mirjankar, Stephen Delwiche

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

Near infrared (NIR) reflectance spectroscopy has been applied to the problem of differentiating four genotypes of durum wheat: ‘waxy’, Wx A1 null null, wx-B1 null and wild type. The test data consisted of 95 NIR reflectance spectra of wheat samples obtained from a USDA-ARSwheat breeding program. A two-step procedure for pattern recognition analysis of NIR spectral data wasemployed. First, thewavelet packet transform [14,15] was applied to the NIR reflectance data usingwavelet filters at different scales to extract and separate low-frequency signal components from high frequency noise components. By applying these filters, each reflectance spectrum was decomposed into wavelet coefficients that …

Nutrient Composition Of Selected Traditional United States Northern Plains Native American Plant Foods, Katherine M. Phillips, Pamela R. Pehrsson, Wanda W. Agnew, Angela J. Scheett, Jennifer R. Follett, Henry C. Lukaski, Kristine Y. Patterson

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

Ten wild plants (cattail broad leaf shoots, chokecherries, beaked hazelnuts, lambsquarters, plains prickly pear, prairie turnips, stinging nettles, wild plums, raspberries, and rose hips) from three Native American reservations in North Dakota were analyzed to expand composition information of traditional foraged plants. Proximates, dietary fiber (DF), vitamins, minerals, carotenoids, and folate vitamers were assayed using standard methods and reference materials. Per serving, all were rich in Mn (100–2808 mg). Several provided >10% DRI of Fe (cattail shoots, steamed lambsquarters, and prairie turnips), Ca (steamed lambsquarters, prickly pear, and prairie turnips), Mg (cattail shoots, lambsquarters, prickly pear, and prairie turnips), vitamins …

Larval Mortality And Development For Rotation-Resistant And Rotation-Susceptible Populations Of Western Corn Rootworm On Bt Corn, N A. Tinsley, J L. Spencer, R E. Estes, J. R. Prasifka, P M. Schrader, B. W. French, M E. Gray

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

The western corn rootworm, Diabrotica virgifera virgifera LeConte, is one of the most economically important insect pests threatening the production of corn, Zea mays (L.), in the United States. Throughout its history, this insect has displayed considerable adaptability by overcoming a variety of pest management tactics, including the cultural practice of annual crop rotation. Since first reported in Illinois in the late 1980s, populations of the rotation-resistant western corn rootworm have spread over a wide area of the eastern Corn Belt. Currently, little information is available concerning the interaction of rotation resistance with the use of genetically modified corn expressing …

Exploring Integrated Crop–Livestock Systems In Different Ecoregions Ofthe United States, R Mark Sulc, Alan J. Franzluebbers

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

Large-scale, energy-intensive, specialized production systems have dominated agricultural production inthe United States for the past half-century. Although highly productive and economically successful, thereis increasing concern with unintended negative environmental impacts of current agricultural systems.Production systems integrating crops and livestock have potential for providing additional ecosystem ser-vices from agriculture by capturing positive ecological interactions and avoiding negative environmentaloutcomes, while sustaining profitability. A diversity of ecologically sound integrated crop-livestock sys-tems have been and can be employed in different ecoregions: sod-based crop rotations, grazing covercrops in cash-crop rotations, crop residue grazing, sod intercropping, dual-purpose cereal crops, and agro-forestry/silvopasture. Improved technologies in conservation tillage, …

Ecotypes Of An Ecologically Dominant Prairie Grass (Andropogon Gerardii) Exhibit Genetic Divergence Across The U.S. Midwest Grasslands’ Environmental Gradient, Miranda M. Grey, Paul St. Amand, Nora M. Bello, Matthew B. Galliart, Mary Knapp, Karen A. Garrett, Theodore J. Morgan, Sarah G. Baer, Brian R. Maricle, Eduard D. Akhunov, Loretta C. Johnson

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

Big bluestem (Andropogon gerardii) is an ecologically dominant grass with wide distribution across the environmental gradient of U.S. Midwest grasslands. This system offers an ideal natural laboratory to study population divergence and adaptation in spatially varying climates.

Objectives were to: (i) characterize neutral genetic diversity and structure within and among three regional ecotypes derived from 11 prairies across the U.S. Midwest environmental gradient, (ii) distinguish between the relative roles of isolation by distance (IBD) vs. isolation by environment (IBE) on ecotype divergence, (iii) identify outlier loci under selection and (iv) assess the association between outlier loci and climate.

Using two …

Combined Effects Of Phosphorus Nutrition And Elevated Carbon Dioxide Concentration On Chlorophyll Fluorescence, Photosynthesis, And Nutrient Efficiency Of Cotton, Shardendu K. Singh, Vangimalla R. Reddy

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

To examine the combined effects of phosphorus (P) nutrition and CO2 on photosynthesis, chlorophyll fluorescence (CF), and nutrient utilization and uptake, two controlled-environment experiments were conducted using 0.01, 0.05 and 0.20 mM external phosphate each at ambient and elevated CO2 (aCO2: 400 and eCO2: 800 mmol mol–1, respectively). The CF parameters were affected more by P nutrition than by CO2 treatment. Photoinhibition of photosystem II (PSII) was due to increased minimal CF (Fo') and decreased maximal CF (Fm'), and efficiency of energy harvesting (Fv'/Fm'). In addition, reduced electron transport rate (ETR), the quantum yield of PSII (FPSII) and CO2 assimilation …

Nucleotide Polymorphism And Copy Number Variant Detection Using Exome Capture And Next-Generation Sequencing In The Polyploid Grass Panicum Virgatum, Joseph Evans, Jeongwoon Kim, Kevin L. Childs, Briaenne Vaillancourt, Emily Crisovan, Aruna Nandety, Daniel J. Gerhardt, Todd A. Richmond, Jeffery A. Jeddeloh, Shawn M. Kaeppler, Michael D. Casler, C Robin Buell

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

Switchgrass (Panicum virgatum) is a polyploid, outcrossing grass species native to North America and has recently been recognized as a potential biofuel feedstock crop. Significant phenotypic variation including ploidy is present across the two primary ecotypes of switchgrass, referred to as upland and lowland switchgrass. The tetraploid switchgrass genome is approximately 1400 Mbp, split between two subgenomes, with significant repetitive sequence content limiting the efficiency of re-sequencing approaches for determining genome diversity. To characterize genetic diversity in upland and lowland switchgrass as a first step in linking genotype to phenotype, we designed an exome capture probe set based on transcript …

Predicting Phosphorus Dynamics In Complex Terrains Using A Variable Source Area Hydrology Model, Amy S. Collick, Daniel R. Fuka, Peter J.A. Kleinman, Anthony R. Buda, Jennifer L. Weld, Mike J. White, Tamie L. Veith, Ray B. Bryant, Carl H. Bolster, Zachary M. Easton

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

Phosphorus (P) loss from agricultural watersheds has long been a critical water quality problem, the control of which has been the focus of considerable research and investment. Preventing P loss depends on accurately representing the hydrological and chemical processes governing P mobilization and transport. The Soil and Water Assessment Tool (SWAT) is a watershed model commonly used to predict run-off and non-point source pollution transport. SWAT simulates run-off employing either the curve number (CN) or the Green and Ampt methods, both assume infiltration-excess run-off, although shallow soils underlain by a restricting layer commonly generate saturation-excess run-off from variable source areas …

Effects Of Including Saponins (Micro-Aid®) On Intake, Rumenfermentation And Digestibility In Steers Fed Low-Qualityprairie Hay, C P. Mcmurphy, A J. Sexten, G L. Mourer, E D. Sharman, S J. Trojan, M J. Rincker, W K. Coblentz, D L. Lalman

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

Sixteen ruminally cannulated crossbred steers (529 ± 45 kg initial body weight, BW) wereused to evaluate in situ dry matter (DM), neutral detergent fiber (aNDF), and N degrada-tion characteristics of low-quality prairie hay, blood urea-N (BUN) and rumen fermentationparameters in steers provided a protein supplement with or without Micro-Aid®(MA; plantderived saponin). Steers were allowed ad libitum access to chopped prairie hay (49 g crudeprotein (CP)/kg DM and 738 g aNDF/kg DM) and randomly assigned to one of four treat-ments: (1) no supplement (C), (2) cottonseed meal and wheat middlings: 920 g DM/d (PC;positive control), (3) MA added to PC to …