Agricultural Science Commons^™

High-Resolution Mapping Of Open Chromatin In The Rice Genome, Wenli Zhang, Yufeng Wu, James C. Schnable, Zixian Zeng, Michael Freeling, Gregory E. Crawford, Jiming Jiang

Department of Agronomy and Horticulture: Faculty Publications

Gene expression is controlled by the complex interaction of transcription factors binding to promoters and other regulatory DNA elements. One common characteristic of the genomic regions associated with regulatory proteins is a pronounced sensitivity to DNase I digestion. We generated genome-wide high-resolution maps of DNase I hypersensitive (DH) sites from both seedling and callus tissues of rice (Oryza sativa). Approximately 25% of the DH sites from both tissues were found in putative promoters, indicating that the vast majority of the gene regulatory elements in rice are not located in promoter regions. We found 58% more DH sites in …

A Mutagenesis-Derived Broad-Spectrum Disease Resistance Locus In Wheat, Jackie Campbell, Hongtao Zhang, Michael J. Giroux, Leila Feiz, Yue Jin, Meinan Wang, Xianming Chen, Li Huang

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

Wheat leaf rust, stem rust, stripe rust, and powdery mildew caused by the fungal pathogens Puccinia triticina, P. graminis f. sp. tritici, P. striiformis f. sp. tritici, and Blumeria graminis f. sp. tritici, respectively, are destructive diseases of wheat worldwide. Breeding durable disease resistance cultivars rely largely on continually introgressing new resistance genes, especially the genes with different defense mechanisms, into adapted varieties. Here, we describe a new resistance gene obtained by mutagenesis. The mutant, MNR220 (mutagenesis-derived new resistance), enhances resistance to three rusts and powdery mildew, with the characteristics of delayed disease …

Development And Application Of Methods Used To Source Prehistoric Southwestern Maize: A Review, Larry Benson

United States Geological Survey: Staff Publications

Archaeological cobs free of mineral contaminants should be used to source the soils in which they were grown. Mineral contaminants often contain much higher concentrations of metals than vegetal materials and can alter a cob’s apparent metal and heavy-isotope content. Cleaning a cob via immersion in an acid solution for more than a few minutes will result in the incongruent and sometimes complete leaching of metals, including strontium (Sr), from the cob. When using ⁸⁷Sr/⁸⁶Sr to determine the location of potential agriculture fields, it is best to either integrate several depth-integrated soil samples or to integrate several …

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 …

Mitigating Agrichemicals From An Artificial Runoff Event Using A Managed Riverine Wetland, Richard E. Lizotte Jr., F. Douglas Shields Jr, Justin N. Murdock, Robert Kröger, Scott S. Knight

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

We examined the mitigation efficiency of a managed riverine wetland amended with a mixture of suspended sediment, two nutrients (nitrogen and phosphorus), and three pesticides (atrazine, metolachlor, and permethrin) during a simulated agricultural runoff event. Hydrologic management of the 500 m-long, 25 mwide riverine wetland was done by adding weirs at both ends. The agrichemical mixture was amended to the wetland at the upstream weir simulating a four-hour, ~1 cm rainfall event from a 16 ha agricultural field. Water samples (1 L) were collected every 30 min within the first 4 h, then every 4 h until 48 h, and …

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 …

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) …

Specific Adaptation And Genetic Progress For Grain Yield In Great Plains Hard Winter Wheats From 1987 To 2010, Robert A. Graybosch, C. James Peterson

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

A previous investigation, using region-wide data from Great Plains wheat (Triticum aestivum L.) breeding trials, indicated a possible plateau in the rate of genetically determined yield potential. Data from the same USDA- Agricultural Research Service (ARS) coordinated long-term regional performance nurseries was used to further examine the rate of genetic improvement of Great Plains winter wheats in specific agroecological or production zones over the time period 1987 to 2010. The absolute grain yield of all entries and of the top fi ve most productive entries increased in the majority of production zones over this time period. The relative rate …

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, …

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 …

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 …

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 …

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 …

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) …