Agriculture Commons^™

Porocercospora Seminalis Gen. Et Comb. Nov., The Causal Organism Of Buffalograss False Smut, Bimal S. Amaradasa, Hugo Madrid, Johannes Z. Groenewald, Pedro W. Crous, Keenan L. Amundsen

Department of Agronomy and Horticulture: Faculty Publications

False smut caused by Cercospora seminalis is an important disease of buffalograss (Buchloe dactyloides) affecting seed production. The pathogen prevents normal caryopsis development and causes considerable yield loss and reduced seed germination. The current taxonomic placement of the false-smut causal pathogen in the genus Cercospora is incorrect based on its morphological characteristics and DNA phylogeny. In the present study the phylogenetic position of C. seminalis is clarified based on DNA sequence analysis of three loci namely the internal transcribed spacer (ITS) region, partial nuclear ribosomal large subunit (LSU) and partial sequences of the RNA polymerase II second largest …

Drought Effects On Composition And Yield For Corn Stover, Mixed Grasses, And Miscanthus As Bioenergy Feedstocks, Rachel Emerson, Amber Hoover, Allison Ray, Jeffrey Lacey, Marnie Cortez, Courtney Payne, Douglas L. Karlen, Stuart Birrell, David Laird, Robert Kallenbach, Josh Egenolf, Matthew Sousek, Thomas Voigt

Department of Agronomy and Horticulture: Faculty Publications

Drought conditions in 2012 were some of the most severe in recent history. The purpose of this study is to examine the impact of drought on quality, quantity, and theoretical ethanol yield (TEY) of three bioenergy feedstocks, corn stover, mixed grasses from Conservation Reserve Program lands, and Miscanthus × giganteus. To assess drought effects on these feedstocks, samples from 2010 (minimal to no drought) and 2012 (severe drought) were compared from multiple locations in the US. In all feedstocks, drought significantly increased extractives and reduced structural sugars and lignin; subsequently, TEYs were reduced 10–15%. Biomass yields were significantly reduced …

Arabidopsis Lipins, Pdat1 Acyltransferase, And Sdp1 Triacylglycerol Lipase Synergistically Direct Fatty Acids Toward Β-Oxidation, Thereby Maintaining Membrane Lipid Homeostasis, Jilian Fan, Chengshi Yan, Rebecca Roston, John Shanklin, Changcheng Xu

Department of Agronomy and Horticulture: Faculty Publications

Triacylglycerol (TAG) metabolism is a key aspect of intracellular lipid homeostasis in yeast and mammals, but its role in vegetative tissues of plants remains poorly defined. We previously reported that PHOSPHOLIPID:DIACYLGLYCEROL ACYLTRANSFERASE1 (PDAT1) is crucial for diverting fatty acids (FAs) from membrane lipid synthesis to TAG and thereby protecting against FA-induced cell death in leaves. Here, we show that overexpression of PDAT1 enhances the turnover of FAs in leaf lipids. Using the trigalactosyldiacylglycerol1-1 (tgd1-1) mutant, which displays substantially enhanced PDAT1- mediated TAG synthesis, we demonstrate that disruption of SUGAR-DEPENDENT1 (SDP1) TAG lipase or PEROXISOMAL TRANSPORTER1 (PXA1) severely decreases …

Identification Of Differentially Expressed Genes Between Sorghum Genotypes With Contrasting Nitrogen Stress Tolerance By Genome-Wide Transcriptional Profiling, Malleswari Gelli, Yongchao Duo, Anji Reddy Konda, Chi Zhang, David R. Holding, Ismail M. Dweikat

Department of Agronomy and Horticulture: Faculty Publications

Background: Sorghum is an important cereal crop, which requires large quantities of nitrogen fertilizer for achieving commercial yields. Identification of the genes responsible for low-N tolerance in sorghum will facilitate understanding of the molecular mechanisms of low-N tolerance, and also facilitate the genetic improvement of sorghum through marker-assisted selection or gene transformation. In this study we compared the transcriptomes of root tissues from seven sorghum genotypes having differential response to low-N stress.

Results: Illumina RNA-sequencing detected several common differentially expressed genes (DEGs) between four low-N tolerant sorghum genotypes (San Chi San, China17, KS78 and high-NUE bulk) and three …

A Genome-Wide Association Study Of Seed Protein And Oil Content In Soybean, Eun-Young Hwang, Qijian Song, Gaofeng Jia, James E. Specht, David L. Hyten, Jose Costa, Perry B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

Background: Association analysis is an alternative to conventional family-based methods to detect the location of gene(s) or quantitative trait loci (QTL) and provides relatively high resolution in terms of defining the genome position of a gene or QTL. Seed protein and oil concentration are quantitative traits which are determined by the interaction among many genes with small to moderate genetic effects and their interaction with the environment. In this study, a genome-wide association study (GWAS) was performed to identify quantitative trait loci (QTL) controlling seed protein and oil concentration in 298 soybean germplasm accessions exhibiting a wide range of …

Seed Guide 2014: Unl Extension Circular 103. Winter Seed Guide -- August 2014, Teshome Regassa, P. Stephen Baenziger, Greg Kruger, Dipak Santra

Department of Agronomy and Horticulture: Faculty Publications

WINTER WHEAT PERFORMANCE

RESULTS AT INDIVIDUAL LOCATIONS

Location Summary for Nebraska Winter Wheat Variety Tests - 2014

Entries and Contact Information

Soil Type, Previous Crop, Fertilizers and Herbicides/Fungicides Applied to Nebraska Winter Wheat Variety Tests -2014

Southeast Dryland Wheat Variety Tests - 2014 Saline, Saunders, and Lancaster Counties & Southeast Dryland Wheat Variety Tests 2010- 2014

South Central Dryland Wheat Variety Test - 2014 Clay County & South Central Dryland Wheat Variety Tests 2010-2014

West Central Dryland Wheat Variety Tests - 2014 Furnas, Red Willow, and Lincoln Counties & West Central Dryland Wheat Variety Tests 2010- 2014

West Dryland Wheat …

Switchgrass (Panicum Virgatum L) Flag Leaf Transcriptomes Reveal Molecular Signatures Of Leaf Development, Senescence, And Mineral Dynamics, Nathan A. Palmer, Teresa Donze-Reiner, David Horvath, Tiffany Heng-Moss, Brian M. Waters, Christian M. Tobias, Gautam Sarath

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass flag leaves can be expected to be a source of carbon to the plant, and its senescence is likely to impact the remobilization of nutrients from the shoots to the rhizomes. However, many genes have not been assigned a function in specific stages of leaf development. Here, we characterized gene expression in flag leaves over their development. By merging changes in leaf chlorophyll and the expression of genes for chlorophyll biosynthesis and degradation, a four-phase molecular roadmap for switchgrass flag leaf ontogeny was developed. Genes associated with early leaf development were up-regulated in phase 1. Phase 2 leaves had …

Comparison Of Winter Strawberry Production In A Commercial Heated High Tunnel Versus A University Greenhouse, Ellen T. Paparozzi, Ryan Pekarek, George E. Meyer, Stacy A. Adams, M. Elizabeth Conley, David P. Lambe, Paul Read, Erin E. Blankenship

Department of Agronomy and Horticulture: Faculty Publications

For the past 4 years, the University of Nebraska strawberry team has worked to develop low cost, sustainable methods for farmers and growers to produce strawberries in a double polyethylene greenhouse during the winter. This past year, this growing system was adapted to become a commercial grower’s heated high tunnel for the winter/spring of 2013-14. The idea was to scale up to a farm-size demonstration and compare it to the university greenhouse production system with a goal to expand marketing opportunities for strawberries into the winter season.

Fate Of C And N From Dung Pats Into Soil, Kenneth Evans, Ana Wingeyer, Martha Mamo, Pamela Sutton, Jeff Bradshaw, Kent M. Eskridge, Matt Judkins, Jenna Beckmann, Erin Hatch

Department of Agronomy and Horticulture: Faculty Publications

No abstract provided.

Greenhouse Gas Emissions From Soil Treated With Dung Pats, Kenneth Evans, Ana Wingeyer, Martha Mamo, Walter H. Schacht, Pamela Sutton, Kent M. Eskridge

Department of Agronomy and Horticulture: Faculty Publications

No abstract provided.

How Do Various Maize Crop Models Vary In Their Responses To Climate Change Factors?, Simon Bassu, Nadine Brisson, Jean-Louis Durand, Kenneth J. Boote, Jon Lizaso, James Jones, Cynthia Rosenzweig, Alex Ruane, Myriam Adam, Christian Baron, Bruno Basso, Christian Biernath, Hendrick Boogaard, Sjaak Conijn, Marc Corbeels, Delphine Deryng, Giacomo De Sanctis, Sebastian Gayler, Patricio Grassini, Jerry Hatfield, Steven Hoek, Cesar Izaurralde, Raymond Jongschaap, Armen Kemanian, Christian Kersebaum, Soo-Hyung Kim, Naresh Kumar, David Makowski, Christoph Muller, Claas Nendel, Eckart Priesack, Maria Virinia Pravia, Federico Sau, Iurii Shcherbak, Fulu Tao, Edmar Teixeira, Dennis Timlin, Katharina Waha

Department of Agronomy and Horticulture: Faculty Publications

Potential consequences of climate change on crop production can be studied using mechanistic crop simulation models. While a broad variety of maize simulation models exist, it is not known whether different models diverge on grain yield responses to changes in climatic factors, or whether they agree in their general trends related to phenology, growth, and yield. With the goal of analyzing the sensitivity of simulated yields to changes in temperature and atmospheric carbon dioxide concentrations [CO2], we present the largest maize crop model intercomparison to date, including 23 different models. These models were evaluated for four locations representing a wide …

Global Changes In Mineral Transporters In Tetraploid Switchgrasses (Panicum Virgatum L.), Nathan A. Palmer, Aaron J. Saathoff, Brian M. Waters, Teresa Donze, Tiffany M. Heng-Moss, Paul Twigg, Christian M. Tobias, Gautam Sarath

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum L) is a perennial, C4 grass with great potential as a biofuel crop. An in-depth understanding of the mechanisms that control mineral uptake, distribution, and remobilization will benefit sustainable production. Nutrients are mobilized from aerial portions to below-ground crowns and rhizomes as a natural accompaniment to above-ground senescence post seed-set. Mineral uptake and remobilization is dependent on transporters, however, little if any information is available about the specific transporters that are needed and how their relative expression changes over a growing season.Using well-defined classes of mineral transporters, we identified 520 genes belonging to 40 different transporter …

Grazing Management Effect On Micro- And Macro- Scale Fate Of C And N In Rangelands, Martha Mamo, Jeff Bradshaw, Richard Ferguson, Kent M. Eskridge, John A. Guretzky, Karla Jenkins, Walter H. Schacht, Jerry Volesky, Sean Whipple, Anita Wingeyer, Haishun Yang

Department of Agronomy and Horticulture: Faculty Publications

No abstract provided.

Quantitative Proteomic Analysis Of The Salmonella-Lettuce Interaction, Yuping Zhang, Renu Nandakumar, Shannon L. Bartelt-Hunt, Daniel D. Snow, Laurie Hodges, Xu Li

Department of Agronomy and Horticulture: Faculty Publications

Human pathogens can internalize food crops through root and surface uptake and persist inside crop plants. The goal of the study was to elucidate the global modulation of bacteria and plant protein expression after Salmonella internalizes lettuce. A quantitative proteomic approach was used to analyse the protein expression of Salmonella enterica serovar Infantis and lettuce cultivar Green Salad Bowl 24 h after infiltrating S. Infantis into lettuce leaves. Among the 50 differentially expressed proteins identified by comparing internalized S. Infantis against S. Infantis grown in Luria Broth, proteins involved in glycolysis were down-regulated, while one protein involved in ascorbate …

Genotyping By Sequencing For Genomic Prediction In A Soybean Breeding Population, Diego Jarquin, Kyle Kocak, Luis Posadas, Katie Hyma, Joseph Jedlicka, George L. Graef, Aaron Lorenz

Department of Agronomy and Horticulture: Faculty Publications

Background: Advances in genotyping technology, such as genotyping by sequencing (GBS), are making genomic prediction more attractive to reduce breeding cycle times and costs associated with phenotyping. Genomic prediction and selection has been studied in several crop species, but no reports exist in soybean. The objectives of this study were (i) evaluate prospects for genomic selection using GBS in a typical soybean breeding program and (ii) evaluate the effect of GBS marker selection and imputation on genomic prediction accuracy. To achieve these objectives, a set of soybean lines sampled from the University of Nebraska Soybean Breeding Program were genotyped using …

Nonsyntenic Genes Drive Highly Dynamic Complementation Of Gene Expression In Maize Hybrids, Anja Paschold, Nick B. Larson, Caroline Marcon, James C. Schnable, Cheng-Ting Yeh, Christa Lanz, Dan Nettleton, Hans-Peter Piepho, Patrick S. Schnable, Frank Hochholdinger

Department of Agronomy and Horticulture: Faculty Publications

Maize (Zea mays) displays an exceptional level of structural genomic diversity, which is likely unique among higher eukaryotes. In this study, we surveyed how the genetic divergence of two maize inbred lines affects the transcriptomic landscape in four different primary root tissues of their F1-hybrid progeny. An extreme instance of complementation was frequently observed: genes that were expressed in only one parent but in both reciprocal hybrids. This single-parent expression (SPE) pattern was detected for 2341 genes with up to 1287 SPE patterns per tissue. As a consequence, the number of active genes in hybrids exceeded that of …

Dt2 Is A Gain-Of-Function Mads-Domain Factor Gene That Specifies Semideterminacy In Soybean, Jieqing Ping, Yunfeng Liu, Lianjun Sun, Meixia Zhao, Yinghui Li, Zongxiang Tang, Hanh Nguyen, Zhixi Tian, Lijuan Qiu, Randall L. Nelson, Thomas E. Clemente, James Specht, Jianxin Ma

Department of Agronomy and Horticulture: Faculty Publications

Similar to Arabidopsis thaliana, the wild soybeans (Glycine soja) and many cultivars exhibit indeterminate stem growth specified by the shoot identity gene Dt1, the functional counterpart of Arabidopsis TERMINAL FLOWER1 (TFL1). Mutations in TFL1 and Dt1 both result in the shoot apical meristem (SAM) switching from vegetative to reproductive state to initiate terminal flowering and thus produce determinate stems. A second soybean gene (Dt2) regulating stem growth was identified, which, in the presence of Dt1, produces semideterminate plants with terminal racemes similar to those observed in determinate plants. Here, we report positional …

Nebraska’S Groundwater Legacy: Nitrate Contamination Beneath Irrigated Cropland, Mary E. Exner Spaulding, Aaron J. Hirsh, Roy F. Spalding

Department of Agronomy and Horticulture: Faculty Publications

A 31 year record of ~44,000 nitrate analyses in ~11,500 irrigation wells was utilized to depict the decadal expansion of groundwater nitrate contamination (N>10 mg/L) in the irrigated corn-growing areas of eastern and central Nebraska and analyze long-term nitrate concentration trends in 17 management areas (MAs) subject to N fertilizer and budgeting requirements. The 1.3 M contaminated hectares were characterized by irrigation method, soil drainage, and vadose zone thickness and lithology. The areal extent and growth of contaminated groundwater in two predominately sprinkler-irrigated areas was only ~20% smaller beneath well-drained silt loams with thick clayey-silt unsaturated layers and unsaturated …

Multilocation Corn Stover Harvest Effects On Crop Yields And Nutrient Removal, Douglas L. Karlen, Stuart J. Birrell, Jane M.F. Johnson, Shannon L. Osborne, Thomas E. Schumacher, Gary E. Varvel, Richard B. Ferguson, Jeff M. Novak, James R. Frederick, John M. Baker, John A. Lamb, Paul R. Alder, Greg W. Roth, Emerson D. Nafziger

Department of Agronomy and Horticulture: Faculty Publications

Corn (Zea mays L.) stover was identified as an important feedstock for cellulosic bioenergy production because of the extensive area upon which the crop is already grown. This report summarizes 239 site-years of field research examining effects of zero, moderate, and high stover removal rates at 36 sites in seven different states. Grain and stover yields from all sites as well as N, P, and K removal from 28 sites are summarized for nine longitude and six latitude bands, two tillage practices (conventional vs no tillage), two stoverharvest methods (machine vs calculated), and two crop rotations {continuous corn (maize) …

Constructing A Block And Fence Growing Bench For Use With A Capillary Mat Irrigation System For Greenhouse Plant Production, Stacy A. Adams, Ellen T. Paparozzi

Department of Agronomy and Horticulture: Faculty Publications

Plant health and productivity of greenhouse grown plants are improved when grown on raised benches where they can have optimal environmental conditions. Often seasonal plant growers set plants directly on the greenhouse floor which is less than optimum due to temperature stratification, cold drafts, poor air movement, and wet conditions. This publication describes how to construct simple and economical growing benches and a irrigation system useful for the specialty crop grower.

Do Cover Crops Increase Or Decrease Nitrous Oxide Emissions? A Meta-Analysis, Andrea D. Basche, F. E. Miguez, T. C. Kaspar, M. J. Castellano

Department of Agronomy and Horticulture: Faculty Publications

There are many environmental benefits to incorporating cover crops into crop rotations, such as their potential to decrease soil erosion, reduce nitrate (NO₃) leaching, and increase soil organic matter. Some of these benefits impact other agroecosystem processes, such as greenhouse gas emissions. In particular, there is not a consensus in the literature regarding the effect of cover crops on nitrous oxide (N₂O) emissions. Compared to site-specific studies, meta-analysis can provide a more general investigation into these effects. Twenty-six peer-reviewed articles including 106 observations of cover crop effects on N₂O emissions from the soil surface …

Challenges And Opportunities In Transdisciplinary Science: The Experience Of Next Generation Scientists In An Agriculture And Climate Research Collaboration, Andrea D. Basche, Gabrielle E. Roesch-Mcnally, Lindsay A. Pease, Christopher D. Eidson, Guy Bou Lahdou, Mike W. Dunbar, Trevor J. Frank, Laura Frescoln, Lei Gu, Ryan Nagelkirk, Jose Pantoja, Adam K. Wilke

Department of Agronomy and Horticulture: Faculty Publications

Agriculture in the twenty-first century faces unprecedented challenges from increasing climate variability to growing demands on natural resources to globalizing economic markets. These emerging agricultural issues, spanning both human and natural dimensions, are uniquely formulated, exceedingly complex, and difficult to address within existing disciplinary domains (Eigenbrode et al. 2007; Reganold et al. 2011; Foley et al. 2005; Hansen et al. 2013). Therefore, the next generation of scientists working on these issues must not only be highly trained within a disciplinary context but must also have the capacity to collaborate with others to solve systems-level problems.

The Carbon-Nitrogen Balance Of The Nodule And Its Regulation Under Elevated Carbon Dioxide Concentration, Marc Libault

Department of Agronomy and Horticulture: Faculty Publications

Legumes have developed a unique way to interact with bacteria: in addition to preventing infection from pathogenic bacteria like any other plant, legumes also developed a mutualistic symbiotic relationship with one gender of soil bacteria: rhizobium. This interaction leads to the development of a new root organ, the nodule, where the differentiated bacteria fix for the plant the atmospheric dinitrogen (atmN₂). In exchange, the symbiont will benefit from a permanent source of carbon compounds, products of the photosynthesis. The substantial amounts of fixed carbon dioxide dedicated to the symbiont imposed to the plant a tight regulation of the …

Common Sunflower Seedling Emergence Across The U.S. Midwest, Sharon A. Clay, Adam Davis, Anita Dille, John Lindquist, Analiza H. M. Ramirez, Christy Sprague, Graig Reicks, Frank Forcella

Department of Agronomy and Horticulture: Faculty Publications

Predictions of weed emergence can be used by practitioners to schedule POST weed management operations. Common sunflower seed from Kansas was used at six Midwestern U.S. sites to examine the variability that 16 climates had on common sunflower emergence. Nonlinear mixed effects models, using a flexible sigmoidal Weibull function that included thermal time, hydrothermal time, and a modified hydrothermal time (with accumulation starting from January 1 of each year), were developed to describe the emergence data. An iterative method was used to select an optimal base temperature (T_b) and base and ceiling soil matric potentials (ψ_b and …

Optimal Copper Supply Is Required For Normal Plant Iron Deficiency Responses, Brian M. Waters, Laura C. Armbrust

Department of Agronomy and Horticulture: Faculty Publications

Iron (Fe) and copper (Cu) homeostasis are tightly linked across biology. Understanding crosstalk between Fe and Cu nutrition could lead to strategies for improved growth on soils with low or excess metals, with implications for agriculture and phytoremediation. Here, we show that Cu and Fe nutrition interact to increase or decrease Fe and/or Cu accumulation in leaves and Fe uptake processes. Leaf Cu concentration increased under low Fe supply, while high Cu lowered leaf Fe concentration. Ferric reductase activity, an indicator of Fe demand, was inhibited at insufficient or high Cu supply. Surprisingly, plants grown without Fe were more susceptible …

Remote Estimation Of Nitrogen And Chlorophyll Contents In Maize At Leaf And Canopy Levels, Michael Schlemmer, Anatoly A. Gitelson, James S. Schepers, Richard B. Ferguson, Y. Peng, J. Shanahan, Donald Rundquist

Department of Agronomy and Horticulture: Faculty Publications

Leaf and canopy nitrogen (N) status relates strongly to leaf and canopy chlorophyll (Chl) content. Remote sensing is a tool that has the potential to assess N content at leaf, plant, field, regional and global scales. In this study, remote sensing techniques were applied to estimate N and Chl contents of irrigated maize (Zea mays L.) fertilized at five N rates. Leaf N and Chl contents were determined using the red-edge chlorophyll index with R2 of 0.74 and 0.94, respectively. Results showed that at the canopy level, Chl and N contents can be accurately retrieved using green and red-edge Chl …

Nebraska Variety And Hybrid Tests: Spring Seed Guide - 2014, Teshome Regassa, Dipak Santra, Charles A. Shapiro, Greg Kruger, Bruce Anderson

Department of Agronomy and Horticulture: Faculty Publications

Corn Hybrid Tests Summary...........3–6

Growing Degree Days and Precipitation by County Charts...........7

Corn Tables 2013 A–F.............8–11

Test Location Map.......................... 11

Corn Hybrid Tests........................12–16

Soybean Variety Tests Summary.....................17–18

Soybean Tables 2013 A–F......19–21

Soybean Variety Tests............22–23

Sunflower Variety Tests......24–28

Pea Variety Test......29

Proso Millet Variety Test .... 30

Automated Conserved Non-Coding Sequence (Cns) Discovery Reveals Differences In Gene Content And Promoter Evolution Among Grasses, Gina Marie Turco, James C. Schnable, Brent S. Pedersen, Michael Freeling

Department of Agronomy and Horticulture: Faculty Publications

Conserved non-coding sequences (CNS) are islands of non-coding sequence that, like protein coding exons, show less divergence in sequence between related species than functionless DNA. Several CNSs have been demonstrated experimentally to function as cis-regulatory regions. However, the specific functions of most CNSs remain unknown. Previous searches for CNS in plants have either anchored on exons and only identified nearby sequences or required years of painstaking manual annotation. Here we present an open source tool that can accurately identify CNSs between any two related species with sequenced genomes, including both those immediately adjacent to exons and distal sequences separated by …

2013 Fall Seed Guide, Teshome Regassa, P. Stephen Baenziger, Greg Kruger, Dipak Santra

Department of Agronomy and Horticulture: Faculty Publications

Nebraska Winter Wheat Variety Tests

Locations for Winter Wheat

Winter Wheat Characteristics

Alfalfa Variety Tests

Cool Season Grasses

Winter Barley Variety Tests

Triticale

NCIA Seed Book

Rate Of Shattercane × Sorghum Hybridization In Situ, Jared J. Schmidt, Jeffrey F. Pedersen, Mark L. Bernards, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Cultivated sorghum [Sorghum bicolor (L.) Moench subsp. bicolor] can interbreed with a feral weedy relative shattercane [S. bicolor nothosubsp. drummondii (Steud.) de Wet ex Davidse]. Traits introduced from cultivated sorghum could contribute to the invasiveness of a shattercane population. An experiment was conducted to determine the potential for pollenmediated gene flow from grain sorghum to shattercane. Shattercane with juicy midrib (dd) was planted in soybean [Glycine max (L.) Merr.] fields during 2 yr in concentric arcs at varying distances from a 0.39 ha sorghum pollen source with dry midrib (DD). The arcs …