Digital Commons Network^™

Expected Economic Potential Of Substituting Legumes For Nitrogen In Bermudagrass Pastures, Jon T. Biermacher, The Samuel Roberts Noble Foundation, Inc. Reuter, M.K. Kering, J.K. Rogers, J. Blanton Jr, John A. Guretzky, T.J. Butler

Department of Agronomy and Horticulture: Faculty Publications

Grazing warm-season grass pastures with stocker cattle (Bos taurus) is an important economic activity in the southern Great Plains, and substantial increases in the price of N fertilizer have negatively affected profi tability of forage producers. The goal of the study was to determine if bermudagrass [Cynodon dactylon (L.) Pers.] pastures interseeded with either annual or perennial legumes are more profitable than the conventional method of fertilizing with 112 kg N ha^–1 commercial fertilizer. A completely randomized design grazing study was conducted in south-central Oklahoma during the spring and summer months of 2008, 2009, and 2010. …

Optimizing Cover Crop Benefits With Diverse Mixtures And An Alternative Termination Method, Samuel E. Wortman, Charles A. Francis, Mark L. Bernards, Rhae A. Drijber, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Previous studies have demonstrated benefits of individual cover crop species, but the value of diverse cover crop mixtures has received less attention. The objectives of this research were to determine the effects of spring-sown cover crop mixture diversity and mechanical cover crop termination method on cover crop and/or cash crop productivity, soil moisture and N, and profitability in an organic cropping system. An experiment was conducted between 2009 and 2011 near Mead, Nebraska, United States, where mixtures of two (2CC), four (4CC), six (6CC), and eight (8CC) cover crop species, or a summer annual weed mixture were included in a …

Brown Midrib2 (Bmr2) Encodes The Major 4-Coumarate: Coenzyme A Ligase Involved In Lignin Biosynthesis In Sorghum (Sorghum Bicolor (L.) Moench), Ana Saballos, Scott Sattler, Emiliano Sanchez, Timothy P. Foster, Zhanguo Xin, Chulhee Kang, Jeffrey F. Pedersen, Wilfred Vermerris

Department of Agronomy and Horticulture: Faculty Publications

Successful modification of plant cell-wall composition without compromising plant integrity is dependent on being able to modify the expression of specific genes, but this can be very challenging when the target genes are members of multigene families. 4-coumarate:CoA ligase (4CL) catalyzes the formation of 4-coumaroyl CoA, a precursor of both flavonoids and monolignols, and is an attractive target for transgenic down-regulation aimed at improving agro-industrial properties. Inconsistent phenotypes of transgenic plants have been attributed to variable levels of down-regulation of multiple 4CL genes. Phylogenetic analysis of the sorghum genome revealed 24 4CL(-like) proteins, five of which cluster with bona fide …

Switchgrass Harvest And Storage, Robert B. Mitchell, Marty R. Schmer

Department of Agronomy and Horticulture: Faculty Publications

The feedstock characteristics of the conversion platform will influence the optimal harvest and post harvest management practices for switchgrass. However, many of the harvest management practices are tied to plant phenology and will be similar across platforms. Proper harvest and storage of switchgrass will help provide a consistent and high-quality feedstock to the biorefinery. Bioenergyspecific switchgrass strains are high-yielding and in most cases can be harvested and baled with commercially available haying equipment. Many options are available for packaging switchgrass for storage and transportation, but large round bales or large rectangular bales are the most readily available and are in …

Quantitative Trait Locus Analysis Of Saturated Fatty Acids In A Population Of Recombinant Inbred Lines Of Soybean, Xianzhi Wang, Guo-Liang Jiang, Marci Green, Roy A. Scott, D. L. Hyten, P. B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

Soybean [Glycine max (L.) Merr.] is an important crop which contributes approximately 58% of the world’s oilseed production. Palmitic and stearic acids are the two main saturated fatty acids in soybean oil. Different levels of saturated fatty acids are desired depending on the uses of the soybean oil. Vegetable oil low in saturated fatty acids is preferred for human consumption, while for industrial applications, soybean oil with higher levels of saturated fatty acids is more suitable. The objectives of this study were to identify quantitative trait loci (QTL) for saturated fatty acids, analyze the genetic effects of single QTL …

Natural Variation In Iron Use Efficiency And Mineral Remobilization In Cucumber (Cucumis Sativus), Brian M. Waters, Grace Troupe

Department of Agronomy and Horticulture: Faculty Publications

Aims: Iron (Fe) is an essential micronutrient, and plant-available Fe is often limited in alkaline soils. Fe deficiency chlorosis decreases plant growth and yield. Identification of germplasm with high and low Fe use efficiency will allow studies to better understand the genetic components for breeding Fe efficient varieties.

Methods: A screen using cucumber (Cucumis sativus) seedlings identified varieties that maintained contrasting levels of chlorophyll under Fe deficiency or limitation. A time course of mineral dynamics in cotyledons was conducted.

Results: The variety Ashley had the highest chlorophyll under Fe deficiency and per unit Fe in the leaf, while …

Guide To Agave, Cinnamomum, Corymbia, Eucalyptus, Pandanus, And Sansevieria In The Flora Of Florida, Alan R. Franck

Molecular Biosciences Faculty Publications

Several species-rich groups of non-native taxa occur in Florida and can be difficult to identify. This synopsis provides identification keys and brief discussions of the naturalized species of six genera in Florida: Agave, Cinnamomum, Corymbia, Eucalyptus, Pandanus, and Sansevieria. Of the genera treated here, only one taxon is presumed to be a pre-Columbian native, Agave decipiens, and all others are considered exotic. Agave neglecta is treated as a synonym of A. weberi. Cinnamomum burmannii, Pandanus odorifer, and Sansevieria trifasciata are here reported for the first time in the flora …

Widespread Triploidy In Western North American Aspen (Populus Tremuloides), Karen E. Mock, Colin M. Callahan, M. Nurul Islam-Faridi, John D. Shaw, Hardeep S. Rai, Stewart C. Sanderson, Carol A. Rowe, Ronald J. Ryel, Michael D. Madritch, Richard S. Gardner, Paul G. Wolf

Aspen Bibliography

No abstract provided.

Possible New Arkansas Endemic Plant Revealed By Dna Sequence Analysis, A, K. P. Fawley, C. T. Witsell, M. W. Fawley, J. S. Breedlove, R. J. Brockman, A. C. Humphrey, J. M. Lawson, K. N. Mccallie, D. A. Prescott, J. T. Rushing, J. M. Whitaker

Journal of the Arkansas Academy of Science

Cardamine angustata var. ouachitana, a wildflower in the mustard family (Brassicaceae), was described by Smith in 1982 to include a form of Cardamine found only in the Ouachita Mountains of Arkansas. This variety is morphologically very similar to typical Cardamine angustata. The major difference noted by Smith for the two varieties was the complete lack of leaf hairs (trichomes) in the new variety, whereas typical Cardamine angustata normally possesses trichomes. However, Al-Shehbaz rejected the variety ouachitana and reduced it to synonymy with the typical C. angustata. The recommendation of Al-Shehbaz has been followed and the taxon Cardamine angustata var. ouachitana …

Tritimovirus P1 Functions As A Suppressor Of Rna Silencing And An Enhancer Of Disease Symptoms, Brock A. Young, Drake C. Stenger, Feng Qu, T. Jack Morris, Satyanarayana Tatineni, Roy French

Department of Plant Pathology: Faculty Publications

Wheat streak mosaic virus (WSMV) is an eriophyid mite-transmitted virus of the genus Tritimovirus, family Potyviridae. Complete deletion of helper component-proteinase (HC-Pro) has no effect on WSMV virulence or disease synergism, suggesting that a different viral protein suppresses RNA silencing. RNA silencing suppression assays using Nicotiana benthamiana 16C plants expressing GFP were conducted with each WSMV protein; only P1 suppressed RNA silencing. Accumulation of GFP siRNAs was markedly reduced in leaves infiltrated with WSMV P1 at both 3 and 6 days post infiltration relative to WSMV HC-Pro and the empty vector control. On the other hand, helper component-proteinase …

Evaluation Of Application Timing Efficacy Of Evito Fungicide On Field Corn In Nebraska, 2010, C. M. Schleicher, T. A. Jackson

Department of Plant Pathology: Faculty Publications

A foliar fungicide efficacy timing trial was conducted at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, NE. DeKalb corn hybrid DKC 61-69, rating of “good” (5 out of 9) for gray leaf spot and “very good” (3 out of 9) for common rust, was planted on 29 Apr in 30-in. rows with a target population of 30,000 plants/A. The trial area was disked the previous fall with a crop history of six years of continuous corn. Three treatments and a non-treated control were replicated six times in a randomized complete block design. Each plot was four …

Evaluation Of Foliar Fungicide Application Timing On Efficacy Of Field Corn At Wcrec In Western Nebraska, 2011, C. M. Schleicher, C. Langemeier, G. Kruger, T. A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

A foliar fungicide efficacy timing trial was conducted at the University of Nebraska-Lincoln West Central Research and Extension Center at North Platte, NE. NuTech corn hybrid 3A513, rating of 5 out of 9 (1=best, 9=worst) for gray leaf spot was planted on 10 May in 30 in. rows with a target population of 32,000 plants/A. The trial area was disked prior to planting with corn as the previous year’s crop. Furrows were built in season for flood irrigation. A herbicide program of Lumax (2.5 qt/A) + Atrazine (1 lb/A) + Glystar (20 oz/A) was applied on 25 Apr. 200 lb …

Evaluation Of Foliar Fungicide Application Timing On Efficacy Of Field Corn At Scal In Central Nebraska, 2011, C. M. Schleicher, T. A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

A foliar fungicide efficacy timing trial was conducted at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, NE. DeKalb corn hybrid DKC 62-54, rating of “good” (6 out of 9) for gray leaf spot (GLS) and “excellent” (2 out of 9) for common rust (CR), was planted on 5 May in 30 in. rows with a target population of 32,000 plants/A. The trial area had soybean as the previous year’s crop. On 9 May before plant emergence, a herbicide program of Roundup (1 pt/A), Verdict (16 fl oz/A) and Atrazine (1 lb/A) was applied to the trial …

Soybean Disease Profiles Ii: Stem And Root Rot Diseases, Loren J. Giesler, Robert M. Harveson, Tamra A. Jackson-Ziems, Kevin A. Korus, Bo Liu, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

Extension Circular 1904 (EC1904).

Photographs and disease descriptions of Brown Stem Rot (BSR), Charcoal Rot, Fusarium Wilt and Root Rot, Phytophthora Root and Stem Rot, Pod and Stem Blight, Phomopsis Seed Decay, Rhizoctonia Root and Cortical Rot, Sclerotinia Stem Rot, Seedling Blights, Soybean Cyst Nematode (SCN), Stem Canker, and Sudden Death Syndrome (SDS).

Corn Disease Profile Iii: Ear Rot Diseases And Grain Molds, Tamra A. Jackson-Ziems, Loren J. Giesler, Robert M. Harveson, Kevin A. Korus, Bo Liu, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

Extension Circular 1901 (EC1901).

Under certain conditions, corn ear rot and grain mold diseases are common and can lead to loss of grain quality. Moldy grain can be docked or rejected at the elevator. Additionally, some ear and grain pathogens may produce secondary metabolites called mycotoxins, which are toxic to animals and humans consuming the contaminated grain. Mycotoxin-contaminated grain can also be docked or rejected. Mycotoxin production may start in the field and continue after harvest, or it may start during storage if mold infection begins there. When grain storage is necessary, drying grain to less than 15 percent moisture …

Sunflower Disease Profiles Ii: Head And Stalk Rots And Wilts, Robert M. Harveson, Loren J. Giesler, Tamra A. Jackson, Bo Liu, Stephen N. Wegulo, Kevin A. Korus

Department of Plant Pathology: Faculty Publications

Extension Circular 1902 (EC1902).

Photographs and disease descriptions of Phoma/Phomopsis Stalk Rots, Bacterial Stalk Rot, Verticillium Wilt, Rhizopus Head Rot, and White Mold/Sclerotina Diseases.

Corn Disease Update, Tamra A. Jackson, Craig B. Langemeier, Greg R. Kruger

Department of Plant Pathology: Faculty Publications

Goss's Bacterial Wilt and Blight ... Symptoms ... Management ... 2011 Survey ... Literature Cited

Gray Leaf Spot

Seedling Diseases and Stalk/Crown Root Diseases

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Factors Influencing Deoxynivalenol Accumulation In Small Grain Cereals, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

Deoxynivalenol (DON) is a mycotoxin produced by the plant pathogenic fungi Fusarium graminearum and F. culmorum. These and other closely related fungi cause a disease known as Fusarium head blight (FHB) in small grain cereals. Other mycotoxins produced by FHB-causing fungi include nivalenol, T-2 toxin, and zearalenone. Ingestion of mycotoxin-contaminated food and feed can lead to toxicosis in humans and animals, respectively. DON is the predominant and most economically important of these mycotoxins in the majority of small grain-producing regions of the world. This review examines the factors that influence DON accumulation in small grain cereals from an agricultural perspective. …

Reflections On Plant And Soil Nematode Ecology: Past, Present And Future, Howard Ferris, Bryan S. Griffiths, Dorota L. Porazinska, Thomas O. Powers, Koon-Hui Wang, Mario Tenuta

Department of Plant Pathology: Faculty Publications

The purpose of this review is to highlight key developments in nematode ecology from its beginnings to where it stands today as a discipline within nematology. Emerging areas of research appear to be driven by crop production constraints, environmental health concerns, and advances in technology. In contrast to past ecological studies which mainly focused on management of plant-parasitic nematodes, current studies reflect differential sensitivity of nematode faunae. These differences, identified in both aquatic and terrestrial environments include response to stressors, environmental conditions, and management practices. Methodological advances will continue to influence the role nematodes have in addressing the nature of …

The Genome Of The Polar Eukaryotic Microalga Coccomyxa Subellipsoidea Reveals Traits Of Cold Adaptation, Guillaume Blanc, Irina V. Agarkova, Jane Grimwood, Alan Kuo, Andrew J. Brueggeman, David Dunigan, James Gurnon, Istvan Ladunga, Erika Lindquist, Susan Lucas, Jasmyn Pangilinan, Thomas Pröschold, Asaf Salamov, Jeremy Schmutz, Donald P. Weeks, Takashi Yamada, Alexandre Lomsadze, Mark Borodovsky, Jean-Michel Claverie, Igor V. Grigoriev, James L. Van Etten

Department of Plant Pathology: Faculty Publications

Background: Little is known about the mechanisms of adaptation of life to the extreme environmental conditions encountered in polar regions. Here we present the genome sequence of a unicellular green alga from the division chlorophyta, Coccomyxa subellipsoidea C-169, which we will hereafter refer to as C-169. This is the first eukaryotic microorganism from a polar environment to have its genome sequenced.

Results: The 48.8 Mb genome contained in 20 chromosomes exhibits significant synteny conservation with the chromosomes of its relatives Chlorella variabilis and Chlamydomonas reinhardtii. The order of the genes is highly reshuffled within synteny blocks, suggesting that intra-chromosomal rearrangements …

Transgenic Expression Of Lactoferrin Imparts Enhanced Resistance To Head Blight Of Wheat Caused By Fusarium Graminearum, Jigang Han, Dilip K. Lakshman, Leny C. Galvez, Sharmila Mitra, P. Stephen Baenziger, Amitava Mitra

Department of Plant Pathology: Faculty Publications

Background: The development of plant gene transfer systems has allowed for the introgression of alien genes into plant genomes for novel disease control strategies, thus providing a mechanism for broadening the genetic resources available to plant breeders. Using the tools of plant genetic engineering, a broad-spectrum antimicrobial gene was tested for resistance against head blight caused by Fusarium graminearum Schwabe, a devastating disease of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) that reduces both grain yield and quality.

Results: A construct containing a bovine lactoferrin cDNA was used to transform wheat using an Agrobacterium …

Assessing Genetic Diversity In The Web Blight Pathogen Thanatephorus Cucumeris (Anamorph = Rhizoctonia Solani) Subgroups Ag-1-Ie And Ag-1-If With Molecular Markers, N. González, James R. Steadman, Robert Higgins, Kent M. Eskridge

Department of Plant Pathology: Faculty Publications

Web blight, an important foliar disease of dry beans in the Americas, is a challenge to manage. We studied genetic variation of 92 isolates of Rhizoctonia solani subgroups AG-1-IE and AG-1-IF using DNA fingerprinting methods and mycelial compatibility grouping. The isolates were collected over 13 years from bean fields in the Dominican Republic, Honduras and Puerto Rico. Cluster and AMOVA analysis of combined data from two universal rice primers and two internal sequence repeats revealed significant genetic variation among and within populations of both subgroups. Variation was influenced by geographic origin and sampling year for AG-1-IE isolates and geographic origin …

Relevance Of Lysine Snorkeling In The Outer Transmembrane Domain Of Small Viral Potassium Ion Channels, Manuela Gebhardt, Leonhard M. Henkes, Sascha Tayefeh, Brigitte Hertel, Timo Greiner, James L. Van Etten, Dirk Baumeister, Christian Cosentino, Anna Moroni, Stefan M. Kast, Gerhard Thiel

Department of Plant Pathology: Faculty Publications

Transmembrane domains (TMDs) are often flanked by Lys or Arg because they keep their aliphatic parts in the bilayer and their charged groups in the polar interface. Here we examine the relevance of this so-called “snorkeling” of a cationic amino acid, which is conserved in the outer TMD of small viral K+ channels. Experimentally, snorkeling activity is not mandatory for KcvPBCV-1 because K29 can be replaced by most of the natural amino acids without any corruption of function. Two similar channels, KcvATCV-1 and KcvMT325, lack a cytosolic N-terminus, and neutralization of their equivalent cationic amino acids inhibits their function. To …

Rna-Seq Analysis Of The Sclerotinia Homoeocarpa – Creeping Bentgrass Pathosystem, Angela M. Orshinsky, Jinnan Hu, Stephen O. Opiyo, Venu Reddyvari-Channarayappa, Thomas K. Mitchell, Michael J. Boehm

Department of Plant Pathology: Faculty Publications

Sclerotinia homoeocarpa causes dollar spot disease, the predominate disease on highly-maintained turfgrass. Currently, there are major gaps in our understanding of the molecular interactions between S. homoeocarpa and creeping bentgrass. In this study, 454 sequencing technology was used in the de novo assembly of S. homoeocarpa and creeping bentgrass transcriptomes. Transcript sequence data obtained using Illumina’s first generation sequencing-by-synthesis (SBS) were mapped to the transcriptome assemblies to estimate transcript representation in different SBS libraries. SBS libraries included a S. homoeocarpa culture control, a creeping bentgrass uninoculated control, and a library for creeping bentgrass inoculated with S. homoeocarpa and incubated for …

Modeling An Improvement In Phosphorus Utilization In Tropical Agriculture, David Edelstein, David J. Tonjes

Technology & Society Faculty Publications

Studies of Terra Preta soils have generated interest in recreating their fertility elsewhere. Much of the research has focused on soil amendment charcoal (“biochar”). Terra Preta also contains bone fragments, producing a high concentration of phosphorus. Some forecast worldwide declines in phosphorus supplies, and better agricultural system management is required to improve phosphorus use efficiency. A conceptual model is offered to consider the influence of charcoal on bioavailability of phosphorus. The model describes a system where improvements in the chemical and biological condition of the soil result in increased phosphorus availability and cycling. Mechanisms of phosphorus/charcoal interaction are considered, and …

Prevalence And Behavior Of Blastobasis Repartella (Dietz) In Switchgrass, Krista Hegge

The Journal of Undergraduate Research

Switchgrass (Panicum virgatum) is growing in recognition as a potential source for biomass. In order to use switchgrass optimally as a crop for biofuel production potential pests need to be detected and studied. Currently, one pest being studied is the stem-boring larva of the moth Blastobasis repartella. The objective of this experiment was to compare effects of larval feeding on rhizome buds for two cultivars of switchgrass, and to observe and document feeding behavior of the larva. The two cultivars of switchgrass used were Pathfinder (PTH), a lowland variety, and Sunburst (SBS), an upland variety. Six, 15-cm2 samples of rhizome …

Sensing Development Of A Soybean Canopy Under P Or K Nutritional Stress, Martin M. Navarro

Theses and Dissertations--Plant and Soil Sciences

The normalized difference vegetative index (NDVI) has been correlated with physiological plant parameters and used to evaluate plant growth. There is little information about the use of this technique to detect soybean nutrient deficiencies. The objective of this work was to determine the ability of the NDVI sensor to detect P and K deficiencies, and grain yield reduction, in soybean. During 2010 and 2011, NDVI measurements were made on a soybean field trial site known to exhibit yield responses to both P and K nutrition. Four replicates of 8 levels each of P and K nutrition were evaluated. The NDVI …

Invasive Ecology Of Exotic Old World Bluestem Grasses And Insights For Coastal Prairie Restoration In South Texas, Marvin E. Ruffner

Theses and Dissertations--Plant and Soil Sciences

Despite the agronomic benefits of exotic grass plantings for pasture and rangeland forage, exotic grass invasions are capable of having dramatic and widespread impacts on native communities and ecosystems. Exotic Old World bluestem grasses (OWBG; Bothriochloa and Dichanthium spp.) have become increasingly invasive throughout the central and southern U.S. Little is known regarding the impacts of OWBG invasion on native grassland and savannah ecology and how to successfully control OWBG invasions in natural areas. Accordingly, this dissertation research had several objectives: 1) Evaluate the efficacy of herbicide and/or disking to control OWBG; 2) Assess the relative competitive ability of the …

The Role Of Auxin Resistant 1 (Axr1) In Arabidopsis Cytokinin Signaling, Yan Li

Theses and Dissertations--Plant and Soil Sciences

The plant hormone cytokinin plays essential roles in many aspects of growth and development. The cytokinin signal is transmitted by a multistep phosphorelay to the members of two functionally antagonistic classes of Arabidopsis response regulators (ARRs): the type-B ARRs (response activators) and type-A ARRs (negative-feedback regulators). Previous studies have shown that mutations in AXR1, encoding a subunit of the E1 enzyme in the related to ubiquitin (RUB) modification pathway, leads to decreased cytokinin sensitivity. This research shows that the cytokinin resistance of axr1 seedlings is suppressed by loss-of-function of type-A ARRs and that the cytokinin resistance caused by …

Antimicrobial Activity, Cytotoxicity And Phytochemical Analyses Of Rhus Aromatica, Rhus Glabra And Sanguinaria Canadensis Native To South Dakota, Gitanjali Nandakafle

Electronic Theses and Dissertations

A total of twenty five South Dakota native medicinal plants were screened against enterotoxigenic Escherichia coli using a disk diffusion assay. Out of these 25 plants, three plants Rhus aromatica, Rhus glabra and Sanguinaria canadensis demonstrated the highest bacterial inhibition. The minimum inhibitory concentrations (MIC) of these plant extracts were determined using a bacterial enumeration assay. Alamar Blue in vitro cytotoxicity test showed that all extracts have some toxic effect to porcine intestinal epithelial cell lines. Phytochemical analysis of these plant extracts indicated the presence high concentration of flavonoids and condensed tannins in R. aromatica and that R. glabra contained …