Agriculture Commons^™

Pheromone–Mediated Mating Disruption In The Millet Stem Borer, Coniesta Ignefusalis (Lepidoptera: Pyralidae), Ousmane Youm, Yacouba Maliki, David R. Hall, Dudley I. Farman, John E. Foster

Department of Entomology: Faculty Publications

The millet stem borer, Coniesta ignefusalis Hampson (Lepidoptera: Pyralidae), is a major pest of pearl millet in the Sahelian region of Africa. The female sex pheromone has been identified and synthesized, and previous research had shown that the synthetic pheromone could cause high levels of reproductive communication disruption in small plots when released at rates of 640 mg/ha/day, using PVC resin formulation renewed every seven days to maintain efficiency. In the present research, in experiments in farmers’ fields in Niger, 86.8% (SE = 2.6%) communication disruption was achieved when polyethylene vials loaded with 0.5 mg pheromone at 400 dispensers/ha were …

An Investigation Of Reflective Mulches For Use Over Capillary Mat Systems For Winter-Time Greenhouse Strawberry Production, George E. Meyer, Ellen T. Paparozzi, Elizabeth Walter-Shea, Erin E. Blankenship, Stacy A. Adams

Department of Agronomy and Horticulture: Faculty Publications

Photosynthethically active radiation (PAR) is a principle environmental variable used by horticultural specialists, agronomists and ecosystem modelers to characterize the quantity and quality of light conducive to plant growth and development. Spatial distribution of PAR in a greenhouse can be quite variable and diffuse throughout the day time photoperiod, especially at low sun angles in northern regions of the United States. Four colors of reflective plastic mulches (white, red, olive, and black) were evaluated for winter-time strawberry (Fragaria × ananassa Duch.) production based on their reflectance and transmittance properties in a double-polyethylene, plastic-glazed Quonset greenhouse inNebraska. The spectral properties …

Inheritance Of Grain Polyphenol Oxidase (Ppo) Activity In Multiple Wheat (Triticum Aestivum L.) Genetic Backgrounds, Somrudee Nilthong, Robert A. Graybosch, P. Stephen Baenziger

Department of Agronomy and Horticulture: Faculty Publications

Grain polyphenol oxidase (PPO) activity can cause discoloration of wheat (Triticum aestivum L.) food products. Five crosses (PI 117635/Antelope; Fielder/ NW03681; Fielder/Antelope; NW07OR1070/Antelope; NW07OR1066/OR2050272H) were selected to study the genetic inheritance of PPO activity. STS markers, PPO18, PPO29 and STS01, were used to identify lines with putative alleles at the Ppo-A1 and Ppo-D1 loci conditioning low or high PPO activity. ANOVA showed significant genotypic effects on PPO activity (P\0.0001) in all populations. The generations and generation 9 genotype effects were not significant in any population. A putative third (null) genotype at Ppo-A1 (no PCR fragments for PPO18) was discovered …

Identification And Characterization Of Four Missense Mutations In Brown Midrib 12 (Bmr12), The Caffeic O-Methyltranferase (Comt) Of Sorghum, Scott E. Sattler, Nathan A. Palmer, Ana Saballos, Ann M. Greene, Zhanguo Xin, Gautam Sarath, Wilfred Vermerris, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Modifying lignin content and composition are targets to improve bioenergy crops for cellulosic conversion to biofuels. In sorghum and other C4 grasses, the brown midrib mutants have been shown to reduce lignin content and alter its composition. Bmr12 encodes the sorghum caffeic O-methyltransferase, which catalyzes the penultimate step in monolignol biosynthesis. From an EMS-mutagenized TILLING population, four bmr12 mutants were isolated. DNA sequencing identified the four missense mutations in the Bmr12 coding region, which changed evolutionarily conserved amino acids Ala71Val, Pro150Leu, Gly225Asp, and Gly325Ser. The previously characterized bmr12 mutants all contain premature stop codons. These newly identified mutants, along …

Agriculture And Food In Crisis: Conflict, Resistance, And Renewal [Book Review], Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Edited by Fred Magdoff and Brian Tokar. 2010. Monthly Review Press, New York, New York, United States. 348 p. Paperback, cloth US$ 75.00, paper US$ 18.95, ISBN-13 978-1-58367-226-6.

That doubling of food production over the next four decades will be needed to adequately nourish our human population is not news, but the incredible steps essential to achieve that goal and their political and social implications are less well reported. In this series of 16 essays edited by Fred Magdoff and Brian Tokar, several thoughtful specialists in global food issues explore the historical, biological, economic, energy, political and social dimensions of …

Estimating Construction Costs For A Low-Cost Quonset-Style Greenhouse, David P. Lambe, Stacy A. Adams, Ellen T. Paparozzi

Department of Agronomy and Horticulture: Faculty Publications

Double polyethylene Quonset-style greenhouses offergrowers and farmers a more cost-effective structure than glass- or acrylic-covered structures for growing plants off-season. These greenhouses are especially applicablefor producing off-season high value crops such as fruits and vegetables for local markets. To support this production alternative, this publication contains a list of greenhouse components, the start-up costs associated with these items and an estimate of the number of person hours required to assemble and outfit a 24-foot-by-72-foot double polyethylene, air-inflated greenhouse structure. As there are many options available for building double polyethylene greenhouses, the main purpose of this publication is to identify the …

The ‘Pi 438489b’ By ‘Hamilton’ Snp-Based Genetic Linkage Map Of Soybean [Glycine Max (L.) Merr.] Identified Quantitative Trait Loci That Underlie Seedling Sds Resistance, Kassem My Abdelmajid, Laura Ramos, Leonor Leandro, Gladys Mbofung, D. L. Hyten, Stella K. Kantartzi, Robert L. Grier Iv, Victor N. Njiti, Khalid Meksem

Department of Agronomy and Horticulture: Faculty Publications

Soybeans [Glycine max (L.) Merr.] are susceptible to many diseases including fungal diseases such as soybean sudden death syndrome (SDS). Several studies reported SDS resistance quantitative trait loci (QTL) on the soybean genome using different recombinant inbred line (RIL) populations and low density genetic linkage maps. High density exclusively single nucleotide polymorphisms-based (SNP-based) maps were not yet reported in soybean. The objectives of this study were (1) to construct a high density SNP-based genetic linkage map of soybean using the ‘PI438489B’ by ‘Hamilton’ (PIxH, n=50) recombinant inbred line population, and (2) to map QTL for SDS resistance using this …

Structural Variants In The Soybean Genome Localize To Clusters Of Biotic Stress-Response Genes, Leah K. Mchale, William J. Haun, Wayne W. Xu, Pudota B. Bhaskar, Justin E. Anderson, D. L. Hyten, Daniel J. Gerhardt, Jeffrey A. Jeddeloh, Robert M. Stupar

Department of Agronomy and Horticulture: Faculty Publications

Genome-wide structural and gene content variations are hypothesized to drive important phenotypic variation within a species. Structural and gene content variations were assessed among four soybean (Glycine max) genotypes using array hybridization and targeted resequencing. Many chromosomes exhibited relatively low rates of structural variation (SV) among genotypes. However, several regions exhibited both copy number and presence-absence variation, the most prominent found on chromosomes 3, 6, 7, 16, and 18. Interestingly, the regions most enriched for SV were specifically localized to gene-rich regions that harbor clustered multigene families. The most abundant classes of gene families associated with these regions …

Identification Of Positive Yield Qtl Alleles From Exotic Soybean Germplasm In Two Backcross Populations, K.-S. Kim, B. W. Diers, D. L. Hyten, M. A. Rouf Mian, J. G. Shannon, R. L. Nelson

Department of Agronomy and Horticulture: Faculty Publications

Increasing seed yield is an important breeding goal of soybean [Glycine max (L.) Merr.] improvement efforts. Due to the small number of ancestors and subsequent breeding and selection, the genetic base of current soybean cultivars in North America is narrow. The objective of this study was to map quantitative trait loci (QTL) in two backcross populations developed using soybean plant introductions as donor parents. The first population included 116 BC₂F₃-derived lines developed using ‘‘Elgin’’ as the recurrent parent and PI 436684 as the donor parent (E population). The second population included 93 BC₃F …

Molecular Mapping Of Soybean Rust Resistance In Soybean Accession Pi 561356 And Snp Haplotype Analysis Of The Rpp1 Region In Diverse Germplasm, Ki-Seung Kim, Jair R. Unfried, D. L. Hyten, Reid D. Frederick, Glen L. Hartman, Randall L. Nelson, Qijian Song, Brian W. Diers

Department of Agronomy and Horticulture: Faculty Publications

Soybean rust (SBR), caused by Phakopsora pachyrhizi Sydow, is one of the most economically important and destructive diseases of soybean [Glycine max (L.) Merr.] and the discovery of novel SBR resistance genes is needed because of virulence diversity in the pathogen. The objectives of this research were to map SBR resistance in plant introduction (PI) 561356 and to identify single nucleotide polymorphism (SNP) haplotypes within the region on soybean chromosome 18 where the SBR resistance gene Rpp1 maps. One-hundred F_2:3 lines derived from a cross between PI 561356 and the susceptible experimental line LD02-4485 were genotyped with genetic …

Advances In Genome Sequencing And Genotyping Technology For Soybean Diversity Analysis, David L. Hyten

Department of Agronomy and Horticulture: Faculty Publications

The completion of a soybean draft whole genome sequence along with advances in sequencing and genotyping technologies are creating a revolution in soybean genomics. The draft whole genome sequence of soybean is allowing researchers to fully take advantage of this new technology and is rapidly changing how soybean germ plasm is mined. Genetic markers such as SNPs can be quickly identified by using next generation sequencing and assayed on a large number of materials using advanced technologies that can genotype tens of thousands of markers on thousands of individuals very rapidly. This ability to qUickly identify and genotype genetic diversity …

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 …

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 …

Enantioselective Demethylation: The Key To The Nornicotine Enantiomeric Composition In Tobacco Leaf, Bin Cai

Theses and Dissertations--Plant and Soil Sciences

Nicotine and nornicotine are the two main alkaloids that accumulate in Nicotiana tabacum L. (tobacco), and nornicotine is the N-demethylation metabolite of nicotine. Nicotine is synthesized in the root, and probably primarily in the root tip. Both nicotine and nornicotine exist as two isomers that differ from each other by the orientation of H atom at the C-2' position on the pyrrolidine ring. (S)-nicotine is the dominant form in tobacco leaf and the enantiomer fraction of nicotine (EF_nic), the fraction of (R)-enantiomer over the total nicotine, is approximately 0.002. Despite considerable efforts to elucidate nicotine and nornicotine …

Method Development For Detecting And Characterizing Manufactured Silver Nanoparticles In Soil Pore Water Using Asymmetrical Flow Field-Flow Fractionation, Annie R. Whitley

Theses and Dissertations--Plant and Soil Sciences

Recent advances in nanotechnology have led to the production of materials with nanoscale dimensions (nm) and properties distinctly different from their bulk (>100 nm) counterparts. With increased use, it is inevitable that nanomaterials will accumulate in the environment and there is concern that the novel properties of nanomaterials could result in detrimental environmental and human health effects. In particular, there has been concern recently regarding the use of silver (Ag) based nanomaterials as antimicrobial agents in consumer and medical products. Current regulations dealing with the discharge of metals into the environment are based on total concentrations with no consideration …

Immunogenicity And Protective Efficacy Of The Mycobacterium Avium Subsp. Paratuberculosis Attenuated Mutants Against Challenge In A Mouse Model, Jenn-Wei Chen, Syed M. Faisal, Subhash Chandra, Sean P. Mcdonough, Maria A.S. Moreira, Joy Scaria, Chao-Fu Chang, J. P. Bannantine, Bruce Akey, Yung-Fu Chang

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

Johne’s disease (JD), caused by Mycobacterium avium subsp. paratuberculosis (MAP), results in serious economic losses worldwide especially in cattle, sheep and goats. To control the impact of JD on the animal industry, an effective vaccine with minimal adverse effects is urgently required. In order to develop an effective vaccine, we used allelic exchange to construct three mutant MAP strains, leuD, mpt64 and secA2. The mutants were attenuated in a murine model and induced cytokine responses in J774A.1 cell. The leuD mutant was the most obviously attenuated of the three constructed mutant strains. Our preliminary vaccine trial in mice demonstrated different …

The Potential Application Of Weather Derivatives To Hedge Harvest Value Risk In The Champagne Region Of France, Andrew W. Yandell

CMC Senior Theses

In Champagne, France grape growers and and winemakers work together to make the world's most iconic sparkling wine. Part of what makes Champagne so celebrated is its reputation for constant quality: only the best grapes are used to make wine. In poor vintage years, grape growers sell less grapes to winemakers; poor vintages are the result of bad weather. This presents the opportunity for grape growers to hedge the risk of poor weather and resulting lower harvest values with weather derivatives. This study explores the potential for grape growers to trade them to effectively hedge against low harvest values by …

Making Changes And Coming Full Circle: A Look At How Women Farmers In Oregon And Washington Define Their Own Identities, Realities, And Contributions, Courtney Bauman

Capstone Collection

This paper investigates how women farmers in Oregon and Washington define their own identities, realities, and contributions as farmers, and it looks at how those definitions may be changing. Primary data was collected by interviewing 14 women farmers in the states of Oregon and Washington. Participants were selected to represent a variety of age groups, cultural backgrounds, years of experience farming, and farm size and type. Thus, in investigating the experiences of women farmers, the realities of young and beginning farmers; aging farmers; immigrant farmers and farmers of color; and small and family farmers are also explored.

Findings reveal that …

The Role Of Local Food In Increasing Access To Healthy Food In Indianapolis, Indiana, Anna Hostetter

Capstone Collection

In the United States today, incidents of obesity are on the rise, currently more than one-third, or 35.7% of U.S. adults are considered obese, up from 30.5% in 2000. These startling numbers are causing news institutions and politicians to refer to it as the “obesity epidemic”.

Obesity is linked to multiple health problems including Type 2 diabetes, coronary heart disease, hypertension, and breast cancer (Aronne, L.J., 2002). There are numerous causes of obesity, including genetics, yet high rates of obesity have also been positively linked with a diet high in processed foods and low in fruits and vegetables (Drewnowski, A. …

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 …