Agricultural Science Commons^™

International Shipping Of Fumonisins From Maize Extracts On C18 Sorbent, R. T. Riley, O. A. Torres, E. Palencia

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

Fumonisins are mycotoxins found in maize. In developing countries, the resources required for analysis are often lacking, and the shipping of maize between countries can be difficult since the importation of plant materials requires permits/ inspection to prevent the entry of pests that frequently infest maize. A simple, safe and legal method for shipping maize extracts to the USA was needed to conduct a survey of fumonisins in Central America. The objective was to develop a method for isolating and shipping maize extracts for fumonisin analysis so as to facilitate a survey of fumonisin exposure. The results indicate that fumonisins …

Improvements In Channel Catfish Growth After Two Generations Of Selection And Comparison Of Performance Traits Among Channel Catfish, Blue Catfish, And Hybrid Catfish Fingerlings In An Aquarium Rack System, Brian C. Small

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

A 9-week growth study was conducted to compare the fingerling performance of two genetic groups of channel catfish Ictalurus punctatus (United States Department of Agriculture [USDA] 103 and USDA303) with that of blue catfish I. furcatus and their hybrid in an aquarium rack system. Fish of approximately 20 g were randomly selected from multifamily populations and acclimated to the aquarium rack system for 2 weeks prior to the start of the 9-week study. Differences in growth indices, feed and protein efficiency, nitrogen retention, whole-body proximate composition, and plasma cortisol levels were determined at the completion of the study. The USDA303 …

Restoration Of Spermatogenesis And Male Fertility By Transplantation Of Dispersed Testicular Cells In The Chicken, Pavel Trefil, Alena Micáková, Jitka Mucksová, Jiń Hejnar, Martin Poplstein, Murray R. Bakst, Jirí Kalina, Jean-Pierre Brillard

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

Transplantation of male germ cells into sterilized recipients has been widely used in mammals for conventional breeding and transgenesis purposes. This study presents a workable approach for germ cell transplantation between male chickens. Testicular cells from adult and prepubertal donors were dispersed and transplanted by injection directly into the testes of recipient males sterilized by repeated gamma irradiation. We describe the repopulation of the recipient seminiferous epithelium up to the production of heterologous sperm in about 50% of transplanted males. In comparison to males transplanted with testicular cell preparations from adult donors, in which the first ejaculates with sperm were …

Human Emanations And Related Natural Compounds That Inhibit Mosquito Host-Finding Abilities, Ulrich R. Bernier, Daniel Kline, Kenneth H. Posey

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

One mechanism by which the action of semiochemicals can be classified is based on the behavioral impact within or external to the species of interest. As such, one can classify a chemical as one of the following^2,3:

1. Pheromone, if it results in response between insects of the same species
2. Kairomone, if it results in response in another species that benefits the species receiving the chemical cue
3. Allomone, if it results in response in another species that benefits the species releasing the chemical cue

However, the distinctions can be more specific by classification of chemical cues …

Laboratory Evaluation Of Avian Odors For Mosquito (Diptera: Culicidae) Attraction, S. A. Allan, Ulrich R. Bernier, D. L. Kline

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

Attraction of Culex quinquefasciatus Say, Culex tarsalis Coquillett, Culex nigripalpus Theobald, and Aedes aegypti (L.) to avian and other host odors was investigated in a dual-port olfactometer. Although attraction to a human arm was high for Ae. aegypti (>80%) and low for all Culex spp. (<25%), all species responded similarly to a chicken (55.3-73.6%). Responses of Ae. aegypti, Cx. quinquefasciatus, and Cx. nigripalpus to feathers were low (<20%) but greater than to controls. There was no difference in attraction of Cx. tarsalis to feathers or controls. Responses to CO₂ (5 ml/min) were low for all species (<15%) except Cx. tarsalis, which were moderate (24.5%). When feathers were combined with CO2, the resulting attraction was additive or lower than responses …

Genetic And Hybridization Evidence Confirms That A Geographic Population Of Gonatocerus Morrilli (Hymenoptera: Mymaridae) From California Is A New Species: Egg Parasitoids Of The Glassy-Winged Sharpshooter Homalodisca Coagulata (Homoptera: Cicadellidae), Jesse H. De León, Walker A. Jones, Mamoudou Sétamou, David J. W. Morgan

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

We investigated the differentiation and reproductive isolation among different geographic populations of Gonatocerus morrilli, egg parasitoids of the glassy-winged sharpshooter (Homalodisca coagulata), to confirm previous observations that there may exist a cryptic species complex or a new species. Two mitochondrial genes [cytochrome oxidase subunits I (COI) and II (COII)] and the internal transcribed spacer region 2 (ITS2) of several individuals per population were sequenced. G. morrilli populations from Texas (TX), Florida (FL), California (CA), and an outgroup (G. ashmeadi) were analyzed. For comparison, a population from Argentina (G. annulicornis) morphologically similar to G. …

Wayne E. Sabbe Arkansas Soil Fertility Studies 2005, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.

Soybean Cultivars Resulted From More Recombination Events Than Unselected Lines In The Same Population, T. R. Stefaniak, D. L. Hyten Jr., V. R. Pantalone, A. Klarer, T. W. Pfeiffer

Department of Agronomy and Horticulture: Faculty Publications

The selection of superior adapted cultivars has contributed to the doubling of soybean [Glycine max (L.) Merr.] yields in the USA since 1930. Genetic variation was required for this selection to be effective. The objective of this study was to evaluate the importance of homologous chromosome meiotic recombination in the creation of soybean cultivars. A set of 10 adapted high-yielding cultivars selected from the cross ‘Williams’ × ‘Essex’ was com-pared with a set of 156 random recombinant inbred lines (RILs) from the same population. Crossover events were identified using 143 simple sequence repeat (SSR) markers span-ning all 20 soybean …

Impacts Of Genetic Bottlenecks On Soybean Genome Diversity, D. L. Hyten, Qijian Song, Youlin Zhu, Ik-Young Choi, Randall L. Nelson, Jose M. Costa, James E. Specht, Randy C. Shoemaker, Perry B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

Soybean has undergone several genetic bottlenecks. These include domestication in Asia to produce numerous Asian landraces, introduction of relatively few landraces to North America, and then selective breeding over the past 75 years. It is presumed that these three human-mediated events have reduced genetic diversity. We sequenced 111 fragments from 102 genes in four soybean populations representing the populations before and after genetic bottlenecks. We show that soybean has lost many rare sequence variants and has undergone numerous allele frequency changes throughout its history. Although soybean genetic diversity has been eroded by human selection after domestication, it is notable that …

Effects Of Substrate And Temperature On Growth Of Aspergillus Flavus In Peanuts From Georgia, Premila Achar, Andres Sachez

Faculty Articles

We investigated the effects of different substrates (potato dextrose agar [PDA], nutrient agar [NA], and corn meal agar [CMA]) and temperatures on growth and aflatoxin production in Aspergillus flavus. Contaminated peanuts from retailers at different locations in Georgia were used throughout the experiment and 200 seeds were selected from each sample. PDA, NA, and CMA served as the substrate to express the mold from the contaminated seeds. Seeds were plated equidistantly on each of the media and incubated at 10° C, 27° C, 30° C, and 37° C, respectively. Seeds incubated on moist filter paper served as control. Neither growth …

Slow Ligand Binding Kinetics Dominate Ferrous Hexacoordinate Hemoglobin Reactivities And Reveal Differences Between Plants And Other Species, Benoit J. Smagghe, Gautam Sarath, Emily Ross, Jean-Louis Hilbert, Mark S. Hargrove

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

Hexacoordinate hemoglobins are found in many living organisms ranging from prokaryotes to plants and animals. They are named “hexacoordinate” because of reversible coordination of the heme iron by a histidine side chain located in the heme pocket. This endogenous coordination competes with exogenous ligand binding and causes multiphasic relaxation time courses following rapid mixing or flash photolysis experiments. Previous rapid mixing studies have assumed a steady-state relationship between hexacoordination and exogenous ligand binding that does not correlate with observed time courses for binding. Here, we demonstrate that this assumption is not valid for some hexacoordinate hemoglobins, and that multiphasic time …

Biotinylation Of K8 And K12 Co-Occurs With Acetylation And Mono-Methylation In Human Histone H4, Yap Ching Chew, Ashraf S. Raza, Gautam Sarath, Janos Zempleni

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

Histones H1, H2A, H2B, H3, and H4 are proteins that are critical for folding of DNA into chromatin. Posttranslational acetylation, methylation, and biotinylation of histones participate in gene silencing, mitotic condensation of chromatin, and the cellular response to DNA damage. Various modifications of histones are known to interact ("cross-talk") in chromatin-remodeling events; interactions may be synergistic or antagonistic. Here, we sought to identify biotinylation sites in human histone H4 by using mass spectrometry (MS/MS), and we sought to determine whether biotinylation co-exists with acetylation and methylation in the same H4 molecule. Nuclear histones from human lymphoid (Jurkat) cells were digested …

Ethylene Could Influence Ferric Reductase, Iron Transporter, And H+-Atpase Gene Expression By Affecting Fer (Or Fer-Like) Gene Activity, Carlos Lucera, Brian M. Waters, Francisco Javier Romera, María José García, María Morales, Esteban Alcántara, Rafael Pérez-Vicente

Department of Agronomy and Horticulture: Faculty Publications

In previous works, it has been shown, by using ethylene inhibitors and precursors, that ethylene could participate in the regulation of the enhanced ferric reductase activity of Fe-deficient Strategy I plants. However, it was not known whether ethylene regulates the ferric reductase gene expression or other aspects related to this activity. This paper is a study of the effects of ethylene inhibitors and precursors on the expression of the genes encoding the ferric reductases and iron transporters of Arabidopsis thaliana (FRO2 and IRT1) and Lycopersicon esculentum (= Solanum lycopersicum) (FRO1 and IRT1) plants. The effects …

Application Of Machine Learning In Snp Discovery, Lakshmi K. Matukumalli, John J. Grefenstette, David L. Hyten, Ik-Young Choi, Perry B. Cregan, Curtis P. Van Tassell

Department of Agronomy and Horticulture: Faculty Publications

Background: Single nucleotide polymorphisms (SNP) constitute more than 90% of the genetic variation, and hence can account for most trait differences among individuals in a given species. Polymorphism detection software PolyBayes and PolyPhred give high false positive SNP predictions even with stringent parameter values. We developed a machine learning (ML) method to augment PolyBayes to improve its prediction accuracy. ML methods have also been successfully applied to other bioinformatics problems in predicting genes, promoters, transcription factor binding sites and protein structures. Results: The ML program C4.5 was applied to a set of features in order to build a SNP classifier …

Snp-Phage – High Throughput Snp Discovery Pipeline, Lakshmi K. Matukumalli, John J. Grefenstette, David L. Hyten, Ik-Young Choi, Perry B. Cregan, Curt P. Van Tassell

Department of Agronomy and Horticulture: Faculty Publications

Background: Single nucleotide polymorphisms (SNPs) as defined here are single base sequence changes or short insertion/deletions between or within individuals of a given species. As a result of their abundance and the availability of high throughput analysis technologies SNP markers have begun to replace other traditional markers such as restriction fragment length polymorphisms (RFLPs), amplified fragment length polymorphisms (AFLPs) and simple sequence repeats (SSRs or microsatellite) markers for fine mapping and association studies in several species. For SNP discovery from chromatogram data, several bioinformatics programs have to be combined to generate an analysis pipeline. Results have to be stored in …

Chemical Composition And Response To Dilute-Acid Pretreatment And Enzymatic Saccharification Of Alfalfa, Reed Canarygrass, And Switchgrass, Bruce S. Dien, Hans-Joachim G. Jung, Kenneth P. Vogel, Michael D. Casler, Joann F. S. Lamb, Loren Iten, Robert C. Mitchell, Gautum Sarath

Department of Agronomy and Horticulture: Faculty Publications

Alfalfa stems, reed canarygrass, and switchgrass; perennial herbaceous species that have potential as biomass energy crops in temperate regions; were evaluated for their bioconversion potential as energy crops. Each forage species was harvested at two or three maturity stages and analyzed for carbohydrates, lignin, protein, lipid, organic acids, and mineral composition. The biomass samples were also evaluated for sugar yields following pretreatment with dilute sulfuric followed by enzymatic saccharification using a commercial cellulase preparation. Total carbohydrate content of the plants varied from 518 to 655 g kg^-1 dry matter (DM) and cellulose concentration from 209 to 322 g kg …

Mutations In Arabidopsis Yellow Stripe-Like1 And Yellow Stripe-Like3 Reveal Their Roles In Metal Ion Homeostasis And Loading Of Metal Ions In Seeds, Brian M. Waters, Heng-Hsuan Chu, Raymond J. Didonato, Louis A. Roberts, Robynn B. Eisley, Brett Lahner, David E. Salt, Elsbeth L. Walker

Department of Agronomy and Horticulture: Faculty Publications

Here, we describe two members of the Arabidopsis (Arabidopsis thaliana) Yellow Stripe-Like (YSL) family, AtYSL1 and AtYSL3. The YSL1 and YSL3 proteins are members of the oligopeptide transporter family and are predicted to be integral membrane proteins. YSL1 and YSL3 are similar to the maize (Zea mays) YS1 phytosiderophore transporter (ZmYS1) and the AtYSL2 iron (Fe)-nicotianamine transporter, and are predicted to transport metal-nicotianamine complexes into cells. YSL1 and YSL3 mRNAs are expressed in both root and shoot tissues, and both are regulated in response to the Fe status of the plant. β-Glucuronidase reporter expression, driven by …