Digital Commons Network^™

Paddlefish Egg Deposition In The Lower Yellowstone River, Montana And North Dakota, Shannon E. Miller, Dennis L. Scarnecchia, Steven R. Fain

The Prairie Naturalist

We used passive egg collectors during May, June, and July of2003 and 2004 in the lower 50 river kiiometers (rkm) of the Yellowstone River, eastern Montana and western North Dakota, to detect egg deposition by spawning paddle fish (Polyodon spathula). Sampling yielded 292 eggs (46 in 2003 and 246 in 2004). All egg collections in 2003 occurred on the descending limb of the spring hydrograph but 99% of egg collections in 2004 occurred before the spring hydrograph began to descend. Catch-per-unit-effort (CPUE) in 2004 was about four times that of 2003. A combination of river conditions, in addition …

Nectar Secondary Compounds Affect Self-Pollen Transfer: Implications For Female And Male Reproduction, Rebecca E. Irwin, Lynn S. Adler

Dartmouth Scholarship

Pollen movement within and among plants affects inbreeding, plant fitness, and the spatial scale of genetic differentiation. Although a number of studies have assessed how plant and floral traits influence pollen movement via changes in pollinator behavior, few have explored how nectar chemical composition affects pollen transfer. As many as 55% of plants produce secondary compounds in their nectar, which is surprising given that nectar is typically thought to attract pollinators. We tested the hypothesis that nectar with secondary compounds may benefit plants by encouraging pollinators to leave plants after visiting only a few flowers, thus reducing self-pollen transfer. We …

Pasteurellosis Transmission Risks Between Domestic And Wild Sheep, Michael W. Miller, Donald P. Knowles, Marie S. Bulgin, Billy R. Clay, Walter E. Cook, Subramaniam Srikumaran, A. David Scarfe, Dale Layfield

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

Disease has contributed significantly to the decline of bighorn sheep (Ovis Canadensis) populations throughout much of western North America, decreasing many native herds to less than 10% of their historical size and imperiling some populations and subspecies (Valdez and Krausman 1999). According to historical accounts (e.g., Grinnell 1928; Honess and Frost 1942; Shillinger 1937; Warren 1910), epidemics in some locations coincided with the advent of domestic livestock grazing in bighorn ranges, suggesting that novel pathogens may have been introduced into some bighorn populations beginning in the 1800s.
Native North American wild sheep species—bighorn sheep and thinhorn (Dall’s and …

Optimization And Validation Of An Enzymatic Method To Quantify Glucose In Potato Tubers, Engil Isadora Pujol Pereira, Tatiana Emanuelli, Dilson Antonio Bisognin, Sergio T. De Freitas

School of Earth, Environmental, & Marine Sciences Faculty Publications

The processing industry requires potato tubers with low levels of reduced sugars, glucose and fructose, which is responsible for the whiteness of the chip color. The objective of this research was to optimize and validate a simple, inexpensive, and precise enzymatic method to quantify glucose in potato tubers. This method will be useful in breeding programs to select clones for processing purposes with low levels of glucose. The validation procedure followed the recommendations described in INMETRO document DOQ-CGCRE-008 in 2003. The method was linear between 1.25 to 40µg of glucose in the sample. The quantification limit was 0.319mg g-1 of …

Chloroplast Fe(Iii) Chelate Reductase Activity Is Essential For Seedling Viability Under Iron Limiting Conditions, Jeeyon Jeong, Christopher Cohu, Loubna Kerkeb, Marinus Pilon, Erin L. Connolly, Mary Lou Guerinot

Dartmouth Scholarship

Photosynthesis, heme biosynthesis, and Fe-S cluster assembly all take place in the chloroplast, and all require iron. Reduction of iron via a membrane-bound Fe(III) chelate reductase is required before iron transport across membranes in a variety of systems, but to date there has been no definitive genetic proof that chloroplasts have such a reduction system. Here we report that one of the eight members of the Arabidopsis ferric reductase oxidase (FRO) family, FRO7, localizes to the chloroplast. Chloroplasts prepared from fro7 loss-of-function mutants have 75% less Fe(III) chelate reductase activity and contain 33% less iron per microgram of chlorophyll than …

"Effect Of Transplant Age, Tobacco Cultivar, Acibenzolar-S-Methyl, And Imidacloprid On Tomato Spotted Wilt Infection In Flue-Cured Tobacco", Claudia Nischwitz

All Current Publications

No abstract provided.

Quantitative Trait Loci For Seedling And Adult Plant Resistance To Stagonospora Nodorum In Wheat, Manisha Shankar, Esther Walker, Hossein Golzar, Rob Loughman, R E. Wilson, Michael Francki

Biosecurity Research Articles

Stagonospora nodorum blotch (SNB) caused by Stagonospora nodorum is a severe disease of wheat (Triticum aestivum) in many areas of the world. S. nodorum affects both seedling and adult plants causing necrosis of leaf and glume tissue, inhibiting photosynthetic capabilities, and reducing grain yield. The aims of this study were to evaluate disease response of 280 doubled haploid (DH) individuals derived from a cross between resistant (6HRWSN125) and susceptible (WAWHT2074) genotypes, compare quantitative trait loci (QTL) for seedling and adult plant resistance in two consecutive years, and assess the contribution of QTL on grain weight. Flag leaves and …

A Critical Role Of Two Positively Charged Amino Acids In The Jas Motif Of Arabidopsis Jaz Proteins In Mediating Coronatine- And Jasmonoyl Isoleucine-Dependent Interactions With The Coi1 F-Box Protein, Maeli Melotto, Christy Mecey, Yajie Niu, Hoo Sun Chung, Leron Katsir, Jian Yao, Weiqing Zeng, Bryan Thines, Paul E. Staswick, John Browse, Gregg A. Howe, Sheng Yang He

Department of Agronomy and Horticulture: Faculty Publications

Coronatine is an important virulence factor produced by several pathovars of the bacterial pathogen Pseudomonas syringae. The structure of coronatine is similar to that of a class of plant hormones called jasmonates (JAs). An important step in JA signaling is the SCF^COI1 E3 ubiquitin ligase-dependent degradation of JAZ repressor proteins. We have recently shown that jasmonoyl isoleucine (JA-Ile) promotes physical interaction between Arabidopsis JAZ1 and COI1 (the F-box component of SCF^COI1) proteins, and that the JAIle- dependent COI1–JAZ1 interaction could be reconstituted in yeast cells (i.e. in the absence of other plant proteins). Here we show …

Center For Grassland Studies Newsletter, Summer 2008, Volume 14, No. 3

Center for Grassland Studies: Newsletters

Contents:
Are the Sandhills Fragile? by James Stubbendieck and Susan J. Tunnell, Department of Agronomy and Horticulture, UNL

Forage Triticale (X Triticosecale Wittmack) Genotypes for the Northern Great Plains by Lekgari Lekgari and P. Stephen Baenziger, Department of Agronomy and Horticulture, UNL

Progress Being Made in Implementing the Nebraska Natural Legacy Plan

Soil and Water Conservation Conference: Farming with Grass

August 1 is Pre-registration Deadline for Nebraska Grazing Conference

We’ve Moved!

The Potential For Crop-To-Wild Gene Flow In Sorghum In Ethiopia And Niger: A Geographic Survey, Tesfaye Tesso, Issoufou Kapran, Cecile Grenier, Allison Snow, Patricia Sweeney, Jeffrey F. Pedersen, David B. Marx, Gurling Bothma, Gebisa Ejeta

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

Information about the potential for crop–wild hybridization is needed to understand how crop genes, including transgenes, affect the population genetics and ecology of sexually compatible relatives. Transgenic sorghum is under development for use by traditional farmers in Africa, the center of origin for sorghum [Sorghum bicolor (L.) Moench], but systematic surveys of the current extent of contact with wild and weedy relatives are lacking. We studied wild and weedy sorghums that are interfertile with the crop and constitute a crop–wild–weed complex. The survey was conducted in 2005 in areas of traditional sorghum cultivation in three regions of Ethiopia and …

Assessing The Effect Of Product Variability On The Management Of The Quality Of Mushrooms (Agaricus Bisporus), Catherine Barry-Ryan, Jesus Maria Frias, Leixuri Aguirre, Helen Grogan

Articles

To study the shelf-life of mushrooms, over 25 batches were subjected to three storage temperatures (T) (5, 15 and 25 ◦ C) and three storage relative humidity (RH) levels (70, 80 and 90%). The effect of T and the RH on the kinetics of quality attributes of the batches was studied by measuring water activity, turgor, colour (L, a* and b* in the Hunter Scale) and weight loss of three different tissues (cap, gills and stipe) of the mushroom. Linear mixed effect models, comprising polynomial models to describe quality kinetics and allowing for batch-to-batch and inside-batch nested variabilitystructure, were built. …

Sfa Gardens Newsletter, Summer 2008, Sfa Gardens, Stephen F. Austin State University

SFA Gardens Newsletters

No abstract provided.

Compost Production And Use In Horticulture, Bob Paulin, Peter O'Malley

Bulletins 4000 -

Maintaining and improving soil organic carbon levels is becoming an increasingly important aspect of modern farming. Compost provides potentially one of the most effective ways of applying organic matter to soils and improving organic carbon levels.

Improving soil organic carbon is directly related to soil quality and performance. Increased quality reflects improved biological function (soil health), fertility and physical attributes that include better drainage, reduced compaction and erosion, and improved moisture-holding capability, at least for lighter soils.

Compost is not the only option available. Others include the use of cover or break crops, reducing the use of cultivations, selecting safe …

Nitrite Reduction By Siderite, Sudipta Rakshit, Christopher J. Matocha, Mark S. Coyne

Plant and Soil Sciences Faculty Publications

Nitrate-dependent Fe(II) oxidation is an important process in the inhibition of soil Fe(III) reduction, yet the mechanisms are poorly understood. One proposed pathway includes chemical reoxidation of mineral forms of Fe(II) such as siderite [FeCO3(s)] by NO2 −. Accordingly, the objective of this study was to investigate the reactivity of FeCO3(s) with NO2 −. Stirred-batch reactions were performed in an anoxic chamber across a range of pH values (5.5, 6, 6.5, and 7.9), initial FeCO3(s) concentrations (5, 10, and 15 g L−1) and initial NO2 − concentrations (0.83–9.3 mmol L−1) for kinetic and stoichiometric determinations. Solid-phase products were characterized using …

Sheep Updates 2008 - Part 2, Meredith L. Sheil, Di Evans, Brown Besier, Tim Scanlon, Andre Martinho De Almeida, Johan Greeff, Tanya Kilminster, John Milton, Chris Oldham, B. L. Mcintyre, Alison Wheatley, John Lucey, Fiona Jones, Nick Costa, Ed Riggall, J. R. L. Hall, Robin Jacob, Dave Pethick, Dave Hopkins, Graham Gardner

Sheep Updates

This session covers eleven papers from different authors: The Sheep Room 1. Analgesia for Surgical Husbandry Procedures in Sheep and Other Livestock, Dr Meredith L. Sheil, Animal Ethics Pty Ltd, Associate Sydney University Faculty of Veterinary Science The Wool Enterprise 2. Unmulsed sheep - implications for chemical use, Di Evans & Brown Besier, Department of Agriculture and Food WA 3. Are Damara and Dorper sheep better adapted than Merinos to nutritional stress? - Growth rates, Tim Scanlon1, Andre Martinho de Almeida2, Johan Greeff1, Tanya Kilminster1, John Milton3, Chris Oldham1, Department of Agriculture and Food WA1, Instituto de Investigacao Cientifica Tropical, …

Citrus Tristeza Virus: Survival At The Edge Of The Movement Continuum, Svetlana Y. Folimonova, Alexey S. Folimonov, Satyanarayana Tatineni, William O. Dawson

Department of Plant Pathology: Faculty Publications

Science, Ltd Systemic invasion of plants by viruses is thought to involve two processes: cell-to-cell movement between adjacent cells and long-distance movement that allows the virus to rapidly move through sieve elements and unload at the growing parts of the plant. There is a continuum of proportions of these processes that determines the degrees of systemic infection of different plants by different viruses. We examined the systemic distribution of Citrus tristeza virus (CTV) in citrus species with a range of susceptibilities. By using a “pure” culture of CTV from a cDNA clone and green fluorescent protein-labeled virus we show that …

Sphingolipid Long-Chain Base Hydroxylation Is Important For Growth And Regulation Of Sphingolipid Content And Composition In Arabidopsis, Ming Chen, Jennifer E. Markham, Charles R. Dietrich, Jan G. Jaworski, Edgar B. Cahoon

Department of Biochemistry: Faculty Publications

Sphingolipids are structural components of endomembranes and function through their metabolites as bioactive regulators of cellular processes such as programmed cell death. A characteristic feature of plant sphingolipids is their high content of trihydroxy long-chain bases (LCBs) that are produced by the LCB C-4 hydroxylase. To determine the functional significance of trihydroxy LCBs in plants, T-DNA double mutants and RNA interference suppression lines were generated for the two Arabidopsis thaliana LCB C-4 hydroxylase genes Sphingoid Base Hydroxylase1 (SBH1) and SBH2. These plants displayed reductions in growth that were dependent on the content of trihydroxy LCBs in sphingolipids. …

Spiderworts: Not Just Another Pretty Face For Science, W. John Hayden

Biology Faculty Publications

Species of Tradescantia, or spiderworts, are handsome plants. Several wild species, including the VNPS wildflower of the Year for 2008 (T. virginiana), can be found in eastern North America and additional species grace gardens, and hothouse conservatories. Spiderworts are not, however, just a bunch of pretty faces. Spiderworts have a long history of service to science, both in terms of teaching and pure research.

Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Quarterly Progress Report, April 1, 2008 To June 30, 2008, Margaret N. Rees

Vegetation Monitoring

Executive Summary

• The Weed Sentry program surveyed over 182 miles of transportation corridors on federal land in Clark County for incipient populations of exotic plants.
• Five manuscripts attained published or in-press status this quarter. The published manuscripts are (1) assessing vegetation in grassy remnants of the Las Vegas Valley (Desert Plants), (2) assessing exotic species distributions in Clark County (Environmental Monitoring and Assessment), (3) a synthesis of burro effects on Mojave Desert vegetation (Environmental Management), and (4) examining canopy-tree influences along a soil parent material gradient in (Journal of the Torrey Botanical Society).
• Staff delivered eight presentations this quarter at …

Mojave Applied Ecology Notes Summer 2008, Doug Merkler, Scott R. Abella, Dianne N. Bangle, Donovan J. Craig, Jessica E. Spencer, Alex Suazo

Mojave Applied Ecology Notes

Soil climate project, rare plant monitoring, JFS update, granivory and Sahara mustard

Joint Fire Science Program – Lake Mead National Recreation Area: Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis: Quarterly Progress Report, April 1— June 30, 2008, Margaret N. Rees

Fire Science

• Cones seeded for competition experiment at Lake Mead nursery.

• Cones monitored for seedling establishment.

• Goodsprings revegetation studies monitored.

• Invasibility data being entered and analyzed.

• Abstract for NAA conference submitted.

• Joint Fire Science update article submitted to Mojave Applied Ecology Notes newsletter.

The Effect Of Ginseng On Biofilm Formation By Wild Type And Mutant Strains Of Pseudomonas Aeruginosa, Premi Shekar

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Premi Shekar on June 25, 2008.

Effect Of Sorghum Seedlings, And Previous Crop, On Soil Fluorescent Pseudomonas Spp., Deanna L. Funnell, Jeffrey F. Pedersen, David B. Marx

Department of Agronomy and Horticulture: Faculty Publications

Hypotheses in which sorghum seedlings [Sorghum bicolor (L.) Moench] of different genotypes will differentially modify soil microorganisms and will affect subsequent planting of wheat (Triticum aestivum L.) seedlings, were tested. Wheat cultivar Lewjain, and sorghum genotypes Redlan and RTx433, were planted into soils previously planted with wheat or sorghum in growth chamber experiments. Total culturable fungi and oomycetes, and fluorescent Pseudomonas spp. numbers (cfu) were determined. Pseudomonads were screened for hydrogen cyanide (HCN) production, for the presence of the phlD gene for 2,4-diacetylphloroglucinol production (Phl) and for a region of the operon involved in phenazine-1-carboxylic acid (PCA) production. …

A Polyadenylation Factor Subunit Implicated In Regulating Oxidative Signaling In Arabidopsis Thaliana, Jingxian Zhang, Bala Subrahmanyam Addepalli, Kil-Young Yun, Arthur G. Hunt, Ruqiang Xu, Suryadevara Rao, Qingshun Q. Li, Deane L. Falcone

Kentucky Tobacco Research and Development Center Faculty Publications

BACKGROUND: Plants respond to many unfavorable environmental conditions via signaling mediated by altered levels of various reactive oxygen species (ROS). To gain additional insight into oxidative signaling responses, Arabidopsis mutants that exhibited tolerance to oxidative stress were isolated. We describe herein the isolation and characterization of one such mutant, oxt6.

METHODOLOGY/PRINCIPAL FINDINGS: The oxt6 mutation is due to the disruption of a complex gene (At1g30460) that encodes the Arabidopsis ortholog of the 30-kD subunit of the cleavage and polyadenylation specificity factor (CPSF30) as well as a larger, related 65-kD protein. Expression of mRNAs encoding Arabidopsis CPSF30 alone was able to …

Method For Efficient Post Transcriptional Gene Slencing Using Intrinsic Direct Repeat Sequences And Utilization Thereof Infunctional Genomics, Amitava Mitra, Chonglie Ma

Department of Plant Pathology: Faculty Publications

It is well documented that transgenes with inverted repeats can efficiently trigger post-transcriptional gene silencing (PTGS), presumably via a double stranded RNA induced by complementary sequences in their transcripts. We show here that transgenes with intrinsic direct repeats can also induce PTGS at a very high frequency (80-100%). A transgene with three or four repeats induced PTGS in almost 100% of the primary transformants, regardless of whether a strong (en hanced 35S promoter) or a relatively weak (chlorophyll a?b binding protein promoter) promoter was used. The PTGS induced by three or four repeats is consistently inherited in Subsequent generations, and …

An Antibiotic Complex From Lysobacter Enzymogenes Strain C3: Antimicrobial Activity And Role In Plant Disease Control, S. Li, C. C. Jochum, F. Yu, K. Zaleta-Rivera, L. Du, Steven D. Harris, Gary Y. Yuen

Department of Plant Pathology: Faculty Publications

Lysobacter enzymogenes C3 is a bacterial biological control agent that exhibits antagonism against multiple fungal pathogens. Its antifungal activity was attributed in part to lytic enzymes. In this study, a heat-stable antifungal factor (HSAF), an antibiotic complex consisting of dihydromaltophilin and structurally related macrocyclic lactams, was found to be responsible for antagonism by C3 against fungi and oomycetes in culture. HSAF in purified form exhibited inhibitory activity against a wide range of fungal and oomycetes species in vitro, inhibiting spore germination, and disrupting hyphal polarity in sensitive fungi. When applied to tall fescue leaves as a partially-purified extract, HSAF at …

Soil Morphology, Depth And Grapevine Root Frequency Influence Microbial Communities In A Pinot Noir Vineyard, Rebecca E. Drenovsky, K. L. Steenwerth, J. J. Lambert, D. A. Kluepfel, K. M. Scow, D. R. Smart

Biology

The composition of microbial communities responds to soil resource availability, and has been shown to vary with increasing depth in the soil profile. Soil microorganisms partly rely on root-derived carbon (C) for growth and activity. Roots in woody perennial systems like vineyards have a deeper vertical distribution than grasslands and annual agriculture. Thus, we hypothesized that vineyard soil microbial communities along a vertical soil profile would differ from those observed in grassland and annual agricultural systems. In a Pinot noir vineyard, soil pits were excavated to ca. 1.6–2.5m, and microbial community composition in ‘bulk’ (i.e., no roots) and ‘root’ (i.e., …

Botany At Eastern Illinois University, Marissa C. Jernegan, Nancy Coutant, Janice M. Coons

Faculty Research & Creative Activity

Eastern Illinois University was established in 1899, and from its beginning recognized the importance of the botanical sciences. Two terms of botany were required for the four year program. Otis W. Caldwell, a botanist, was one of the original faculty members. He taught all of the biology courses and initiated the acquisition of a greenhouse. Caldwell was the first of a series of talented and dedicated botany professors including Edgar N. Transeau, Ernest L. Stover, Hiram F. Thut and John E. Ebinger. These and many other professors incorporated a field component into almost all classes. This dedication to the study …

Variation In Resource Acquisition And Utilization Traits Between Native And Invasive Perennial Forbs, Rebecca E. Drenovsky, Christina E. Martin, Molly R. Falasco, Jeremy J. James

Biology

Understanding the functional traits that allow invasives to outperform natives is a necessary first step in improving our ability to predict and manage the spread of invaders. In nutrient-limited systems, plant competitive ability is expected to be closely tied to the ability of a plant to exploit nutrient-rich microsites and use these captured nutrients efficiently. The broad objective of this work was to compare the ability of native and invasive perennial forbs to acquire and use nutrients from nutrient-rich microsites. We evaluated morphological and physiological responses among four native and four invasive species exposed to heterogeneous (patch) or homogeneous (control) …

Seed Invasion Filters And Forest Fire Severity, Tom R. Cottrell, Paul F. Hessburg, Jonathan A. Betz

Biology Faculty Scholarship

Forest seed dispersal is altered after fire. Using seed traps, we studied impacts of fire severity on timing of seed dispersal, total seed rain, and seed rain richness in patches of high and low severity fire and unburned Douglas-fir (Pseudotsuga menziesii) forests in the Fischer and Tyee fire complexes in the eastern Washington Cascades. Unburned plots had the lowest average seed production. The high severity fire patches in the Fischer Fire Complex had a higher total seed production than low severity fire patches of the same complex. At the Tyee Fire Complex, the total seed production for each …