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Genetic Investigation Of The Pathology Of Ustilago Bullata, Erin Ladle, Dr. Jeff Maughan

Journal of Undergraduate Research

Bromus tectorum L., commonly known as cheatgrass, is an invasive annual grass species that dominates millions of hectares of land in the Great Basin area, in the western United States.1 The widespread invasion of cheatgrass has increased fire incidence in some areas of the Great Basin from every 30-100 years to every 5 years. Moreover, once cheatgrass becomes the dominant vegetative species, it monopolizes resources, significantly contributing to the endangerment of many native plant species.

Multifactorial Analysis Of Mortality Of Soybean Cyst Nematode (Heterodera Glycines Ichinohe) Populations In Soybean And In Soybean Fields Annually Rotated To Corn In Nebraska, Oscar Perez-Hernandez

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The soybean cyst nematode (SCN; Heterodera glycines Ichinohe) is the most economically important pathogen of soybean in the U.S. The effect of annual corn rotation, soil properties, weather, and agronomic factors on SCN population densities was quantified in 45 fields in Nebraska over three years. SCN population densities (eggs/100 cm³ of soil) in each field were determined before (Pi) and after (Pf) annual corn rotation. Average SCN population density reduction was 50.62%. Multivariate analysis was used to describe the relationship of soil texture (% of sand, silt, and clay), Pi, and Pf. Two principal components explained 92% of the …

Back Matter Agricultural Research Magazine August 2013

Agricultural Research Magazine

U.S. Department of Agriculture

Agricultural Research Magazine

5601 Sunnyside Ave.

Beltsville, MD 20705-5128

Prescription For Curing Citrus Greening, Dennis O’Brien, Yongping Duan

Agricultural Research Magazine

Huanglongbing (HLB), or citrus greening, is the most serious threat to the Florida citrus industry in its history and is costing millions of dollars each year. Working with the Florida Department of Agriculture and Consumer Services (FDACS), Yongping Duan and his Agricultural Research Service colleagues in Fort Pierce, Florida, have found a formula for curbing HLB, offering the industry a glimmer of hope.

Duan has published details of work showing that heating potted citrus seedlings in greenhouses kills off the HLB bacterium and can rid the seedlings of citrus greening symptoms. Monitoring efforts show that the benefit can last for …

Early Weaning: A Good Bet For Beef Producers In Drought-Stricken Areas, R.C. Waterman, Sandra Avant

Agricultural Research Magazine

At the beginning of 2013, cattle-ranchers in the Northern Plains were among U.S. agricultural producers still feeling the lingering effects of the sweltering 2012 drought, the worst in half a century.

Beef cow numbers were at the lowest in 50 years as U.S. beef producers—severely affected by extended drought—tried to recover from some of the driest months on record.

Across the Northern and Southern Plains, beef producers hit the hardest by drought are threatened by limited forage resources for cows, which restricts calf growth, resulting in lighter calf weaning weights. In addition, drought can decrease cow body weight and condition …

Scientific Works Of Art Reveal A Hidden World, Gary Bauchan, Jan Suszkiw

Agricultural Research Magazine

It has been said that a picture is worth a thousand words, and at the Agricultural Research Service’s Electron and Confocal Microscopy Unit (ECMU) in Beltsville, Maryland, this adage couldn’t be more true. Led by unit director Gary Bauchan, the ECMU is tasked with producing highresolution images that provide a window to the extraordinary world of the unseen.

“We have observed viruses, bacteria, fungi, nematodes, insects, mites, and parasites that threaten global food security, and we’ve contributed to the discovery of how pathogens spread by helping elucidate their relationship to the environment, hosts, and vectors,” says Bauchan. “We’ve also described …

Novel Ways To Combat Plant Pathogens, Deborah Fravel, Gail C. Wisler

Agricultural Research Magazine

Plant diseases must be managed to successfully and reliably produce crops to meet humanity’s growing food, fiber, feed, and fuel needs. Plant disease management relies on many different types of tools—from disease-resistant plant varieties and pesticides to cultural and biological strategies. Agricultural Research Service scientists are seeking new methods of managing plant diseases, more efficient means of using older methods, and combinations of these methods. Two of the oldest ways of reducing plant diseases are crop rotation and organic amendments to soil.

In Orono, Maine, for example, ARS scientists are evaluating a holistic approach to suppressing soilborne pathogens of potato, …

Possible Links Between Soil Microbial Communities And Stroke Risk, Ann Perry

Agricultural Research Magazine

“A big part of our Agricultural Research Service culture is cross-talking with outside researchers,” says ARS soil and water scientist Patrick Hunt. “Partnerships are what we do.”

So one day in 2011, Hunt called Medical University of South Carolina professor Daniel Lackland to discuss a paper Lackland had published about stroke risk in the state. South Carolina is part of the U.S. “Stroke Belt,” where residents have a significantly higher incidence of stroke than the rest of the U.S. population. South Carolina counties with the highest rates of stroke—between 89 and 115 cases per 100,000 residents—are found within the Southern …

Fungal Foam Tested Against Avocado Threat, Jan Suszkiw

Agricultural Research Magazine

Avocados aren’t just nutritional powerhouses; they’re also the chief ingredient in such party favorites as guacamole dip.

More than 99 percent of the nation’s $322 million avocado crop is grown in south Florida and southern California (less than 1 percent is produced in Hawaii), which makes recent infestations of groves there by invasive, wood-boring ambrosia beetles so alarming. A host of counter strategies are in the works, including a biobased foam originally developed by Agricultural Research Service scientists for use against Formosan subterranean termites.

In Miami-Dade County, Florida, avocado growers are contending with Xyleborus glabratus, the redbay ambrosia beetle. …

Fire Ant Venom Compounds May Be Useful As A Fungicide, Jan Suszkiw, Jian Chen, Xixuan Jin

Agricultural Research Magazine

Red imported fire ants are named for the firelike burn of their sting. Now, the same venom that packs such a painful wallop may actually do some good for a change.

Studies by scientists at the Agricultural Research Service’s Biological Control of Pests Research Unit in Stoneville, Mississippi, have shown that certain alkaloid compounds in the venom—namely, piperideines and piperidines—can hinder growth of Pythium ultimum, a top crop pathogen worldwide.

Chemical controls, delayed plantings, and crop rotation are among methods now used against P. ultimum, which causes damping-off diseases that decay the seed or seedlings of vegetable, horticultural, …

August 2013- Locations Featured In This Magazine Issue

Agricultural Research Magazine

Albany, California

9 research units ■ 241 employees

San Joaquin Valley Agricultural Sciences Center, Parlier, California

3 research units ■ 125 employees

Northwest Watershed Research Center, Boise, Idaho

1 research unit ■ 18 employees

Tucson, Arizona

2 research units ■ 54 employees

U.S. Sheep Experiment Station, Dubois, Idaho

1 research unit ■ 10 employees

Fort Keogh Livestock and Range Research Laboratory, Miles City, Montana

1 research unit ■ 25 employees

Roman L. Hruska U.S. Meat Animal Research Center, Clay Center, Nebraska

6 research units ■ 117 employees

Grazinglands Research Laboratory, El Reno, Oklahoma

2 research units ■ 43 employees

National …

Ars Validates Soil Moisture Data Collected Via Satellite, Ann Perry

Agricultural Research Magazine

The European Space Agency’s Soil Moisture and Ocean Salinity (SMOS) mission includes the latest advance in using Earth-orbiting satellites for estimating soil moisture across the globe. The SMOS satellite was launched in 2009 and was designed to estimate soil moisture levels to within 4 percent, which is like measuring a teaspoon of water in a handful of dry soil.

To capture this data, SMOS uses a new sensor technology that is the first passive L-band system—measuring microwave radiation emitted around the frequency of 1.4 gigahertz—in routine operation. But the accuracy of the information collected by this new technology still needs …

New Strategies To Thwart Pecan Scab, Sharon Durham

Agricultural Research Magazine

Pecans are great for eating out of the shell or in a myriad of recipes. But abundant pickings of high-quality nuts are only possible if the tree escapes the devastating disease called “pecan scab.” Caused by the fungus Fusicladium effusum, it is the most destructive disease of pecan in the southeastern United States. When scab is severe, most often when rainfall is above average, nut size is reduced, and total crop loss might occur.

Scientists at the Southeastern Fruit and Tree Nut Research Laboratory in Byron, Georgia, are working to help pecan growers mitigate the effect of pecan scab. …

Screening Fresh Oranges With Uv Study Pinpoints New Value Of Detection Tactic, David M. Obenland, Joseph L. Smilanick, Marcia Wood

Agricultural Research Magazine

Fresh, deliciously sweet navel oranges, on display at your local supermarket, may have been quickly inspected with ultraviolet (UV) light when they were still at the packinghouse. Usually, the purpose of this special sorting and screening is to see if circular spots—which glow a bright, fluorescent yellow and may be about the size of a quarter or larger—show up on the fruit’s peel.

More often than not, these spots, which scientists refer to as “lesions,” are telltale indicators of the presence of microbes that cause decay, namely Penicillium italicum, responsible for blue mold, or P. digitatum, the culprit …

Agricultural Research Magazine August 2013

Agricultural Research Magazine

Table of Contents

4 Prescription for Curing Citrus Greening: Apply Heat and Wait

7 Screening Fresh Oranges With UV: Study Pinpoints New Value of Detection Tactic

8 Breed Matters: Selecting Rams for Rangeland Production

10 Scientific Works of Art Reveal a Hidden World

13 ARS Validates Soil Moisture Data Collected Via Satellite

14 New Strategies To Thwart Pecan Scab

15 Fire Ant Venom Compounds May Be Useful as a Fungicide

16 Possible Links Between Soil Microbial Communities and Stroke Risk

18 Early Weaning: A Good Bet for Beef Producers in Drought-Stricken Areas

20 Fungal Foam Tested Against Avocado Threat

21 …

Cause And Impacts Of The Early Season Collapse Of Lilium Grayi (Gray’S Lily), On Roan Mountain, Tn/Nc, Russell J. Ingram

Electronic Theses and Dissertations

A population of the rare Southern Appalachian endemic species Lilium grayi, (Gray’s lily) Roan Mountain, TN/NC was monitored for 2 years to determine the cause and impact of an early season collapse. High concentrations of the Lilium spp. host-specific fungal phytopathogen, Pseudocercosporella inconspicua (G. Winter) U. Braun were associated with 19/20 symptomatic and 0/30 asymptomatic plants. Strength of the association between pathogen and disease and the replication of disease symptoms in 4/4 healthy hosts showed that P. inconspicua was the causal agent of the disease referred to as lily leaf spot. Disease had a severe impact on the population …

Nebline, August 2013

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Feature: 8 Tips for Better-Tasting Fruits & Vegetables

Farm Views

Urban Agriculture

Food & Fitness

Home & Family Living

Horticulture

Environmental Focus

4-H & Youth

Community Focus

Extension Calendar

Nutrition Education Program

Family and Community Education (FCE) Clubs

and other extension news and events

2013 Lancaster County Super Fair Schedule & Map Special Pullout Section

Functional Analysis Of A Glutathione S-Transferase Gene From Reniform Nematode On Soybean, Jing Hou

All Theses

Nematode glutathione S-transferases (GSTs) have been implicated in plant-nematode interactions as effector proteins with an important role in the establishment of feeding sites. Studies with root-knot nematode in Arabidopsis thaliana suggest that GSTs may protect the nematode against oxidative plant defenses and modulate plant responses to parasitism. Our objective was to study the function of a GST from reniform nematode (Rotylenchulus reniformis) in soybean. We used a virus-induced gene silencing (VIGS) system, utilizing a Bean pod mottle virus (BPMV)-based vector and a partial sequence of gsts-1 from Meloidogyne incognita to silence the putative reniform nematode homolog. The effect of silencing …

Factors Influencing The Distribution And Structure Of Tropical Vascular Epiphyte Communities At Multiple Scales, Carrie Woods

All Dissertations

Understanding the factors that determine species distributions is a central question in ecology. Niche-based theories stress the importance of environmental heterogeneity in influencing species distributions while neutral-based theories emphasize the effects of dispersal limitation. The relative importance of these factors in influencing species distributions may depend on spatial scale - deterministic factors may be more important at small spatial scales where fine-scale habitat factors become more relevant and stochastic factors may be more important at larger spatial scales where dispersal limitation becomes more relevant. I examined the influence of deterministic and stochastic factors on the distribution and structure of vascular …

Quick Start Guide To Soil Methods For Ecologists, Lora Perkins, Robert R. Blank, Scot D. Ferguson, Dale W. Johnson, William C. Lindemann, Ben M. Rau

Natural Resource Management Faculty Publications

Increasingly biologists and ecologists are becoming aware of the vital importance of soil to processes observed above ground and are incorporating soil analyses into their research. Because of the dynamic and heterogeneous nature of soil, proper incorporation of soil analysis into ecological studies requires knowledge and planning. Unfortunately, many ecologists may not be current (or trained at all) in soil science.We provide this review, based on our cumulative >60 years of work in soil science,to help familiarize researchers with essential information to appropriately incorporate soil analyses into ecological studies. Specifically, we provide a brief introduction into soils and then discuss …

The Characterization Of Algae Grown On Nutrient Removal Systems And Evaluation Of Potential Uses For The Resulting Biomass, Kristin Hampel

Dissertations

Eutrophication resulting from excess nutrient loads is a major environmental issue that affects surface water quality and causes surplus primary production, thereby reducing dissolved oxygen concentrations. A method for managing nutrients in surface waters involves absorption of excess nutrients by deliberately cultivating benthic algal turf biomass, then harvesting it for a variety of uses, including biofuels, soil amendments, or feed supplements, thus coupling nutrient removal to additional economic drivers.

The goals of this work are to (1) evaluate the composition of algal biomass grown to remove surface water nutrients, (2) compare biomass grown at different geographic locations and in dissimilar …

A Force Of Nature: Molecular Mechanisms Of Mechanoperception In Plants, Gabriele B. Monshausen, Elizabeth S. Haswell

Biology Faculty Research

The ability to sense and respond to a wide variety of mechanical stimuli-gravity, touch, osmotic pressure, or the resistance of the cell wall-is a critical feature of every plant cell, whether or not it is specialized for mechanotransduction. Mechanoperceptive events are an essential part of plant life, required for normal growth and development at the cell, tissue, and whole-plant level and for the proper response to an array of biotic and abiotic stresses. One current challenge for plant mechanobiologists is to link these physiological responses to specific mechanoreceptors and signal transduction pathways. Here, we describe recent progress in the identification …

Establishment Guide For Sub-Tropical Grasses : Key Steps To Success, Geoff Allan Moore, Ronald J. Yates, Phil Barrett-Lennard, Phil Nichols, Brad Wintle, John Titterington, Chris Loo

Bulletins 4000 -

Sub-tropical perennial grasses are now widely sown in the Northern Agricultural region (NAR) and on the south coast of Western Australia (WA). Since 2000, more than 50 000 ha have been sown to perennial grasses in the NAR and about 150 000 ha on the south coast, mainly kikuyu.

Systematics, Climate, And Ecology Of Fossil And Extant Nyssa (Nyssaceae, Cornales) And Implications Of Nyssa Grayensis Sp. Nov. From The Gray Fossil Site, Northeast Tennessee, Nathan R. Noll

Electronic Theses and Dissertations

The Late Hemphillian (latest Miocene or earliest Pliocene, 7-4.5 Ma) Gray Fossil Site in northeastern Tennessee is interpreted to represent a lacustrine paleokarst fed by a river or stream. This research focuses on the morphological and systematic relations of Nyssa endocarps (fruit pits) from the fossil site to extinct and extant Nyssa species. A combination of metric and nonmetric traits allows recognition of a new species: Nyssa grayensis sp. nov. This fossil species shares the most similarities with the extant Nyssa ogeche Bartram ex Marshall from southeast North America and the Eocene fossil Nyssa eolignitica Berry from western Tennessee. Affinities …

Thorns Of Native Lower Rio Grande Valley Plants Are Colonized By Potentially Pathogenic Bacteria, Felicia A. Charles

Theses and Dissertations - UTB/UTPA

Epiphytic pathogenic bacteria on the thorns of native LRGV plants may provide a defense mechanism for the plants. To test this, plant thorns were collected from LRGV plant species and aerobic and anaerobic bacteria were isolated in thioglycollate medium. Tests were performed to characterize the bacterial cultures. The 16S rRNA gene was sequenced to allow for species identification. Sixty-nine bacterial cultures were isolated, including gram-positive and gram-negative cell types. All utilized a variety of carbon sources for nutrients and 23% of isolates displayed hemolysis. Bacterial identification included members of the genus Bacillus, Pseudomonas, Serratia, and others. Most were opportunistic pathogens. …

A Review Of Apomixis And Differential Expression Analyses Using Microarrays, Jonathan Harris Cardwell

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Apomixis is a complex trait of great interest to the agricultural community, as it has the potential to fix hybrid vigor in many agriculturally significant crops. Although apomixis has been studied extensively morphologically, the genetic and epigenetic factors responsible for apomixis are still very poorly understood. As no apomictic species has been sequenced and annotated, various low-cost tools and techniques are being utilized to begin profiling the trait. These include cross-species microarrays using probe masking, which deletes information from array probes that do not hybridize to the genomic DNA of the cross species. Despite their limitations, these tools are providing …

Abiotic And Biotic Factors Affecting The Japanese Beetle In Arkansas, Bryan Mathew Petty

Graduate Theses and Dissertations

Japanese beetles are a relatively new pest to Arkansas. During my Ph.D. research I investigated the pathogens and environmental factors influencing Japanese beetle populations in the state. The prevalence of various pathogens and parasitoids attacking Popillia japonica were recorded annually from wild populations. Of specific interest was the microsporidian pathogen Ovavesicula popilliae, which I introduced as a biological control agent in the state. Details of the relationship between this pathogen and the Japanese beetle were investigated, including dose response, host range, and spore production. Additionally, annual abundance of the beetle in the region was recorded and tracked over the course …

Genome-Wide Association Mapping Identifies Qtls And Candidate Genes For Salt Tolerance In Soybean, Lei Huang

Graduate Theses and Dissertations

Salinity is a common abiotic stress causing soybean yield loss worldwide. Use of tolerant cultivars is an effective and economic approach to coping with this stress. Toward this, research is needed to identify salt-tolerant germplasm and better understand the genetic and molecular basis of salt tolerance in soybean. The objectives of this study were to identify salt-tolerant genotypes, to search for SNPs and QTLs associated with salt tolerance, and to identify candidate salt tolerance genes. A total of 192 diverse soybean lines and cultivars were screened for salt tolerance in the greenhouse based on visual leaf scorch scores after 15 …

Study Of Thermotolerance Mechanism In Gossypium Hirsutum Through Identification Of Heat Stress Genes, Jin Zhang

Graduate Theses and Dissertations

ABSTRACT

Heat stress causes major losses to cotton seed and lint yield. Introduction of heat stress tolerance to Arkansas cotton varieties is highly desirable. However, very little is known about the molecular basis of heat stress tolerance in cotton. The present study attempted to identify heat stress tolerance genes in two heat-tolerant cotton cultivars, VH260 and MNH456, originating from Pakistan. Towards this, the expression profile of the cotton orthologs of sevenArabidopsisheat stress tolerance genes was studied in these two cultivars, and compared with the two heat-susceptible cotton cultivars, ST213 and ST4288, originating from Mississippi Delta region. In addition, physiological parameters …

The Phaseolus Vulgaris Zip Gene Family: Identification, Characterization, Mapping, And Gene Expression, Carolina Astudillo, Andrea C. Fernandez, Matthew W. Blair, Karen A. Cichy

Agricultural and Environmental Sciences Faculty Research

Zinc is an essential mineral for humans and plants and is involved in many physiological and biochemical processes. In humans, Zn deficiency has been associated with retarded growth and reduction of immune response. In plants, Zn is an essential component of more than 300 enzymes including RNA polymerase, alkaline phosphatase, alcohol dehydrogenase, Cu/Zn superoxidase dismutase, and carbonic anhydrase. The accumulation of Zn in plants involves many genes and characterization of the role of these genes will be useful in biofortification. Here we report the identification and phlyogenetic and sequence characterization of the 23 members of the ZIP (ZRT, IRT like …