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Plant Sciences

2013

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A Northward Range Extension Of The Hispid Cotton Rat (Sigmodon Hispidus) In Missouri, Cody W. Thompson, Elmer J. Finck Dec 2013

A Northward Range Extension Of The Hispid Cotton Rat (Sigmodon Hispidus) In Missouri, Cody W. Thompson, Elmer J. Finck

The Prairie Naturalist

The hispid cotton rat (Sigmodon hispidus) is a widely distributed rodent with a geographic range extending from north-central Mexico to southern Nebraska and central Virginia and from southeastern Arizona east to Florida (Carleton et al. 1999, Peppers and Bradley 2000, Wilson and Reeder 2005) with isolated populations in Arizona (Bradley et al. 2012) and California (Clark 1972). Range expansions for the species have been well documented (Clark 1972, Farney 1975, Benedict et al. 2000, Wright et al. 2010, Wills et al. 2011). The majority of these range expansions have occurred across the Central Plains during the 20th century …


Use Of Seeded Exotic Grasslands By Wintering Birds, Andrew D. George, Timothy J. O'Connell, Karen R. Hickman, David M. Lesliee Jr. Dec 2013

Use Of Seeded Exotic Grasslands By Wintering Birds, Andrew D. George, Timothy J. O'Connell, Karen R. Hickman, David M. Lesliee Jr.

The Prairie Naturalist

Despite widespread population declines of North American grassland birds, effects of anthropogenic disturbance on wintering habitat of this guild remain poorly understood. We compared avian abundance and habitat structure in fields planted to the exotic grass Old World bluestem (Bothriochloa ischaemum; OWB) to that in native mixed-grass prairie. During winters of 2007–2008 and 2008–2009, we conducted bird and vegetation surveys in six native grass and six OWB fields in Garfield, Grant, and Alfalfa counties, Oklahoma. We recorded 24 species of wintering birds in native fields and 14 species in OWB monocultures. While vegetation structure was similar between field …


Whooping Cranes Consume Plains Leopard Frogs At Migratory Stopover Sites In Nebraska, Keith Geluso, Brad T. Krohn, Mary J. Harner, Michael J. Assenmacher Dec 2013

Whooping Cranes Consume Plains Leopard Frogs At Migratory Stopover Sites In Nebraska, Keith Geluso, Brad T. Krohn, Mary J. Harner, Michael J. Assenmacher

The Prairie Naturalist

Whooping cranes (Grus americana) currently consist of a single, wild population that migrates annually from breeding grounds at Wood Buffalo National Park, Canada, to wintering grounds on and around the Aransas National Wildlife Refuge along the Texas coast, USA (NRC 2005). This population reached a low of less than 20 individuals in 1941 (Allen 1952) but has rebounded to over 250 individuals (Chavez-Ramirez and Wehtje 2012, Gil-Weir et al. 2012). Whooping cranes migrate approximately 4,000 km each spring and autumn, traversing much of the North American Great Plains (Lewis 1995) and periodically landing along rivers, wetlands, and other …


Relationships Among Walleye Mercury, Selenium, Stable Isotopes, Size And Age, Mark J. Fincel, Robert P. Hanten, Shannon Minerich Dec 2013

Relationships Among Walleye Mercury, Selenium, Stable Isotopes, Size And Age, Mark J. Fincel, Robert P. Hanten, Shannon Minerich

The Prairie Naturalist

Bioaccumulation of mercury is well-documented in aquatic ecosystems and occurs as mercury is accumulated and passed up food chains (Kidd et al. 1995, Atwell et al. 1998, Downs et al. 1998). Trophic level correlations have been widely reported for mercury (Snodgrass et al. 2000) and other metals (Barron 1995). Generally, within a system, carnivores have the highest mercury loadings, omnivores intermediate and herbivores the lowest (Phillips et al. 1980). However, little research has focused on the differences in mercury bioaccumulation for a single species that ranges across multiple trophic levels (Burger et al. 2001).

Stable isotope analysis has expanded the …


Dual Capture Of A Piñon Deer Mouse And A Silky Pocket Mouse Resulting In Consumption Of The Smaller Animal, Jon C. Pigage, Roger D. Peyton Dec 2013

Dual Capture Of A Piñon Deer Mouse And A Silky Pocket Mouse Resulting In Consumption Of The Smaller Animal, Jon C. Pigage, Roger D. Peyton

The Prairie Naturalist

Intraspecific dual captures of rodents are uncommon, but not rare. There are several reports of brown rats (Rattus norvegicus), white-footed deer mice (Peromyscus leucopus), North American deer mice (P. maniculatus), western harvest mice (Reithrodontomys megalotis) and meadow voles (Microtus pennsylvanicus) caught simultaneously in the same trap (i.e. a door-closing live-trap; Davis 1955, Getz 1961, Blaustein and Rothstein 1978, Jenkins and Llewellyn 1981, Novak 1983). Some reports are incidental whereas others are interpreted as social associations or bonding between conspecifics. Interspecific dual captures are rarely reported in the literature. The earliest report of …


A Simple Device For Measuring The Minimum Current Velocity To Maintain Semi-Buoyant Fish Eggs In Suspension, Julias S. Mueller, Brandon D. Cheek, Qingman Chen, Jillian Groeschel, Shannok K. Brewer, Timothy B. Grabowski Dec 2013

A Simple Device For Measuring The Minimum Current Velocity To Maintain Semi-Buoyant Fish Eggs In Suspension, Julias S. Mueller, Brandon D. Cheek, Qingman Chen, Jillian Groeschel, Shannok K. Brewer, Timothy B. Grabowski

The Prairie Naturalist

Pelagic broadcast spawning cyprinids are common to Great Plains rivers and streams. This reproductive guild produces non-adhesive semi-buoyant eggs that require sufficient current velocity to remain in suspension during development. Although studies have shown that there may be a minimum velocity needed to keep the eggs in suspension, this velocity has not been estimated directly nor has the influence of physicochemical factors on egg buoyancy been determined. We developed a simple, inexpensive flow chamber that allowed for evaluation of minimum current velocity needed to keep semi-buoyant eggs in suspension at any time frame during egg development. The device described here …


Associations Between Iron Concentration And Productivity In Montane Streams Of The Black Hills, South Dakota, Cari-Ann Hayer, Benjamin M. Holocmb, Steven R. Chipps Dec 2013

Associations Between Iron Concentration And Productivity In Montane Streams Of The Black Hills, South Dakota, Cari-Ann Hayer, Benjamin M. Holocmb, Steven R. Chipps

The Prairie Naturalist

Iron is an important micronutrient found in aquatic systems that can influence nutrient availability (e.g. phosphorus) and primary productivity. In streams, high iron concentrations often are associated with low pH as a result of acid mine drainage, which is known to affect fish and invertebrate communities. Streams in the Black Hills of South Dakota are generally circumneutral in pH, yet select streams exhibit high iron concentrations associated with natural iron deposits. In this study, we examined relationships among iron concentration, periphyton biomass, macroinvertebrate abundance, and fish assemblages in four Black Hills streams. The stream with the highest iron concentration (~5 …


Red-Tailed Hawk Nesting In Kansas: Influence Of Landscape Characteristics, William Langley Dec 2013

Red-Tailed Hawk Nesting In Kansas: Influence Of Landscape Characteristics, William Langley

The Prairie Naturalist

Factors that affect nest site selection in red-tailed hawks (Buteo jamaicensis) include the physical features surrounding the nest and landscape characteristics. Features surrounding nests include: tree height, tree diameter (dbh), percent canopy cover, slope, nest openness, and density of woody plants or shrubs (Titus and Mosher 1981, Bechard et al. 1990, Tietje et al. 1997, Actkinson et al. 2007). Landscape characteristics that influence nest-site selection by red-tailed hawks vary across regions. In Georgia, red-tailed hawks selected nest site in areas with greater area of agriculture and open pasture (Moorman and Chapman 1996), whereas in Oklahoma prairies, the hawks …


Quantitative Trait Loci Associated With Waterlogging Tolerance In A Soft Red Winter Wheat Mapping Population, Diana Carolina Ballesteros Benavides Dec 2013

Quantitative Trait Loci Associated With Waterlogging Tolerance In A Soft Red Winter Wheat Mapping Population, Diana Carolina Ballesteros Benavides

Graduate Theses and Dissertations

Waterlogging is caused when water stays superficially in the soil for an extended period of time, creating an anaerobic environment which decreases plant growth and grain yield at maturity. Despite the impact of waterlogging on wheat production both globally and in the southeastern U.S., very little is known about the genetic control of waterlogging tolerance in wheat. The objective of this study was to determine the amount of genetic variation for vegetative stage waterlogging tolerance present within a wheat recombinant inbred line (RIL) population and to identify quantitative trait loci (QTL) associated with tolerance and productivity. Experiments were carried out …


A Comparison Of Milled Rice Fissuring Kinetics Of Hybrid And Pureline Cultivars, Semehar Haile Tesfaye Dec 2013

A Comparison Of Milled Rice Fissuring Kinetics Of Hybrid And Pureline Cultivars, Semehar Haile Tesfaye

Graduate Theses and Dissertations

Over the past decade, the use of hybrid rice cultivars has greatly increased, and this has led to questions about the processing behavior of hybrid cultivars. This study compares the milled rice fissuring kinetics of hybrid and pureline cultivars. Also, this study elucidates the effects of kernel type (long-grain vs. medium-grain rice cultivars), surface lipid content (SLC), and kernel thickness on fissuring rates.

Three hybrid (CL XL745, CL XL729 and XL753) and five pureline (Wells, CL151, Cheniere, Jupiter and CL261) cultivar lots were procured. Jupiter and CL261 are medium-grain cultivars, whereas the rest are long-grain cultivars. Two experiments were conducted. …


Risk Return Of Farmer-Elevator Contracts For Soybeans And Corn In Arkansas, Marei Undine Houpert Dec 2013

Risk Return Of Farmer-Elevator Contracts For Soybeans And Corn In Arkansas, Marei Undine Houpert

Graduate Theses and Dissertations

In Arkansas the contribution of Agriculture to the states GDP is comparatively high. To help farmer's return risk the grain industry developed several marketing tools to support farmers. Literature in this research field finds different results for different locations, commodities, marketing tools and marketing years. As Agriculture in Arkansas is important for its economy this study focuses on soybeans and corn produced in the fertile north-eastern area of Arkansas that uses Memphis Tennessee as a spot market palace. The examined marketing tools are pre-harvest futures hedges and forward contracts as well as post-harvest storage strategies and minimum price contracts. All …


Phytophthora Foliage Blight Of Garden Phlox: Phytophthora Nicotianae On Phlox Paniculata, Daniel Drechsler Dec 2013

Phytophthora Foliage Blight Of Garden Phlox: Phytophthora Nicotianae On Phlox Paniculata, Daniel Drechsler

All Theses

Phytophthora foliage blight of garden phlox (Phlox paniculata ) - caused by Phytophthora nicotianae - is a devastating disease that has been seen consistently in nursery production facilities in South Carolina. However, this disease has not been characterized previously. This project was composed of three separate studies, each of which followed one of the three major components of the disease triangle (i.e., the synchronous occurrence of a susceptible host and a virulent pathogen within a conducive environment) to investigate the pathogenicity of P. nicotianae on P. paniculata . In one study, the efficacies of three inoculation methodologies to cause …


Managing Fusarium Wilt In Watermelon Production, Zachary Snipes Dec 2013

Managing Fusarium Wilt In Watermelon Production, Zachary Snipes

All Theses

Fusarium wilt of watermelon, caused by Fusarium oxysporum f. sp. niveum , was first described in 1894 in South Carolina and Georgia and has become a limiting factor in watermelon production worldwide. In recent years, restriction on use of the soil fumigant methyl bromide and the recent development of more virulent races of Fusarium oxysporum f. sp. niveum has created a critical need for alternative management techniques. In 2011-2013 field experiments were designed to evaluate the efficacy of incorporating a cover crop of hairy vetch into the soil to manage Fusarium wilt. Colony-forming units (CFU) of Fusarium oxysporum were sampled …


Commelina Benghalensis New To Virginia, W. John Hayden Dec 2013

Commelina Benghalensis New To Virginia, W. John Hayden

Biology Faculty Publications

This is the first report of Commelina benghalensis (Benghal dayflower, tropical spiderwort) in Virginia. Three mature plants with intertwined stems bearing numerous chasmogamous and cleistogamous flowers were discovered as weeds in a landscape planting of hybrid Hemerocallis, hybrid Iris, and a dwarf cultivar of Nandina domestica; nine nonreproductive seedlings were found about one meter distant in the same flower bed.


Forage And Biomass Dual-Purpose Harvest System Using Native Warm-Season Grasses, David Weston Mcintosh Dec 2013

Forage And Biomass Dual-Purpose Harvest System Using Native Warm-Season Grasses, David Weston Mcintosh

Masters Theses

There has been increasing interest in utilizing native warm-season grasses (NWSGs), especially switchgrass, as a biomass feedstock for cellulosic ethanol production. Millions of hectares of crop and pasture in the mid-South are forecast to potentially be planted with switchgrass for biomass feedstock production. This could have a substantial impact on the region’s cattle industry, reducing forage production hectares. This study was conducted to determine the effect of early season harvest timing on forage and biomass of NWSGs designed for use in cellulosic ethanol production. The over-all hypothesis was to determine if an early forage harvest can be included in a …


The Performance Of Bacterial Phytosensing Transgenic Tobacco Under Field Conditions, Michael Harrison Fethe Dec 2013

The Performance Of Bacterial Phytosensing Transgenic Tobacco Under Field Conditions, Michael Harrison Fethe

Masters Theses

Currently the platforms for wide-area detection of environmental contamination are limited. Therefore, there is interest in developing new platforms, especially for use in crop plants to detect and report the presence of biotic and abiotic stress agents. A biosensor uses a biological organism or substrate to detect the presence of an elicitor (i.e., heavy metal, TNT, or bacteria). The foundational groundwork to create biosensors in transgenic plants exists. The creation of bacterial phytosensing transgenic tobacco containing an orange fluorescent protein (OFP) reporter driven by synthetic pathogen-inducible promoters provides a fluorescent signal when infected with phytopathogens for earlier detection in the …


The Influence Of Hydrogeomorphology, Soil Redox Conditions, And Salinity On The Spatial Zoning Of Saltgrass, Salt Rush, And Cattails In Scotts Creek Marsh, Swanton Pacific Ranch, Ca, Mark D. Gormley Dec 2013

The Influence Of Hydrogeomorphology, Soil Redox Conditions, And Salinity On The Spatial Zoning Of Saltgrass, Salt Rush, And Cattails In Scotts Creek Marsh, Swanton Pacific Ranch, Ca, Mark D. Gormley

Master's Theses

Scotts Creek Marsh (SCM) is a small coastal wetland ecosystem in Davenport, CA. The vegetation of SCM is dominated by three halophytic zones comprised of saltgrass, salt rush, cattails. The objectives of the study were (i) to investigate the variables that influence the zoning of the three dominant halophyte communities in SCM and (ii) to the test the effectiveness of Indicator of Reduction in Soil (IRIS) tubes to indicate the reduction of S. The study examined the following parameters from April 6 to July 21, 2013: (i) the HGM of Scotts Creek Marsh, (ii) soil oxidation and reduction (redox) conditions, …


Tracking The Cellulolytic Activity Of Clostridium Thermocellum Biofilms, Alexandru Dumitrache, Gideon M. Wolfaardt, David Allen, Steven N. Liss, Lee R. Lynd Nov 2013

Tracking The Cellulolytic Activity Of Clostridium Thermocellum Biofilms, Alexandru Dumitrache, Gideon M. Wolfaardt, David Allen, Steven N. Liss, Lee R. Lynd

Dartmouth Scholarship

Microbial cellulose conversion by Clostridium thermocellum 27405 occurs predominantly through the activity of substrate-adherent bacteria organized in thin, primarily single cell-layered biofilms. The importance of cellulosic surface exposure to microbial hydrolysis has received little attention despite its implied impact on conversion kinetics.


Revsys: Systematics Of Amelanchier (Rosaceae), Christopher S. Campbell Nov 2013

Revsys: Systematics Of Amelanchier (Rosaceae), Christopher S. Campbell

University of Maine Office of Research Administration: Grant Reports

Amelanchier contains about 20 species of trees and shrubs of the North Temperate Zone. These plants bear attractive flowers, their fruits are important to wildlife, and they are valued horticulturally. Shadbushes and serviceberries, as these plants are commonly called, are native to every state of the United States except Hawaii. It has been a challenge to define the species of Amelanchier because hybridization is frequent, and novel kinds of plants created by hybridization can be widely dispersed. Some forms of shadbushes are easy to distinguish while others differ from one another in minute ways. The goal of this research is …


Botryoccocus Braunii Triterpene Synthase Proteins And Nucleic Acid Molecules, And Methods For Their Use, Joe Chappell, Okada Shigeru, Tom Neihaus, Tim Devarenne Nov 2013

Botryoccocus Braunii Triterpene Synthase Proteins And Nucleic Acid Molecules, And Methods For Their Use, Joe Chappell, Okada Shigeru, Tom Neihaus, Tim Devarenne

Plant and Soil Sciences Faculty Patents

This application relates to the functional identification and characterization of a nucleic acid molecule encoding a triterpene synthase, in particular botryococcene synthase. Also described are host cells comprising the nucleic acid molecules of this invention, proteins encoded by the nucleic acid molecules and methods for using the nucleic acid molecules, transformed hosts and encoded proteins to produce high levels of triterpene hydrocarbons.


Our Gendered Food Chain, Jasmine T. Colahan Nov 2013

Our Gendered Food Chain, Jasmine T. Colahan

SURGE

Over the past four decades, the number of women-operated farms has nearly doubled. Including both primary and secondary operators, one million women make up thirty percent of all U.S. farmers.

Headlines such as “Females Take the Reins,” “Meet the New face of Agriculture,” “Old McDonald Might Be a Lady” demonstrate this gender shift. And, it is true in my life too. As I worked on the Painted Turtle Farm this summer, the majority of my role models, co-workers, and mentors working in agriculture, whether rural or urban, were primarily women. [excerpt]


Ceratobasidium Root Rot: A New Disease Of Watermelon In Arizona, Claudia Nischwitz Nov 2013

Ceratobasidium Root Rot: A New Disease Of Watermelon In Arizona, Claudia Nischwitz

All Current Publications

No abstract provided.


Myb10 And Myb72 Are Required For Growth Under Iron-Limiting Conditions, Christine M. Palmer, Maria N. Hindt, Holger Schmidt, Stephan Clemens, Mary Lou Guerinot Nov 2013

Myb10 And Myb72 Are Required For Growth Under Iron-Limiting Conditions, Christine M. Palmer, Maria N. Hindt, Holger Schmidt, Stephan Clemens, Mary Lou Guerinot

Dartmouth Scholarship

Iron is essential for photosynthesis and is often a limiting nutrient for plant productivity. Plants respond to conditions of iron deficiency by increasing transcript abundance of key genes involved in iron homeostasis, but only a few regulators of these genes have been identified. Using genome-wide expression analysis, we searched for transcription factors that are induced within 24 hours after transferring plants to iron-deficient growth conditions. Out of nearly 100 transcription factors shown to be up-regulated, we identified MYB10 and MYB72 as the most highly induced transcription factors. Here, we show that MYB10 and MYB72 are functionally redundant and are required …


Arabidopsis 56–Amino Acid Serine Palmitoyltransferase- Interacting Proteins Stimulate Sphingolipid Synthesis, Are Essential, And Affect Mycotoxin Sensitivity, Athen N. Kimberlin, Saurav Majumder, Gongshe Han, Ming Chen, Rebecca E. Cahoon, Julie M. Stone, Teresa M. Dunn, Edgar B. Cahoon Nov 2013

Arabidopsis 56–Amino Acid Serine Palmitoyltransferase- Interacting Proteins Stimulate Sphingolipid Synthesis, Are Essential, And Affect Mycotoxin Sensitivity, Athen N. Kimberlin, Saurav Majumder, Gongshe Han, Ming Chen, Rebecca E. Cahoon, Julie M. Stone, Teresa M. Dunn, Edgar B. Cahoon

Center for Plant Science Innovation: Faculty and Staff Publications

Maintenance of sphingolipid homeostasis is critical for cell growth and programmed cell death (PCD). Serine palmitoyltransferase (SPT), composed of LCB1 and LCB2 subunits, catalyzes the primary regulatory point for sphingolipid synthesis. Small subunits of SPT (ssSPT) that strongly stimulate SPT activity have been identified in mammals, but the role of ssSPT in eukaryotic cells is unclear. Candidate Arabidopsis thaliana ssSPTs, ssSPTa and ssSPTb, were identified and characterized. Expression of these 56–amino acid polypeptides in a Saccharomyces cerevisiae SPT null mutant stimulated SPT activity from the Arabidopsis LCB1/LCB2 heterodimer by >100-fold through physical interaction with LCB1/LCB2. ssSPTa transcripts were …


Response Of Near-Isogenic Sorghum Lines, Differing At The P Locus For Plant Colour, To Grain Mould And Head Smut Fungi, Deanna L. Funnell-Harris, L. K. Prom, Scott E. Sattler, Jeffrey F. Pedersen Nov 2013

Response Of Near-Isogenic Sorghum Lines, Differing At The P Locus For Plant Colour, To Grain Mould And Head Smut Fungi, Deanna L. Funnell-Harris, L. K. Prom, Scott E. Sattler, Jeffrey F. Pedersen

Department of Plant Pathology: Faculty Publications

Leaves and stalks of many sorghum genotypes accumulate dark red or purple pigments upon wounding while some plants, called ‘tan,’ do not. Grains with unpigmented ‘white’ pericarps grown on tan plants are more desirable for food. The hypothesis tested was that pigments in plants protected grain against the panicle diseases grain mould and head smut. Near-isogenic tan or purple plant color genotypes with white grain were planted at Lincoln and Ithaca, NE and Corpus Christi, TX. The field grown grain was plated onto semi-selective media to detect the presence of grain colonisation by mould genera Alternaria, Fusarium and Curvularia. …


Early Flowering Mutant Chia And Uses Thereof, David Hildebrand, Watchareewan Jamboonsri, Timothy Phillips Nov 2013

Early Flowering Mutant Chia And Uses Thereof, David Hildebrand, Watchareewan Jamboonsri, Timothy Phillips

Plant and Soil Sciences Faculty Patents

The invention relates to early flowering Chia (Salvia hispanica L.) strains that are suitable for culturing in a temperate area for seed production. Mutations are introduced to wild type chia seeds. Desired mutant progeny having normal appearance and an altered flora organ development is subsequently identified.


An Intergenic Region Shared By At4g35985 And At4g35987 In Arabidopsis Thaliana Is A Tissue Specific And Stress Inducible Bidirectional Promoter Analyzed In Transgenic Arabidopsis And Tobacco Plants, Joydeep Banerjee, Dipak K. Sahoo, Nrisingha Dey, Robert Houtz, Indu B. Maiti Nov 2013

An Intergenic Region Shared By At4g35985 And At4g35987 In Arabidopsis Thaliana Is A Tissue Specific And Stress Inducible Bidirectional Promoter Analyzed In Transgenic Arabidopsis And Tobacco Plants, Joydeep Banerjee, Dipak K. Sahoo, Nrisingha Dey, Robert Houtz, Indu B. Maiti

Kentucky Tobacco Research and Development Center Faculty Publications

On chromosome 4 in the Arabidopsis genome, two neighboring genes (calmodulin methyl transferase At4g35987 and senescence associated gene At4g35985) are located in a head-to-head divergent orientation sharing a putative bidirectional promoter. This 1258 bp intergenic region contains a number of environmental stress responsive and tissue specific cis-regulatory elements. Transcript analysis of At4g35985 and At4g35987 genes by quantitative real time PCR showed tissue specific and stress inducible expression profiles. We tested the bidirectional promoter-function of the intergenic region shared by the divergent genes At4g35985 and At4g35987 using two reporter genes (GFP and GUS) in both orientations in transient tobacco protoplast and …


Resilience To Stress And Disturbance, And Resistance To Bromus Tectorum L. Invasion In Cold Desert Shrublands Of Western North America, Jeanne C. Chambers, Bethany A. Bradley, Cynthia S. Brown, Carla D'Antonio, Matthew J. Germino, James B. Grace, Stuart P. Hardegree, Richard F. Miller, David A. Pyke Nov 2013

Resilience To Stress And Disturbance, And Resistance To Bromus Tectorum L. Invasion In Cold Desert Shrublands Of Western North America, Jeanne C. Chambers, Bethany A. Bradley, Cynthia S. Brown, Carla D'Antonio, Matthew J. Germino, James B. Grace, Stuart P. Hardegree, Richard F. Miller, David A. Pyke

Articles

Alien grass invasions in arid and semi-arid ecosystems are resulting in grass–fire cycles and ecosystem-level transformations that severely diminish ecosystem services. Our capacity to address the rapid and complex changes occurring in these ecosystems can be enhanced by developing an understanding of the environmental factors and ecosystem attributes that determine resilience of native ecosystems to stress and disturbance, and resistance to invasion. Cold desert shrublands occur over strong environmental gradients and exhibit significant differences in resilience and resistance. They provide an excellent opportunity to increase our understanding of these concepts. Herein, we examine a series of linked questions about (a) …


Differences In Temperature Responses Of Achene Types In Centaurea Melitensis, Kandee L. Bain Nov 2013

Differences In Temperature Responses Of Achene Types In Centaurea Melitensis, Kandee L. Bain

LUX: A Journal of Transdisciplinary Writing and Research from Claremont Graduate University

Southern California has a Mediterranean climate with wet winters and hot dry summers. This type of environment is associated with irregular temperature patterns and rainfall, which can be unpredictable. Unpredictable environments, can threaten the germination and survival of plants like Centaurea melitensis. To ensure germination and survival under unpredictable environmental conditions, some plants may develop characteristic structures like cleistogamous flower heads, and in some cases they will develop heteromorphic achenes. Morphological differences between peripheral and center achenes may indicate variable responses to temperature. Additionally, unpredictable environmental conditions may lead to differences in the number of peripheral to center achenes …


Wheat Streak Mosaic Virus Infects Systemically Despite Extensive Coat Protein Deletions: Identification Of Virion Assembly And Cell-To-Cell Movement Determinants, Satyanarayana Tatineni, Frank A. Kovacs, Roy C. French Nov 2013

Wheat Streak Mosaic Virus Infects Systemically Despite Extensive Coat Protein Deletions: Identification Of Virion Assembly And Cell-To-Cell Movement Determinants, Satyanarayana Tatineni, Frank A. Kovacs, Roy C. French

Department of Plant Pathology: Faculty Publications

Viral coat proteins function in virion assembly and virus biology in a tightly coordinated manner with a role for virtually every amino acid. In this study, we demonstrated that the coat protein (CP) of Wheat streak mosaic virus (WSMV) (genus Tritimovirus; family Potyviridae) is unusually tolerant of extensive deletions with continued virion assembly and/or systemic infection. A series of deletion and point mutations were created in the CP cistron of wild-type and/or GFP-tagged WSMV and examined the effects of these mutations on cell-to-cell and systemic transport and virion assembly of WSMV. Mutants with overlapping deletions comprising N-terminal amino …