Digital Commons Network^™

Life History Of An Exotic Soft Scale Insect Phalacrococcus Howertoni (Hemiptera: Coccidae) Found In Florida, Kaushalya G. Amarasekare, Catharine M. Mannion

Agricultural and Environmental Sciences Faculty Research

We investigated the life history of an exotic soft scale insect, Phalacrococcus howertoni Hodges and Hodgson that damages croton and several other economically important ornamental and fruit plants in Florida. There was no difference in the development, survival, and reproduction of this scale insect species when reared either on croton or on buttonwood at 27 ± 1°C, 12:12 (L:D) h and 65% R. H. The scale insect practiced ovoviviparity. We observed that eggs that came out from vulva hatched to first instars immediately. Newly hatched nymphs had a tendency stay underneath the female body for somewhat less than approximately 24 …

Rna-Mediated Silencing In Algae: Biological Roles And Tools For Analysis Of Gene Function, Heriberto Cerutti, Xinrong Ma, Joseph Msanne, Timothy Repas

Center for Plant Science Innovation: Faculty Publications

Algae are a large group of aquatic, typically photosynthetic, eukaryotes that include species from very diverse phylogenetic lineages, from those similar to land plants to those related to protist parasites. The recent sequencing of several algal genomes has provided insights into the great complexity of these organisms. Genomic information has also emphasized our lack of knowledge of the functions of many predicted genes, as well as the gene regulatory mechanisms in algae. Core components of the machinery for RNA-mediated silencing show widespread distribution among algal lineages, but they also seem to have been lost entirely from several species with relatively …

Muts Homolog1 Is A Nucleoid Protein That Alters Mitochondrial And Plastid Properties And Plant Response To High Light, Ying-Zhi Xu, Maria P. Arrieta-Montiel, Kamaldeep S. Virdi, Wilson B. M. De Paula, Joshua R. Widhalm, Gilles J. Basset, Jaime I. Davila, Thomas Elthon, Christian G. Elowsky, Shirley J. Sato, Thomas E. Clemente, Sally Ann Mackenzie

Center for Plant Science Innovation: Faculty Publications

Mitochondrial-plastid interdependence within the plant cell is presumed to be essential, but measurable demonstration of this intimate interaction is difficult. At the level of cellular metabolism, several biosynthetic pathways involve both mitochondrial- and plastid-localized steps. However, at an environmental response level, it is not clear how the two organelles intersect in programmed cellular responses. Here, we provide evidence, using genetic perturbation of the MutS Homolog1 (MSH1) nuclear gene in five plant species, that MSH1 functions within the mitochondrion and plastid to influence organellar genome behavior and plant growth patterns. The mitochondrial form of the protein participates in DNA recombination …

Nebline, September 2011

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Feature: 4-H Helps Build Successful Scientists

Farm Views

Horticulture

Food & Fitness

Home & Family Living

Environmental Focus

Urban Agriculture

4-H & Youth

Community Focus

Extension Calendar

Nutrition Education Program

Family and Community Education (FCE) Clubs

and other extension news and events

Economic And Social Impacts Of Wildfires And Invasive Plants In American Deserts: Lessons From The Great Basin, Mark W. Brunson, John Tanaka

Articles

Research on the impacts of wildfire and invasive plants in rangelands has focused on biophysical rather than human dimensions of these environmental processes. We offer a synthetic perspective on economic and social aspects of wildfire and invasive plants in American deserts, focusing on the Great Basin because greater research attention has been given to the effects of cheatgrass expansion than to other desert wildfire/invasion cycles. We focus first on impacts at the level of the individual decision-maker, then on impacts experienced at the human community or larger socio-political scales. Economic impacts of wildfire differ from those of invasive grasses because …

Evaluation Of Perennial Forage Legumes And Herbs In Six Mediterranean Environments, Daniel Real, Guangdi D. Li, Steve Clark, Tony Albertsen, Richard C. Hayes, Matt D. Denton, Mario F. D'Antuono, B S. Dear

Grain and Other Field Crops Research Articles

There is an absence of drought tolerant herbaceous perennial forage legume and herb options other than lucerne (Medicago sativa L.) for environments with Mediterranean-like climates common in extensive areas of Southern Australia, the Mediterranean basin, and Chile. Therefore, a collection of 174 forage perennial legume and herb entries from 103 species and 32 genera was evaluated for adaptation in a diverse range of Mediterranean climatic environments in Southern Australia. The seasonal rainfall distribution varied from moderately to highly winter dominant with long term average annual rainfall ranging from 318 to 655 mm. The entries were rated for productivity and …

Effects Of In Situ Freezing On Soil Net Nitrogen Mineralization And Net Nitrification In Fertilized Grassland Of Northern China, X. Zhang, W. Bai, Frank S. Gilliam, Q. Wang, X. Han, L. Li

Biological Sciences Faculty Research

Effects of soil freezing on nitrogen (N) mineralization have been the subject of increased attention in the ecological literature, though fewer studies have examined N mineralization responses to successive mild freezing, severe freezing and cyclic freeze–thaw events. Even less is known about relationships of responses to soil N status. This study measured soil N mineralization and nitrification in the field along an experimental N gradient in a grassland of northern China during the dormant season (October 2005–April 2006), a period in which freezing naturally occurs. Net N mineralization exhibited great temporal variability, with nitrification being the predominant N transformation process. …

Increased Floral Divergence In Sympatric Monkeyflowers, Dena L. Grossenbacher, Justen B. Whittall

Biology

Sympatric sister species are predicted to have greater divergence in reproductive traits than allopatric sister species, especially if mating system shifts, such as the evolution of self-fertilization, are more likely to originate within the geographic range of the outcrossing ancestor. We present evidence that supports this expectation-sympatric sister species in the monkeyflower genus, Mimulus, exhibit greater divergence in flower size than allopatric sister species. Additionally, we find that sympatric sister species are more likely to have one species with anthers that overtop their stigmas than allopatric sister species, suggesting that the evolution of automatic self-pollination may contribute to this pattern. …

Single Molecule Analysis Of The Arabidopsis Fra1 Kinesin Shows That It Is A Functional Motor Protein With Unusually High Processivity, Chuanmei Zhu, Ram Dixit

Biology Faculty Research

The Arabidopsis FRA1 kinesin contributes to the organization of cellulose microfibrils through an unknown mechanism. The cortical localization of this kinesin during interphase raises the possibility that it transports cell wall-related cargoes along cortical microtubules that either directly or indirectly influence cellulose microfibril patterning. To determine whether FRA1 is an authentic motor protein, we combined bulk biochemical assays and single molecule fluorescence imaging to analyze the motor properties of recombinant, GFP-tagged FRA1 containing the motor and coiled-coil domains (designated as FRA1(707)–GFP). We found that FRA1(707)–GFP binds to microtubules in an ATP-dependent manner and that its ATPase activity is dramatically stimulated …

A New Species Of Diploid Quillwort (Isoetes, Isoetaceae, Lycophyta) From Lebanon, Jay F. Bolin, Rebecca D. Bray, Lytton John Musselman

Biological Sciences Faculty Publications

A new species, Isoetes libanotica Musselman, Bolin & B. D. Bray (Isoetaceae, Lycophyta), is described from Akkar District of northern Lebanon. It is a seasonal terrestrial species of basaltic soils, diploid (2n = 22), with complete velum coverage. Megaspore diameter ranges from 338 to 477 mu m with remote, low tuberculate ornamentation and a low to obsolete equatorial girdle; microspore length ranges from 25 to 30 mu m, with echinate ornamentation. At the type locality of I. libanotica, two other Isoetes L. species occur sympatrically. These superficially similar Isoetes species can be differentiated from I. libanotica using megaspore …

Substantial Equivalence Assessment Of Transgenic Corn Plants, Martina Garda

Student Theses and Dissertations

Transgenic crops are regulated until they are judged to be as safe as non-transgenic plants. To grow them without permits, they must attain regulatory approval. . A lot of data are needed to show "substantial equivalence" and safety . This work deals with corn lines that contain cellulase genes. We hypothesize that no difference exists between Genetically Engineered (GE) and non-Genetically Engineered (non-GE) corn seeds at the morphological, protein, and DNA levels, except for the protein expressed specifically from the corresponding gene. This research will address concerns in commercializing GE crops, such as those containing a gene for either an …

A Comparative Risk Assessment Framework For Wildland Fire Management: The 2010 Cohesive Strategy Science Report, David E. Calkin, Alan Ager, Matthew P. Thompson, Mark A. Finney, Danny C. Lee, Thomas M. Quigley, Charles W. Mchugh, Karin L. Riley, Julie M. Gilbertson-Day

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

The FLAME Act of 2009 requires the U.S. Department of Agriculture Forest Service and the U.S. Department of Interior to submit to Congress a Cohesive Wildfire Management Strategy. In this report, we explore the general science available for a risk-based approach to fire and fuels management and suggest analyses that may be applied at multiple scales to inform decisionmaking and tradeoff analysis. We discuss scientific strengths and limitations of wildfire risk assessment frameworks, including the benefit of broad scalability as demonstrated by four recent case studies. We further highlight the role of comparative risk assessment, which extends the analysis to …

Propagation System Manual, Margaret Kane

Hydroponic Center

Contained in this manual you will find the required materials, assembly instructions, operation procedures and safety protocols to construct, run and maintain a hydroponic propagation system.

The Propagation System is designed to provide an environment for seeds to germinate with optimal conditions for seedling growth. The purpose of the Propagator is to create an environment that is suitable for seedlings to develop a strong root system and uprooted stem so they can be transplanted into a new system where they are able to fully develop and be harvested. This procedure introduces plants, vegetables, and fruits to a new system of …

Classifying And Mapping Diversity In A Species-Poor System: The Mangrove Meta-Community Of Laguna Chacahua National Park, Oaxaca, Mexico, Elizabeth Kay Weisgerber

Master's Theses

ABSTRACT

Classifying and Mapping Diversity in a Species-Poor System: the mangrove meta-community of Laguna Chacahua National Park, Oaxaca, Mexico

by

Elizabeth Kay Weisgerber

Both field transects and imagery grid plots were analyzed with the goal of creating a community classification map for the mangrove forest of Parque Nacional Lagunas de Chacahua. In total, data was collected in 49 sites throughout the park, recording measures such as DBH, basal area, estimated dominance, frequency, cover and relative dominance. Field locations were marked and georeferenced with a GPS and grid plots overlaid on satellite imagery of the park were generated via a random …

Aronia Mitschurinii: Solving A Horticultural Enigma, Peter J. Leonard

Master's Theses

Aronia (Medik.), commonly known as chokeberry, is a taxonomically misunderstood genus currently experiencing a renaissance in North America as both an ornamental and fruit crop. Three species of chokeberry are commonly accepted as native in North America: A. arbutifolia (L.) Pers. red chokeberry; A. melanocarpa (Michx.) Elliot, black chokeberry; and A. prunifolia (Marshall) Rehder, or purple chokeberry. In Europe a fourth species of human origin is recognized as Aronia mitschurinii (A.K.Skvortsov & Maitul.), or cultivated, black-fruited Aronia. It is widely speculated that this genotype originated in the early 20^th century with Russian pomologist Ivan Michurin, as the product …

Selecting Improved Lotus Nodulating Rhizobia To Expedite The Development Of New Forage Species, John Gregory Howieson, Ross Andrew Ballard, Ronald J. Yates, Nigel Charman

Grain and Other Field Crops Research Articles

Aims

In the past decades the increasing focus by Australian pasture development programs on the genus Lotus has seen the evaluation of many species previously untested in Australia. In field trials, nodulation failure was commonplace. This work was undertaken to select effective symbionts for Lotus to ensure further agronomic evaluation of the genus was not compromised. The symbiotic needs of Lotus ornithopodioides were a particular focus of the studies.

Methods

Glasshouse experiments were undertaken to evaluate symbiotic relationships between 15 Lotus spp and 23 strains of nodulating Mesorhizobium loti. This was followed by evaluation of elite rhizobial strains for …

The Role Of A Transcription Factor In Regulating Rice Response To Drought Stress, Diana Ha, Liyuan A. Zhang, Jeffery Shen

Undergraduate Research Opportunities Program (UROP)

The current water shortage is a major concern in regard to our global climate change crisis. A decrease in the availability of water will have direct effects on the development of plants. Some crops, such as Oryza sativa, or commonly known as rice, requires an abundant amount of water for adequate growth. With the water shortage crisis, it will become extremely difficult to harvest such crops to meet the world’s food demand. However, many plants have evolved mechanisms for overcoming and tolerating stresses such as drought. My research focuses on studying the proteins involved with these mechanisms. The WRKY superfamily …

Biological Effects On Serpentinite Weathering, Mary H. Evert, Julie Baumeister, Elisabeth Hausrath

Undergraduate Research Opportunities Program (UROP)

Serpentinites, perhaps more than any other rock type, control the composition and evolution of the development of the surrounding ecosystems. The bulk chemistry of serpentinite rocks, high in Mg and trace elements, and low in nutrients such as Ca, K, P, and N, causes an extreme and stressful environment for ecosystems. However, the role that those serpentine ecosystems play in development of serpentine soils has not been examined.

Due to the unusual chemistry of serpentine soils, serpentine ecosystems have deeper and better-developed root systems than other ecosystems. The rhizosphere of serpentine systems, documented to produce abundant organic acids and siderophores, …

Temperature Thresholds And Degree-Day Model For Marmara Gulosa (Lepidoptera: Gracillariidae), M. J. O'Neal, David H. Headrick, Gregory H. Montez, E.E. Grafton-Cardwell

Horticulture and Crop Science

The developmental thresholds for Marmara gulosa Guillen & Davis (Lepidoptera: Gracillariidae) were investigated in the laboratory by using 17, 21, 25, 29, and 33°C. The lowest mortality occurred in cohorts exposed to 25 and 29°C. Other temperatures caused >10% mortality primarily in egg and Þrst and second instar sap-feeding larvae. Linear regression analysis approximated the lower developmental threshold at 12.2°C. High mortality and slow developmental rate at 33°C indicate the upper developmental threshold is near this temperature. The degree-day (DD) model indicated that a generation requires an accumulation of 322 DD for development from egg to adult emergence. Average daily …

Digital Mapping As A Student And Staff Communication Tool, Ryan Gyurkovitz

Horticulture and Crop Science

A study in the use of Geographic Information Systems in the development of digital maps for use by students and staff in Plant Identification Courses.

Comparative Ecology Of Sarcobatus Baileyi And Sarcobatus Vermiculatus In Eastern California, Rebecca E. Drenovsky, Alynn M. Martin, Molly R. Falasco, James H. Richards

Biology

Greasewood (Sarcobatus) is a succulent-leaved, halophytic shrub of North American origin. The genus comprises 2 species: Sarcobatus baileyi and Sarcobatus vermiculatus. Sarcobatus vermiculatus is common throughout much of western North America, but S. baileyi is much more limited in distribution and was previously thought to be endemic to Nevada. Here we document and describe a S. baileyi population in eastern California, comparing its morphology and ecology to an adjacent S. vermiculatus population. Morphologically, S. baileyi is smaller in stature but produces larger seeds; however, fewer S. baileyi seeds germinated and survived a 20-day laboratory incubation compared to seeds of S. …

Relationships Among Rubus (Rosaceae) Species Used In Traditional Chinese Medicine, Yinu Wang

Masters Theses & Specialist Projects

Traditional Chinese medicine has a long history of using plants therapeutically including multiple species of the genus Rubus (Rosaceae). Fruits and other parts of Rubus plants have had a significant effect on human health and nutrition in both ancient and modern times. The pharmacological effects of Rubus include anti-inflammatory, antibacterial, anti-stress, anti-cancer and anti-aging properties. One of the current challenges limiting further development of Rubus resources in traditional Chinese medicine is a poor understanding of phylogenetic relationships among Rubus species in general and especially among Asian species, and also the need for additional studies of phytochemicals. Several confounding factors are …

Magnolia : Polyploidy, Genome Size, And Refinement Of Protocols For Micropropagation, James Parris

All Theses

The genus Magnolia includes over 250 species that range in ploidy level from diploid to hexaploid. Although there is basic information on ploidy levels of various species, sampling is limited with specific cultivars and hybrids. The objective of this research was to determine relative genome sizes and relationships to ploidy levels among a diverse collection of species, hybrids, and cultivars using flow cytometry. Nuclei were extracted, stained with 4’, 6–diamidino–2–phenylindole (DAPI), and analyzed using a flow cytometer. Relative genome sizes were determined using Pisum sativum as the reference genome. Genome size was calibrated with ploidy level for species with documented …

The Rate Of Shattercane X Sorghum Hybridization In Situ, Jared J. Schmidt

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

Cultivated sorghum (Sorghum bicolor subsp. bicolor) can interbreed with its close weedy relative shattercane (S. bicolor subsp. drummondii). The introduction of traits from cultivated sorghum into a shattercane population could contribute to the invasiveness of the wild shattercane population. An in situ experiment was conducted across two years to determine the potential for pollen-mediated gene flow from grain sorghum to shattercane. Shattercane with juicy midrib (dd) was planted in a soybean field in concentric arcs at varying distances from a sorghum pollen source with dry midrib (DD). The arcs were placed …

Gata-Family Transcription Factors In Magnaporthe Oryzae, Cristian F. Quispe

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

The filamentous fungus, Magnaporthe oryzae, responsible for blast rice disease, destroys around 10-30% of the rice crop annually. Infection begins when the specialized infection structure, the appressorium, generates enormous internal turgor pressure through the accumulation of glycerol. This turgor acts on a penetration peg emerging at the base of the cell, causing it to breach the leaf surface allowing its infection.

The enzyme trehalose-6- phosphate synthase (Tps1) is a central regulator of the transition from appressorium development to infectious hyphal growth. In the first chapter we show that initiation of rice blast disease requires a regulatory mechanism involving an …

Climate And Vegetation Change In The Newberry Mountains, Southern Clark County, Nevada, Ross Joseph Guida

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ecological studies have shown worldwide that vegetation is being affected by climate change. Species are shifting to new elevations and physiographic positions to adapt to changes in their environment. More specifically, paleoecology studies in the Mojave Desert have shown shifting vegetation patterns in response to past warming and precipitation changes. Recent studies have shown mortality among desert plants related to extended drought and warming. However, few studies have shown how the geographic distribution of Mojave Desert species has changed during this most recent period of warming. This study addresses this gap in the literature by focusing on several plant species …

Disease And Insect Resistance And Quality Characterization Of Six Cimmyt Synthetic Hexaploid Wheats, Kayse Onweller

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

The germplasm sources of common wheat (Triticum aestivum L.) are eroded by selection pressures applied by plant breeders and the disappearance of landraces. The erosion causes a loss of potentially useful resistance genes, among other agronomic and quality genes. Continuously changing pathogen races and insect biotypes affecting the Great Plains requires identification of new sources of resistance. Synthetic hexaploid wheats (SHWs), T. turgidum (BBAA) x T. tauschii (DD) hybridizations, offer ways to utilize resistances trapped in the diploid and tetraploid ancestors of common wheat. Six SHWs were assayed for resistance to a variety of fungal diseases, viruses, and aphids …

Remarkable Features Of The Hotdog-Fold Thioesterases Involved In Phylloquinone (Vitamin K1) Biosynthesis, Joshua R. Widhalm

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

Phylloquinone (vitamin K₁) is a bipartite molecule, consisting of a naphthoquinone ring attached to a phytyl side chain, that is synthesized by plants and certain cyanobacteria to serve as an electron carrier in photosystem I. The coupling of the ring and isoprenyl moieties relies on the cleavage of the CoA-thioester linkage with 1,4-dihydroxy-2- naphthoate (DHNA). It has long been a mystery if this hydrolysis is an enzymatic or chemical process. Using comparative genomics, protein biochemistry, genetics and metabolic profiling, we identified a cyanobacterial thioesterase responsible for the in vivo hydrolysis of DHNA-CoA. This enzyme bears a signature domain …

B. R. Wells Rice Research Studies 2010, R. J. Norman, K. A. K. Moldenhauer

Arkansas Agricultural Experiment Station Research Series

The 2010 Rice Research Verification Program ( RRVP) was conducted on twenty-two commercial rice fields across the state. Counties rarticirating in the program included Arkansas, Ashley, Chicot, Clark, Clay, Cross, Desha, Drew, Greene, Jackson, Jefferson, Lafayette, Lawrence, Lonoke, Mississippi, Phillips, Poinsett (2 fields), Prairie, Randolph, St. Francis, and White for a total of 1456 acres. Grain yield in the 2010 RRVP averaged 167 bu/acre ranging from 113 to 215 bu/acre. The 2010 RRVP average yield was 25 bu/acre greater than the estimated Arkansas state average of 142 bu/acre. The highest yielding field was in Clay County with a grain yield …

Aiding Conservation Of The Federally Threatened Scutellaria Montana (Lamiaceae, Large-Flowered Skullcap) Through Abundance Monitoring And Transplantation Studies, Heather Mae Kile

Masters Theses and Doctoral Dissertations

Scutellaria montana Chapm. (large-flowered skullcap) is a federally threatened species endemic to Georgia and Tennessee. This thesis presents conservation work on this species through abundance monitoring at a single site in Catoosa County, Georgia, and transplantation experiments at two sites located in Hamilton County, Tennessee, and Catoosa County, Georgia. Plants naturally occurring in the fixed plots surveyed over seven years had an overall stable growth status, though relatively low floral induction and seedlings. Transplantation revealed influences of abiotic and biotic factors. One transplantation site was fenced to prevent human trampling and apparently discouraged vertebrate grazing, resulting in dramatic flower number …