Biology Commons^™

Low Leaf N And P Resorption Contributes To Nutrient Limitation In Two Desert Shrubs, Rebecca E. Drenovsky, J. H. Richards

Biology

Both water and nutrients are limiting in arid environments, and desert plants have adapted to these limitations through numerous developmental and physiological mechanisms. In the Mono Basin, California, USA, co-dominant Sarcobatus vermiculatus and Chrysothamnus nauseosus ssp. consimilis are differentially N and P limited. We hypothesized that low leaf N resorption contributes to N-limitation in Sarcobatus and that low leaf P resorption contributes to P-limitation in Chrysothamnus. As predicted, Sarcobatus resorbed proportionally 1.7-fold less N than Chrysothamnus, but reduced leaf P in senescent leaves to lower levels than Chrysothamnus (8.0–10.8-fold lower based on leaf area or mass, respectively), consistent with N, …

Transport Of E. Coli In Egyptian Agricultural Soils As A Result Of Reclaimed Wastewater Use For Irrigation, Aimen Badawy

Archived Theses and Dissertations

Limited water resources are one of the main constraints to socio-economic development and even a source of insecurity at national and regional levels. The increasing demand for water in the agricultural sector stimulated the use of reclaimed wastewater for irrigation. Comprehending health and environment risks resulting from contaminants that may often be associated with reclaimed wastewater will lead to the sustainable use of this resource, as well as the conservation of other water resources.

In the present study the fate and transport of one important wastewater constituent, namely E. Coli bacteria, in three Egyptian soils of typical agricultural use was …

Terpenes And Carbohydrate Source Influence Rumen Fermentation, Digestibility, Intake, And Preference In Sheep, J. J. Villalba, F. D. Provenza, K. C. Olson

Green Canyon Environmental Research Area, Logan Utah

We hypothesized that toxins and nutrients in foods interact to influence foraging behavior by herbivores. Based on this hypothesis we predicted that 1) terpenes in big sagebrush (Artemisia tridentata) influence intake and preference in sheep for diets varying in sources of nonstructural (barley grain) and structural (sugar beet pulp) carbohydrates, and 2) these effects are due to the differential effects of terpenes on fermentation products and apparent digestibility of each class of carbohydrates. Lambs were fed 2 isoenergetic and isonitrogenous diets with varying proportions of the same ingredients (beet pulp- and barley grain-based diet) or offered a choice between the …

Fungal Spore Dispersal By The Eastern Box Turtle (Terrapene Carolina Carolina), S. C. Jones, W. J. Jordan, Scott J. Meiners, A. N. Miller, A. S. Methven

Faculty Research & Creative Activity

Although spores from most macrofungi are wind- or water-dispersed, dispersal may also occur via biotic vectors. The Eastern box turtle (Terrapene carolina carolina) is a facultative mycovore that may play an important role in fungal spore dispersal although, to date, no information exists on fungi occurring in fecal samples of box turtles or on the ecological significance of box turtles as spore dispersal vectors. Consequently, a study of the potential for Eastern box turtles to act as vectors for spore dispersal was initiated by capturing wild turtles and collecting fecal samples. Serial dilutions from fecal samples were made to enumerate …

Fungal Spore Dispersal By The Eastern Box Turtle (Terrapene Carolina Carolina), S. Jones, W. Jordan, Scott Meiners, A. Miller, A. Methven

Faculty Research & Creative Activity

Although spores from most macrofungi are wind- or water-dispersed, dispersal may also occur via biotic vectors. The Eastern box turtle (Terrapene carolina carolina) is a facultative mycovore that may play an important role in fungal spore dispersal although, to date, no information exists on fungi occurring in fecal samples of box turtles or on the ecological significance of box turtles as spore dispersal vectors. Consequently, a study of the potential for Eastern box turtles to act as vectors for spore dispersal was initiated by capturing wild turtles and collecting fecal samples. Serial dilutions from fecal samples were made to enumerate …

Rack1 Mediates Multiple Hormone Responsiveness And Developmental Processes In Arabidopsis, Hemayet Ullah

Department of Biology Faculty Publications

The scaffold protein RACK1 (Receptor for Activated C Kinase 1) serves as an integrative point for diverse signal transduction pathways. The Arabidopsis genome contains three RACK1 orthologues, however, little is known about their functions. It is reported here that one memberof this gene family, RACK1A, previously identified as the Arabidopsis homologue of the tobacco arcA gene, mediates hormone responses and plays a regulatory role in multiple developmental processes. RACK1A expresses ubiquitously in Arabidopsis. Loss-of-function mutations in RACK1A confer defects in multiple developmental processes including seed germination, leaf production, and flowering. rack1a mutants displayed reduced sensitivity to gibberellin and brassinosteroid in …

Roles Of Intra-Fruit Oxygen And Carbon Dioxide In Controlling Pepper (Capsicum Annuum L.) Seed Development And Storage Reserve Deposition, J. Blasiak, Anxiu Kuang, Chakavak S. Farghangi, M. E. Musgrave

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Seeds developing within a locular space inside hollow fruit experience chronic exposure to a unique gaseous environment. Using two pepper cultivars, `Triton' (sweet) and `PI 140367' (hot), we investigated how the development of seeds is affected by the gases surrounding them. The atmospheric composition of the seed environment was characterized during development by analysis of samples withdrawn from the fruit locule with a gas-tight syringe. As seed weight plateaued during development, the seed environment reached its lowest O2 concentration (19%) and highest CO2 concentration (3%). We experimentally manipulated the seed environment by passing different humidified gas mixtures through the fruit …

Ltr Retrotransposon Evolution In Wild Sunflowers, Kaitlin Marie Stimpson

Presidential Scholars Theses (1990 – 2006)

Transposable elements are DNA sequences that are able to move from place to place in the genome, and in some cases, make copies of themselves and reinsert back into the genome. Transposable elements are divided into three classes based on their method of transposition. Class I elements transpose by an RNA intermediate, and these include L TR (long terminal repeat) and non-L TR retrotransposons. Class II elements relocate in the genome without duplication. Interestingly, class III elements entirely lack genes and rely on products of other elements for transposition. Transposable elements are no longer considered unusual or unique components of …

Climatic Unpredictability And Parasitism Of Caterpillars: Implications Of Global Warming, John Stireman, Lee Dyer, D. Janzen, M. Singer, J. Lill, R. Marquis, R. Ricklefs, G. Gentry, W. Hallwachs, P. Coley, J. Barone, H. Greeney, H. Connahs, P. Barbosa, H. Morais, I. Diniz

Biology Department Faculty Works

Insect outbreaks are expected to increase in frequency and intensity with projected changes in global climate through direct effects of climate change on insect populations and through disruption of community interactions. Although there is much concern about mean changes in global climate, the impact of climatic variability itself on species interactions has been little explored. Here, we compare caterpillar–parasitoid interactions across a broad gradient of climatic variability and find that the combined data in 15 geographically dispersed databases show a decrease in levels of parasitism as climatic variability increases. The dominant contribution to this pattern by relatively specialized parasitoid wasps …

Contributions Of Heterosis And Epistasis To Hybrid Fitness, Mitchell B. Cruzan

Biology Faculty Publications and Presentations

Early-generation hybrid fitness is difficult to interpret because heterosis can obscure the effects of hybrid breakdown. We used controlled reciprocal crosses and common garden experiments to distinguish between effects of heterosis and nuclear and cytonuclear epistasis among morphotypes and advanced-generation hybrid derivative populations in the Piriqueta caroliniana (Turneraceae) plant complex. Seed germination, growth, and sexual reproduction of first-generation hybrids, inbred parental lines, and outbred parental lines were compared under field conditions. Average vegetative performance was greater for hybrids than for inbred lines, and firstseason growth was similar for hybrids and outbred parental lines. Hybrid survival surpassed that of inbred lines …

First Report Of Phytophthora Insolita And P. Inflata On Rhododendron In Ohio, Antonino Testa, Mikael Schilb, Jeffery S. Lehman, Gennaro Cristinzio, Pierluigi Bonello

Biology and Earth Science Faculty Scholarship

During August 2003, we conducted a statewide survey of rhododendrons to determine if Phytophthora ramorum was present in Ohio ornamental nurseries. In total, 240 samples were randomly collected in 12 nurseries throughout Ohio from rhododendrons showing foliar necrotic lesions and twig dieback symptoms.

A New Species Of Streptanthus (Brassicaceae) From Three Peaks In Lake County, California, Rebecca W. Dolan, Richard O'Donnell

Scholarship and Professional Work - LAS

Streptanlhus vernalis is a newly described species inhabiting serpentine rock outcrops in the Three Peaks area in Lake County, California. Morphological and allozyme data indicate that this taxon is related to the S. morrisonii complex.

Interspecific Divergence In Foliar Nutrient Dynamics And Stem Growth In A Temperate Forest In Response To Chronic Nitrogen Inputs, Jeffrey D. May, Sarah Beth Burdette, Frank S. Gilliam, Mary Beth Adams

Biological Sciences Faculty Research

We studied the effects of excessive nitrogen (N) fertilization on foliar nutrient dynamics and stem growth in three important tree species in a mixed-deciduous forest. Stem diameter growth, foliar N concentrations, nitrogen–phosphorus (N/P) ratios, and nutrient resorption were determined for Acer rubrum L. (ACRU), Liriodendron tulipifera L. (LITU), and Prunus serotina Ehrh. (PRSE) on two 30-year-old watersheds at the Fernow Experimental Forest, West Virginia, USA: WS3, fertilized annually with 35 kg ammonium sulfate·ha^-1 since 1989, and WS7, an untreated control watershed. In an earlier (1992) study, foliar N concentrations of all three species averaged 11% higher in WS3 than …

Effects Of Density On Timing Of Emergence And Its Consequences For Survival And Growth In Two Communities Of Annual Plants, Roy Turkington, Deborah E. Goldberg, Linda Olsvig-Whittaker, Andrew R. Dyer

Faculty Publications

We tested whether increasing seed density results in a change in the timing of emergence in two communities of sand dune annual plants in Israel. Specifically we tested (i) if emergence is accelerated or delayed due to high seed density. We also tested two predictions about the consequences of changes in the timing of emergence; (ii) seedlings emerging earlier will have higher survival and growth; (iii) the advantage of earlier emergence increases as seed density increases. We examined these predictions for both monocots and dicots growing under different irrigation regimes and using species from a desert and a semi-arid community …

Relationship Among Genes Conferring Partial Resistance To Leaf Rust (Puccinia Triticina) In Wheat Lines Ci 13227 And L-574-1., Jeffery S. Lehman, Karin A. Hanson, Gregory Shaner

Biology and Earth Science Faculty Scholarship

This study describes the segregation of genes for resistance to the fungus Puccinia triticinain a cross between partially resistant wheat lines L-574-1 and CI 13227 with two and four genes for resistance, respectively. The objectives of this study were to use parental, F1, F2, and backcross populations to quantify maternal effects, degree of dominance, and transgressive segregation, and to determine whether CI 13227 and L-574-1 share any resistance genes for long latent period or small uredinia. In two experiments conducted in the greenhouse, the uppermost leaf of adult wheat plants was inoculated prior to heading with P. triticina. On days …

Seed And Seedling Ecology Of Acer Saccharum And Acer Platanoides: A Contrast Between Native And Exotic Congeners, Scott J. Meiners

Faculty Research & Creative Activity

The exotic tree, Acer platanoides, is increasing in forests of northeastern North America, largely within the range of its native congener, Acer saccharum. A combination of field and controlled experiments was used on seeds and seedlings of these congeners to determine species characteristics that may be contributing to these floristic changes. Acer platanoides experienced lower rates of seed predation than A. saccharum in field experiments. Differences in the dispersal and allocation characteristics of the two species were small and not likely to explain the relative success of A. platanoides. Greenhouse- grown seedlings of A. platanoides were much larger than those …

Seed And Seedling Ecology Of Acer Saccharum And Acer Platanoides: A Contrast Between Native And Exotic Congeners, Scott Meiners

Faculty Research & Creative Activity

The exotic tree, Acer platanoides, is increasing in forests of northeastern North America, largely within the range of its native congener, Acer saccharum. A combination of field and controlled experiments was used on seeds and seedlings of these congeners to determine species characteristics that may be contributing to these floristic changes. Acer platanoides experienced lower rates of seed predation than A. saccharum in field experiments. Differences in the dispersal and allocation characteristics of the two species were small and not likely to explain the relative success of A. platanoides. Greenhouse- grown seedlings of A. platanoides were much larger than those …

The Relationship Between Community Diversity And Exotic Plants: Cause Or Consequence Of Invasion?, Scott J. Meiners, Mary L. Cadenasso

Faculty Research & Creative Activity

Invasion ecology has suffered from the artificial separation of invasibility and impact processes in understanding the ationship between diversity and plant invasion. By studying these independently functioning stages of invasion in concert, we can gain great insight into the biological causes and consequences of invasions, and develop crucial information for the generation of adequate management strategies. Our conceptual framework provides a structure to synthesize the current body of research, suggests research needed to fill the gaps in understanding and to organize results from future research. The framework is a powerful tool to guide ecological understanding of the relationship between invasion …

Antifungal Activity Of Camptothecin, Trifolin, And Hyperoside Isolated From Camptotheca Acuminata, Shiyou Li, Zhizhen Zhang, Abigail Cain, Bo Wang, Melissa Long, Josephine Taylor

Faculty Publications

Leaf spots and root rots are major fungal diseases in Camptotheca acuminata that limit cultivation of the plant for camptothecin (CPT), a promising anticancer and antiviral alkaloid. Bioassays showed that pure CPT and flavonoids (trifolin and hyperoside) isolated from Camptotheca effectively control fungal pathogens in vitro, including Alternaria alternata, Epicoccum nigrum, Pestalotia guepinii, Drechslera sp., and Fusarium avenaceum, although antifungal activity of these compounds in the plant is limited. CPT inhibited mycelial growth by approximately 50% (EC₅₀) at 10−30 μg/mL and fully inhibited growth at 75−125 μg/mL. The flavonoids were less effective than CPT …

The Malagasy Endemic Dendroportulaca (Portulacaceae) Is Referable To Deeringia (Amaranthaceae): Molecular And Morphological Evidence [Abstract], Wendy L. Applequist, Donald B. Pratt

Faculty Publications

No abstract provided.

The Relationship Between Community Diversity And Exotic Plants: Cause Or Consequence Of Invasion?, Scott Meiners, Mary Cadenasso

Faculty Research & Creative Activity

Invasion ecology has suffered from the artificial separation of invasibility and impact processes in understanding the ationship between diversity and plant invasion. By studying these independently functioning stages of invasion in concert, we can gain great insight into the biological causes and consequences of invasions, and develop crucial information for the generation of adequate management strategies. Our conceptual framework provides a structure to synthesize the current body of research, suggests research needed to fill the gaps in understanding and to organize results from future research. The framework is a powerful tool to guide ecological understanding of the relationship between invasion …

Plant Ontology (Po): A Controlled Vocabulary Of Plant Structures And Growth Stages, Pankaj Jaiswal, Shulamit Avraham, Katica Ilic, Elizabeth Kellogg, Susan Mccouch, Anuradha Pujar, Leonore Reiser, Seung Rhee, Martin Sachs, Mary Schaeffer, Lincoln Stein, Peter Stevens, Leszek Vincent, Doreen Ware, Felipe Zapata

Biology Department Faculty Works

The Plant Ontology Consortium (POC) (www.plantontology.org) is a collaborative effort among several plant databases and experts in plant systematics, botany and genomics. A primary goal of the POC is to develop simple yet robust and extensible controlled vocabularies that accurately reflect the biology of plant structures and developmental stages. These provide a network of vocabularies linked by relationships (ontology) to facilitate queries that cut across datasets within a database or between multiple databases. The current version of the ontology integrates diverse vocabularies used to describe Arabidopsis, maize and rice (Oryza sp.) anatomy, morphology and growth stages. Using the ontology browser, …

2005 Virginia Wildflower Of The Year: Bloodroot, Sanguinaria Canadensis, W. John Hayden

Biology Faculty Publications

Bloodroot is an herbaceous perennial that grows from a persistent, branched underground stem or rhizome. Early each spring, while the forest canopy is still bare, each well-developed rhizome tip produces one leaf and one flower stalk. The leaf is kidney-shaped in its overall outline, but it is also divided into a pattern of rounded lobes and sinuses, rendering a complex overall shape. At flowering time, bloodroot leaves form a loose vertically-oriented collar around the flower stalk with the bluish-green lower leaf surface forming the outside of the collar; as the season progresses, the leaves open flat and expand to their …

The Vascular Flora Of Powhatan County, Virginia, Michael Austin Terry

Master's Theses

The project was undertaken with three main goals in mind: to provide as current and complete an account as possible of the flora of Powhatan County in the form of an annotated checklist; to integrate the information obtained from the inventory into phytogeographical and ecological generalizations currently being developed for the state of Virginia; and, to report any significant or anomalous discoveries. There is no previous county-wide inventory of plant diversity for Powhatan County. However, Corcoran (1981) published a list of plants from the Jones and Mill Creek watershed located in the Fine Creek Mills area of northeastern Powhatan.

Plant Composition Of Mixed-Grass Prairie Of Cedar Point Biological Research Station, Keith County, Nebraska, David A. Mckenzie

Biology Faculty Publications

This study involved a vegetation analysis of 15 permanent plots established on the short-grass and mixed grass prairie slopes at the Cedar Point Biological Station in Keith County, Nebraska. Ninety-nine species were found in the plots, including members of 75 genera and 31 families. Twenty-one were graminoids, 71 were forbs or succulents, 6 were shrubs and one was a tree. Bouteloua gracilis (19 % cover) and Carex filifolia (15 % cover) were the dominant graminoids at the site, while Yucca glauca (1% cover) and Artemisia frigida (1% cover) were the most frequent forbs. Comparisons of species richness by slope categories …

Rich Mesic Forests: Edaphic And Physiographic Drivers Of Community Variation In Western Massachusetts, J. Bellemare, G. Motzkin, D. R. Foster

Biological Sciences: Faculty Publications

Rich Mesic Forest, a Northeastern variant of the species-rich Mixed Mesophytic Forest association of eastern North America, is an Acer saccharum-dominated forest type typically associated with calcareous bedrock and nutrient-rich, mull soils. Rich Mesic Forest (RMF) is a priority for conservation in the Northeast due to its limited areal extent, high plant species richness, and numerous rare taxa, yet the community characteristics and environmental correlates of this forest type are incompletely understood. This study undertook a quantitative classification of RMF of the northeastern edge of the Berkshire Plateau in western Massachusetts. Cluster analysis of data from ten sites identified two …

Patterns Of Fitness And Fluctuating Asymmetry Across A Broad Hybrid Zone, Mitchell B. Cruzan

Biology Faculty Publications and Presentations

We estimated levels of developmental instability in leaves, as indicated by fluctuating asymmetry (i.e., random deviations from perfect bilateral symmetry), across a broad hybrid zone between two taxa in the Piriqueta caroliniana complex. Previous studies have indicated that this hybrid zone was initiated in southern Florida and has expanded northward. We found that plants from the hybrid zone generally had higher levels of leaf developmental instability than plants from allopatric regions, but the increase in asymmetry was not substantial. Although it is usually assumed that developmental instability is associated with lower fitness, these Piriqueta hybrids from central Florida are similar …

Chloroplast Dna Rearrangements In Campanulaceae: Phylogenetic Utility Of Highly Rearranged Genomes, Mary E. Cosner, Linda A. Raubeson, Robert K. Jansen

All Faculty Scholarship for the College of the Sciences

Background

The Campanulaceae (the "hare bell" or "bellflower" family) is a derived angiosperm family comprised of about 600 species treated in 35 to 55 genera. Taxonomic treatments vary widely and little phylogenetic work has been done in the family. Gene order in the chloroplast genome usually varies little among vascular plants. However, chloroplast genomes of Campanulaceae represent an exception and phylogenetic analyses solely based on chloroplast rearrangement characters support a reasonably well-resolved tree.

Results

Chloroplast DNA physical maps were constructed for eighteen representatives of the family. So many gene order changes have occurred among the genomes that characterizing individual mutational …

Agribusiness Sheep Updates - 2004 Part 3, Ken Hart, Keith Croker, Rob Davidson, Mario D'Antuono, Evan Burt, Tanya Kilminster, Diana Fedorenko, Darryl Mcclements, Robert Beard, Sandy Turton, Martin Atwell, Robert Beard

Sheep Updates

Posters Can Merino Ewes be Teased to Synchronise Oestrus for a Summer/Autumn Mating? Ken Hart, Keith Croker, Department of Agriculture Western Australia, Rob Davidson, School of Animal Biology, University of Western Australia. Mario D'Antuono, Department of Agriculture Western Australia Damara Sheep: Now Looking Domestic Evan Burt and Tanya Kilminster, Department of Agriculture Western Australia Production and Water Use of Lucerne and French Serradella Under Three Sowing Rates Diana Fedorenko1,4, Darryl McClements1,4 , Robert Beard3,4 1Department of Agriculture, 3 Farmer, Meckering, 4CRC for Plant-based Management of Dryland Salinity. E-SHEEP - Individual Animal Management is here Sandy Turton & Martin Atwell, Department …

Genetic Control Of Branching In Foxtail Millet, Andrew Doust, Katrien Devos, Michael Gadberry, Mike Gale, Elizabeth Kellogg

Biology Department Faculty Works

Reduction in vegetative branching is commonplace when crops are domesticated from their wild progenitors. We have identified genetic loci responsible for these changes in foxtail millet (Setaria italica), a crop closely related to maize but whose genetics are little known. Quantitative trait locus (QTL) analysis and comparative genomics reveal that basal branching (tillering) and axillary branching are partially controlled by separate loci, and that the orthologue of teosinte branched1, the major gene controlling branching phenotype in maize, has only a minor and variable effect. We identify other candidate genes for control of branching, including a number of hormone biosynthesis pathway …