Plant Sciences Commons^™

Registration Of ‘Newell’ Smooth Bromegrass, K P. Vogel, R B. Mitchell, B L. Waldron, M R. Haferkamp, J D. Berdahl, D D. Baltensperger, Galen Erickson, T J. Klopfenstein

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

Establishment And Spread Of A Single Parthenogenic Genotype Of The Mediterranean Arundo Wasp, Tetramesa Romana1, In The Variable Climate Of Texas, John A. Goolsby, John F. Gaskin, Daniel V. Tarin, Alan E. Pepper, Don C. Henne, Allan Auclair, Alexis Racelis, Kenneth R. Summy, Patrick J. Moran, Donald B. Thomas

Biology Faculty Publications and Presentations

As part of a biological control program for the invasive weed, Arundo donax L., several genotypically unique populations of the parthenogenetic stemgalling wasp, Tetramesa romana Walker (Hymenoptera: Eurytomidae), from Spain and France were released in an infested riparian zone along the Rio Grande from Brownsville to Del Rio, TX. An adventive population of the wasp of unknown origin with limited distribution in Texas was also discovered, evaluated, and released as part of the program. More than 1.2 million wasps representing the mixture of genotypes were aerially released from 2009 to 2011. Wasps dispersed from their original release locations and now …

Traversing Swanton Road, 17th Ed., James A. West

Academic, Government & Associated Organizational Research Resources

Situated at the northwest end of Santa Cruz County and occupying circa 30 square miles of sharply contrasted terrain, the Scott Creek Watershed concentrates within its geomorphological boundaries, at least 10-12% of California's flora, both native and introduced. Paradoxically, the use/abuse that the watershed has sustained over the past 140+ years, has not necessarily diminished the biodiversity and perhaps parallels the naturally disruptive but biologically energizing processes (fire, flooding, landslides and erosion), which have also been historically documented for the area for +60 years. This is an early edition of an extensive document by James A. West. Please visit the …

Column-Scale Unsaturated Hydraulic Conductivity Estimates In Coarse-Textured Homogeneous And Layered Soils Derived Under Steady-State Evaporation From A Water Table, Morteza Sadeghi, Markus Tuller, Mohammed R. Gohardoust, Scott B. Jones

Plants, Soils, and Climate Faculty Publications

Steady-state evaporation from a water table has been extensively studied for both homogeneous and layered porous media. For layered media it is of interest to find an equivalent homogeneous medium and define ‘‘effective’’ hydraulic properties. In this paper a new solution for steady-state evaporation from coarse-textured porous media is presented. Based on this solution, the evaporation rate represents a macroscopic (column-scale) measure of unsaturated hydraulic conductivity at the pressure head equal to the maximum extent of the hydraulically connected region above the water table. The presented approach offers an alternative method for determination of unsaturated hydraulic conductivity of homogeneous coarse-textured …

Publication Trends In Model Organism Research, Michael Dietrich, Rachel Ankeny, Patrick Chen

Dartmouth Scholarship

In 1990, the National Institutes of Health (NIH) gave some organisms special status as designated model organisms. This article documents publication trends for these NIH-designated model organisms over the past 40 years. We find that being designated a model organism by the NIH does not guarantee an increasing publication trend. An analysis of model and nonmodel organisms included in GENETICS since 1960 does reveal a sharp decline in the number of publications using nonmodel organisms yet no decline in the overall species diversity. We suggest that organisms with successful publication records tend to share critical characteristics, such as being well …

Minimal Effects Of An Invasive Flowering Shrub On The Pollinator Community Of Native Forbs, Y Anny Chung, Laura A. Burkle, Tiffany M. Knight

Biology Faculty Publications & Presentations

Biological invasions can strongly influence species interactions such as pollination. Most of the documented effects of exotic plant species on plant-pollinator interactions have been observational studies using single pairs of native and exotic plants, and have focused on dominant exotic plant species. We know little about how exotic plants alter interactions in entire communities of plants and pollinators, especially at low to medium invader densities. In this study, we began to address these gaps by experimentally removing the flowers of a showy invasive shrub, Rosa multiflora, and evaluating its effects on the frequency, richness, and composition of bee visitors to …

Allopolyploidy, Diversification, And The Miocene Grassland Expansion, Matt Estep, Michael Mckain, Dilys Diaz, Jinshun Zhong, John Hodge, Trevor Hodkinson, Daniel Layton, Simon Malcomber, Rémy Pasquet, Elizabeth Kellogg

Biology Department Faculty Works

The role of polyploidy, particularly allopolyploidy, in plant diversification is a subject of debate. Whole-genome duplications precede the origins of many major clades (e.g., angiosperms, Brassicaceae, Poaceae), suggesting that polyploidy drives diversification. However, theoretical arguments and empirical studies suggest that polyploid lineages may actually have lower speciation rates and higher extinction rates than diploid lineages. We focus here on the grass tribe Andropogoneae, an economically and ecologically important group of C4 species with a high frequency of polyploids. A phylogeny was constructed for ca. 10% of the species of the clade, based on sequences of four concatenated low-copy nuclear loci. …

Spatial Variation In Carbon And Nitrogen In Cultivated Soils In Henan Province, China: Potential Effect On Crop Yield, Xuelin Zhang, Qun Wang, Frank S. Gilliam, Yilun Wang, Feina Cha, Chaohai Li

Biological Sciences Faculty Research

Improved management of soil carbon (C) and nitrogen (N) storage in agro-ecosystems represents an important strategy for ensuring food security and sustainable agricultural development in China. Accurate estimates of the distribution of soil C and N stores and their relationship to crop yield are crucial to developing appropriate cropland management policies. The current study examined the spatial variation of soil organic C (SOC), total soil N (TSN), and associated variables in the surface layer (0–40 cm) of soils from intensive agricultural systems in 19 counties within Henan Province, China, and compared these patterns with crop yield. Mean soil C and …

Warming, Competition, And Bromus Tectorum Population Growth Across An Elevation Gradient, Aldo Compagnoni, Peter B. Adler

Green Canyon Environmental Research Area, Logan Utah

Cheatgrass (Bromus tectorum) is one of the most problematic invasive plant species in North America and climate change threatens to exacerbate its impacts. We conducted a two‐year field experiment to test the effect of warming, competition, and seed source on cheatgrass performance across an elevation gradient in northern Utah. We hypothesized that warming would increase cheatgrass performance, but that warming effects would be limited by competing vegetation and by local adaptation of cheatgrass seed sources. The warming treatment relied on open top chambers, we removed vegetation to assess the effect of competition from neighboring vegetation, and we reciprocally …

Growing Conditions For Algae, Angeles Mora, Tamar Melkonian, Alejandro Calderon-Urrea

STAR Program Research Presentations

With the growing demands of water in California and the increasing cost of fossil fuels to operate water-cleaning equipment, Algae was cultivated in different concentrations of Nitrogen, Phosphorus, and Potassium (NPK) during different trails to identify the best growing conditions for the removal water contaminates. Before testing algae in waste water, the Algae: Dunaliella Primolecta, Chlorella Vulgaris, and Scenedesmus Dimorphus were cultivated in four different media containing distilled water and plant vitamins. The different mediums used include: Orchid Grow More (20-20-20), Miracle Grow (30-10-10), Murashige & Skoog, and Orchid Bloom Boster (11-35-15). As a result of the investigation, the algae, …

Xrf Analyses Of Prehanford Orchards, Komal Rana

STAR Program Research Presentations

Subsequent to 1943, the use of Lead Arsenic was banned from the Orchards standing on the Hanford site. This use of Lead Arsenate pesticide was popular among the orchard owners and was dispersed over the site in a myriad of ways. The presence of the traces of lead and arsenic are found today, more than half a century later. Using a portable X-ray florescence analyzer (XRF), the values of lead and arsenic are evaluated while determining the efficiency of the equipment itself. Samples from different decision sites were collected, with lead arsenic values in the low, high and medium range …

Are Local Filters Blind To Provenance? Ant Seed Predation Suppresses Exotic Plants More Than Natives, Dean Pearson, Nadia S. Icasatti, Jose L. Hierro, Benjamin J. Bird

Biological Sciences Faculty Publications

The question of whether species’ origins influence invasion outcomes has been a point of substantial debate in invasion ecology. Theoretically, colonization outcomes can be predicted based on how species’ traits interact with community filters, a process presumably blind to species’ origins. Yet, exotic plant introductions commonly result in monospecific plant densities not commonly seen in native assemblages, suggesting that exotic species may respond to community filters differently than natives. Here, we tested whether exotic and native species differed in their responses to a local community filter by examining how ant seed predation affected recruitment of eighteen native and exotic plant …

Leaf Mechanical Strength Corresponds To Tissue Water Relations In Twelve Species Of California Ferns, Breahna M. Gillespie, Stephen D. Davis, Jarmila Pittermann

Biology

The dominant vegetation types in southern California’s coastal foothills are chaparral and costal sage scrub. Chaparral shrubs have mechanically strong evergreen leaves whereas coastal sage scrubs bear mechanical weak, facultative deciduous leaves. What about the ferns that live in the understory of these vegetation types, especially considering their adaptations to a summer dry, Mediterranean-type climate? We tested the hypothesis that some fern leaves are stronger than others and mechanically strong leaves are associated with greater dehydration tolerance. Twelve fern species were examined. Tissue water relations were assessed via pressure volume curves using Scholander-Hammel pressure chambers. We estimated osmotic potential at …

Relationship Between Dehydration Tolerance Of California Ferns And The Mechanical Strength Of Their Stipes, Helen I. Holmlund, Stephen D. Davis

Biology

In recent years, experts in plant physiology have begun to explore the functional traits of ferns, especially in regards to their tissue-water relations. However, to our knowledge, no scientist had yet examined the relationship between fern biomechanics and physiology. We examined the mechanical properties of fern stipes (stems) and attempted to relate those properties to ecological and physiological traits. Based on our knowledge of fern anatomy, we hypothesized that stipe mechanical strength would not correlate with water-stress resistance as it does in seed-bearing plants.

We assessed mechanical strength using Modulus of Elasticity (MOE) and tissue-water relations using pressure-volume curves. Water-stress …

Transcriptome Analysis Of A Petal Anthocyanin Polymorphism In The Arctic Mustard, Parrya Nudicaulis, Timothy Butler, Cynthia Dick, Matthew L. Carlson, Justen B. Whittall

Biology

Angiosperms are renown for their diversity of flower colors. Often considered adaptations to pollinators, the most common underlying pigments, anthocyanins, are also involved in plants’ stress response. Although the anthocyanin biosynthetic pathway is well characterized across many angiosperms and is composed of a few candidate genes, the consequences of blocking this pathway and producing white flowers has not been investigated at the transcriptome scale. We take a transcriptome-wide approach to compare expression differences between purple and white petal buds in the arctic mustard, Parrya nudicaulis, to determine which genes’ expression are consistently correlated with flower color. Using mRNASeq and de …

Germination Season And Watering Regime, But Not Seed Morph, Affect Life History Traits In A Cold Desert Diaspore-Heteromorphic Annual, Juan J. Lu, Dun Y. Tan, Jerry M. Baskin, Carol C. Baskin

Biology Faculty Publications

Seed morph, abiotic conditions and time of germination can affect plant fitness, but few studies have tested their combined effects on plasticity of plant life history traits. Thus, we tested the hypothesis that seed morph, germination season and watering regime influence phenotypic expression of post-germination life history traits in the diaspore-heteromorphic cold desert winter annual/spring ephemeral Diptychocarpus strictus. The two seed morphs were sown in watered and non-watered plots in late summer, and plants derived from them were watered or not-watered throughout the study. Seed morph did not affect phenology, growth and morphology, survival, dry mass accumulation and allocation or …

[Accepted Article Manuscript Version (Postprint)] Auxin Input Pathway Disruptions Are Mitigated By Changes In Auxin Biosynthetic Gene Expression In Arabidopsis, Gretchen Spiess, Amanda Hausman, Peng Yu, Jerry Cohen, Rebekah Rampey, Bethany Zolman

Biology Department Faculty Works

Auxin is a phytohormone involved in cell elongation and division. Levels of indole-3-acetic acid (IAA), the primary auxin, are tightly regulated through biosynthesis, degradation, sequestration, and transport. IAA is sequestered in reversible processes by adding amino acids, polyol or simple alcohols, or sugars, forming IAA conjugates, or through a two-carbon elongation forming indole-3-butyric acid. These sequestered forms of IAA alter hormone activity. To gain a better understanding of how auxin homeostasis is maintained, we have generated Arabidopsis (Arabidopsis thaliana) mutants that combine disruptions in the pathways, converting IAA conjugates and indole-3-butyric acid to free IAA. These mutants show phenotypes indicative …

Traversing Swanton Road, 16th Ed., James A. West

Academic, Government & Associated Organizational Research Resources

Situated at the northwest end of Santa Cruz County and occupying circa 30 square miles of sharply contrasted terrain, the Scott Creek Watershed concentrates within its geomorphological boundaries, at least 10-12% of California's flora, both native and introduced. Paradoxically, the use/abuse that the watershed has sustained over the past 140+ years, has not necessarily diminished the biodiversity and perhaps parallels the naturally disruptive but biologically energizing processes (fire, flooding, landslides and erosion), which have also been historically documented for the area for +60 years. This is an early edition of an extensive document by James A. West. Please visit the …

Nitrogen Deposition Contributes To Soil Acidification In Tropical Ecosystems, Xiankai Lu, Qinggong Mao, Frank S. Gilliam, Yiqi Luo, Jiangming Mo

Biological Sciences Faculty Research

Elevated anthropogenic nitrogen (N) deposition has greatly altered terrestrial ecosystem functioning, threatening ecosystem health via acidification and eutrophication in temperate and boreal forests across the northern hemisphere. However, response of forest soil acidification to N deposition has been less studied in humid tropics compared to other forest types. This study was designed to explore impacts of long-term N deposition on soil acidification processes in tropical forests. We have established a long-term N deposition experiment in an N-rich lowland tropical forest of Southern China since 2002 with N addition as NH₄NO₃ of 0, 50, 100 and 150 kg …

Pitcher Plants (Sarracenia) Provide A 21st-Century Perspective On Infraspecific Ranks And Interspecific Hybrids: A Modest Proposal* For Appropriate Recognition And Usage, Aaron M. Ellison, Charles C. Davis, Pat Calie, Robert F. C. Naczi

Biological Sciences Faculty and Staff Research

The taxonomic use of infraspecific ranks (subspecies, variety, subvariety, form, and subform), and the formal recognition of interspecific hybrid taxa, is permitted by the International Code of Nomenclature for algae, fungi, and plants. However, considerable confusion regarding the biological and systematic merits is caused by current practice in the use of infraspecific ranks, which obscures the meaningful variability on which natural selection operates, and by the formal recognition of those interspecific hybrids that lack the potential for inter-lineage gene flow. These issues also may have pragmatic and legal consequences, especially regarding the legal delimitation and management of threatened and endangered …

Traversing Swanton Road, 15th Ed., James A. West

Academic, Government & Associated Organizational Research Resources

Situated at the northwest end of Santa Cruz County and occupying circa 30 square miles of sharply contrasted terrain, the Scott Creek Watershed concentrates within its geomorphological boundaries, at least 10-12% of California's flora, both native and introduced. Paradoxically, the use/abuse that the watershed has sustained over the past 140+ years, has not necessarily diminished the biodiversity and perhaps parallels the naturally disruptive but biologically energizing processes (fire, flooding, landslides and erosion), which have also been historically documented for the area for +60 years. This is an early edition of an extensive document by James A. West. Please visit the …

Antimicrobial And Antiinsectan Phenolic Metabolites Of Dalea Searlsiae, Gil Belofsky, Mario Aronica, Eric Foss, Jane Diamond, Felipe Santana, Jacob Darley, Patrick F. Dowd, Christina M. Coleman, Daneel Ferreira

All Faculty Scholarship for the College of the Sciences

Continued interest in the chemistry of Dalea spp. led to investigation of Dalea searlsiae, a plant native to areas of the western United States. Methanol extractions of D. searlsiae roots and subsequent chromatographic fractionation afforded the new prenylated and geranylated flavanones malheurans A–D (1–4) and known flavanones (5 and 6). Known rotenoids (7 and 8) and isoflavones (9 and 10) were isolated from aerial portions. Structure determination of pure compounds was accomplished primarily by extensive 1D- and 2D-NMR spectroscopy. The absolute configurations of compounds 1–5, 7 …

Visual Responses Of Adult Asian Citrus Psyllid (Hemiptera: Liviidae) To Colored Sticky Traps On Citrus Trees, Mamoudou Setamou, A. Sanchez, R. R. Saldaña, J. M. Patt, Kenneth R. Summy

Biology Faculty Publications and Presentations

The effects of five differently-colored sticky traps in capturing adult Diaphorina citri were evaluated in citrus orchards. Trap catches of D. citri were monitored fortnightly on blue, green, red, white and yellow sticky cards placed on three citrus varieties during D. citri active flight period from April to July in south Texas. Evaluation of mean trap catches of each color by repeated measures analysis of variance produced three separate groups: yellow traps caught significantly more D. citri adults than the other four traps; red and green traps caught significantly more D. citri than blue and white traps, which were not …

Novel Functional Roles For Perianthia And Seuss During Floral Organ Identity Specification, Floral Meristem Termination, And Gynoecial Development, April N. Wynn, Andrew A. Seaman, Ashley L. Jones, Robert G. Franks

Biological Sciences Research

The gynoecium is the female reproductive structure of angiosperm flowers. In Arabidopsis thaliana the gynoecium is composed of two carpels that are fused into a tube-like structure. As the gynoecial primordium arises from the floral meristem, a specialized meristematic structure, the carpel margin meristem (CMM), develops from portions of the medial gynoecial domain. The CMM is critical for reproductive competence because it gives rise to the ovules, the precursors of the seeds. Here we report a functional role for the transcription factor PERIANTHIA (PAN) in the development of the gynoecial medial domain and the formation of ovule primordia. This function …

[Sabbatical Report], Lawrence Alan Alice

Sabbatical Reports

My goals as proposed were to: 1) increase resolution and support for a chloroplast DNA phylogeny by acquiring more sequence data, 2) generate a robust nuclear DNA phylogeny by sequencing several single-copy genes, 3) use flow cytometry to estimate DNA quantity per cell (i.e., ploidy level) in R. ursinus and NCGR specimens of unknown ploidy level, 4) identify highly variable DNA microsatellite (or simple-sequence repeats) regions to assess genetic diversity in R. bartonianus and test species boundaries, and 5) prepare and submit manuscripts if sufficient data have been generated.

Sexual Dimorphism Of Staminate- And Pistillate-Phase Flowers Of Saponaria Officinalis (Bouncing Bet) Affects Pollinator Behavior And Seed Set, Dana A. Dudle, Leah M. Freestone, Peter Konieczny, Michael B. Tobin, Michael M. Britton

Biology Faculty publications

The sequential separation of male and female function in flowers of dichogamous species allows for the evolution of differing morphologies that maximize fitness through seed siring and seed set. We examined staminate- and pistillate-phase flowers of protandrous Saponaria officinalis for dimorphism in floral traits and their effects on pollinator attraction and seed set. Pistillate-phase flowers have larger petals, greater mass, and are pinker in color, but due to a shape change, pistillate-phase flowers have smaller corolla diameters than staminate-phase flowers. There was no difference in nectar volume or sugar content one day after anthesis, and minimal evidence for UV nectar …

What Kind Of Seed Dormancy Might Palms Have?, Jerry M. Baskin, Carol C. Baskin

Biology Faculty Publications

Palm diaspores are reported to have various kinds of dormancy. However, (1) the embryo is underdeveloped; (2) the endocarp is water permeable; and (3) the diaspores take a long time to germinate. Thus, we conclude that the diaspores of the majority of palm species have morphophysiological dormancy (MPD). The ones that do not have MPD are morphologically dormant.

Bulk Elastic Moduli And Solute Potentials In Leaves Of Freshwater, Coastal, And Marine Hydrophytes. Are Marine Plants More Rigid?, Brant W. Touchette, Sarah E. Marcus, Emily C. Adams

Biological Sciences Faculty Publications

Bulk modulus of elasticity (ɛ), depicting the flexibility of plant tissues, is recognized as an important component in maintaining internal water balance. Elevated ɛ and comparatively low osmotic potential (Ψ_π) may work in concert to effectively maintain vital cellular water content. This concept, termed the ‘cell water conservation hypothesis’, may foster tolerance for lower soil-water potentials in plants while minimizing cell dehydration and shrinkage. Therefore, the accumulation of solutes in marine plants, causing decreases in Ψ_π, play an important role in plant–water relations and likely works with higher ɛ to achieve favourable cell …

Biogeomorphology Of A Mojave Desert Landscape — Configurations And Feedbacks Of Abiotic And Biotic Land Surfaces During Landform Evolution, Rebecca E. Drenovsky, N. Pietrasiak, L. S. Santiago, R. C. Graham

Biology

Terrestrial ecosystems can be more holistically understood by investigating the morphology of landscape mosaics, the assemblage of their ecological communities, and the linkages and feedbacks between the mosaics and communities. The overarching objectives of this study were to: (1) study the abiotic and biotic configurations of landform units as mosaics within a Mojave Desert chronosequence; and (2) elucidate their potential feedbacks, interactions, and dynamics during landform evolution. Seven landform units distributed over three geomorphic ages were identified, including: young bars and swales; intermediate-aged flattened bars, flattened swales, and bioturbation units; and old desert pavements and shrub zones. These landform units …

Warming, Soil Moisture, And Loss Of Snow Increase Bromus Tectorum’S Population Growth Rate, Aldo Compagnoni, Peter B. Adler

Green Canyon Environmental Research Area, Logan Utah

Climate change threatens to exacerbate the impacts of invasive species. In temperate ecosystems, direct effects of warming may be compounded by dramatic reductions in winter snow cover. Cheatgrass (Bromus tectorum) is arguably the most destructive biological invader in basins of the North American Intermountain West, and warming could increase its performance through direct effects on demographic rates or through indirect effects mediated by loss of snow. We conducted a two-year experimental manipulation of temperature and snow pack to test whether 1) warming increases cheatgrass population growth rate and 2) reduced snow cover contributes to cheatgrass’ positive response to …