Digital Commons Network^™

Product Comparison Of Foliar Fungicide Efficacy On Diseases Of Field Corn In Nebraska, 2013, C. M. Schleicher, T. A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

A foliar fungicide efficacy trial was conducted at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, NE. Corn hybrid NK ‘N68B’, rating of “fair” (7 out of 9) for gray leaf spot (GLS), not rated for common rust (CR), and “excellent” (2 out of 9) for southern rust (SR), was planted on 15 May in 30-in. rows at a target population of 31,763 plants/A. The trial area was disked with corn as the previous year’s crop. Eight treatments and a non-treated control were replicated six times in a randomized complete block design. Each plot was four rows …

A National Approach For Integrating Wildfire Simulation Modeling Into Wildland Urban Interface Risk Assessments Within The United States, Jessica R. Haas, David E. Calkin, Matthew P. Thompson

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

Ongoing human development into fire-prone areas contributes to increasing wildfire risk to human life. It is critically important, therefore, to have the ability to characterize wildfire risk to populated places, and to identify geographic areas with relatively high risk. A fundamental component of wildfire risk analysis is establishing the likelihood of wildfire occurrence and interaction with social and ecological values. A variety of fire modeling systems exist that can provide spatially resolved estimates of wildfire likelihood, which when coupled with maps of values-at-risk enable probabilistic exposure analysis. With this study we demonstrate the feasibility and utility of pairing burn probabilities …

Impacts Of Drought On Plant Water Relations And Nitrogen Nutrition In Dryland Perennial Grasses, Albina Khasanove, Jeremy J. James, Rebecca E. Drenovsky

Biology

Extensive worldwide dryland degradation calls for identification of functional traits critical to dryland plant performance and restoration outcomes. Most trait examination has focused on drought tolerance, although most dryland systems are water and nutrient co-limited. We studied how drought impacts both plantwater relations and nitrogen (N) nutrition.
We grew a suite of grasses common to the Intermountain West under both well-watered and drought conditions in the greenhouse. These grasses represented three congener pairs (Agropyron, Elymus, Festuca) differing in their habitat of origin ("wetter" or "drier"). We measured growth, water relations, N resorption efficiency and proficiency and photosynthetic N use efficiency …

Native Grass And Forb Establishment In Post-Agricultural Soil, Courtney D. Hall

Electronic Theses and Dissertations

Restoration of degraded and abandoned agricultural land in arid and semiarid climates is a global problem. The erratic patterns of precipitation these lands experience makes restoration of a plant community difficult. Application of supplemental irrigation and inoculation with arbuscular mycorrhizal fungi (AMF) are two restoration techniques that have been suggested to overcome deficits in natural precipitation. The effects and the interactions of irrigation and seeding date on the ground cover of intended species and unintended exotic species were tested in a post-agricultural restoration experiment in south-central Colorado, USA. The greatest ground cover of intended species and lowest ground cover of …

The Role Of Elevation And Soil Chemistry In The Distribution And Ion Accumulation Of Floral Morphs Of Streptanthus Polygaloides Gray (Brassicaceae), A Californian Nickel Hyperaccumulator, N Pope, M Fong, R Boyd, N Rajakaruna

Faculty Publications, Biological Sciences

Background: The flora of serpentine/ultramafic soils provides an excellent model system for the study of natural selection in plant populations. Streptanthus polygaloides is a nickel hyperaccumulator that is endemic to serpentine soils in the Sierra Nevada of California, and has four floral morphs (yellow, purple, yellow-to-purple and undulate). Aims: We investigate three hypotheses: (1) the purple morph occurs in colder, wetter climates than the yellow morph; (2) tissue–soil ionic relationships differ among morphs; and (3) morphs occur on soils with differing elemental concentrations. Methods: We queried herbarium records to investigate patterns of occurrence among the yellow and purple floral morphs, …

Volume 1, Chapter 6-1: Limiting Factors And Limits Of Tolerance, Janice M. Glime

Bryophyte Ecology Subchapters

No abstract provided.

Volume 1, Chapter 8-1: Nutrient Relations: Requirements And Sources, Janice M. Glime

Bryophyte Ecology Subchapters

No abstract provided.

Beech Bark Disease Distribution And Resistance In Michigan And Fungal Endophyte Ecology Of Resistant And Susceptible Beech (Fagus Grandifolia Ehrh.), Rachel E. Griesmer-Zakhar

Dissertations, Master's Theses and Master's Reports - Open

Beech bark disease (BBD), a non-native association of the fungal pathogen Neonectria faginata and the beech scale insect Cryptococcus fagisuga, has dramatically affected American beech within North American forests. To monitor the spread and effects of BBD in Michigan, a network of forest health monitoring plots was established in 2001 following the disease discovery in Ludington State Park (Mason County). Forest health canopy condition and basic forestry measurements including basal area were reassessed on beech trees in these plots in 2011 and 2012. The influence of bark-inhabiting fungal endophytes on BBD resistance was investigated by collecting cambium tissue from …

Sequoiadendron Giganteum (Cupressaceae) At Lake Fulmor, Riverside County, California, Rudolf Schmid, Mena Schmid

Aliso: A Journal of Systematic and Floristic Botany

A GPS census made on 19 June 2012 of the Lake Fulmor area, northwestern San Jacinto Mountains, Riverside County, California, revealed seven trees of the Sierra Nevada endemic Sequoiadendron giganteum (Cupressaceae). The trees occur in a 234-meter-long narrow strip along the northwestern side of the lake. The population appears to be naturalizing. The largest tree (45 cm DBH, about 20 m tall), planted in 1980, is reproductively mature. Its six offspring to the northeast and southwest are 3–5 m tall and do not presently bear cones.

Ua12/13 Big Red, Small Planet, Christian Ryan-Downing , Editor, Leslie North , Editor

Sustainability Publications and Resources

At WKU, “The Spirit Makes the Master”. Our commitment to continuous improvement is clearly reflected in our sustainability efforts. WKU’s commitment to sustainability, whether demonstrated in campus operations or in educational programs, helps to ensure that our graduates are prepared to address the complicated environmental, social and economic issues we face today. They will be able to think critically, solve problems creatively and be engaged citizens. If that’s all we accomplish then we will have achieved great success. But our sustainability commitment pays dividends, as it also leads us to reduce our environmental footprint, practice social responsibility, and conserve natural …

Synergistic Effects Of The Invasive Chinese Tallow (Triadica Sebifera) And Climate Change On Aquatic Amphibian Survival, Daniel Saenz, Erin M. Fucik, Matthew Kwiatkowski

Faculty Publications

Changes in climate and the introduction of invasive species are two major stressors to amphibians, although little is known about the interaction between these two factors with regard to impacts on amphibians. We focused our study on an invasive tree species, the Chinese tallow (Triadica sebifera), that annually sheds its leaves and produces leaf litter that is known to negatively impact aquatic amphibian survival. The purpose of our research was to determine whether the timing of leaf fall from Chinese tallow and the timing of amphibian breeding (determined by weather) influence survival of amphibian larvae. We simulated a …

Kalinia, A New North American Genus For A Species Long Misplaced In Eragrostis (Poaceae, Chloridoideae), Hester L. Bell, J. Travis Columbus, Amanda L. Ingram

Aliso: A Journal of Systematic and Floristic Botany

Eragrostis obtusiflora (Poaceae, Chloridoideae), a species distributed from the southwestern United States to central Mexico, has long been recognized for exhibiting morphological and anatomical features atypical of Eragrostis. Phylogenetic analyses of nuclear internal transcribed spacer sequences and plastid sequences demonstrate that E. obtusiflora should be excluded from Eragrostis (Eragrostideae) and instead be placed in Cynodonteae, although its position within this tribe was unresolved. Additional data, including anatomical and micromorphological characters, suggest a close relationship with Distichlis. However, differences in spikelet and rhizome characters prevent its inclusion in Distichlis. Therefore, the species is transferred to a newly described …

A New Species Of Linanthus (Polemoniaceae) From San Bernardino County, California, Naomi S. Fraga, Duncan S. Bell

Aliso: A Journal of Systematic and Floristic Botany

Linanthus bernardinus is described as new from San Bernardino County, California. It is morphologically similar to L. killipii and L. orcuttii subsp. pacificus but differs from plants of these taxa in height, corolla length, seed morphology, and habitat. Linanthus bernardinus can be found growing in vernally moist areas within Joshua tree woodland, often in shallow depressions, or on gentle slopes, in decomposed granite sand that is surrounded by large granite boulder fields.

Carbon Benefits From Protected Areas In The Conterminous United States, Daolan Zheng, Linda S. Heath, Mark J. Ducey

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

Background: Conversion of forests to other land cover or land use releases the carbon stored in the forests and reduces carbon sequestration potential of the land. The rate of forest conversion could be reduced by establishing protected areas for biological diversity and other conservation goals. The purpose of this study is to quantify the efficiency and potential of forest land protection for mitigating GHG emissions.

Results: The analysis of related national-level datasets shows that during the period of 1992–2001 net forest losses in protected areas were small as compared to those in unprotected areas: -0.74% and −4.07%, respectively. …

Complementarity To An Mirna Seed Region Is Sufficient To Induce Moderate Repression Of A Target Transcript In The Unicellular Green Alga Chlamydomonas Reinhardtii, Tomohito Yamasaki, Adam Voshall, Eun-Jeong Kim, Etsuko N. Moriyama, Heriberto Cerutti, Takeshi Ohama

Center for Plant Science Innovation: Faculty Publications

MicroRNAs (miRNAs) are 20–24 nt noncoding RNAs that play important regulatory roles in a broad range of eukaryotes by pairing with mRNAs to direct post-transcriptional repression. The mechanistic details of miRNA-mediated post-transcriptional regulation have been well documented in multicellular model organisms. However, this process remains poorly studied in algae such as Chlamydomonas reinhardtii, and specific features of miRNA biogenesis, target mRNA recognition and subsequent silencing are not well understood. In this study, we report on the characterization of a Chlamydomonas miRNA, cre-miR1174.2, , which is processed from a near-perfect hairpin RNA. Using Gaussia luciferase (gluc) reporter genes, …

Potential And Realized Nutrient Resorption In Serpentine And Non-Serpentine Chaparral Shrubs And Trees, Rebecca E. Drenovsky, Catherine E. Koehler, Kathryn Skelly, James H. Richards

Biology

Low-nutrient adapted species have numerous mechanisms that aid in nutrient conservation. Hypothetically, species adapted to nutrient-poor soils should have tighter internal nutrient recycling, as evidenced by greater resorption. However, literature results are mixed. We suggest methodological factors may limit our understanding of this process. We hypothesized that plants adapted to serpentine soils would be more proficient in resorbing N and P than plants adapted to non-serpentine soils, although there would be differences among functional groups within each soil type. For six growing seasons, we sampled senescent leaf tissue from the dominant and co-dominant shrubs and trees found in serpentine and …

Camelina Seed Transcriptome: A Tool For Meal And Oil Improvement And Translational Research, Huu T. Nguyen, Jillian E. Silva, Ram Podicheti, Jason Macrander, Wenyu Yang, Tara J. Nazarenus, Jeong-Won Nam, Jan G. Jaworski, Chaofu Lu, Brian E. Scheffler, Keithanne Mockaitis, Edgar B. Cahoon

Center for Plant Science Innovation: Faculty Publications

Camelina (Camelina sativa), a Brassicaceae oilseed, has received recent interest as a biofuel crop and production platform for industrial oils. Limiting wider production of camelina for these uses is the need to improve the quality and content of the seed protein-rich meal and oil, which is enriched in oxidatively unstable polyunsaturated fatty acids that are deleterious for biodiesel. To identify candidate genes for meal and oil quality improvement, a transcriptome reference was built from 2047 Sanger ESTs and more than 2 million 454-derived sequence reads, representing genes expressed in developing camelina seeds. The transcriptome of approximately 60K transcripts …

Comparative Analyses Of Two Geraniaceae Transcriptomes Using Next-Generation Sequencing, Jinxin Zhang, Tracey A. Ruhlman, Jeffrey P. Mower, Robert K. Jansen

Center for Plant Science Innovation: Faculty Publications

Background: Organelle genomes of Geraniaceae exhibit several unusual evolutionary phenomena compared to other angiosperm families including accelerated nucleotide substitution rates, widespread gene loss, reduced RNA editing, and extensive genomic rearrangements. Since most organelle-encoded proteins function in multi-subunit complexes that also contain nuclear-encoded proteins, it is likely that the atypical organellar phenomena affect the evolution of nuclear genes encoding organellar proteins. To begin to unravel the complex co-evolutionary interplay between organellar and nuclear genomes in this family, we sequenced nuclear transcriptomes of two species, Geranium maderense and Pelargonium x hortorum.

Results: Normalized cDNA libraries of G. maderense and …

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 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 LCB …

Pseudomonas Syringae Pv. Syringae Uses Proteasome Inhibitor Syringolin A To Colonize From Wound Infection Sites, Johana C. Misas-Villamil, Izabella Kolodziejek, Emerson Crabill, Farnusch Kaschani, Sherry Niessen, Takayuki Shindo, Markus Kaiser, James R. Alfano, Renier A. L. Van De Hoorn

Center for Plant Science Innovation: Faculty Publications

Infection of plants by bacterial leaf pathogens at wound sites is common in nature. Plants defend wound sites to prevent pathogen invasion, but several pathogens can overcome spatial restriction and enter leaf tissues. The molecular mechanisms used by pathogens to suppress containment at wound infection sites are poorly understood. Here, we studied Pseudomonas syringae strains causing brown spot on bean and blossom blight on pear. These strains exist as epiphytes that can cause disease upon wounding caused by hail, sand storms and frost. We demonstrate that these strains overcome spatial restriction at wound sites by producing syringolin A (SylA), a …

Functional Modeling Identifies Paralogous Solanesyl-Diphosphate Synthases That Assemble The Side Chain Of Plastoquinone-9 In Plastids, Anna Block, Rikard Fristedt, Sara Rogers, Jyothi Kumar, Brian Barnes, Joshua Barnes, Christian Elowsky, Yashitola Wamboldt, Sally Ann Mackenzie, Kevin Redding, Sabeeha S. Merchant, Gilles J. Basset

Center for Plant Science Innovation: Faculty Publications

Background: Plastid isoforms of solanesyl-diphosphate synthase catalyze the elongation of the prenyl side chain of plastoquinone-9.

Results: Corresponding mutants display lower levels of plastoquinone-9 and plastochromanol-8 and display intact levels of vitamin E.

Conclusion: Plastochromanol-8 originates from a subfraction of non-photoactive plastoquinol-9 and is not essential for seed longevity.

Significance: Viable plastoquinone-9 mutants are invaluable tools for understanding plastid metabolism.

Mutational Analyses Of A Fork Head Associated Domain Protein, Dawdle, In Arabidopsis Thaliana, Lakshmi Ayiloor Narayanan, Dipaloke Mukherjee, Shuxin Zhang, Bin Yu, David Chevalier

Center for Plant Science Innovation: Faculty Publications

DAWDLE (DDL) gene encodes a protein that contains an N-terminal arginine-rich domain and a C-terminal Fork Head Associated (FHA) domain in Arabidopsis thaliana. DDL protein is believed to function in microRNA biogenesis by mediating the recruitment of pri-microRNA to DICER-LIKE 1 and also stabilizing the microRNA. The aim of this study was to conduct a structure-function analysis to identify the regions in DDL that are of functional significance. Targeted Induced Local Lesions in Genome screen was performed in the Columbia erecta-105 background of Arabidopsis resulting in the identification of eight point mutations spanning DDL. The mutants were characterized by …

Cdc5, A Dna Binding Protein, Positively Regulates Posttranscriptional Processing And/Or Transcription Of Primary Microrna Transcripts, Shuxin Zhang, Meng Xie, Guodong Ren, Bin Yu

Center for Plant Science Innovation: Faculty Publications

CDC5 is a MYB-related protein that exists in plants, animals, and fungi. In Arabidopsis, CDC5 regulates both growth and immunity through unknown mechanisms. Here, we show that CDC5 from Arabidopsis positively regulates the accumulation of microRNAs (miRNAs), which control many biological processes including development and adaptations to environments in plants. CDC5 interacts with both the promoters of genes encoding miRNAs (MIR) and the DNA-dependent RNA polymerase II. As a consequence, lack of CDC5 reduces the occupancy of polymerase II at MIR promoters, as well as MIR promoter activities. In addition, CDC5 is associated with the DICER–LIKE1 complex, …

Evaluating The Success Of Seed Sowing In A New England Grassland, Chad C. Jones, Glenn D. Dreyer, Nels Barrett

Botany Faculty Publications

Grassland habitat is declining in the northeastern United States, leading to a decline in associated native species. Consequently, there is considerable interest by land managers in conserving and restoring grassland habitats in the Northeast. However, unlike the Great Plains and Europe, quantitative monitoring of restoration sites is uncommon, making it difficult to improve new restoration projects. Here we evaluate a grassland restoration in Waterford, Connecticut to determine if mechanical clearing of woody vegetation combined with sowing 23 native grasses and forbs led to successful establishment of these species. We also compared cover, diversity, and colonization by exotic and woody species …

Mohave Desert—An Overview And Byu's Lytle Preserve, Stanley L. Welsh, Larry St. Clair

Books by Faculty of the Monte L. Bean Life Science Museum

Table of Contents

Introduction

The Mohahve or Mohave (Mojave) gets its Explorer and its Name (sort of?)

The Frémont Odyssey through the Mohahve

What of the Crossing of the Mohahve?

References

BYU's Lytle Preserve

Acknowledgments

Species Status Of Sclerocactus Brevispinus, S. Wetlandicus, And S. Glaucus: Inferences From Morphology, Chloroplast Dna Sequences, And Aflp Markers, J. Mark Porter, Jennifer Cruse-Sanders, Linda Prince, Robert Lauri

Aliso: A Journal of Systematic and Floristic Botany

We examine patterns of variation in 12 continuous morphological traits, chloroplast DNA sequences from 10 intergenic spacer regions (petA-psbJ, psbk-trnS, psbM-trnD, rpob-trnC, trnC-trnD, trnGCU-trnG2S, trnFM-trnUGA, atpF-atpH, trnT-trnD, trnQ-psbk), atpF, and rpl16, and Amplified Fragment Length Polymorphism (AFLP) genetic markers in Sclerocactus glaucus sensu lato (= S. brevispinus, S. glaucus, and S. wetlandicus), a complex that historically has been considered conspecific and afforded protection …

A Polygon-Based Modeling Approach To Assess Exposure Of Resources And Assets To Wildfire, Matthew P. Thompson, Joe Scott, Jeffrey D. Kaiden, Julie W. Gilbertson-Day

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

Spatially explicit burn probability modeling is increasingly applied to assess wildfire risk and inform mitigation strategy development. Burn probabilities are typically expressed on a per-pixel basis, calculated as the number of times a pixel burns divided by the number of simulation iterations. Spatial intersection of highly valued resources and assets (HVRAs) with pixel-based burn probability estimates enables quantification of HVRA exposure to wildfire in terms of expected area burned. However, statistical expectations can mask variability in HVRA area burned across all simulated fires. We present an alternative, polygon-based formulation for deriving estimates of HVRA area burned. This effort enhances investigations …

Interpretation Of Gypsy Moth Frontal Advance Using Meteorology In A Conditional Algorithm, K. L. Frank, P. C. Tobin, H. W. Thistle Jr., Laurence S. Kalkstein

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

The gypsy moth, Lymantria dispar, is a nonnative species that continues to invade areas in North America. It spreads generally through stratified dispersal where local growth and diffusive spread are coupled with long-distance jumps ahead of the leading edge. Longdistance jumps due to anthropogenic movement of life stages is a well-documented spread mechanism. Another mechanism is the atmospheric transport of early instars and adult males, believed to occur over short distances. However, empirical gypsy moth population data continue to support the possibility of alternative methods of longrange dispersal. Such dispersal events seemed to have occurred in the mid- to …

Discovery: The Student Journal Of Dale Bumpers College Of Agricultural, Food And Life Sciences - Volume 14 2013, Several Authors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Crop-Friendly Bacteria Tapped To Battle Fungal Marauders, Patricia Okubara, Jan Suszkiw

Agricultural Research Magazine

Soil-dwelling bacteria that depend on wheat and barley roots for their “room and board” could soon make good on their debt. Researchers are investigating the microbes’ potential to biologically control root-rot fungi that cause crop yield losses of 10-30 percent annually in the U.S. Pacific Northwest and other parts of the world.

The bacteria are members of the genus Pseudomonas and include 11 strains that stymie the growth of Pythium and Rhizoctonia fungi, which are responsible for dampingoff and root-rot diseases of wheat and barley. The pathogens thrive in cool, moist soils and can reach especially high levels in crop …