Plant Biology Commons^™

Genetic Diversity Of Seed Dormancy And Molecular Evolution Of Weedy Red Rice, Te Ming Tseng

Graduate Theses and Dissertations

Rice is the grain with the third-highest global production. In the US, Arkansas is the largest rice producing state; however, an estimated 62% of the rice fields in the state are infested with red rice, and can cause up to 80% yield reduction in rice. Among its weedy traits, seed dormancy plays an important role in its persistence, and helps red rice escape weed management techniques thereby increasing the red rice soil seedbank. Red rice also has the potential to hybridize among themselves and with cultivated rice, thus resulting in diverse phenotypes and genotypes. In this study we measured variation …

Dark Green Color Index As A Method Of Real-Time In-Season Corn Nitrogen Measurement And Fertilization, Upton Siddons

Graduate Theses and Dissertations

Corn (Zea mays L.) requires higher rates of nitrogen fertilizer than any other major U.S. crop partly because N fertilizers are subject to loss through various mechanisms. Because of this, corn may suffer from inadequate nitrogen fertilization or producers may over-apply nitrogen to compensate for early-season nitrogen losses. A timely, accurate, and precise method for measuring in-season corn N status is needed to allow producers to keep nitrogen use efficiency high within a growing season.

Using appropriate software, hue, saturation, and brightness values of digital images can be combined in a dark green color index (DGCI) which is closely associated …

Response Of Nebraska Horseweed (Conyza Canadensis) Populations To Dicamba, Roberto Crespo, Mark L. Bernards, Greg Kruger, Donald Lee, Robert Wilson Jr.

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

Dicamba-resistant soybeans are being developed to provide an additional herbicide mechanism-of-action for postemergence weed control in soybean. Numerous broadleaf species, including horseweed, have evolved resistance to glyphosate. It is anticipated that dicamba will be used by farmers as a primary tool to manage these weeds. Studying and understanding variability in horseweed response to dicamba will aid in developing appropriate risk management strategies to extend the utility of the dicamba-resistance technology. Horseweed plants from ten Nebraska populations were treated with one of nine doses of dicamba in greenhouse experiments. At 28 days after treatment (DAT) visual injury estimations were made and …

Using The Unispec To Test The Difference In Reflectance Of The Yellow Petals Of Encelia Californica, Encelia Farinosa, And Spartium Junceum, Mariam E. Fam, Valerie E. Espinoza

Featured Research

The reflectance spectrum of three yellow flowered species (Encelia californica, Encelia farinosa, and Spartium junceum), all grown on the coast of California, was tested to determine if reflectance among the yellow flowers was significantly different. It was hypothesized that there would be a significant difference in reflectance in the 400-700 nm wavebands for the three different species of flowers which all possess yellow petals. Using a Unispec Spectral Analysis System to obtain reflectance spectra for 12 yellow petals of three flowered species, a custom index was created in order to observe differences in the yellow color of the petals, which …

The Effects Of Leaf Hydration On Light Reflectance In Salvia Leucophylla And S. Mellifera, Logan A. Schmitz, Kolina Mah-Ginn, Hayley Presthus

Featured Research

The presence of trichomes on a plant affect the plant’s ability to retain water; this, in turn, must affect light propagation and reflectance. It was hypothesized that a plant with a higher trichome density (Salvia leucophylla) would have a greater change in reflectance when exposed to a more aired or hydrated environment than a species with a lower trichome density (S. mellifera). Results obtained using a Unispec suggest that Salvia mellifera is more resistant to change in NDVI in response to drying and wetting. Water potential data suggest this may be related to the plant’s resistance to actual drying and …

Fire Edge Effect On Water Potential And Stomatal Conductance In Salvia Leucophylla, Brigid N. Bergin, Paul Chung, Laura C. Miranda

Featured Research

While most plants caught in the middle of wildfires are completely incinerated, many in the edges survive despite suffering partial incineration and/or heat-induced damage. We hypothesized that heat damaged Salvia leucophylla will display a decrease in both stomatal conductance and water potential. We suspected that applying excess heat would lower the plant’s water levels and damage functional components necessary for photosynthesis, so the stomata would close to conserve water. S. leucophylla was chosen to study due to the likelihood of this widespread coastal sage to be found in the edges of wildfires in the Santa Monica Mountains. Using a heat …

Comparative Study Of The Mechanical Strength In Two Species Of Ferns: Polystichum Munitum And Pteridium Aquilinum, Russell P. Baetiong, Victoria M. Lekson, Olivier B. Monty

Featured Research

A comparative study of the mechanical strength in two species of ferns, the winter deciduous Pteridium aquilinum and the evergreen Polystichum munitum, was done. The mechanical strength of the leaf and stipe were used as a means for comparison. Additional data such as specific leaf mass (g/cm2) were also collected. The first hypothesis was that the evergreen fern would have higher leaf mechanical strength, while the second hypothesis was that there would be no difference in the mechanical strength of the stipe. The mechanical strength of the stipe was compared through the Modulus of Elasticity (MOE), while the leaf tensile …

Top And Bottom Photosynthetic Activity In Nerium Oleander And Pandanus Baptistii, Ryan Arima, Jacob Gonzalez

Featured Research

Photosynthesis can be performed on any part of a leaf, yet many plants orient their leaves in different ways and are composed of different leaf anatomies. In this experiment we attempted to discover if there is a significant difference between photosynthesis on the top and bottom of Nerium oleander, a dicot that orients its dorsal face towards the sun, and Pandanus baptistii, a monocot that does not orient its leaves specifically to the sun. To perform this experiment, we used both the LI-6400 and the LiCor Integrating Sphere. With the LI-6400, we measured the photosynthetic rate of the top and …

Mechanical Strength Comparison Of Hydrated And Dehydrated Pteridium Stems, Michelle I. Kang, Kevin M. Ko, John H. Noh, Veronica R. Vega

Featured Research

In this experiment, the mechanical strength of Pteridium stems was tested in two differing conditions: hydrated and dehydrated. It was hypothesized that there would be an increased performance of hydrated stems in the presence of mechanical stress. In order to test this hypothesis, twelve 20 cm pieces of stems were cut in alternation, separating those that would be dehydrated (6) with those that were hydrated (6). The dehydrated specimens were left to dry over a period of 24 hours. The diameters of each individual stem were measured to account for variation in size and remove excess variables. All twelve stems …

Environmental And Physiological Influences On Productivity And Carbon Isotope Discrimination In Eelgrass (Zostera Marina L.), Meredith Leigh Mcpherson

OES Theses and Dissertations

A short-term longitudinal study was used to examine the relations of achievement motivation, general motivation, interest, and self-regulatory predictors to cognitive strategy use and academic performance. A total of 102 college undergraduates enrolled in their first college-level introductory psychology course completed an Achieving Tendency Scale of achievement motivation, the Motivated Strategies For Learning Questionnaire, and an Interest Profile in psychology during the first two weeks of the semester. At midterm they completed the Study Activity Survey of cognitive strategy use. At the end of the semester exam grades, total points earned in the course, and grade point average were obtained. …

Neofusicoccum Luteum As A Pathogen On Tejocote (Crataegus Mexicana), Anthony O. Adesemoye, Joey S. Mayorquin, Akif Eskalen

Department of Plant Pathology: Faculty Publications

Tejocote (Crataegus mexicana), a small pome crab-apple-like fruit, is becoming economically important in California with increasing production, so consideration of diseases that hinder the yield is important. Diseased trees of tejocote were observed in four orchards of Riverside and San Diego Counties of California. Ten symptomatic/asymptomatic samples were studied from each of the orchards. Five most frequently isolated fungi were identified on the basis of morphological characters and sequence data of the internal transcribed spacer ITS1-5.8SITS2 and partial β-tubulin gene. Three isolates were identified as Neofusicoccum luteum and two as Phomopsis sp. Pathogenicity tests were conducted by inoculating …

Anti-Helicobacter Pylori Activity And Inhibition Of Helicobacter Pylori-Induced Release Of Il-8 In Ags Cells By Plant Extracts, Javed Yakoob, Zaigham Abbas, Rustam Khan, Muhammad Waqas Usman, Saeed Hamid, Safia Awan, Kanza Shamim, Syed Faisal Zaidi, Toshiro Sugiyama, Wasim Jafri

Section of Gastroenterology

Plants used in popular diet were studied for anti-Helicobacter pylori activity and their effect on the expression of interleukin-8 (IL-8) from H. pylori infected gastric epithelial cells. Extracts were prepared of Allium sativum (A. sativum), Cuminum cyminum (C. cyminum),Piper nigrum (P. nigrum) and their mix in two different dilutions. AGS cell line and H. pyloristrains were used for co-culture experiments. Extracts bactericidal activity was determined by a viable colony count. ELISA (Enzyme linked immunosorbent assay) was used to determine IL-8 expression. DNA extracted from bacterial cells was used for polymerase chain reaction (PCR) …

Survey Of Suitable Plants For Cal Poly's Green Wall, Katrina Burritt

Horticulture and Crop Science

Green wall technology is a growing industry in the United States and has been very successful for a several years throughout Europe. The objective of this survey was to study the success of several different species of plants on a vertical wall facing south at Cal Poly’s Horticultural Department Unit. At first the focus was aimed at using California native species, because it was thought that natives would be better acclimated to the exposure in this specific location. It became apparent that plants should not be selected for the wall based just on the fact that they are California natives. …

Pseudomonas Hopu1 Modulates Plant Immune Receptor Levels By Blocking The Interaction Of Their Mrnas With Grp7, Valerie Nicaise, Anna Joe, Byeong-Ryool Jeong, Christin Korneli, Freddy Boutrot, Isa Westedt, Dorothee Staiger, James R. Alfano, Cyril Zipfel

Center for Plant Science Innovation: Faculty Publications

Pathogens target important components of host immunity to cause disease. The Pseudomonas syringae type III-secreted effector HopU1 is a mono-ADP-ribosyltransferase required for full virulence on Arabidopsis thaliana. HopU1 targets several RNA-binding proteins including GRP7, whose role in immunity is still unclear. Here, we show that GRP7 associates with translational components, as well as with the pattern recognition receptors FLS2 and EFR. Moreover, GRP7 binds specifically FLS2 and EFR transcripts in vivo through its RNA recognition motif. HopU1 does not affect the protein–protein associations between GRP7, FLS2 and translational components. Instead, HopU1 blocks the interaction between GRP7 and FLS2 and …

Small Interfering Rna–Mediated Translation Repression Alters Ribosome Sensitivity To Inhibition By Cycloheximide In Chlamydomonas Reinhardtii, Xinrong Ma, Eun-Jeong Kim, Insun Kook, Fangrui Ma, Adam Voshall, Etsuko N. Moriyama, Heriberto D. Cerutti

Center for Plant Science Innovation: Faculty Publications

Small RNAs (sRNAs; approximately 20 to 30 nucleotides in length) play important roles in gene regulation as well as in defense responses against transposons and viruses in eukaryotes. Their biogenesis and modes of action have attracted great attention in recent years. However, many aspects of sRNA function, such as the mechanism(s) of translation repression at postinitiation steps, remain poorly characterized. In the unicellular green alga Chlamydomonas reinhardtii, sRNAs derived from genomeintegrated inverted repeat transgenes, perfectly complementary to the 39 untranslated region of a target transcript, can inhibit protein synthesis without or with only minimal mRNA destabilization. Here, we report …

Strong Genetic Differentiation Between North American And European Populations Of Phytophthora Alni Subsp. Uniformis, Jaime Aguayo, Gerard C. Adams, Fabien Halkett, Mursel Catal, Claude Husson, Zoltán Á. Nagy, Everett M. Hansen, Benoît Marçais, Pascal Frey

Department of Plant Pathology: Faculty Publications

Alder decline caused by Phytophthora alni has been one of the most important diseases of natural ecosystems in Europe during the last 20 years. The emergence of P. alni subsp. alni—the pathogen responsible for the epidemic—is linked to an interspecific hybridization event between two parental species: P. alni subsp. multiformis and P. alni subsp. uniformis. One of the parental species, P. alni subsp. uniformis, has been isolated in several European countries and, recently, in North America. The objective of this work was to assess the level of genetic diversity, the population genetic structure, and the putative reproduction …

Distance And Sex Determine Host Plant Choice By Herbivorous Beetles, Daniel J. Ballhorn, Stefanie Kautz, Martin Heil

Biology Faculty Publications and Presentations

Background: Plants respond to herbivore damage with the release of volatile organic compounds (VOCs). This indirect defense can cause ecological costs when herbivores themselves use VOCs as cues to localize suitable host plants. Can VOCs reliably indicate food plant quality to herbivores?

Methodology: We determined the choice behavior of herbivorous beetles (Chrysomelidae: Gynandrobrotica guerreroensis and Cerotoma ruficornis) when facing lima bean plants (Fabaceae: Phaseolus lunatus) with different cyanogenic potential, which is an important constitutive direct defense. Expression of inducible indirect defenses was experimentally manipulated by jasmonic acid treatment at different concentrations. The long-distance responses of male and female beetles to …

Isolation And Characterization Of The Grain Mold Fungi Cochliobolus And Alternaria Spp. From Sorghum Using Semiselective Media And Dna Sequence Analyses, Deanna L. Funnell-Harris, Louis K. Prom, Jeffrey F. Pedersen

Department of Plant Pathology: Faculty Publications

Mold diseases, caused by fungal complexes including Alternaria, Cochliobolus, and Fusarium species, limit sorghum grain production. Media were tested by plating Fusarium thapsinum, Alternaria sp., and Curvularia lunata, individually and competitively. Dichloran chloramphenicol rose bengal (DRBC) and modified V8 juice (ModV8) agars, found to be useful, were compared with commonly used agar media, dichloran chloramphenicol peptone (DCPA) and pentachloronitrobenzene (PCNB). Radial growth, starting with mycelia or single-conidia and hyphal tips, demonstrated an effect of media. For isolation of grain fungi, DRBC and ModV8 were similar or superior to DCPA and PCNB. When seedlings were inoculated with conidia of C. lunata, …

Occurrence And Distribution Of Triticum Mosaic Virus In The Central Great Plains, E. Byamukama, D. L. Seifers, G. L. Hein, E. De Wolf, N. A. Tisserat, M. A. C. Langham, L. E. Osborne, A. Timmerman, S. N. Wegulo

Department of Plant Pathology: Faculty Publications

Wheat curl mite (WCM)-transmitted viruses—namely, Wheat streak mosaic virus (WSMV), Triticum mosaic virus (TriMV), and the High Plains virus (HPV)—are three of the wheat-infecting viruses in the central Great Plains of the United States. TriMV is newly discovered and its prevalence and incidence are largely unknown. Field surveys were carried out in Colorado, Kansas, Nebraska, and South Dakota in spring and fall 2010 and 2011 to determine TriMV prevalence and incidence and the frequency of TriMV co-infection with WSMV or HPV in winter wheat. WSMV was the most prevalent and was detected in 83% of 185 season–counties (= s-counties), 73% …

Chapter 6 - Technological And Commercial, Janice M. Glime

Bryophyte Ecology Volume 5: Uses

Explore the contents of Bryophyte Ecology, Volume 5, Chapter 6 - Technological and Commercial by clicking the link above. For the Contents section of this ebook, as well as Volumes 1 through 5, please visit the Bryophyte Ecology Main Page.

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Ebook sponsored by Michigan Technological University and the International Association of Bryologists.

Chapter 2 - Medicine, Janice M. Glime

Bryophyte Ecology Volume 5: Uses

Explore the contents of Bryophyte Ecology, Volume 5, Chapter 2 - Medicine by clicking the link above. For the Contents section of this ebook, as well as Volumes 1 through 5, please visit the Bryophyte Ecology Main Page.

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Ebook sponsored by Michigan Technological University and the International Association of Bryologists.

Chapter 2 - Laboratory Techniques, Janice M. Glime, David H. Wagner

Bryophyte Ecology Volume 3: Methods

Explore the contents of Bryophyte Ecology, Volume 3, Chapter 2 - Laboratory Techniques by clicking the links above. For the Contents section of this ebook, as well as Volumes 2 through 5, please visit the Bryophyte Ecology Main Page.

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Ebook sponsored by Michigan Technological University and the International Association of Bryologists.

Chapter 3 - Herbarium Methods And Exchanges, Janice M. Glime, D. H. Wagner

Bryophyte Ecology Volume 3: Methods

Explore the contents of Bryophyte Ecology, Volume 3, Chapter 3 - Herbarium Methods and Exchanges by clicking the link above. For the Contents section of this ebook, as well as Volumes 2 through 5, please visit the Bryophyte Ecology Main Page.

Use CTRL+F to easily search within PDF files.

Ebook sponsored by Michigan Technological University and the International Association of Bryologists.

Developmental Variation And Distyly In Hedyotis Caerulea (Rubiaceae), Dennis A. Sampson, Robert A. Krebs

Biological, Geological, and Environmental Faculty Publications

The development of distyly is thought to arise from differential growth patterns in the pin and thrum morphs. However, few detailed studies exist on the early floral development of distylous flowers, and fewer still look at variation in these traits among populations. Buds at multiple stages of development were collected from five populations of Hedyotis caerulea to quantify how pins and thrums diverge with respect to the initiation, rate, and termination of growth between the stamens and stigmas. The growth rate of anthers varied little spatially across five populations and temporally in both pins and thrums, although thrum anthers grew …

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 …

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, …

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, …

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 …