Digital Commons Network^™

Can Bangladesh Produce Enough Cereals To Meet Future Demand?, J. Timsina, J. Wolf, N. Guilpart, L G. J. Van Bussel, P. Grassini, J. Van Wart, A. Hossain, H. Rashid, S. Islam, M. K. Van Ittersum

Department of Agronomy and Horticulture: Faculty Publications

Bangladesh faces huge challenges in achieving food security due to its high population, diet changes, and limited room for expanding cropland and cropping intensity. The objective of this study is to assess the degree to which Bangladesh can be self-sufficient in terms of domestic maize, rice and wheat production by the years 2030 and 2050 by closing the existing gap (Yg) between yield potential (Yp) and actual farm yield (Ya), accounting for possible changes in cropland area. Yield potential and yield gaps were calculated for the three crops using well-validated crop models and site-specific weather,management and soil data, and upscaled …

Parallel Altitudinal Clines Reveal Trends In Adaptive Evolution Of Genome Size In Zea Mays, Paul Bilinski, Patrice S. Albert, Jeremy J. Berg, James A. Birchler, Mark N. Grote, Anne Lorant, Juvenal Quezada, Kelly Swarts, Jinliang Yang, Jeffrey Ross-Ibarra

Department of Agronomy and Horticulture: Faculty Publications

While the vast majority of genome size variation in plants is due to differences in repetitive sequence, we know little about how selection acts on repeat content in natural populations. Here we investigate parallel changes in intraspecific genome size and repeat content of domesticated maize (Zea mays) landraces and their wild relative teosinte across altitudinal gradients in Mesoamerica and South America. We combine genotyping, low coverage whole-genome sequence data, and flow cytometry to test for evidence of selection on genome size and individual repeat abundance. We find that population structure alone cannot explain the observed variation, implying that …

Genomic Prediction Accuracy For Switchgrass Traits Related To Bioenergy Within Differentiated Populations, Jason D. Fiedler, Christina Lanzatella, Serge J. Edme, Nathan A. Palmer, Gautam Sarath, Rob Mitchell, Christian M. Tobias

Department of Agronomy and Horticulture: Faculty Publications

Background: Switchgrass breeders need to improve the rates of genetic gain in many bioenergy-related traits in order to create improved cultivars that are higher yielding and have optimal biomass composition. One way to achieve this is through genomic selection. However, the heritability of traits needs to be determined as well as the accuracy of prediction in order to determine if efficient selection is possible.

Results: Using five distinct switchgrass populations comprised of three lowland, one upland and one hybrid accession, the accuracy of genomic predictions under different cross-validation strategies and prediction methods was investigated. Individual genotypes were collected using GBS …

Method For The Production Of High Saturated, Low Polyunsaturated Soybean Oil, Thomas E. Clemente, Hyunwoo Park, Edgar B. Cahoon, Hanh Nguyen

Department of Agronomy and Horticulture: Faculty Publications

Methods of genetically modifying soybean plants to alter the fatty acid properties of the oil are described.

Comparison Of Soil-Applied And Postemergence Herbicides With Multiple Sites Of Herbicidal Activity On Two Populations Of Herbicide-Resistant Palmer Amaranth In Kentucky, Nicholas J. Fleitz

Theses and Dissertations--Plant and Soil Sciences

With the introduction of herbicide resistant Palmer amaranth into Kentucky during the past 10 years there has been an increasing concern for effective control measures in grain production. Field trials were performed in 2016 and 2017 near Barlow and Paris, KY to determine efficacy of chemical control programs targeting herbicide resistant Palmer amaranth. Percent visual control, effects on plant density and plant height were measured in 2016 to determine treatment effectiveness. Treatments containing four different sites of herbicide activity achieved an average of 98% control. Treatments containing only 3, 2 or 1 site of activity only achieved 64%, 45% and …

Bacterial Inoculants, Endophytic Bacteria And Their Influence On Nicotiana Physiology, Development And Microbiome, Andrea Marisa Sanchez Barrios

Theses and Dissertations--Plant and Soil Sciences

Soil and root microbial communities have been studied for decades, and the incorporation of high-throughput techniques and analysis has allowed the identification of endophytic/non-culturable organisms. This has helped characterize and establish the core microbiome of many model plant species which include underground and aboveground organs. Unfortunately, the information obtained from some of these model plants is not always transferable to other agronomic species. In this project, we decided to study the microbiome of the Nicotiana genus because of its importance in plant physiological and plant-microbe interactions studies. The data obtained was used as baseline information that allowed us to better …

Chemical Topping Burley Tobacco, Mitchell D. Richmond

Theses and Dissertations--Plant and Soil Sciences

The act of topping tobacco (Nicotiana tabacum L.) involves the removal of the terminal bud or inflorescence of the tobacco plant. This practice ordinarily is accomplished by manually removing the top of each tobacco plant in an entire field which is labor intensive and costly. Chemical topping utilizes sucker control products to inhibit the terminal bud and axillary bud growth without manually removing the top of the tobacco plant. There were several research objectives in order to determine the utility of a chemical topping system: 1) determine if burley tobacco could be chemically topped with currently registered suckercide products …

Can Increasing Grass-Fungal Endophyte Symbiotic Diversity Enhance Grassland Ecosystem Functioning?, Mahtaab Bagherzadeh

Theses and Dissertations--Plant and Soil Sciences

The relationship between biodiversity and ecosystem functioning is important in maintaining agroecosystem sustainability. Plant-microbe symbioses, such as exists between the grass tall fescue (Schedonorus arundinaceum) and the asexual fungal endophyte Epichloë coenophiala, can be utilized to enhance agroecosystem functions, such as herbivore resistance. “Novel” E. coenophiala strains that vary in the production of mammal- and insect-toxic compounds have been identified, inserted into tall fescue cultivars, and are planted in pastures globally. Novel fungal endophyte-tall fescue associations may have divergent ecosystem function effects. This study assessed effects of different fescue-endophyte symbiotic combinations on pasture ecosystem function, including aboveground …

Exploring Spatial And Temporal Variability Of Soil And Crop Processes For Irrigation Management, Javier Reyes

Theses and Dissertations--Plant and Soil Sciences

Irrigation needs to be applied to soils in relatively humid regions such as western Kentucky to supply water for crop uptake to optimize and stabilize yields. Characterization of soil and crop variability at the field scale is needed to apply site specific management and to optimize water application. The objective of this work is to propose a characterization and modeling of soil and crop processes to improve irrigation management. Through an analysis of spatial and temporal behavior of soil and crop variables the variability in the field was identified. Integrative analysis of soil, crop, proximal and remote sensing data was …

Characterizing Nitrogen Loss And Greenhouse Gas Flux Across An Intensification Gradient In Diversified Vegetable Systems, Debendra Shrestha

Theses and Dissertations--Plant and Soil Sciences

The area of vegetable production is growing rapidly world-wide, as are efforts to increase production on existing lands in these labor- and input-intensive systems. Yet information on nutrient losses, greenhouse gas emissions, and input efficiency is lacking. Sustainable intensification of these systems requires knowing how to optimize nutrient and water inputs to improve yields while minimizing negative environmental consequences. This work characterizes soil nitrogen (N) dynamics, nitrate (NO₃¯) leaching, greenhouse gas emissions, and crop yield in five diversified vegetable systems spanning a gradient of intensification that is characterized by inputs, tillage and rotational fallow periods. The study systems …

Evolution Of Floral Morphology And Symmetry In The Miconieae (Melastomataceae), Maria Gavrutenko

Dissertations and Theses

Analyses of evolution of floral morphology and symmetry broaden our understanding of the drivers of angiosperm diversification. Integrated within a flower, labile floral characters produce different phenotypes that promote variable interactions with pollinators. Thus, investigation of floral evolution may help infer potential historic transitions in pollinator modes and ecological pressures that generated present diversity. This study aims to explore morphological evolution of flowers in Miconieae, a species-rich Neotropical tribe within family Melastomataceae. Despite a constrained floral plan, Melastomataceae manage to achieve a variety of floral traits appealing to diverse pollinator types, with majority of the species requiring specialized “buzz pollination” …

Quantitative And Molecular Analysis Of Habituation At The Maize R1 Locus, Robert C. Lindsay

Theses and Dissertations

Epigenetics is the study of heritable changes in phenotypes that are not the result of changes in DNA sequence. Examples of epigenetic affecters include methylation changes, chromatin modifications, transcription factors, and RNA-based changes. The molecular mechanisms behind epigenetic changes are not fully understood. Canalization is the buffering of gene expression against environmental changes over time, while habituation is semi-stable expression change over time due to selection. This work characterized the molecular changes associated with the kernel color changes of the R-sc:86-17pale allele at the maize red color1 (r1) locus to determine if the changes are epigenetic in nature. …

Natural And Anthropogenic Drivers Of Tree Evolutionary Dynamics, Brandon M. Lind

Theses and Dissertations

Species of trees inhabit diverse and heterogeneous environments, and often play important ecological roles in such communities. As a result of their vast ecological breadth, trees have become adapted to various environmental pressures. In this dissertation I examine various environmental factors that drive evolutionary dynamics in threePinusspecies in California and Nevada, USA. In chapter two, I assess the role of management influence of thinning, fire, and their interaction on fine-scale gene flow within fire-suppressed populations of Pinus lambertiana, a historically dominant and ecologically important member of mixed-conifer forests of the Sierra Nevada, California. Here, I find evidence …

An Efficient Protocol For Root Studies In The Common Sunflower Using Composite Plants, Tyler Parks

Masters Theses

Sunflower, Helianthus annuus, is one of the most important oilseed crop in the world. Oil from the seeds is prized for its' exceptional quality and flavor. Despite this, sunflowers have been forced onto marginal lands often on semi-arid and non-fertile soil, due to disease pressures and economics making it critical to produce more resilient lines and varieties to withstand these new stresses. The recent availability of the sunflower genome can allow genome-wide characterization of gene families. Stable transformation protocols, which can be used for characterization studies, have been developed for H. annuus using Agrobacterium tumefaciens, but they produce …

The Distribution Of Centric Diatoms In Different Rivercatchments In The Anatolian Peninsula, Turkey, Cüneyd Nadi̇r Solak, Maxim Kulikovski, Tihammer Keve Kiss, Muhammet Aydin Kaleli̇, John Patrick Kociolek, Eva Ács

Turkish Journal of Botany

The diatoms are one of the most important groups of organisms for biomonitoring studies. In Turkey, most previous applications of diatoms to water quality monitoring have focused on the pennate diatoms, with almost no attention given to the centric forms. The paper presents the centric diatoms in some river catchments in Central Anatolia (Konya closed catchment and Kızılırmak) and Western Anatolia (Marmara, Sakarya, Susurluk, Akarçay, Küçük Menderes, and Meriç-Ergene in the Marmara and Aegean regions). The survey of these catchments is based on samples collected between 2009 and 2013 from 33 different locations, including some springs from Türkmen Mountain and …

Achene Morphology Of The Genus Cota J.Gay (Asteraceae)From Turkey And Its Taxonomic Significance, Mehmet Ufuk Özbek, Funda Özbek, Meci̇t Vural

Turkish Journal of Botany

Twenty-two taxa of the genus Cota J.Gay (Asteraceae) from Turkey were examined with a stereomicroscope and scanning electron microscope (SEM) in order to describe their achene macro- and micromorphologies and to evaluate the diagnostic value of these features. The achenes are obpyramidal, obconical, and oblong. Achene width ranges from 0.26 to 1.68 mm and achene length from 1.13 to 3.46 mm. They show variation in color: brown, dark brown, grayish-brown, reddish-brown, purplish-brown, black, and purplish. All investigated species have slime cells, but prismatic cells on epicarpic cells are found only in two species. Four types of ornamentations were recognized via …

Phenotypic Plasticity And Specialization Along An Altitudinal Gradient In Trifolium Repens, Fati̇h Fazlioğlu, Justin S.H. Wan, Stephen P. Bonser

Turkish Journal of Botany

Phenotypic plasticity and specialization represent seemingly contrasting strategies to heterogeneous environments. Specialization is associated with the loss of phenotypic plasticity, particularly in functional traits. However, it is equivocal if this loss of plasticity is observed only in the specific habitat and stress type where the specialization occurs or a general loss of plasticity is seen across habitats. We examined populations of Trifolium repens L. following an expansion during the colonization of Australia from relatively good low altitude habitats to more stressful high altitude habitats in the Blue Mountains region, New South Wales, Australia. We examined if specialization to abiotic stress …

A New Species Of Barssia (Ascomycota, Helvellaceae) From Turkey, Hasan Hüseyi̇n Doğan, Fuat Bozok, Hatira Taşkin

Turkish Journal of Botany

A new species of the genus Barssia was identified from Turkey using both morphological and phylogenetic analysis of the ribosomal internal transcribed spacer region (ITS rDNA) and nuclear ribosomal large subunit (LSU rDNA) gene sequences. Macroscopic and microscopic features of the fresh samples were photographed and a diagnostic key of the genus Barssia was built considering characteristics of known species.

Noccaea Ali-Atahanii (Brassicaceae): A New Species From Southern Anatolia, Yelda Güzel, Bariş Özüdoğru, Sami̇m Kayikçi, Kurtuluş Özgi̇şi̇

Turkish Journal of Botany

Noccaea ali-atahanii , a new Brassicaceae species from southern Anatolia, is described herein. It is mostly similar to N. aghrica , but can be readily distinguished by the presence of apical placentation and orbiculate fruit with wings extending almost evenly from the base to the apex. Its phylogenetic relationships within the genus are provided based on the nuclear-encoded ribosomal internal transcribed spacer region. Carpological and ecological features of N. ali-atahanii and related species are also discussed.

Effects Of Management On Functional Diversity In Restored Tallgrass Prairie Plant Communities, Anna K. Farrell

Graduate Research Theses & Dissertations

While recent studies have embraced evaluating ecosystems through functional diversity, the focus on interspecific trait changes may limit their usefulness and application. Functional traits (traits that explain species’ responses to environmental conditions and their ecosystem roles) can provide a more nuanced understanding of how disturbances shape plant communities and the functions they perform. Further, the inclusion of intraspecific trait responses can explain a significant portion of these relationships. In ecosystem restorations, management strategies can act as environmental drivers and disturbances that affect community structure. This study examined how three environmental drivers (grazer presence, prescribed fire, and age) in restored grasslands …

The Effect Of Self-Recognition In The Competition Between Genets Of Solidago Altissima, Charles Jaques

Masters Theses

Competition is a major driving force in the abundance, distribution, and diversity within any biological system. Plants are more likely to suffer reductions in fitness as a consequence of competition, as they typically occur in dense communities. Individuals within these populations must respond to both inter- and intraspecific competition. Recent studies suggest that the ability to distinguish kin from non-kin may play an integral role in the success of individuals within different plant populations and communities. However, a less known interaction is that between individual clones within a genet as they grow, spread, and begin to interact with nearby rival …

Impact Of Giant Miscanthus (Miscanthus X Giganteus) Cultivation On Midwestern Farmland Birds, Matthew Craffey

Masters Theses

Giant Miscanthus (Miscanthus x giganteus) is a promising bioenergy feedstock, newly introduced to North America. However, the qualities that make Giant Miscanthus an attractive bioenergy feedstock may pose challenges to local wildlife. To assess the impacts of Giant Miscanthus on Midwestern farmland birds, I conducted point count and vegetation surveys at three sites in east-central Illinois where Giant Miscanthus was being cultivated. I used occupancy modeling to assess the relative influence of Giant Miscanthus on five species relative to other habitat and landscape characteristics. Dickcissel (Spiza Americana), Eastern Meadowlark (Sturnella magna), and Red-Winged Blackbird …

Investigation Of A Putative Membrane-Bound Protein In Arabidopsis Thaliana And Nicotiana Tabacum, Allen Potter

Masters Theses

The NLG (Novel Leaf Gene) is a recently discovered gene from aspen (Populus tremula x alba). Previous research indicates that NLG impacts leaf shape. Our preliminary analyses indicate that NLG may function as a membrane bound protein with possible localization in plasma membrane and/or nucleus. Sequence and phylogenetic analyses in Arabidopsis thaliana and Populus trichocarpa identified four homologous genes in Arabidopsis and five in Populus. Gene expression analysis was done using online tools and indicated that NLG is expressed in multiple tissue types but predominately in stem and flowers. The protein coding region of the NLG orthologs genes from aspen …

The Transcriptional Response Of Trametes Versicolor To Growth On Maple Chips And Miscanthus Straw, Maha Alanazi

Masters Theses

This thesis research explored the transcriptional response of Trametes versicolor, a white-rot fungus, in response to fundamentally different types of lignocellulosic biomass (miscanthus and maple) and rich medium (malt extract agar). After five weeks of growth by the fungus on the biomass, the fungal RNA was extracted from three biological replicates per biomass type and mRNA was sequenced (approximately 30 million reads per sample). The reads were processed using ArrayStar to covert to RPKM and annotated using JGI's T. versicolor GO annotation file along with NCBI's BLAST. Comparisons were made between average gene expression of the fungus grown on …

Growing South Dakota (Winter 2018), College Of Agriculture &. Biological Sciences

Growing South Dakota (Publication of the College of Agriculture, Food and Environmental Sciences)

[Page] 2 Learn About Our Leaders
[Page] 4 Academic Programs at a Glace
[Page] 6 New Precision Ag Major Takes Off
[Page] 9 Raven Gives $5 Million Gift
[Page] 10 New Plant Science Research Facility
[Page] 13 Technical Training to Four-Year Degree
[Page] 15 Ag-Bio Career Fair Hits Record
[Page] 16 Breaking Ground : SD ADRDL
[Page] 19 Distinguished Professor Eric Nelson
[Page] 20 SDSU’s Veterinary Students
[Page] 24 Conservation Planning and Park Management
[Page] 25 Natural Resource Law Enforcement
[Page] 26 Medical Stethoscope Ceremony
[Page] 29 Master’s Degree in Human Biology
[Page] 30 Scott Pedersen Prepares Students
[Page] 32 …

Birds And Vegetation Structure Of Isolated Juniper And Oak Communities In The Trans-Pecos Chihuahuan Desert., Kayla Garza

Open Access Theses & Dissertations

Birds of the Trans-Pecos region are historically understudied, with most literature covering birds of desert grasslands and scrub in New Mexico and Northern Mexico. A multitude of vegetation communities within the Chihuahuan Desert have also been neglected due to this gap in the research, for reasons including lack of access to public or preserve land in West Texas, and rough terrain. Indio Mountains Research Station (IMRS), is located 42-km southwest of Van Horn, Texas and encompasses many different vegetation communities, including juniper-oak habitats of arroyo and canyon systems. The purpose of this study was to document the bird species utilizing …

The Role Of Climate In The Dynamics Of Annual Plants In A Chihuahuan Desert Ecosystem, Danielle D. Ignace, Nancy Huntly, Peter Chesson

Biology Faculty Publications

Question: What is the role of temporal climate fluctuations in the dynamics of desert winter annual plants in the Portal Bajada, and in the sustained irruption of the non-native annual plant species, Erodium cicutarium?

Field site: Portal Bajada, San Simon Valley, Arizona, USA.

Methods: We counted plants at flowering over a 21-yeaer period on twelve permanent plots and related these numbers to weather data collected at an on-site weather station, supplemented by observations from the National Climate Data Center. Specific summary climate variables considered most relevant to annual plant biology were developed as candidate predictors of plant response variables. …

A New Anatomically-Preserved Plant From The Lower Devonian Of Quebec (Canada): Implications For Euphyllophyte Phylogeny And Early Evolution Of Structural Complexity, Selin Toledo

Cal Poly Humboldt theses and projects

An abrupt transition in the fossil record between Early Devonian plants with simple structure and structurally-complex later Devonian plants, has frustrated efforts to understand patterns of phylogeny across the Early/Middle Devonian boundary and the evolution of complex forms. Both these aspects have important implications for lignophyte and seed plant evolution. In the first chapter, I evaluate phylogenetic relationships between the earliest seed plants, Aneurophytales, and Stenokoleales, using comprehensive taxon sampling (28 species, including all relevant permineralized species) and a set of 40 discrete and nine continuous morpho-anatomical characters. Analysis of this dataset supports the three traditional taxonomic groups (seed plants, …

Assessing Spatio-Temporal Patterns Of Forest Decline Across A Diverse Landscape In The Klamath Mountains Using A 28-Year Landsat Time-Series Analysis, Drew S. Bost

Cal Poly Humboldt theses and projects

Rates of tree mortality in California and the Pacific Northwest have greatly increased in recent years, driven largely by pest and pathogen outbreaks as well as the effects of hotter, warmer droughts. While there have been a multitude of regional-scale assessments of mortality and forest decline, landscape-level studies are necessary to better identify forests that are most vulnerable to decline and to anticipate future changes. This need is particularly notable in the remote and little-studied mountains of northwest California, which are renowned for their diverse, heterogeneous vegetation types. A recent observation of elevated levels of Shasta red fir (Abies …

Jeweled Spider Flies (Eulonchus Tristis) Are Important Pollinators Of Iris Bracteata, A Rare Siskiyou Mountain Endemic, Jean-Paul E. Ponte

Cal Poly Humboldt theses and projects

Little is known about the pollination biology of the Pacific Coast Irises (Iris: series Californicae, hereafter PCI), especially who visits and pollinates their flowers. In general, Iris flowers are considered bee-pollinated, however, flies in the genus Eulonchus (Acroceridae) are known to visit some PCI members. Therefore, I assessed the relative importance of Eulonchus and other insect visitors to the pollination of a rare PCI species native to the Siskiyou Mountains, I. bracteata.

Methods. I quantified pollinator importance for all flower visitors at sites in northern California and southern Oregon as the product of average visit rate and …