Digital Commons Network^™

Engineering Triterpene Metabolism In Tobacco, Zuodong Jiang

Theses and Dissertations--Plant and Soil Sciences

Terpenes comprise a large diverse class of natural products and many of them attract interest because of their physiological function, therapeutic and industrial values. Triterpene oils including squalene (C30), botrycococcene (C30) and their methylated derivatives (C31-C37) generated by the green algae Botryococcus braunii race B, which have recently received significant attention because of their utility for advanced biofuels. However, the slow growth habit of B. braunii makes it impractical as a robust biofuel production system. In this thesis, we firstly evaluated the potential of generating high levels of triterpene (C30) production in tobacco plants by diverting carbon flux from cytosolic …

Conservation Agriculture In Kentucky: Investigating Nitrogen Loss And Dynamics In Corn Systems Following Wheat And Hairy Vetch Cover Crops, Rebecca Erin Shelton

Theses and Dissertations--Plant and Soil Sciences

Unintentional nitrogen (N) loss from agroecosystems produces greenhouse gases, induces eutrophication, and is costly for farmers; therefore, adoption of conservation agricultural management practices, such as no-till and cover cropping, has increased. This study assessed N loss via leaching, NH₃ volatilization, N₂O emissions, and N retention in plant and soil pools of corn conservation agroecosystems across a year. Three systems were evaluated: 1) an unfertilized organic system with cover crops Vicia villosa, Triticum aestivum, or a mix of the two; 2) an organic system with a Vicia cover crop employing three fertilization schemes (0 N, organic N, …

Soil Management And Nitrogen Dynamics In Burley Tobacco Rotations, Congming Zou

Theses and Dissertations--Plant and Soil Sciences

Agronomic practices, including tillage, crop rotation and N fertilization, have been developed to efficiently manage soil N dynamics and crop N nutrition. These practices can affect soil organic carbon (SOC) and soil total nitrogen (STN) sequestration, and consequently influence soil nitrogen mineralization (SNM) and crop N nutrition. However, little research has been systematically and simultaneously conducted to examine the effect of agronomic management on (1) SOC and STN stocks; (2) SNM; and (3) crop N nutrition. Burley tobacco (Nicotiana tobacum L.) is a N demanding crop and subject to inefficiency in N fertilization. Moreover, conservation tillage and rotation have been …

Unveiling Novel Aspects Of D-Amino Acid Metabolism In The Model Bacterium Pseudomonas Putida Kt2440, Atanas D. Radkov

Theses and Dissertations--Plant and Soil Sciences

D-amino acids (D-AAs) are the α-carbon enantiomers of L-amino acids (L- AAs), the building blocks of proteins in known organisms. It was largely believed that D-AAs are unnatural and must be toxic to most organisms, as they would compete with the L-counterparts for protein synthesis. Recently, new methods have been developed that allow scientists to chromatographically separate the two AA stereoisomers. Since that time, it has been discovered that D-AAs are vital molecules and they have been detected in many organisms. The work of this dissertation focuses on their place in bacterial metabolism. This specific area was selected due to …

Urea Formulations On The Productivity Of Bermudagrass And Bermudagrass-White Clover Pastures, Caitlin Timberlake

Theses and Dissertations--Plant and Soil Sciences

Bermudagrass (Cynodon dactylon L.) is a perennial warm-season grass that is very responsive to nitrogen (N) fertilization. Excessive N applications have negative environmental consequences and make maintaining mixed swards difficult. This study determined the effects of enhanced efficiency (EE) N fertilizers and fertilizer rate on bermudagrass yields, nutritive values, and white clover persistence. Nitrogen sources included urea, urea formulated with Agrotain^® (U+A), urea with Agrotain^® and dicyandiamide (SuperU), a polymer-coated urea (ESN), ESN+urea (75% ESN, 25% urea), and methylene urea (MU). In the urea formulation trial, SuperU and U+A maximized forage yields at lower N rates. The …

Applying Wetland Rating Systems To Assess Functions Of Depressional Wetlands Created By A Mass Wasting Feature, Table Mountain, Washington, Thomas S. Wachholder

All Master's Theses

The formation of wetlands in the Swauk Watershed has been primarily controlled by mass wasting events, which includes landslide activity. Landslide activity has been the primary influential process in shaping the landscape where wetland systems have formed on the surface of landslide deposits. The wetland sites used in this study, near the base of Table Mountain, were chosen because they inhabit the same ancient landslide, have the same underlying geology, and vary in aspect and elevation. The elevational gradient of the sites ranges from 1300 – 1600 m and the individual wetlands differ in terms of north- and south-facing aspects. …

Bacterial Expression Of Plant Pyruvate Kinase, Kristina Fuller

STAR Program Research Presentations

Pyruvate kinases serve an important role in regulating glycolysis pathways. Different pyruvate kinase isozymes can dictate which of several different products will be formed during the final step of glycolysis. Being able to reliably copy active pyruvate kinases (PK) would allow study of the different isozymes, with the goal of eventually creating plants that are more nutritionally beneficial for humans. This study focused on improving the protocol for replicating each of two isolated PK isozymes from the model plant Arabidopsis thaliana. Previous attempts had resulted in the PK denaturing and consequently precipitating out of solution and so we manipulated the …

Focus Paddocks Trial Report - Benchmarked Result Summary 2010 - 14, Martin Harries, Geoff Anderson

Grain and other field crops published reports

This report was co-funded by GRDC through project no. DAW00213 - Putting the Focus on Profitable Crop and Pasture Sequences in WA.

Crop and pasture sequences in south-western Australia have changed in the past decade. These survey results from the Focus Paddock project provide data to help growers employ profitable and sustainable crop and pasture sequences. The project compiled information on the nature, suitability and productivity of crop and pasture sequences from 184 paddocks over five years. The results of the analyses of chemical and physical attributes of the soil, weed counts and disease management are presented here.

The survey …

2015 Virginia Wildflower Of The Year: Sweet Pepperbush, Clethra Alnifolia, W. John Hayden

Biology Faculty Publications

Clethra alnifolia is a rhizomatous shrub with aerial stems from 1 to 3 m tall. Leaves are simple, alternate, and bear stellate hairs; petioles are short, 5–10 mm long; leaf blades are obovate to oblong, 5–10 cm long, with relatively blunt apices, cuneate (wedgelike) bases, and margins that are entire toward the base but finely serrate above the middle; venation is pinnate with secondary veins that extend to leaf margins. Stipules are lacking. Flowers are borne on erect terminal racemes that may be solitary or accompanied by additional racemes terminating few-leaved branches arising from upper nodes. Raceme axes and pedicels …

The Functional Role Of Leaf Nutrients In An Old-Field Successional Community, Kirstin I. Duffin

Masters Theses

In functional ecology, traits that capture aspects of plant performance are used to understand how organisms interact with their environment. Leaf nutrients are an example of a functional trait that directly links to plant metabolic processes and therefore may describe plant assemblage dynamics. Multivariate leaf nutrient analyses may be used with other functional traits to understand ecological strategies because they are a direct measure of leaf metabolic processes and can describe nuances in plant allocation patterns. In this thesis, I explored (1) whether a suite of leaf nutrients (carbon, nitrogen, phosphorus, potassium, calcium, and magnesium) was related to plant growth …

Investigating The Effects Of Short- And Long-Term Climatic Variation On The Water Use Of Three Northern Hardwood Tree Species, Alex R. Collins

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

Many tree species are expected to decline in the northern Midwestern United States due to climate change increasing annual temperature 3-5º C by 2100. Sugar maple (Acer saccharum), an economically important timber and syrup species, is not expected to be sustainable in its current range under projected future climate, while trembling aspen (Populus tremuloides) and red maple (Acer rubrum) are expected to react more favorably to climate change. The success of individual tree species is dependent on how climate change will alter a species environment in regards to water use. Climate change could …

An Assessment Of Biochar Amended Soilless Media For Nursery Propagation Of Northern Rocky Mountain Native Plants, Clarice P. Matt

Graduate Student Theses, Dissertations, & Professional Papers

A study was conducted to better inform nursery practitioners of the potential benefits of biochar application in common nursery media for native plant propagation. Biochar – a carbon-rich, recalcitrant charred organic co-product of the bioenergy pyrolysis process – has emerged as a promising potential replacement for various components of soilless media, namely peat, perlite, and vermiculite, in nursery seedling propagation. A strong conceptual basis exists for biochar as a nursery media amendment, but empirical data on biochar-based plant propagation is limited. This greenhouse study examined the effects of biochar displacement of standard soilless nursery media at rates of 0%, 15%, …

A New Species Of Teucrium Sect. Scordium (Lamiaceae) From Se Of Turkey, Taner Özcan, Tuncay Di̇rmenci̇, Fati̇h Coşkun, Ekrem Akçi̇çek, Özal Güner

Turkish Journal of Botany

A new species of Teucrium L. from Southeast Anatolia (Turkey), Teucrium sirnakense Özcan & Dirmenci, is described and illustrated. The new species belongs to the sect. Scordium Boiss. and is closely related to Teucrium melissoides Boiss. & Hausskn. and Teucrium scordium L. s.l. The differences between the new species and its allies are discussed. A description, distribution map, ITS nrDNA phylogeny, and taxonomic comments on the new species are provided.

Differentiation Of Globular Phytoliths In Arecaceae And Other Monocotyledons: Morphological Description For Paleobotanical Application, Maria Laura Benvenuto, Mariana Fernandez Honaine, Margarita Luisa Osterrieth, Eduardo Morel

Turkish Journal of Botany

Globular phytoliths have been mainly assigned to palms, woody trees, and other monocotyledon families from tropical regions. The lack of detailed descriptions of this phytolith morphology and its correct assignments to particular groups could lead to erroneous interpretations of phytolith records. In order to improve paleobotanical interpretations of phytoliths records, we analyzed the phytolith content and described the quantitative and qualitative characters of globular phytoliths of Arecaceae, Bromeliaceae, Cannaceae, Marantaceae, Orchidaceae, Strelitziaceae, and Zingiberaceae species from Argentina. Phytoliths were extracted by calcination and multivariate analyses were used to analyze their taxonomic relevance. Phytolith assemblages allowed the differentiation 1) among Zingiberales …

Foliar Spray Of Phyto-Extracts Supplemented With Silicon: An Efficacious Strategy To Alleviate The Salinity-Induced Deleterious Effects In Pea (Pisum Sativum L.), Muhammad Adnan Shahid, Rashad Mukhtar Balal, Muhammad Aslam Pervez, Tahira Abbas, Muhammad Anjum Aqueel, Muhammad Mansoor Javaid, Francisco Garcia-Sanchez

Turkish Journal of Botany

A pot culture study was conducted to assess the ameliorative effect of silicon, Melia azadirachta leaf extract, and sugar beet root extract, each applied individually or in different combinations, on salinity-induced detrimental effects in pea (Pisum sativum L.). Salinity markedly inhibited the growth, various gas exchange attributes, total phenol contents, membrane stability index, and productivity. On the other hand, lipid peroxidation, electrolyte leakage, H2O2 content, antioxidant activities, and leaf free proline and glycinebetaine contents were significantly enhanced by salinity. However, exogenously applied Si and phyto-extracts markedly alleviated the salinity-induced drastic effects on growth, gas exchange attributes, and productivity. Both phyto-extracts …

Metacordyceps Dhauladharensis Sp. Nov., A New Entomopathogenic Fungus From India, Sapan Kumar Sharma, Nandini Gautam

Turkish Journal of Botany

This paper describes a new species of Clavicipitaceae fungi belonging to the genus Metacordyceps G.H. Sung, J.M. Sung, Hywel-Jones and Spatafora, defined as Metacordyceps dhauladharensis sp. Nov., from India. The diagnostic features of this new species are stipitate stromata of brownish color and an elongated fertile head on a Hymenopteran host. The perithecium size of this species was measured as 152-257 × 65-72 µm, and the asci were measured as 30-48 µm in length and 2.5 µm in breadth. Based on molecular studies, the sequence of 469 bp of this species showed only 86% homology with Metacordyceps indigotica (Kobayasi and …

Genetic Improvement Of Rice For Biotic And Abiotic Stress Tolerance, Mahmood Ur Rahman Ansari, Tayyaba Shaheen, Shazai Bukhari, Tayyab Husnain

Turkish Journal of Botany

Rice (Oryza sativa L.) is among the most important food crops that provide a staple food for nearly half of the world's population. Rice crops are prone to various types of stresses, both biotic and abiotic. Biotic stresses include insect pests, fungus, bacteria, viruses, and herbicide toxicity. Among abiotic stresses, drought, cold, and salinity are also well studied in rice. Various genes have been identified, cloned, and characterized to combat these stresses and protect rice crops. The identified genes are successfully transformed into rice plants to produce transgenic plants. These transgenic rice plants are being evaluated under field conditions in …

Growing South Dakota (Winter 2015), College Of Agriculture &. Biological Sciences

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

This issue includes the 2014 SDSU Agricultural Experiment Station Annual Report.

[Page] 2 AES Director’s Message
[Page] 3 Better Beans: Innovative Research Seeks To Increase Soybean’s Nitrogen-Fixing Ability
[Page] 6 Bioprocessing Adds Value: Researchers Turn Agricultural Residue Into Energy Storage Material
[Page] 8 Protecting Water Quality: Conservation Practices Minimize Erosion, Surface Runoff
[Page] 10 Balancing Ag & Wildlife: Cover Crop Food Plots Help Manage Deer Population
[Page] 11 Industry Insight: Beef Consumers Get Information From Websites, Social Media
[Page] 12 Evaluating Efficiency: Swine Nutritional Studies Underway; New Facility Will Allow For Expanded Research
[Page] 14 SDSU Hosts National Ag Leaders …

Germplasm Enhancement For Resistance To Pyrenophora Tritici-Repentis In Wheat, Manisha Shankar, Diane E. Mather, Dorthe Jorgensen, Hossein Golzar, Ken J. Chalmers, Grant J. Hollaway, Mark S. Mclean, Stephen M. Neate, Rob Loughman

Conference papers and presentations

Yellow spot (syn. tan spot), caused by Pyrenophora tritici-repentis, is an important foliar disease of wheat in Australia that causes losses exceeding 50 % when conditions are favourable for disease development. Although good progress has been made internationally to understand yellow spot resistance, relatively few resistance genes have been identified and mapped in Australian germplasm and only one (tsn1 on chromosome 5BL) is in general and known use in Australian breeding programs. Although tsn1 is an important yellow spot resistance gene, it doesn’t explain the full spectrum of resistance and there is a significant opportunity to enhance expression …

Dispersal: A Multidisciplinary Investigation Of Plant Life, Alexandra E. Arzt

Theses and Dissertations

Using plants as a basis for exploring the interstices between the human and nonhuman, this thesis investigates ideas of awareness, intelligence, deep time, animism, and the fluctuating human perception of the agency of Nature. It outlines environmental art practices since the 1950s involving vegetal life. In addition, the paper provides a critical analysis of plant perception of Jakob von Uexküll’s work and theories of vital materialism and “critical plant studies” while noting recent studies in plant neurobiology. In my work, plants become active participants via their movement, seeding, and smell. This study takes the form of imitation, purposeful symbiosis, anthropomorphism, …

Using The Past To Restore The Future: Quantifying Historical Vegetation To Assist In Tidal Freshwater Wetland Restoration, Christopher D. Gatens

UROP Posters

Wetlands have been providing humans with critical natural ecosystem services throughout our time on Earth. Nevertheless, these invaluable ecosystems have been habitually altered as a cost of human progression. Two of the most common alterations to wetlands are damming and filling. Both occurred along Kimages Creek in Charles City County, VA during the 19^th and 20^th centuries. In 2010 the Lake Charles dam was partially removed, restoring the creek’s tidal communication with the James River. Upon the recession of the body of water, numerous woody stumps were revealed. We studied these stump remnants in an attempt to assess …

Predicting Carbon Isotope Discrimination In Eelgrass (Zostera Marina L.) From The Environmental Parameters- Light, Flow, And [Dic], Meredith L. Mcpherson, Richard C. Zimmerman, Victoria J. Hill

OES Faculty Publications

Isotopic discrimination against ¹³C during photosynthesis is determined by a combination of environmental conditions and physiological mechanisms that control delivery of CO₂ to RUBISCO. This study investigated the effects of light, flow, dissolved inorganic carbon (DIC) concentration, and its speciation, on photosynthetic carbon assimilation of Zostera marinaL. (eelgrass) using a combination of laboratory experiments and theoretical calculations leading to a mechanistic understanding of environmental conditions that influence leaf carbon uptake and determine leaf stable carbon isotope signatures δ¹³C. Photosynthesis was saturated with respect to flow at low velocity ~ 3 cm s^-1, but …

Detection Of Temporal Changes In Vegetative Cover On South Padre Island, Texas Using Image Classifications Derived From Aerial Color-Infrared Photographs, Ruben A. Mazariegos, Kenneth R. Summy, Frank W. Judd, Robert I. Lonard, James H. Everitt

Physics & Astronomy Faculty Publications

Supervised image classifications developed from 23 x 23 cm aerial color-infrared aerial photographs (1:5,000 scale) were used to evaluate temporal changes in vegetative cover occurring within three 150 x 300-m research sites on South Padre Island, Texas. Use of high-resolution digitized imagery (ground pixel resolution of ca. 0.1 m) and survey-grade GPS for positional measurements of ground control points (20-25 1.0m2 targets within each research site) resulted in consistently high levels of geometric accuracy, with root mean square errors (RMSEs) ranging between 0.397 – 2.867. Similarly, use of relatively simple information categories (dry and wet sand, live and dead vegetative …

The Phytotronist And The Phenotype: Plant Physiology, Big Science, And A Cold War Biology Of The Whole Plant., David Munns

Publications and Research

This paper describes how, from the early twentieth century, and especially in the early Cold War era, the plant physiologists considered their discipline ideally suited among all the plant sciences to study and explain biological functions and processes, and ranked their discipline among the dominant forms of the biological sciences. At their apex in the late-1960s, the plant physiologists laid claim to having discovered nothing less than the “basic laws of physiology.” This paper unwraps that claim, showing that it emerged from the construction of monumental big science laboratories known as phytotrons that gave control over the growing environment. Control …

Matrix And Edge Effects On The Maintenance Of Ecological Function In An Afromontane Protected Area, Robin M. Martino

Antioch University Dissertations & Theses

Land use type in the human dominated matrix surrounding tropical forest can influence edge effects at the forest-matrix interface. Edge effects can alter ecological processes and impact the function of forest edge ecosystems. A key ecological process that helps maintain tropical forest and is affected by forest disturbance is seed dispersal by large, fruit eating vertebrates (frugivores). This dissertation examines how the type of vegetation in the matrix, the `soft’ edge contrast of pine plantations and the `hard’ edge contrast of tea plantations, affect seed dispersal behavior of large frugivores, and the structure and composition of tree species, in forest …

Variation In Mineral Content Of Prairie Forb Species And Content Changes Over Winter Related To Slagging Potential, Jennifer Nyla Wahl Rupp

Dissertations and Theses @ UNI

Coal fired power plants are responsible for more than 75 percent of the energy produced in Iowa. Burning coal releases large amount of carbon dioxide and other chemical compounds into the atmosphere.

A variety of types of biomass, including prairie vegetation, are being proposed as biofuel alternatives for electrical generation. Tilman et al. (2006) determined that biofuels from mixtures of prairie vegetation of increasing diversity provide more usable energy, reduce greenhouse gases and produce less agriculture pollutants. The Prairie Power Project of the Tallgrass Prairie Center is testing four mixtures of prairie species for maximum production of biomass. A primary …

Above- And Belowground Biomass And Soil Respiration In A Low-Input Perennial Biofuel Production System, Jordan Young, Jessica Abernathy, Kenneth Elgersma

Undergraduate Student Work

Backgroud

• Global climate change largely depends on the atmospheric carbon balance, of which soil respiration is a significant component.
• Native perennial prairie vegetation is being tested as an alternative to corn for renewable biofuel production.
• Mixtures of this vegetation are considered ‘carbon negative’ because net CO2 sequestration exceeds atmospheric release¹.
• Studies have shown that aboveground biomass and the rate of carbon sequestration are both increased by planting a diverse mixture of species versus a monoculture¹.

Research Question:

How does the diversity of biofuel vegetation mixtures affect soil respiration, aboveground biomass and belowground biomass?

Prairie Power Project: Determining Maximum Sustainable Production Of Biomass With A Mixture Of Prairie Species, Cynthia Cambardella, Kenneth Elgersma, Eric Giddens, Mark Myers, Mark Sherrard, Daryl Smith

Tallgrass Prairie Publications and Reports

Native prairie species mixtures appear to have great promise as bioenergy feedstocks. These perennial plants store carbon and produce greater net energy than row crops because: (1) after initial establishment they require little or no energy input such as cultivation, fertilizer, pesticides and irrigation; (2) they sequester excess CO2; and (3) all above ground biomass is used rather than just the seed. Furthermore, prairie grows well on non-prime, nutrient-poor, agricultural soils and will not displace food crops from higher quality agricultural land.

Glomalin Accumulated In Seagrass Sediments Reveals Past Alterations In Soil Quality Due To Land-Use Change, Lourdes López-Merino, Oscar Serrano, María Fernanda Adame, Miguel-Ángel Mateo, Antonio Martínez Cortizas

Research outputs 2014 to 2021

Arbuscular mycorrhizal fungi (AMF), symbionts with most terrestrial plants, produce glomalin-related soil protein (GRSP), which plays a major role in soil structure and quality. Both fungi hyphae and protein production in soils are affected by perturbations related to land-use changes, implying that GRSP is a sensitive indicator of soil quality. Unfortunately, GRSP degrades within years to decades in oxic environments, preventing its use as palaeoecological proxy. However, GRSP is transported to marine, near-shore anoxic sediments, where it accumulates and remains non-degraded, enabling the assessment of its potential as a palaeoecological proxy for soil ecosystem's health. Exploiting this fact, we have …

Butterfly And Floral Community Dynamics At A Native Prairie Agrofuel Research Site, Benjamin J. Hoksch

Dissertations and Theses @ UNI

Agrofuel production in the Midwest has historically relied upon monoculture food crops (Zea mays and Glycine max) that do little to support biodiversity or maintain soil and water quality. The University of Northern Iowa’s Tallgrass Prairie Center is investigating the feasibility of establishing and harvesting diverse mixes of native prairie vegetation for use as a sustainable agrofuel. In 2009 48 research plots were established on three soil types, on land with a >30 year history of row crop production in Black Hawk County, IA. Each plot was seeded with one of four native prairie agrofuel crops: (1) Switchgrass1, (2) Grasses5 …