Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 34

Full-Text Articles in Entire DC Network

Interactions Between Cover Crops And Weed Management In Iowa's Conventional Cropping Systems, Meaghan Jean Bryan Anderson Jan 2014

Interactions Between Cover Crops And Weed Management In Iowa's Conventional Cropping Systems, Meaghan Jean Bryan Anderson

Graduate Theses and Dissertations

The effect of different levels of cereal rye (Secale cereale L.) residue on common waterhemp (Amaranthus rudis Sauer) and common lambsquarters (Chenopodium album L.) emergence was determined. Cereal rye seeding date had a greater effect on rye biomass accumulation and percent cover than seeding rate. Common waterhemp emergence was equal to or increased in the presence of cereal rye residue in both 2013 and 2014 compared to the control. Common lambsquarters emergence was increased in two treatments in 2014 but was otherwise unaffected by cereal rye. The presence of cereal rye residue increased the time to 10% and 50% emergence ...


The Effects Of Canopy Management Practices On Fruit Quality Of Northern-Hardy Interspecific Hybrids Of Vitis Spp., Dylan Paul Rolfes Jan 2014

The Effects Of Canopy Management Practices On Fruit Quality Of Northern-Hardy Interspecific Hybrids Of Vitis Spp., Dylan Paul Rolfes

Graduate Theses and Dissertations

The recent release of interspecific hybrid grape cultivars that are hardy for the northern climates of the United States has led to a rapid expansion of the grape and wine industry in the Upper Midwest, as well as other cold-climate regions. These cultivars often exhibit high vegetative vigor and possess fruit quality concerns when their grapes are to be used in wine production. Adaptation in the viticultural practices used to produce the grapes may help to improve fruit quality for winemaking, which could promote increased sales and profitability of the grape and wine industry in the Upper Midwest.

This study ...


Effects Of Ilevo® On Soybean Sudden Death Syndrome And Soybean Cyst Nematode, Edward R. Zaworski Jan 2014

Effects Of Ilevo® On Soybean Sudden Death Syndrome And Soybean Cyst Nematode, Edward R. Zaworski

Graduate Theses and Dissertations

Fusarium virguliforme, the causal agent of soybean sudden death syndrome (SDS), and Heterodera glycines, soybean cyst nematode (SCN), are two of the most important pathogens of soybean. Host resistance is currently the main management strategy for both pathogens, and there are few other options available for each pathogen. Seed treatments are now an option for farmers for use of pesticides in early plant development. Bayer CropScience recently registered a seed treatment, ILeVO® (fluopyram), with reported activity against both SDS and SCN. The research described in the following manuscript tested ILeVO® in different combinations with currently available seed treatment products for ...


Germplasm Enhancement Of Maize: Utilization Of Doubled Haploid Breeding On Adapted Tropical Sources, Andrew Smelser Jan 2014

Germplasm Enhancement Of Maize: Utilization Of Doubled Haploid Breeding On Adapted Tropical Sources, Andrew Smelser

Graduate Theses and Dissertations

The allelic diversity (AD) project of the Germplasm Enhancement of Maize program utilized the double haploid (DH) breeding method to expedite release of lines from 300 exotic maize races. Differential effects on haploid induction rates (HIR) and chromosome doubling rates (DR) associated with the recurrent parents PHB47 and PHZ51, the elevation that the race is traditionally grown at, and the race itself were examined. Races from the AD project were grouped by elevation (high, middle, or low altitude) of their country of origin. Six races per elevation were randomly selected and backcrossed using both recurrent parents to generate 36 populations ...


Adaptability Potential Of Corn For Groundcover Cropping Systems, Nickolas James Bowden Jan 2014

Adaptability Potential Of Corn For Groundcover Cropping Systems, Nickolas James Bowden

Graduate Theses and Dissertations

Experiments were conducted from 2008-2010 to determine genetic adaptability potential of corn when grown in competition with cover crops or living mulches. Cover crops were grown simultaneously with corn crop. Genetic potential was identified in female inbred lines more so than in male inbred lines when tested in hybrid combination.


Integrating Scale And Uncertainty To Understand Microbially Derived Agroecosystem Processes, Ryan James Williams Jan 2014

Integrating Scale And Uncertainty To Understand Microbially Derived Agroecosystem Processes, Ryan James Williams

Graduate Theses and Dissertations

Soil microorganisms are largely responsible for biogeochemical fluxes in the terrestrial biosphere that effect ecosystem productivity and alter global climate patterns. Though the importance of soil microorganisms is easy to state, little is known about interactions between microbes necessary for the production of ecosystem-scale fluxes. Furthermore, measurement of biogeochemical fluxes at the scale of microorganisms or ecosystems is far from straightforward; the lack of understanding regarding linkages between these two scales (microbial habitat and ecosystem) remains as an important knowledge gap in ecology. For my dissertation I focused on studying microbial communities among soil aggregates, aggregate-scale fluxes of soil carbon ...


Corn Production With Instinct Nitrification Inhibitor Applied With Urea-Ammonium Nitrate Solution And Liquid Swine Manure, Aaron Michael Sassman Jan 2014

Corn Production With Instinct Nitrification Inhibitor Applied With Urea-Ammonium Nitrate Solution And Liquid Swine Manure, Aaron Michael Sassman

Graduate Theses and Dissertations

Improving N use efficiency of applied N by corn (Zea mays L.), in order to minimize N losses from agricultural fields, is of concern to both producers and environmentalists. Use of nitrification inhibitors is thought to slow the conversion of applied NH4 to NO3, which would reduce N losses from the soil while increasing corn plant N uptake. This thesis includes two, small plot field studies designed to evaluate the effect Instinct (Dow AgroSciences, Indianapolis, IN) nitrification inhibitor had on corn production. The first study evaluated the effect of Instinct spring preplant applied with urea-ammonium nitrate (UAN) solution on corn ...


Stage Of Maturation, Crop Load, And Shoot Density Affect The Fruit Quality Of Cold-Hardy Grape Cultivars, Randall Vos Jan 2014

Stage Of Maturation, Crop Load, And Shoot Density Affect The Fruit Quality Of Cold-Hardy Grape Cultivars, Randall Vos

Graduate Theses and Dissertations

Wine grape production in the Upper Midwest and other cold-climate regions is increasing due to the release of cold-hardy grape cultivars that are interspecific hybrids. Grape production practices for Vitis vinifera L. cultivars in regions with long growing seasons, such as California, are standardized more than in other regions due to the extensive amount of research on cultivars of V. vinifera. In spite of that, few researchers document changes in grape composition as fruits mature, and those that do primarily only report soluble solids, pH, and titratable acidity.

Two experiments were designed to examine the changes in soluble solids, pH ...


Efficiency Study Of Testing And Selection In Progeny-Row Yield Trials And Multiple-Environment Yield Trials In Soybean Breeding, Minghui Sun Jan 2014

Efficiency Study Of Testing And Selection In Progeny-Row Yield Trials And Multiple-Environment Yield Trials In Soybean Breeding, Minghui Sun

Graduate Theses and Dissertations

your words


An Integrative Approach For Germplasm Utilization, Genetic Diversity And Qtl Mapping In Camelina Spp. And Crop-Production Issues In Thlaspi Arvense, New Promising Oilseed Crops For Bioenergy And Industrial Uses, Ivan Mauricio Ayala Diaz Jan 2014

An Integrative Approach For Germplasm Utilization, Genetic Diversity And Qtl Mapping In Camelina Spp. And Crop-Production Issues In Thlaspi Arvense, New Promising Oilseed Crops For Bioenergy And Industrial Uses, Ivan Mauricio Ayala Diaz

Graduate Theses and Dissertations

Fuel demands continue to increase to satisfy current energy needs. Fossil fuels are the primary source of energy and supply 80% of the total demand, 58% of which is used for transportation purposes. However, decreasing oil reserves, rising prices and negative environmental implications have all contributed to growing demand for alternative energy sources, such as bioenergy crops. Ideally a good bioenergy crop has low input requirements (able to grow in marginal zones), fast growth and maturity, tolerance to biotic and abiotic stress conditions, and high productivity. Camelina (Camelina sativa (L.) Crantz) and pennycress (Thlaspi arvense L.) have been targeted as ...


Integrating Soybean Aphid And Soybean Cyst Nematode Management, Michael Thomas Mccarville Jan 2014

Integrating Soybean Aphid And Soybean Cyst Nematode Management, Michael Thomas Mccarville

Graduate Theses and Dissertations

Soybean aphid, Aphis glycines, and soybean cyst nematode (SCN), Heterodera glycines, can interact through the soybean plant resulting in increased SCN reproduction on both SCN-resistant and SCN-susceptible varieties. The management of SCN is heavily reliant on the planting of PI 88788-derived SCN-resistant varieties to limit yield loss to SCN in the current year and future years. Virulence to PI 88788 is increasing in SCN field populations due to its extensive use. Therefore, it is increasingly important to manage any factor that increases SCN reproduction on SCN-resistant varieties. Here I examined management tactics including host-plant resistance and insecticidal seed treatments to ...


Relationships Between Foliar Applied Micronutrients, Soil And Tissue Tests, And Grain Yield In Soybean, Joshua T. Enderson Jan 2014

Relationships Between Foliar Applied Micronutrients, Soil And Tissue Tests, And Grain Yield In Soybean, Joshua T. Enderson

Graduate Theses and Dissertations

There has been little research with foliar application of micronutrients for soybean [Glycine max (L.) Merr.] in the Corn Belt, and results have been inconsistent. This study's objectives were to (1) evaluate the soybean grain yield response to foliar application of B, Cu, Mn, and Zn; and (2) study relationships between soil and plant-tissue test results for these micronutrients. Forty-two field trials were conducted in Iowa during 2012 and 2013 that involved 23 soil series. Six treatments replicated four times were a control, each nutrient applied separately, and their mixture sprayed twice (at the V6 and R2/R3 growth ...


A Carbon Assessment Of Iowa State University's Land, Catherine Rosson Delong Jan 2014

A Carbon Assessment Of Iowa State University's Land, Catherine Rosson Delong

Graduate Theses and Dissertations

In 1862, Iowa State University was the first college to become a land-grant university. Today, their mission has expanded beyond the Iowa farmer to the global farmer and more broadly the agricultural world. As part of this global perspective, Iowa State University has chosen to be the first US university to evaluate itself in an environmental context through a carbon assessment of its soils. The carbon content of Iowa State's 6,392 hectares was evaluated to an 18 and 100 cm depth using two databases. The carbon flux of Iowa State University's land, given a change in management ...


Anion Exchange Capacity Of Biochar, Michael Lawrinenko Jan 2014

Anion Exchange Capacity Of Biochar, Michael Lawrinenko

Graduate Theses and Dissertations

Nutrient loss, specifically of nitrate and phosphate, from agricultural land often incurs harmful consequences for environmental and groundwater quality and many efforts have been attempted to reduce the discharge of agricultural nutrients to open waters and groundwater, yet no approach has shown to be robust. Biochar has been demonstrated to alter soil properties, thus soils modified with biochar having significant anion exchange capacity (AEC) may exhibit reduced nutrient loss. Our goal in this study was to determine what chemical functional groups contribute AEC to biochar and investigate what production conditions and raw material choices yield biochar with appreciable AEC. Further ...


New Insights Into The Functional Organization Of Xyloglucan Biosynthetic Enzymes And Their Catalytic Mechanism, Yi-Hsiang Chou Jan 2014

New Insights Into The Functional Organization Of Xyloglucan Biosynthetic Enzymes And Their Catalytic Mechanism, Yi-Hsiang Chou

Graduate Theses and Dissertations

Xyloglucan (XyG) is the major hemicellulosic polysaccharide in the primary cell walls of most vascular dicotyledonous plants, and has important structural and physiological functions in plant growth and development. In Arabidopsis thaliana, a glucan synthase CSLC4, three xylosyltransferases, XXT1, XXT2, and XXT5, two galactosyltransferase, MUR3 and XLT2 and a fucosyltransferase, FUT1 synthesize xyloglucan in Golgi. The functional organization of these enzymes is not clear. To study the functional organization of these enzymes, Bimolecular Fluorescence Complementation (BiFC), in vitro pull-down assay and co-immunoprecipitation were used to elucidate the interactions among CSLC4, XXTs, MUR3, XLT2 and FUT1 proteins both in vivo and ...


Real-Time Pcr Analysis Of Maize Seedlings For Assessment Of Seed Treatment Efficacy And Genetic Resistance To Infection By Sphacelotheca Reiliana, Samuel James Anderson Jan 2014

Real-Time Pcr Analysis Of Maize Seedlings For Assessment Of Seed Treatment Efficacy And Genetic Resistance To Infection By Sphacelotheca Reiliana, Samuel James Anderson

Graduate Theses and Dissertations

Head smut caused by Sphacelotheca reiliana (S. reiliana) is a devastating disease of maize that has been reported to account for up to 80% yield loss in fields. This disease exists in many major maize growing regions and the disease incidence is rising. It has become a major constraint in seed production areas as the spores it produces adhere to and contaminate seeds. The fungus infects systemically during the seedling stage and usually does not produce symptoms until the plant reaches its reproductive stages when the fungus replaces the inflorescences with large black masses of teliospores known as sori. When ...


A New Metric For Parental Selection In Plant Breeding, Ye Han Jan 2014

A New Metric For Parental Selection In Plant Breeding, Ye Han

Graduate Theses and Dissertations

Plant breeding is the art of genetic improvement through creation and selection for novel characteristics in plants. Parental selection provides the raw materials for creating each new generation of genetic improvements. Ultimately, the probability of successfully meeting the breeding objectives depends on selection of parents for intermating. With the application of operations research, we developed a new metric, parental breeding value (PBV), based on application of conditional probability distribution to help to solve the parental selection problem to accelerate the process of plant breeding and save resources at the same time. The water pipe model is provided in the thesis ...


Genome-Wide Association Studies To Dissect The Genetic Architecture Of Yield-Related Traits In Maize And The Genetic Basis Of Heterosis, Jinliang Yang Jan 2014

Genome-Wide Association Studies To Dissect The Genetic Architecture Of Yield-Related Traits In Maize And The Genetic Basis Of Heterosis, Jinliang Yang

Graduate Theses and Dissertations

This dissertation includes a general introduction (Chapter 1), three journal manuscripts (Chapters 2 to 4) and a section of general conclusions (Chapter 5). The paper in Chapter 2, which compares three statistical approaches for conducting GWAS and identifies the genetic architecture controlling for KRN trait, has been submitted for publication. I made major contributions include designing and performing the experiments, analyzing data and writing the manuscript under the guidance of Dr. Schnable. Dr. Nettleton and Dr. Dekkers provided technical support and conceptual advice for this work. The paper in Chapter 3, which investigates the modes of inheritance of trait-associated variants ...


Mobile Mrna: A Long Distance Signaling System In Potato, Tian Lin Jan 2014

Mobile Mrna: A Long Distance Signaling System In Potato, Tian Lin

Graduate Theses and Dissertations

Mobile mRNA is one of the most important long-distance signals in plant vascular system. They play important roles in responding to environmental cues, such as photoperiod. There are numerous studies on mobile mRNAs in plants and thousand of mRNAs have been detected in phloem sap. One of the BEL1-like genes, designated StBEL5, has transcripts that move long distance from leaf to stolon tips and enhance tuberization. However, not many mobile mRNAs have been characterized. The mechanism of the long-distance movement of mRNAs is not clear. In this dissertation, we conducted research on different levels to characterize known mobile mRNA and ...


Influence Of Heterodera Glycines Infection, Plant Age And Water Availability On Foliar Symptoms Of Sudden Death Syndrome, Root Symptom Severity And Root Morphology Of Soybean Plants Infected By Fusarium Virguliforme, Nenad Tatalović Jan 2014

Influence Of Heterodera Glycines Infection, Plant Age And Water Availability On Foliar Symptoms Of Sudden Death Syndrome, Root Symptom Severity And Root Morphology Of Soybean Plants Infected By Fusarium Virguliforme, Nenad Tatalović

Graduate Theses and Dissertations

Fusarium virguliforme Aoki, O'Donnell, Homma and Lattanzi (FV), a causal organism of sudden death syndrome (SDS), and Heterodera glycines Ichinohe, the soybean cyst nematode (SCN), are two of the most important soil-borne pathogens affecting soybean production in the USA. These pathogens often occur together in production fields and interact, which results in significant yield losses. In co-infected plants, SDS symptoms appear earlier and are more severe than in plants infected by FV alone. However, the mechanism of the SCN-FV interaction remains unclear. Fusarium virguliforme is able to infect soybean plants of different growth stages, but plants infected at younger ...


A Comparison Of Carbon Storage Potential In Corn- And Prairie-Based Agroecosystems, Ranae Dietzel Jan 2014

A Comparison Of Carbon Storage Potential In Corn- And Prairie-Based Agroecosystems, Ranae Dietzel

Graduate Theses and Dissertations

Increasing carbon (C) in the soil is important both for removing harmful C from the atmosphere and improving the health of the soil. In this dissertation, I set out to examine how planting and harvesting prairies on soils suitable for corn affected soil C storage potential when compared to corn-based systems. I addressed three questions designed to a) improve our understanding of the fundamental differences between how prairies and corn grow throughout the year, b) test how prairies and corn add C to the soil after establishment, and c) use our current understanding of prairie and corn growth and C ...


Genetic Analysis Of The Ibm2syn10-Dh Maize Population For Response To Low And High Nitrogen Input, Pedro José Gonzalez-Portilla Jan 2014

Genetic Analysis Of The Ibm2syn10-Dh Maize Population For Response To Low And High Nitrogen Input, Pedro José Gonzalez-Portilla

Graduate Theses and Dissertations

Maize growth and development depends highly in the capacity of the plants to absorb Nitrogen (N) from the soil. Producing a high-yielding maize crop that requires less N input is currently one important goal of maize breeding programs. In order to understand the dynamics of N use in maize, the study of phenotypic and genetic response to N deficiency must be performed. Using lines from the high resolution IBM2Syn10-DH population, the goals of this study were: 1) to identify the phenotypic response of the root system architecture (RSA) of 14-day old maize seedlings grown under contrasting levels of N; 2 ...


Biochar's Fitness As An Amendment In Bell Pepper Transplant And Field Production, Brandon Henry Carpenter Jan 2014

Biochar's Fitness As An Amendment In Bell Pepper Transplant And Field Production, Brandon Henry Carpenter

Graduate Theses and Dissertations

Biochar, a carbon-rich co-product derived from the pyrolysis of biomass for fuel for energy production, often exhibits beneficial chemical and physical properties when added to soils and soilless substrates. Research into the use of biochar to improve plant productivity and growth has increased over the past decade. Much of this research has been done in controlled environments, and often these experiments focus on using biochar as an alternative to sphagnum peat, or on how biochar affects plants grown in soil. Few studies have investigated biochar's effects on a specific plant in both greenhouse and field production, and from seed ...


Photosynthetically Active Radiation And Root-Zone Temperature Effects On High-Tunnel Primocane Red Raspberry Growth And Development, Leah Beth Riesselman Jan 2014

Photosynthetically Active Radiation And Root-Zone Temperature Effects On High-Tunnel Primocane Red Raspberry Growth And Development, Leah Beth Riesselman

Graduate Theses and Dissertations

High-tunnel primocane red raspberry production is beneficial in the North Central Region of the United States where production is dependent upon the length of the growing season. Advantages of growing Rubus iadaeus L. (red raspberries) in high-tunnels include improved climatic conditions, reduced winter-cane injury, decreased disease incidence, improved berry size and quality, advanced fruit maturation and harvest, and a 50% extension of the harvest season. Improved climatic conditions of high-tunnels also have affected primocane red raspberry growth and production negatively, by reducing shoot growth, fruiting lateral development, yield, and berry quality, due to increased PAR and air- and root-zone temperature ...


Loose And Baled Corn Cob Management And Storage In Field Effects On Subsequent Crop Growth And Soil Health, Carlos Gilberto Tenesaca Jan 2014

Loose And Baled Corn Cob Management And Storage In Field Effects On Subsequent Crop Growth And Soil Health, Carlos Gilberto Tenesaca

Graduate Theses and Dissertations

Companies in the U.S have started using corn (Zea mays L.) residue as feedstock for cellulosic ethanol production. However, concerns including field storage and removal methods effects on crop growth and development, soil health, and environmental quality have been raised requiring the investigation of management and strategies to mitigate such effects. In the Mid-west corn cob have being utilized as feedstock material for cellulosic ethanol production in addition to corn residue. Nevertheless, there are many management issues that need to be addressed in order to efficiently store and remove corn cob from the field with minimum damage to subsequent ...


Effect Of Short-Term Versus Prolonged Freezing On Freeze-Thaw Injury And Post-Thaw Recovery In Spinach: Importance In Laboratory Freeze-Thaw Protocols, Kyungwon Min Jan 2014

Effect Of Short-Term Versus Prolonged Freezing On Freeze-Thaw Injury And Post-Thaw Recovery In Spinach: Importance In Laboratory Freeze-Thaw Protocols, Kyungwon Min

Graduate Theses and Dissertations

Spinach (Spinacia oleracea L.) is a cool-season vegetable crop which can be damaged by intermittent spring frost that is needed to better understand freezing tolerance of spinach. This thesis focused on the physiology of spinach's freezing tolerance through duration of freezing, including an ability of recovery, using freeze-thaw injured spinach tissues exposed to various durations of freezing at two sub-lethal temperatures. Various physiological parameters [electrolyte leakage, Fv/Fm ratio (efficiency of PSII), MDA test (an indicator of lipid peroxidation), and histochemical detection of ROS (i.e. superoxide (O2-) and hydrogen peroxide (H2O2)] were quantified. Based on the LT50 of ...


Evaluating Horticultural Practices For Sustainable Tomato Production In Kamuli, Uganda, Sharon Mbabazi Tusiime Jan 2014

Evaluating Horticultural Practices For Sustainable Tomato Production In Kamuli, Uganda, Sharon Mbabazi Tusiime

Graduate Theses and Dissertations

Tomatoes are a source of income and food security for small-landholder farmers across Uganda, including the Kamuli District. Studies regarding sustainable practices are needed to increase production of the crop and improve farmers' livelihoods. This study investigated three tomato cultivars, Heinz 1370, Nuru F1, and MT 56, pesticide application, staking, and mulching for their effect on yield, disease severity and gross margin of tomato production in the Kamuli District of Uganda. The treatments were tested in a randomized complete block design with a factorial and split-plot arrangement during two growing seasons in 2013. Total and marketable fruit number, marketable fruit ...


Values-Based Supply Chains: Local And Regional Food Systems In The Upper Midwest United States, Kevin Richard Duerfeldt Jan 2014

Values-Based Supply Chains: Local And Regional Food Systems In The Upper Midwest United States, Kevin Richard Duerfeldt

Graduate Theses and Dissertations

In recent years there has been growing public interest in sustainable food systems. One effect of growing interest is the proliferation of values-based supply chains or local food systems. The main limiting factor of local food systems is infrastructure for aggregation and access to supply chains. Food hubs have been identified as one solution. My purpose is to capture valuable data about the state of local foods industries in 2012 and inform organizations developing food hubs. To do this I surveyed characteristics of established food hubs and analyzed local Iowa vineyards and wineries, as a case study of an established ...


A Comparison Of Cellulosic Fuel Yields And Separated Soil-Surface Co2 Fluxes In Maize And Prairie Biofuel Cropping Systems, Virginia Nichols Jan 2014

A Comparison Of Cellulosic Fuel Yields And Separated Soil-Surface Co2 Fluxes In Maize And Prairie Biofuel Cropping Systems, Virginia Nichols

Graduate Theses and Dissertations

It has been suggested that strategic incorporation of perennial vegetation into agricultural landscapes could provide ecosystem services while maintaining agricultural productivity. To evaluate potential use of prairie as a Midwestern cellulosic feedstock, we investigated theoretical cellulosic fuel yields, as well as soil-surface carbon dioxide emissions of prairie-based biofuel systems as compared to maize-based systems on fertile soils in Boone County, IA, USA. Investigated systems were: a maize-soybean rotation grown for grain only, continuous maize grown for grain and stover both with and without a winter rye cover crop, and a 31-species reconstructed prairie grown with and without spring nitrogen fertilization ...


Function Of Class One Nonsymbiotic Plant Hemoglobins, Xiaoguang Wang Jan 2014

Function Of Class One Nonsymbiotic Plant Hemoglobins, Xiaoguang Wang

Graduate Theses and Dissertations

Plants lack a circulatory system for oxygen. Thus hypoxia and anoxia are potential problems for plants. Environmental factors like flooding can make such problems even worse. At hypoxia and anoxia conditions, both nitrogen metabolism enzymes and nonsymbiotic hemoglobins in plants are up-regulated. Meanwhile, nitrite and nitric oxide are accumulated. Two physiological roles of plant nonsymbiotic hemoglobins were proposed: 1) nitric oxide scavenging during plant hypoxia using NOD function involving ascorbate and monodehydroascorbate reductase; 2) dissimilatory nitrite reduction during plant hypoxia or anoxia cooperating with other factors (since plant hemoglobin itself cannot reduce nitrite to ammonium in vitro). This thesis includes ...