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Full-Text Articles in Life Sciences

The Role Of The Auxin Biosynthesis And Signaling In Soybean Root Nodule Development, Mucahid Bozkus Jan 2021

The Role Of The Auxin Biosynthesis And Signaling In Soybean Root Nodule Development, Mucahid Bozkus

Electronic Theses and Dissertations

Nitrogen(N) is one of the most important plant nutrients for plant growth and yield, however, its abundance in the soil is not sufficient for profitable crop production. The use of chemical fertilizers helps address soil N deficiency in agriculture. However, due to the environmental pollution resulting from excessive use of fertilizers, alternative forms of N for agriculture are a necessity. Leguminous plants such as soybean (Glycine max) form a symbiotic association with N-fixing rhizobia to meet their N demands. Legume-rhizobia symbiosis results in the formation of unique structures called nodules where rhizobia convert atmospheric nitrogen into plant usable forms, thus …


A Biocontrol Pesticide Derived From Mycovirus-Infected Sclerotinia Sclerotiorum Can Induce Plant Resistance, Connor Pedersen Jan 2021

A Biocontrol Pesticide Derived From Mycovirus-Infected Sclerotinia Sclerotiorum Can Induce Plant Resistance, Connor Pedersen

Electronic Theses and Dissertations

Soybean leaf-associated gemycircularvirus-1 (SlaGemV-1) is a novel mycovirus discovered through the metagenomic sequencing of soybean leaves which is capable of inducing hypovirulence in the highly pathogenic fungus Sclerotinia sclerotiorum. RNASeq analysis techniques were used to determine the transcriptional changes caused by the infection of virus in S. sclerotiorum, as well as the transcriptional changes in Glycine max caused by the colonization of hypovirulent, SlaGemV-1-infected S. sclerotiorum. RNASeq results indicate that viral infection leading to hypovirulence may attenuate expression of genes relating to cell wall synthesis, microtubule formation, and metabolism of steroids and natural antibiotics. Cytochrome P450-related genes, kinesin domain genes, …


Implications Of Broadleaf, Grass, And A Blend Of Broadleaf And Grass Cover Crops On Soil Health And Corn Production In South Dakota, Hunter Bielenberg Jan 2021

Implications Of Broadleaf, Grass, And A Blend Of Broadleaf And Grass Cover Crops On Soil Health And Corn Production In South Dakota, Hunter Bielenberg

Electronic Theses and Dissertations

Cover crops have recently gained attention in the U.S. Midwest because of their potential to increase soil organic matter and protect overall soil health. This study was conducted to determine the effects of different cover crop mixtures on soil health measurements and corn grain yield at increasing nitrogen (N) rates. Cover crops were planted in the fall after small grains harvest as a dominantly grass mixture, dominantly broadleaf mixture, or a 50/50 grass and broadleaf mixture with a no cover crop control. Soil and cover crop biomass samples were collected in the fall before winter cold termination and in the …


Soil Organic Carbon, Hydro-Physical Properties, Pore Structure And Greenhouse Gas Fluxes Under Integrated Crop-Livestock System, Jashanjeet Kaur Dhaliwal Jan 2021

Soil Organic Carbon, Hydro-Physical Properties, Pore Structure And Greenhouse Gas Fluxes Under Integrated Crop-Livestock System, Jashanjeet Kaur Dhaliwal

Electronic Theses and Dissertations

Integrated crop-livestock system (ICLS) can improve soil organic carbon (SOC), enhance soil hydro-physical properties, and mitigate greenhouse gas (GHG) emissions. The objectives of this study were to: (i) investigate the influence of grazing, cover crop (CC), and a combination of grazing and CC on labile soil carbon (C) and nitrogen (N) fractions and soil enzyme activity, (ii) assess the impacts of short-term (3-4 years) and long-term (>30 years) ICLS on SOC, bulk density, structural quality and water infiltration, (iii) evaluate soil pore structural properties such as porosity, number of pores, pore size, pore shape, fractal dimension, anisotropy and tortuosity …


Auxin-Based Herbicide Program And Rhizobia Application For Weed Control And Nodulation Potential In Auxin Tolerant Soybean, Joy Amajioyi Jan 2021

Auxin-Based Herbicide Program And Rhizobia Application For Weed Control And Nodulation Potential In Auxin Tolerant Soybean, Joy Amajioyi

Electronic Theses and Dissertations

Foliar-applied Bradyrhizobia to V4 soybean has been reported to increase yield up to 5%. However, a stand-alone product application may not be practical. Applying with other treatments such as post-emergence herbicide application may be economical but herbicide and/or additives may be deleterious to rhizobial growth. A laboratory study investigated the impact of herbicides (glyphosate and dicamba), additives (an oil to improve absorption and spreading; and AMS used to overcome hard water impacts on glyphosate), and herbicide + additives on bacterial growth. Optical density (OD) measurements at the wavelength of 650 nm assessed solution turbidity, a surrogate measure of bacterial growth. …


Evaluation Of Biotype 4 Aphis Glycines (Hemiptera: Aphididae) Induced Susceptibility On Soybean And Soja, Jakob David Hicks Jan 2021

Evaluation Of Biotype 4 Aphis Glycines (Hemiptera: Aphididae) Induced Susceptibility On Soybean And Soja, Jakob David Hicks

Electronic Theses and Dissertations

Soybean aphids have been a significant pest of soybeans in North America since 2000. Before 2000, soybeans did not face significant insect pest pressure from any arthropods with piercing-sucking mouthparts. It is estimated that economic damage from soybean aphids range from $1billion to $4.7 billion annually. Research efforts focused on the identification of host plant resistance genes in soybean and discovered many resistant to Aphis glycines genes (i.e., Rag genes) in soybean. However, the adoption of commercially released Rag soybean cultivars has been limited. The prospect of management with Rag genes was further complicated by the identification of three virulent …


Quantifying The Impacts Of An Integrated Crop-Livestock System On Plant Nutrient Accumulation, Crop Yield, And Economic Performance, Teerath Singh Rai Jan 2021

Quantifying The Impacts Of An Integrated Crop-Livestock System On Plant Nutrient Accumulation, Crop Yield, And Economic Performance, Teerath Singh Rai

Electronic Theses and Dissertations

Integrated crop-livestock systems (ICLs), if managed properly, have the potential for enhancing crop production and economics. Cover crops in ICL can be grazed to provide feed for livestock and improve nutrient recycling. This dissertation focused on assessing the impacts of ICL on crop yield and economics using field and modeling studies. Specific objectives of this dissertation are: (i) evaluating the impacts of the ICL on crop yield, and economic performance in a 3-yr oat (Avena sativa L.) – maize (Zea mays L.) – soybean (Glycine max (L.) Merr.) rotation, (ii) assessing the impacts of the ICL on maize biomass accumulation, …


Studying Morphological, Physiological, And Molecular Regulation Of Stomatal Conductance And Its Relationship To Water Use Efficiency In Alfalfa, Surbhi Gupta Jan 2021

Studying Morphological, Physiological, And Molecular Regulation Of Stomatal Conductance And Its Relationship To Water Use Efficiency In Alfalfa, Surbhi Gupta

Electronic Theses and Dissertations

Alfalfa (Medicago sativa), being a leguminous, highly fibrous, and proteinaceous plant has always been one of the top choices for the forage production but has high cost of irrigation in many dry and warm areas such as California and Arizona. Thus, a reduction of irrigation by using the higher water use efficiency (WUE) varieties can help the growers in reducing the cost and is critical for sustainable agriculture production. WUE is closely related to water loss through transpiring stomata. A study in our lab reported that Riverside (RS) an alfalfa genotype that has naturized in the national grassland in South …


Evaluating Canola Genotypes For Growth And Yield Under Different Environmental Conditions In South Dakota, Unius Arinaitwe Jan 2021

Evaluating Canola Genotypes For Growth And Yield Under Different Environmental Conditions In South Dakota, Unius Arinaitwe

Electronic Theses and Dissertations

Canola (Brassica napus L) and carinata (Brassica carinata A. Braun) are potential oilseed crops for diversifying cropping systems and expanding into marginal lands impacted by saline and sodic soils in South Dakota (SD). However, genotypes that are high yielding, with high agronomic adaptability and stability over diverse environments, and salt tolerant have not been selected. One field experiment was conducted at two environments (Brookings - eastern SD and Pierre - western SD) from 2019 to 2020 to evaluate genotypes for growth and yield stability. Three greenhouse experiments were conducted to evaluate genotypes for salt tolerance in …


Studies On Genetic Characterization Of Agronomic Traits And Disease Resistance In Bread Wheat, Jyotirmoy Halder Jan 2021

Studies On Genetic Characterization Of Agronomic Traits And Disease Resistance In Bread Wheat, Jyotirmoy Halder

Electronic Theses and Dissertations

A steady increase in wheat yield is vital to feed the continuously rising world population. Systematic exploitation of wheat germplasm and a better understanding of the underlying genetic control could be pivotal in accelerating the genetic gain for yield and disease management. Various modern techniques such as genome-wide association study (GWAS), genomic selection (GS), fine mapping, and cloning can expedite wheat improvement and broaden our understanding of the complex wheat genome. In the first objective of this study, we evaluated the Watkins core set of 121 landrace cultivars (LCs) to identify novel sources of resistance against the tan spot, Stagonospora …


Genome-Wide Association Analysis Permits Characterization Of Stagonospora Nodorum Blotch (Snb) Resistance In Hard Winter Wheat, Rami Altameemi Jan 2021

Genome-Wide Association Analysis Permits Characterization Of Stagonospora Nodorum Blotch (Snb) Resistance In Hard Winter Wheat, Rami Altameemi

Electronic Theses and Dissertations

Stagonospora nodorum blotch (SNB) is an economically important wheat disease caused by the necrotrophic fungus Parastagonospora nodorum. SNB resistance in wheat is controlled by several quantitative trait loci (QTLs). Thus, the identifying of novel resistance/susceptibility QTLs is crucial for continuous improvement of the SNB resistance. Here, the hard winter wheat association mapping panel (HWWAMP) comprising accessions from breeding programs in the Great Plains region of the US, was evaluated for SNB resistance and necrotrophic effectors (NEs) sensitivity at the seedling stage. A genome-wide association study (GWAS) was performed to identify singlenucleotide polymorphism (SNP) markers associated with SNB resistance and …


Genome Wide Association Study On Kernel Size In Avena Sativa (Oats), Koryne Ann Carlson Jan 2021

Genome Wide Association Study On Kernel Size In Avena Sativa (Oats), Koryne Ann Carlson

Electronic Theses and Dissertations

Kernel size is a vital milling characteristic for Avena sativa L. (oats), with larger kernel size being desirable for milling facilities. This project evaluated the effect of genotype, environment, and their genotype by environment interaction (G by E) on kernel width, length, and area for a set of 27 oat cultivars grown at multiple locations in South Dakota over three years. Findings indicated significant differences among oat varieties, and that environment had a substantial effect on kernel size. However, we did not see a strong influence of genotype by environment interaction on kernel size. The lack of impact for genotype …


Influence Of Cover Crops On Water And Nutrient Cycles In South Dakota, Sam Ireland Jan 2021

Influence Of Cover Crops On Water And Nutrient Cycles In South Dakota, Sam Ireland

Electronic Theses and Dissertations

A major concern of farmers implementing cover crops into a crop rotation is a potential reduction in soil moisture and nutrients available for the following cash crop. If soil moisture or nutrients are limited, the following cash crop yield suffers. One option to conserve soil moisture is to terminate cover crops with herbicides prior to a killing freeze. The purpose of this study is to develop a better understanding of the impact of cover crops and termination timing to the water and nutrient cycles and furthermore, the agronomic impact to the following cash crop (corn). Field experiments were conducted in …