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Full-Text Articles in Life Sciences

Horizontal Transmission Of Helicoverpa Armigera Nucleopolyhedrovirus (Hearnpv) In Soybean Fields Infested With Helicoverpa Zea (Boddie), Joseph Lee Black Dec 2017

Horizontal Transmission Of Helicoverpa Armigera Nucleopolyhedrovirus (Hearnpv) In Soybean Fields Infested With Helicoverpa Zea (Boddie), Joseph Lee Black

Graduate Theses and Dissertations

Helicoverpa armigera Nucleopolyhedrovirus (HearNPV) is a commercially available viral biopesticide that targets Heliothines, including Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), the most damaging pest of soybean (Glycine max (L.) Merrill) in the Mid-South. Previous formulations of HearNPV have been well studied; however, no research has been published on current formulations. The first objective of this thesis was to assess the rate of horizontal transmission of HearNPV in a soybean field infested with H. zea when HearNPV was applied as a bio-insecticide, and to identify arthropods that are important obligate carriers in dissemination. HearNPV spread 200 feet in 3 fields, and was …


Distinguishing Isolates Of Rotylenchulus Reniformis Endemic In Louisiana On The Basis Of Root-Associated Females And Egg Masses, Benjamin Mcinnes Nov 2017

Distinguishing Isolates Of Rotylenchulus Reniformis Endemic In Louisiana On The Basis Of Root-Associated Females And Egg Masses, Benjamin Mcinnes

LSU Master's Theses

The reniform nematode Rotylenchulus reniformis is a major pathogen of soybean and cotton in Louisiana. Previous studies have shown that populations of reniform nematode throughout the southern United States vary in reproduction and pathogenicity. Limited studies have been conducted to evaluate the reproduction and pathogenicity of populations of R. reniformis endemic in Louisiana. Studies with isolates of the nematode from eight cotton-producing parishes focused solely on reproduction of the root-associated infective and swollen female life stages with and without attached egg masses on the cotton genotypes MT2468 Ren3, M713 Ren5, and Stoneville 4946GLB2 and the soybean genotypes PI 548316, PI …


Characterization Of The Relationships Between Soybean Yield, Trifoliolate Leaf Chloride Concentration, And Cultivar Chloride Inclusion/Exclusion Rating, Dillon Cox Aug 2017

Characterization Of The Relationships Between Soybean Yield, Trifoliolate Leaf Chloride Concentration, And Cultivar Chloride Inclusion/Exclusion Rating, Dillon Cox

Graduate Theses and Dissertations

Chloride toxicity is recognized as yield limiting problem in soybean [Glycine max (L.) Merr.] production. Limited information is available to accurately diagnose and manage Cl toxicity. The only recommendation for Cl toxicity management is to plant an excluder cultivar, however the cultivar Cl sensitivity rating system (excluder, includer, and mixed) does not appear to capture the variability in cultivar Cl tolerance. The objectives of this research were to i) develop critical tissue-Cl concentrations in which yield loss occurs for excluder and includer cultivars and ii) investigate the variability in cultivar Cl ratings. A study was conducted across five site-years using …


Genomic And Physiological Approaches To Improve Drought Tolerance In Soybean, Avjinder Kaler Aug 2017

Genomic And Physiological Approaches To Improve Drought Tolerance In Soybean, Avjinder Kaler

Graduate Theses and Dissertations

Drought stress is a major global constraint for crop production, and improving crop tolerance to drought is of critical importance. Direct selection of drought tolerance among genotypes for yield is limited because of low heritability, polygenic control, epistasis effects, and genotype by environment interactions. Crop physiology can play a major role for improving drought tolerance through the identification of traits associated with drought tolerance that can be used as indirect selection criteria in a breeding program. Carbon isotope ratio (δ13C, associated with water use efficiency), oxygen isotope ratio (δ18O, associated with transpiration), canopy temperature (CT), canopy wilting, and canopy coverage …


Gmmyb176 Interactome And Regulation Of Isoflavonoid Biosynthesis In Soybean, Arun Kumaran Anguraj Vadivel Jun 2017

Gmmyb176 Interactome And Regulation Of Isoflavonoid Biosynthesis In Soybean, Arun Kumaran Anguraj Vadivel

Electronic Thesis and Dissertation Repository

MYB transcription factors are one of the largest transcription factor families characterized in plants. They are classified into four types: R1 MYB, R2R3 MYB, R3 MYB and R4 MYB. GmMYB176 is an R1MYB transcription factor that regulates Chalcone synthase (CHS8) gene expression and isoflavonoid biosynthesis in soybean. Silencing of GmMYB176 suppressed the expression of the GmCHS8 gene and reduced the accumulation of isoflavonoids in soybean hairy roots. However, overexpression of GmMYB176 does not alter either GmCHS8 gene expression or isoflavonoid levels suggesting that GmMYB176 alone is not sufficient for GmCHS8 gene regulation. I hypothesized that GmMYB176 acts cooperatively with another …


Effect Of The Mutant Danbaekkong Or Stem Termination Alleles On Soybean Seed Protein Concentration, Amino Acid Composition, And Other Seed Quality And Agronomic Traits, Mia Justina Cunicelli May 2017

Effect Of The Mutant Danbaekkong Or Stem Termination Alleles On Soybean Seed Protein Concentration, Amino Acid Composition, And Other Seed Quality And Agronomic Traits, Mia Justina Cunicelli

Masters Theses

Soybean [Glycine max (L.) Merr.] is the world’s leading source of vegetable oil and high quality protein meal. Increasing soybean protein concentration through selection while maintaining oil concentration and yield has been a constant goal for plant breeders, as there is a negative correlation between protein and oil and protein and yield. The objective of this study was to determine if marker assisted selection (MAS) for the Danbaekkong (Dan) protein allele influences agronomic and seed quality traits. A population of 24 F8:10 [eighth filial generation advanced to the tenth filial generation] near isogenic lines (NILs) of soybean was …


Increasing Renewable Oil Content And Utility, William Richard Serson Jan 2017

Increasing Renewable Oil Content And Utility, William Richard Serson

Theses and Dissertations--Plant and Soil Sciences

Since the dawn of agriculture man has been genetically modifying crop plants to increase yield, quality and utility. In addition to selective breeding and hybridization we can utilize mutant populations and biotechnology to have greater control over crop plant modification than ever before. Increasing the production of plant oils such as soybean oil as a renewable resource for food and fuel is valuable. Successful breeding for higher oil levels in soybean, however, usually results in reduced protein, a second valuable seed component. We show that by manipulating a highly active acyl-CoA: diacylglycerol acyltransferase (DGAT) the hydrocarbon flux to oil in …


Documentation Of Siderophore Activity, Metal Binding, And Its Effect On Symptomatology Of Cercospora Leaf Blight Caused In Soybean By Cercosporin From Cercospora Cf. Flagellaris, Brian Michael Ward Jan 2017

Documentation Of Siderophore Activity, Metal Binding, And Its Effect On Symptomatology Of Cercospora Leaf Blight Caused In Soybean By Cercosporin From Cercospora Cf. Flagellaris, Brian Michael Ward

LSU Doctoral Dissertations

Cercospora leaf blight of soybean (Glycine max) is a serious problem in the mid-south of the United States and is present in most soybean-growing regions of the world. The causal organisms, Cercospora kikuchii, C. cf. flagellaris and C. cf. sigesbeckiae, utilize the photo-activated toxin cercosporin as the primary pathogenicity factor. The disease has historically been understood to progress from a purpling or bronzing of the leaves to a blight in which tissue dies. Previous literature showed possible binding of cercosporin to metals and previous work in our group showed possible use of minor element nutrition in the plant to reduce …


Regulation Of Arf16-2 By Microrna160 During Soybean Root Nodule Development, Spencer Schreier Jan 2017

Regulation Of Arf16-2 By Microrna160 During Soybean Root Nodule Development, Spencer Schreier

Electronic Theses and Dissertations

Soybean is an excellent candidate for sustainable agriculture due to its production of nutritious, versatile beans and the ability to form symbiotic organs called root nodules that perform nitrogen fixation. As demand for both yield and sustainable agriculture continue to increase, root nodules offer an attractive alternative to expensive and environmentally harmful nitrogen fertilizers. Understanding root nodule formation may open genetic engineering avenues for optimizing nitrogen fixation performance and transferring the nodule-formation ability to other plants. A major determinant of nodule numbers and quality in soybean is microRNA 160 (miR160), which dictates developmental stage-specific auxin sensitivity by targeting repressor auxin …


The Roles Of Avr4 In Fungal Virulence,Cercosporin Biosynthesis And Its Potential Use In Host Induced Gene Silencing For Controlling Cercospora Leaf Blight Disease Of Soybeans, Josielle Santos Rezende Jan 2017

The Roles Of Avr4 In Fungal Virulence,Cercosporin Biosynthesis And Its Potential Use In Host Induced Gene Silencing For Controlling Cercospora Leaf Blight Disease Of Soybeans, Josielle Santos Rezende

LSU Doctoral Dissertations

The AVR4 effector, secreted by Cladosporium fulvum, has been demonstrated to be involved in pathogen virulence. Recent studies further demonstrated that Avr4 is highly conserved among several Cercospora species, indicating a potential important role of this gene in fungal virulence. Therefore, investigation to determine whether this fungal effector gene is present in Cercospora cf. flagellaris (previously known as C. kikuchii), the causal agent of soybean cercospora leaf blight (CLB) disease, and whether it plays any role in CLB disease development, is of great interest. In the present study, the Avr4 gene from C. cf. flagellaris was cloned and mutants lacking …


Phytophthora Sojae Infecting Soybean: Pathotype Diversity, New Sources Of Resistance And Interaction With The Soybean Cyst Nematode, Rawnaq Nazneen Chowdhury Jan 2017

Phytophthora Sojae Infecting Soybean: Pathotype Diversity, New Sources Of Resistance And Interaction With The Soybean Cyst Nematode, Rawnaq Nazneen Chowdhury

Electronic Theses and Dissertations

Phytophthora root and stem rot, caused by Phytophthora sojae Kaufmann and Gerdemann, is an important disease of soybean (Glycine max L.) in South Dakota. To gain a better understanding of the importance of P. sojae in South Dakota, specifically pathotype diversity, identification of new resistance sources and the interaction with the soybean cyst nematode (Heterodera glycines Ichinohe, SCN), this research was undertaken with the following objectives - 1) to characterize the pathotype diversity of P. sojae causing Phytophthora root and stem rot on soybean in commercial fields in South Dakota; 2) to compare inoculation methods to evaluate for …