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Discovering Potential Protein, Carbohydrate, And Lipid Based Food Ingredients In A Co-Culture Of Microalgae, Chelsea Tyus
Discovering Potential Protein, Carbohydrate, And Lipid Based Food Ingredients In A Co-Culture Of Microalgae, Chelsea Tyus
LSU Doctoral Dissertations
Louisiana Native Co-Culture of Microalgae (Chlorella Vulgaris L. and Cyanobacteria Leptolyngbya sp.) (CCA) was studied. CCA is a viable coculture for further investigation as a food component. This research characterized the proteins, carbohydrates, and lipids present in CCA. Algae cultivation parameters were controlled and analyzed. Treatment (Trt) 1 was CCA grown in cultures exposed to average scalar irradiance (ASI) of 1041 ± 269.18 μmol m-2 s-1 PAR and trt 2 was CCA grown in cultures exposed to ASI of 430 ± 96.03 μmol m-2 s-1 PAR. The trt (irradiance exposure) had the desired response on CCA species ratio Trt …
Persistent Rna Viruses Of Common Bean (Phaseolus Vulgaris): Distribution And Interaction With The Host And Acute Plant Viruses, Surasak Khankhum
Persistent Rna Viruses Of Common Bean (Phaseolus Vulgaris): Distribution And Interaction With The Host And Acute Plant Viruses, Surasak Khankhum
LSU Doctoral Dissertations
Common bean (Phaseolus vulgaris) is the most important legume for direct human consumption. Common bean originated and was domesticated in the Americas but now is grown worldwide. As in the case of other crops, common bean can be infected with acute and persistent plant viruses. A modified dsRNA extraction method was developed and used in this study. The method was fast, economic, versatile, and required relatively small amounts of desiccated plant tissue. The method was successfully used to extract dsRNAs from plants infected with RNA plant viruses and to investigate the occurrence of two endornaviruses, Phaseolus vulgaris endornavirus 1 (PvEV1) …
Characterization Of Xylella Fastidiosa In Rabbiteye Blueberry, Mary Helen Ferguson
Characterization Of Xylella Fastidiosa In Rabbiteye Blueberry, Mary Helen Ferguson
LSU Doctoral Dissertations
Xylella fastidiosa colonizes the xylem of a wide range of plants and causes symptoms in many of them. It was of interest to determine how widespread X. fastidiosa was and what its potential impact might be in rabbiteye blueberry. X. fastidiosa was detected from two of 17 Louisiana orchards from which samples were collected. A yield study was conducted at one of these orchards, and mean yields of X. fastidiosa-positive plants were 55% and 62% less than those of X. fastidiosa-negative plants in 2013 and 2014, respectively. Average berry weight was also lower in X. fastidiosa-positive plants. However, plants that …
Evaluation Of Ammonia Volatilization And Zinc Nutrition Of Experimental Zinc Sulfate Coated Urea Fertilizers In A Drill-Seeded Delayed Flood Rice Production System, Nutifafa Adotey
LSU Doctoral Dissertations
Approaches in controlling nitrogen (N) loss from preflood fertilizer applications in delayed flood rice (Oryza stiva) production in the mid-southern U.S.A. typically involves treating urea with urease inhibitors like N-(n-butyl) thiophosphoric triamide (NBPT). Limited research exists on managing N utilizing the combined effects of treating urea with a urease inhibitor and subsequently adding a physical zinc (Zn) sulfate coating. Zinc deficiency is also a major soil fertility constraint in flooded rice production. The objectives of this study were to: (i) determine the ammonia volatilization potential of experimental zinc sulfate coated urea (ZSCU) fertilizers on four rice soils in a controlled …
Integration Of Optical Remote Sensor-Based Yield Prediction And Impact Of Nitrogen Fertilization, Harvest Date, And Planting Scheme On Yield, Quality, And Biomass Chemical Composition In Energy Cane Production In Louisiana, Marilyn Sebial Dalen
LSU Doctoral Dissertations
The established sugarcane industry in Louisiana is perceived as an advantage for biofuel industry because of the similarities of energy cane and sugarcane by way they are cultivated, harvested, and processed. This study was conducted at the LSU AgCenter Sugar Research Station in St. Gabriel, LA from 2013-2015 to evaluate the influence of planting scheme, N rate, and harvest date on energy cane yield, quality parameters, nutrient uptake, and biomass chemical composition. The relationship of vegetation indices (VI) with stalk, fiber yield, and N uptake of energy cane harvested at different dates was also evaluated. The experiments consisted of variety …
Identification Of Genes Associated With Resistance To Brown Rust In Sugarcane And Prevalence Of One Major Gene, Mavir Carolina Avellaneda Barbosa
Identification Of Genes Associated With Resistance To Brown Rust In Sugarcane And Prevalence Of One Major Gene, Mavir Carolina Avellaneda Barbosa
LSU Doctoral Dissertations
Development of resistant cultivars is the main control measure against sugarcane brown rust caused by Puccinia melanocephala. Durability is uncertain, since the pathogen possesses adaptive ability to overcome host plant resistance. A differential gene expression study utilizing suppressive subtraction hybridization was conducted to improve understanding of brown rust resistance mechanisms in sugarcane. The expression patterns of 11 unigenes representing biosynthetic pathways, defense-related genes, and signaling genes were analyzed in L 99-233, a cultivar exhibiting quantitative resistance, L 01-299, a resistant cultivar with the major resistance gene Bru1, and two susceptible cultivars, Ho 95-988 and L 09-125, at 24 h, 48 …
Molecular Genetics Of Salinity Tolerance In Rice (Oryza Sativa L.), Teresa Bermejo De Leon
Molecular Genetics Of Salinity Tolerance In Rice (Oryza Sativa L.), Teresa Bermejo De Leon
LSU Doctoral Dissertations
Due to the threat of salinity stress to Louisiana rice production, an effort was made to understand the molecular genetics of salinity tolerance with the overall goal of developing salt tolerant varieties. The objectives of this study were to 1) determine if salinity tolerance exist in the US rice varieties, 2) map the additive and epistatic QTLs for traits related to seedling salinity tolerance in recombinant inbred lines (RILs) using genotyping-by-sequencing (GBS)-derived SNP markers, and 3) identify and validate stable QTLs and their effects in introgression lines (ILs) of Pokkali in Bengal background. All experiments for phenotypic characterization were conducted …
Development Of Functional Markers For Resistance To Leaf Scald In Sugarcane, Andres Felipe Gutierrez Viveros
Development Of Functional Markers For Resistance To Leaf Scald In Sugarcane, Andres Felipe Gutierrez Viveros
LSU Doctoral Dissertations
Leaf scald, caused by Xanthomonas albilineans, is a major sugarcane disease worldwide. The disease is managed primarily with resistant cultivars obtained through classical breeding; however, the erratic symptom expression hinders the reliability and reproducibility of the selection process. The development of molecular markers associated with incompatible/compatible reaction can overcome this limitation. Suppression subtractive hybridization (SSH) and quantitative trait locus (QTL) mapping were the strategies used to find leaf scald resistance-associated genes and molecular markers in sugarcane. SSH results showed that genes involved in signal perception and transduction, and DNA binding, were highly expressed in the resistant clone LCP 85-384 compared …
Study Of Factors Affecting Growth And Development Of Narrow Brown Leaf Spot Of Rice Caused By Cercospora Janseana (Racib.) O. Const., Kirandeep Kaur Mani
Study Of Factors Affecting Growth And Development Of Narrow Brown Leaf Spot Of Rice Caused By Cercospora Janseana (Racib.) O. Const., Kirandeep Kaur Mani
LSU Doctoral Dissertations
Studies evaluated the effects of planting date, cultivar susceptibility, fungicide application timing, nitrogen management, and tillage practices on the severity of narrow brown leaf spot of rice (NBLS) caused by Cercospora janseana. All factors evaluated affected NBLS severity. The mid-April planted rice had less NBLS as compared to mid-May, late planted rice. Propiconazole fungicide (Tilt) application at panicle initiation or early boot stage was found equally effective in terms of disease reduction in mid-April planting while panicle initiation stage was the best time to apply fungicide in the late planting (mid-May). Early onset and higher severity of NBLS was observed …
Evolutionary Relationships Among Fungal Soybean Pathogens And Molecular Marker Development In The Genus Cercospora, Sebastian Albu
Evolutionary Relationships Among Fungal Soybean Pathogens And Molecular Marker Development In The Genus Cercospora, Sebastian Albu
LSU Doctoral Dissertations
Cercospora leaf blight (CLB) and purple seed stain (PSS) are common soybean diseases in the Gulf South of the United States (USA). For nearly a century, Cercospora kikuchii has been considered as the only pathogen causing these diseases. However, previous reports of genetic diversity among isolates collected throughout Louisiana suggested the presence of multiple lineages or species. Recent systematic studies classified species of Cercospora using a taxonomic system based on phylogenetic analysis of five nuclear loci (legacy genes). Using a similar approach, cercosporoid fungi tentatively identified as C. kikuchii were evaluated along with 53 other species of Cercospora. No …
Genetics And Genomics Studies Of Rice Disease Resistance And Development Of Alternative Disease Management Methods For Bacterial Panicle Blight And Sheath Blight, Bishnu Kumar Shrestha
Genetics And Genomics Studies Of Rice Disease Resistance And Development Of Alternative Disease Management Methods For Bacterial Panicle Blight And Sheath Blight, Bishnu Kumar Shrestha
LSU Doctoral Dissertations
Bacterial panicle blight (BPB) and sheath blight (SB), caused by the bacteria Burkholderia glumae and B. gladioli, and the fungus Rhizoctonia solani, respectively, are two major rice diseases in southern rice growing regions of US. No completely resistant rice cultivars have been identified for these diseases. However, a medium-grain cultivar, Jupiter, showed partial resistance to BPB. In order to understand the mechanisms of rice resistance against BPB and SB, rice genetics and genomics studies have been conducted. Alternative methods to suppress BPB and SB were also studied. Broad-sense heritability and correlations were calculated for the traits, BPB and SB disease …
Characterization Of A Novel Negative Regulator Of Toxoflavin Production, Ntpr, In The Plant Pathogen Burkholderia Glumae That Causes Bacterial Panicle Blight Of Rice, Rebecca Ann Melanson
Characterization Of A Novel Negative Regulator Of Toxoflavin Production, Ntpr, In The Plant Pathogen Burkholderia Glumae That Causes Bacterial Panicle Blight Of Rice, Rebecca Ann Melanson
LSU Doctoral Dissertations
Burkholderia glumae is the major causal agent of bacterial panicle blight of rice, a disease that can cause significant yield losses. This bacterial pathogen produces a number of virulence factors that contribute to disease development. The phytotoxin, toxoflavin is required for full virulence and is the most important virulence factor in B. glumae. The known regulatory cascade of toxoflavin production involves the TofI-TofR quorum-sensing system, the transcriptional activators ToxJ and ToxR, and the toxoflavin biosynthesis and transport genes. Transposon mutagenesis of toxoflavin-producing B. glumae strains generated a number of mutants with increased toxoflavin production. Several of these mutants contained …
Integrated Functional Anlaysis Of Quorum-Sensing In The Rice Pathogenic Bacterium Burkholderia Glumae, Ruoxi Chen
Integrated Functional Anlaysis Of Quorum-Sensing In The Rice Pathogenic Bacterium Burkholderia Glumae, Ruoxi Chen
LSU Doctoral Dissertations
Quorum sensing (QS) is a cell-to-cell communication mechanism that allows bacterial cells to collectively behave like a multicellular organism. It regulates the expression of toxoflavin, one of the major virulence factors of the rice pathogen, Burkholderia glumae. The QS system of B. glumae is mediated by the core genes, tofI and tofR. N-octanoyl-L-homoserine lactone, the primary QS signal molecule of B. glumae, is synthesized by tofI and binds to the cognate receptor tofR at the quorum point. However, tofI and tofR null mutants produce toxoflavin in certain growth conditions, indicating the presence of tofI- and tofR-independent pathways for toxoflavin production. …
A Novel System To Study Seed Recalcitrance And Dormancy - Comparative Proteomics Between Two Spartina Species, Yi Wang
LSU Doctoral Dissertations
Spartina alterniflora is a dominant salt marsh cordgrass along the U.S. Atlantic and Gulf coasts, and the species is widely used for wetland restoration in Louisiana. S. alterniflora seeds are shed dormant from the mother plant. However, long-term preservation of S. alterniflora seeds is challenging because the seeds are recalcitrant, losing viability when dried below 45% water content. In this dissertation, I investigated the following three aspects of S. alterniflora: recalcitrance, dormancy release by cold stratification and the effect of drying temperature on the critical water content. Comparative proteomics between S. alterniflora and orthodox, desiccation tolerant Spartina pectinata seeds identified …
Sensitivity And Resistance Of Cercospora Kikuchii, Causal Agent Of Cercospora Leaf Blight And Purple Seed Stain Of Soybean, To Selected Fungicides, Paul Patrick Price, Iii
Sensitivity And Resistance Of Cercospora Kikuchii, Causal Agent Of Cercospora Leaf Blight And Purple Seed Stain Of Soybean, To Selected Fungicides, Paul Patrick Price, Iii
LSU Doctoral Dissertations
ABSTRACT Isolates of Cercospora kikuchii, the causal agent of Cercospora leaf blight (CLB) and purple seed stain (PSS), were used to determine baseline sensitivities to selected quinone outside inhibitor (QoI) and demethylation inhibitor (DMI) fungicides by conducting radial growth assays on fungicide-amended media. The effective concentration to inhibit 50% radial growth (EC50) for each isolate was calculated by linear interpolation of the dose-response relationship. All baseline distributions were non-normal with outliers towards the less sensitive ends of the spectra, and median EC50 values for azoxystrobin, pyraclostrobin, trifloxystrobin, flutriafol, propiconazole, and tetraconazole were 0.081, 0.013, 0.012, 0.273, 0.143, 1.47 µg/ml, respectively. …
A Genetic Study On The Virulence Mechanism Of Burkholderia Glumae And, Rice Resistance To Bacterial Panicle Blight And Sheath Blight, Hari Sharan Karki
A Genetic Study On The Virulence Mechanism Of Burkholderia Glumae And, Rice Resistance To Bacterial Panicle Blight And Sheath Blight, Hari Sharan Karki
LSU Doctoral Dissertations
Burkholderia glumae is a rice pathogenic bacterium that causes bacterial panicle blight. Some strains of this pathogen produce dark brown pigments when grown on the casamino-acid peptone glucose (CPG) agar medium. A pigment-positive and highly virulent strain of B. glumae, 411gr-6, was randomly mutagenized with mini-Tn5gus, and the resulting mini-Tn5gus derivatives showing altered pigmentation phenotypes were screened on CPG agar plates to identify the genetic elements governing the pigmentation of B. glumae. In this study, several positive and negative regulators, for the pigmentation of B. glumae were identified. During this study, a novel two-component regulatory system (TCRS) composed of the …
Dynamics Of The Sweetpotato Potyvirus Aphid Pathosystem In Louisiana, Everlyne Nafula Wosula
Dynamics Of The Sweetpotato Potyvirus Aphid Pathosystem In Louisiana, Everlyne Nafula Wosula
LSU Doctoral Dissertations
Sweetpotato potyviruses [Sweet potato feathery mottle virus (SPFMV), Sweet potato virus G (SPVG) and Sweet potato virus 2 (SPV2)] commonly infect sweetpotato and weedy morning glories in the USA. These viruses are transmitted in a non-persistent manner by various aphid species and cause up to 15% yield loss. Sweetpotato is vegetatively propagated, and in the USA growers are supplied with virus tested propagation material to minimize impact of viruses. However the rapid re-infection of these materials with viruses warranted further studies to determine factors that influence the epidemiology of these viruses. The objectives of this study were: (i) to determine …
Molecular Approaches To Detect And Control Cercospora Kikuchii In Soybeans, Ashok Kumar Chanda
Molecular Approaches To Detect And Control Cercospora Kikuchii In Soybeans, Ashok Kumar Chanda
LSU Doctoral Dissertations
Cercospora leaf blight (CLB) caused by Cercospora kikuchii, has become a troublesome disease in the southern United States. C. kikuchii produces a non-hostspecific phytotoxin and a pathogenicity factor known as cercosporin during infection of soybean. A quantitative real-time PCR assay was developed for detection and quantification of C. kikuchii. The sensitivity of detection is 1 pg of genomic DNA. The assay detected the presence of C. kikuchii in soybean leaves long before the appearance of disease symptoms. C. kikuchii DNA levels in soybean leaves increased slowly during early soybean development, followed by a quick increase at late reproductive stages. Results …
Simplicillium Lanosoniveum, A Mycoparasite Of Phakopsora Pachyrhizi And Its Use As A Biological Control Agent, Nicole A. Ward
Simplicillium Lanosoniveum, A Mycoparasite Of Phakopsora Pachyrhizi And Its Use As A Biological Control Agent, Nicole A. Ward
LSU Doctoral Dissertations
In 2007, a filamentous fungus was recovered from sori of soybean rust (SBR), caused by Phakopsora pachyrhizi, collected from Louisiana and Florida. This fungus was identified as Simplicillium lanosoniveum on the basis of ITS sequence data and morphological traits. Simplicillium lanosoniveum was found coiling within sori and around urediniospores and showed a trophic attraction to rust sori, extending from sorus to sorus. In co-inoculated soybean leaves, the fungus did not grow or establish on leaf surfaces until sori erupted. Similarly, S. lanosoniveum colonized within 3 days and sporulated within 4 days on leaves showing disease symptoms. In field studies, when …
Comparative Proteome And Qpcr Analysis Of The Sugarcane Reaction To Leaf Scald Caused By Xanthomonas Albilineans, Freddy Fernando Garces-Obando
Comparative Proteome And Qpcr Analysis Of The Sugarcane Reaction To Leaf Scald Caused By Xanthomonas Albilineans, Freddy Fernando Garces-Obando
LSU Doctoral Dissertations
Leaf scald is an important disease of sugarcane caused by Xanthomonas albilineans (Xa). Leaf scald is controlled by the development and planting of resistant cultivars. However, erratic symptom expression makes conventional screening for resistance difficult. In addition, the mechanisms of resistance to leaf scald are not completely understood. Real-time, quantitative polymerase-chain-reaction (qPCR) assays were developed utilizing SYBR Green for a highly sensitive detection method or a TaqMan probe to quantify Xa populations in infected plants. Xa populations detected by qPCR followed similar trends to disease severity ratings and vascular infection results for two resistant and two susceptible cultivars under greenhouse …
New Binary Ti Vectors With Co-Directional Replicons For Agrobacterium Tumefaciens-Mediated Transformation Of Higher Plants, Seokhyun Lee
New Binary Ti Vectors With Co-Directional Replicons For Agrobacterium Tumefaciens-Mediated Transformation Of Higher Plants, Seokhyun Lee
LSU Doctoral Dissertations
Small, high-yielding binary Ti vectors of Agrobacterium tumefaciens were constructed. All four basic components of the vector, ColE1 replicon (715 bp) for Escherichia coli, VS1 replicon (2,659 bp) for A. tumefaciens, a bacterial kanamycin resistance gene (999 bp), and the T-DNA region (170 bp), were modified to reduce the vector size to 4,566 bp and to introduce a number of mutations to increase the copy number and other functionality. The transcriptional direction of VS1 replicon can be the same as that of ColE1 replicon (co-directional transcription), or opposite (head-on transcription) as in the case of widely used vectors (pPZP or …
Study Of Host-Fungus Interactions Between Soybean And Phakopsora Pachyrhizi Using Proteomics, Sunjung Park
Study Of Host-Fungus Interactions Between Soybean And Phakopsora Pachyrhizi Using Proteomics, Sunjung Park
LSU Doctoral Dissertations
Asian soybean rust, caused by Phakopsora pachyrhizi, is an emerging disease in the continental U. S. and resistant commercial varieties have not been reported. In an effort to understand the interactions during rust infection of soybean, protein profile changes were examined over a 14-day period in soybean leaves of one susceptible commercial line (Pioneer 93M60) with or without soybean rust inoculation using proteomics in this study. Forty protein spots differentially expressed after rust inoculation were identified and fourteen of them were recovered and sequenced. These included proteins involved in plant defense, stress, metabolism, and other biological processes. During the time-course …
Molecular Diversity And Coat Protein Expression Of Sweet Potato Leaf Curl Virus, Dina Lida Gutierrez Reynoso
Molecular Diversity And Coat Protein Expression Of Sweet Potato Leaf Curl Virus, Dina Lida Gutierrez Reynoso
LSU Doctoral Dissertations
Leaf curl virus diseases have been reported in sweetpotato throughout the world. One of the causal agents is Sweet potato leaf curl virus (SPLCV) which belongs to the genus Begomovirus (family Geminiviridae). In the United States, SPLCV has been found infecting an ornamental sweetpotato and several breeding lines but not in sweetpotatoes grown for commercial production. SPLCV does not cause symptoms on Beauregard, the predominant sweetpotato cultivar in the US, but it can reduce its yield. Since SPLCV could become an important constraint for sweetpotato production; diagnosis, identification, and characterization are essential steps to develop an effective management program. The …
Is Oxidative Stress The Cause Of Death When Recalcitrant Spartina Alterniflora Seeds Are Dried?, James Hammond Chappell
Is Oxidative Stress The Cause Of Death When Recalcitrant Spartina Alterniflora Seeds Are Dried?, James Hammond Chappell
LSU Doctoral Dissertations
Recalcitrant seeds, which die when desiccated, can be difficult to study because of their generally large size, high metabolism, and poor storage properties. However, recalcitrant seeds from the salt-marsh grass Spartina alterniflora are unique when compared to most other recalcitrant species because the seeds are dormant and small; Spartina pectinata and S. spartinae, which produce orthodox seeds, can be used as controls. Because of these somewhat rare characteristics, S. alterniflora is a good model system to study recalcitrance. In the present study, the following physiological parameters were examined: Cardinal temperatures for germination, a viability test to determine if seeds are …
The Influence Of Morningglory (Ipomoea Lacunosa), Hemp Sesbania (Sesbania Exaltata), And Johnsongrass (Sorghum Halepense) On Reproduction Of Rotylenchulus Reniformis On Cotton Gossypium Hirsutum L. And Soybean Glycine Max. (L.) Merrill, Michael John Pontif
LSU Doctoral Dissertations
Microplot studies were conducted to evaluate the effects of cotton (LA. 887), soybean (Pioneer 96B21), and three endemic weed species, pitted morningglory (Ipomoea lacunosa), hemp sesbania (Sesbania exaltata), and johnsongrass (Sorghum halepense), on reproduction of the reniform nematode, (Rotylenchulus reniformis). Over two microplot trials the co-culture of cotton with any of the three weeds suppressed numbers of reniform nematode juveniles in soil. When grown singly, reniform nematode reproductive values after 60 days on cotton averaged 69.0, while those for morningglory, hemp sesbania, and johnsongrass averaged 42.0, 23.5, and 18.0, respectively. Reproductive values for cotton co-cultured with morningglory averaged 38.7. Those …
Assessment Of Interactions Amoung Viruses Infecting Sweetpotato, Charalambos D. Kokkinos
Assessment Of Interactions Amoung Viruses Infecting Sweetpotato, Charalambos D. Kokkinos
LSU Doctoral Dissertations
Viral diseases, especially those caused by mixed infections, are among the economically most important diseases of sweetpotato. Real-time PCR assays were developed for the detection and quantification of the potyviruses Sweet potato feathery mottle virus (SPFMV), Sweet potato virus G (SPVG), Ipomoea vein mosaic virus (IVMV); the crinivirus Sweet potato chlorotic stunt virus (SPCSV), and the begomovirus Sweet potato leaf curl virus (SPLCV) directly from infected sweetpotato plants. Titers of SPFMV, IVMV, and SPVG were lower in singly-infected sweetpotato plants compared to singly-infected plants of the standard indicator host Brazilian morning-glory (Ipomoea setosa) and the standard propagation host I. nil …
Tissue Culture And Transformation Of Introducing Genes Useful For Pest Management In Rice, Shuli Zhang
Tissue Culture And Transformation Of Introducing Genes Useful For Pest Management In Rice, Shuli Zhang
LSU Doctoral Dissertations
Sheath blight (SB), caused by Rhizoctonia solani K¨¹hn, is a major rice disease internationally and in the southern rice area of the Unites States, including Louisiana. Breeders have incorporated partial resistance into commercial rice varieties to control the disease, but a higher level of resistance is needed. It has been demonstrated that the pathogenesis-related (PR) proteins ¦Â-1, 3-glucanase and chitinase are components of effective defense mechanisms for protecting plants against fungal pathogens. This research was conducted to co-transform the ¦Â-1, 3-glucanase, chitinase and bar genes into the rice variety Taipei 309 using the hpt gene for resistance to hygromycin B …
Cercospora Leaf Blight Of Soybean: Pathogen Vegetative Compatibility Groups, Population Structure, And Host Resistance, Guohong Cai
LSU Doctoral Dissertations
Nitrogen nonutilizing mutants were used to assess vegetative compatibility of 58 isolates of Cercospora kikuchii, 55 of which were isolated from soybean plants in Louisiana. Only 16 of 56 self-compatible isolates were assigned to six multi-member vegetative compatibility groups (VCGs), 01-06, with two or three isolates in each VCG. The other 40 isolates were not vegetatively compatible with any isolates other than themselves. All six multi-member VCGs contained isolates from different soybean cultivars, and three included isolates from different locations. Only one VCG included isolates both from soybean leaves and from seeds, while two and three multi-member VCGs included isolates …
Biology And Ecology Of Leptographium Species And Their Vectos As Components Of Loblolly Pine Decline, Lori G. Eckhardt
Biology And Ecology Of Leptographium Species And Their Vectos As Components Of Loblolly Pine Decline, Lori G. Eckhardt
LSU Doctoral Dissertations
Loblolly pine (Pinus taeda L.) decline (LPD) has been present in upland sites of central Alabama since the 1960s. Symptoms of LPD (fine root deterioration, short chlorotic needles, sparse crowns, reduced radial growth) begin in the 30-40 yr age class, resulting in premature death at ages 35-50. Previously, declining loblolly was diagnosed as littleleaf disease (LLD); however, site conditions associated with LPD are different from LLD sites. Littleleaf disease only occurs on eroded, heavy clay soils and is secondarily associated with the fungus, Phytophthora cinnamomi. In contrast, LPD occurs on sandy, well-drained soils and is associated with Leptographium spp., as …
Studies On Rice Transformation And The Use Of Transformed Plants [Electronic Resource], Qiming Shao
Studies On Rice Transformation And The Use Of Transformed Plants [Electronic Resource], Qiming Shao
LSU Doctoral Dissertations
This research was conducted to enhance utilization of the Liberty herbicide resistance transgene in rice. Non-lethal methods to determine the sensitivity of transgenic rice plants to hygromycin B and Liberty were developed, tested and used in this research. Four homozygous transformed plants were selected to make reciprocal crosses with their non-transformed parent cultivars Taipei 309 and Nipponbare. Their resistances to Liberty and hygromycin B were controlled by the closely linked single dominant genes bar and hpt. Some non-resistant phenotypes in the F2 populations were due to gene silencing. The bar gene in some of these plants were allelic and some …