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Evaluation Of The Microbial Quality Of Cantaloupe Fruit Produced On Raised Or Flat Beds Following A Flooding Event, Isaack Kikway

LSU Master's Theses

Floodwater can contain microbial contaminants such as plant and foodborne pathogens and can compromise the quality of fresh fruit and vegetables produced in Louisiana. The goal of this research was to determine the impact of flooding on microbial quality (foodborne and plant pathogens) of cantaloupe fruit produced on raised or flat beds. Cantaloupe fruit produced on 30 cm raised beds or flat ground, were flooded with a mixture of surface and well water spiked with three generic Escherichia coli strains (ATCC 23716, 25922, 11775). Mean baseline generic Escherichia coli and total coliform populations in flood water (mixture of spiked well …

Nealley's Sprangletop (Leptochloa Nealleyi Vasey) Management And Interference In Rice Production, Eric Allen Bergeron

LSU Master's Theses

A glasshouse study was conducted on the Louisiana State University campus in Baton Rouge to evaluate herbicide activity on Nealley's sprangletop. Herbicides were applied to Nealley’s sprangletop plants in the one-two tiller stage with height of 20-30 cm. Nealley's sprangletop control, leaf number, height, tiller number, and fresh weight biomass were evaluated. Nealley's sprangletop treated with glyphosate, quizalofop, fenoxaprop, and clethodim was controlled 89 to 99%. A field study was conducted at the LSU AgCenter Rice Research Station (RRS) and a grower location (GL) to evaluate herbicide rates and timings for control of Nealley's sprangletop in drill-seeded rice. Herbicide treatments …

Quizalofop-P-Ethyl Herbicide Interactions In Accase-Resistant Rice Production, Samer Y. Rustom Jr.

LSU Master's Theses

A field study was conducted in 2015 and 2016 at the H. Rouse Caffey Rice Research Station (RRS) to evaluate mixture interactions of quizalofop and ALS-inhibiting herbicides. Quizalofop was applied at 120 g ai ha-1. Mixture herbicides included penoxsulam at 40 g ha-1, penoxsulam plus triclopyr at 352 g ha-1, halosulfuron at 53 g ha-1, bispyribac at 34 g ha-1, orthosulfamuron plus halosulfuron at 94 g ha-1, orthosulfamuron plus quinclorac at 491 g ha-1, imazosulfuron at 211 g ha-1, and bensulfuron at 43 g ha-1. All ALS herbicides mixed with quizalofop indicated antagonistic responses for weedy rice or barnyardgrass control …

Comparison Of Two Near-Isogenic Lines Of Bell Pepper (Capsicum Annuum): One Endornavirus-Infected And The Other Endornavirus-Free, Cesar Escalante Guardado

LSU Master's Theses

Bell pepper (Capsicum annuum) is an economically important food crop cultivated worldwide. So far, all tested commercial cultivars have been shown to be infected with Bell pepper endornavirus (BPEV). Although BPEV does not cause apparent disease, the effect of this virus on bell pepper has not been investigated. A comparative study that included plant phenotype and some physiological characteristics was conducted with two near-isogenic lines (NIL) of the bell pepper cv. Marengo: one infected with BPEV and the other BPEV-free. The interaction of BPEV with a disease-causing virus of pepper, Pepper mild mottle virus (PMMoV), was also investigated. Differences in …

Chapter 16 - Birds, Janice M. Glime

Bryophyte Ecology Volume 2: Bryological Interaction

Explore the contents of Bryophyte Ecology, Volume 2, Chapter 16 - Birds by clicking the links above. For the Contents section of this ebook, as well as Volumes 1 through 5, please visit the Bryophyte Ecology Main Page.

Ebook sponsored by Michigan Technological University and the International Association of Bryologists.

Chapter 12 - Terrestrial Insects, Janice M. Glime

Bryophyte Ecology Volume 2: Bryological Interaction

Bryophyte Ecology, Volume 2, Chapter 12 - Terrestrial Insects is coming soon. For the Contents section of this ebook, as well as Volumes 1 through 5, please visit the Bryophyte Ecology Main Page.

Ebook sponsored by Michigan Technological University and the International Association of Bryologists.

Estimating Yield Gaps At The Cropping System Level, Nicolas Guilpart, Patricio Grassini, Victor O. Sadras, Jagadish Timsina, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

Yield gap analyses of individual crops have been used to estimate opportunities for increasing crop production at local to global scales, thus providing information crucial to food security. However, increases in crop production can also be achieved by improving cropping system yield through modification of spatial and temporal arrangement of individual crops. In this paper we define the cropping system yield potential as the output from the combination of crops that gives the highest energy yield per unit of land and time, and the cropping system yield gap as the difference between actual energy yield of an existing cropping system …

Modeling Pollen-Mediated Gene Flow From Glyphosate-Resistant To -Susceptible Giant Ragweed (Ambrosia Trifida L.) Under Field Conditions, Zahoor A. Ganie, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

A field experiment was conducted to quantify pollen mediated gene flow (PMGF) from glyphosateresistant (GR) to glyphosate-susceptible (GS) giant ragweed under simulated field conditions using glyphosate resistance as a selective marker. Field experiments were conducted in a concentric design with the GR giant ragweed pollen source planted in the center and GS giant ragweed pollen receptors surrounding the center in eight directional blocks at specified distances (between 0.1 and 35 m in cardinal and ordinal directions; and additional 50 m for ordinal directions). Seeds of GS giant ragweed were harvested from the pollen receptor blocks and a total of 100,938 …

Gene Silencing Of Argonaute5 Negatively Affects The Establishment Of The Legume-Rhizobia Symbiosis, Maria Del Rocio Reyero-Saavedra, Zhenzhen Qiao, Maria Del Socorro Sanchez-Correa, M. Enrique Diaz-Pineda, Jose L. Reyes, Alejandra A. Covarrubias, Marc Libault, Oswaldo Valdes-Lopez

Department of Agronomy and Horticulture: Faculty Publications

The establishment of the symbiosis between legumes and nitrogen-fixing rhizobia is finely regulated at the transcriptional, posttranscriptional and posttranslational levels. Argonaute5 (AGO5), a protein involved in RNA silencing, can bind both viral RNAs and microRNAs to control plant-microbe interactions and plant physiology. For instance, AGO5 regulates the systemic resistance of Arabidopsis against Potato Virus X as well as the pigmentation of soybean (Glycine max) seeds. Here, we show that AGO5 is also playing a central role in legume nodulation based on its preferential expression in common bean (Phaseolus vulgaris) and soybean roots and nodules. We also …

Activity Of Benzobicyclon Herbicide In Common Louisiana Rice Production Practices, Benjamin M. Mcknight

LSU Doctoral Dissertations

A study was conducted at the LSU AgCenter H. Rouse Caffey Rice Research Station (RRS) to evaluate benzobicyclon herbicide application timing on water-seeded rice. Benzobicyclon was applied at seven different timings, at 246 g ai ha-1 in a water-seeded rice production system. Benzobicyclon controlled ducksalad above 90% when applied into the pinpoint flood. Barnyardgrass control was greater than 90% from applications made on pegging rice and immediately following pinpoint flood establishment. At 49 days after treatment (DAT), yellow nutsedge control exceeded 90% following benzobicyclon treatment with a pegging rice or pinpoint flood timing. Ducksalad control was greater than 90% following …

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 …

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 …

Characterization Of Small Rna Populations In Non-Transgenic Andaflatoxin-Reducing-Transformed Peanut, Imana L. Power, Phat M. Dang, Victor S. Sobolev, Valerie Orner, Joseph L. Powell, Marshall C. Lamb, Renée S. Arias

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Aflatoxin contamination is a major constraint in food production worldwide. In peanut (Arachis hypogaea L.), these toxic and carcinogenic aflatoxins are mainly produced by Aspergillus flavus Link and A. parasiticus Speare. The use of RNA interference (RNAi) is a promising method to reduce or prevent the accumula-tion of aflatoxin in peanut seed. In this study, we performed high-throughput sequencing of small RNApopulations in a control line and in two transformed peanut lines that expressed an inverted repeattargeting five genes involved in the aflatoxin-biosynthesis pathway and that showed up to 100% less aflatoxin B1 than the controls. The objective was …

Systematic Studies On The Zygophyllaceae Of Saudi Arabia: New Combinationsin Tetraena Maxim., Dhafer Alzahrani, Enas Albokhari

Turkish Journal of Botany

During 2013 and 2014, fresh material of Tetraena hamiensis (Schweinf.) Beier & Thulin was collected from four different localities in Saudi Arabia. Some morphological differences, especially in leaf, flower parts, and fruit characters, were observed among individuals of this species within the same location. Principal coordinates analysis and the unweighted pair group method with arithmetic algorithm clustering test split off individuals of T. hamiensis with these morphological varieties as three clusters; one comprises individuals with characters overlapping those of T. hamiensis, one comprises individuals with characters overlapping those of T. qatarensis, and one comprises individuals with characters overlapping those of …

Pollen Viability And Meiotic Abnormalities In Brome Grasses(Bromus L., Section Ceratochloa) From Argentina, Gabriela Leofanti, Elsa Lucila Camadro

Turkish Journal of Botany

Bromus Section Ceratochloa includes temperate forage species. South American species form a morphologically very variable hexaploid complex (2n = 6x = 42), with a controversial taxonomic classification. Reproductive biology has been studied in several of them, but the number of analyzed plants has seldom been reported. Further investigations might clarify breeding relations and the adequacy of current classifications. Pollen viability and size, which can provide evidence of spontaneous hybridization, were studied in seven accessions (six plants/accession) classified as B. catharticus var. catharticus, var. elata, and var. rupestris; B. parodii; B. bonariensis; B. lithobius; and B. coloratus. Variability was detected among …

Two New Rhodocybe Species (Sect. Rufobrunnea, Entolomataceae)From The East Black Sea Coast Of Turkey, Ertuğrul Sesli̇, Alfredo Vizzini

Turkish Journal of Botany

Two new species of Rhodocybe, R. asanii and R. asyae (Entolomataceae), are described and illustrated from the East Black Sea coast of Turkey. The new species are known from two different localities in Trabzon Province. Diagnostic morphological and molecular (nrITS and nrLSU sequences) characters between the new species and their allies are compared and discussed. Rhodocybe asanii is easily distinguished from related species by its small, reddish beige, convex to plate, or irregular, fragile pileus; adnexed to sinuate lamellae; a pruinose stipe; small basidiospores; and unique sequences. Rhodocybe asyae is recognized well by a rather small, thin, salmon pink, smooth, …

Evaluating The Utility Of Rbcl In Identifying Nigerian Speciesof The Genus Afzelia Sm. (Fabaceae; Caesalpinioideae), Aramide Oshingboye, George Nodza, Temitope Onuminya, Oluwatoyin Ogundipe

Turkish Journal of Botany

The genus Afzelia Sm. (Fabaceae) represents one of the most useful tree species in tropical Africa. These trees have huge socioeconomic and ecological importance, but are under serious threat from incessant exploitation. This has caused a decline of the species in the wild; several species are now registered as threatened and endangered in the IUCN red list. However, conserving this species for posterity has been hampered by the complexity of morphological characters that exist among Afzelia species. In our study, we evaluated the utility of rbcL as a single barcode region, exploring its performance to accurately identify Nigerian Afzelia species …

A Taxonomic Study Of The Silene Sections Behenantha And Dichotomae (Caryophyllaceae) In Turkey Based On The Micromorphology Of Their Seed And Pollen, Mehmet Kuh, Kemal Yildiz, Ersi̇n Mi̇nareci̇

Turkish Journal of Botany

The seed and pollen grain micromorphologies of 10 taxa of the Silene sections Behenantha and Dichotomae (Caryophyllaceae) were analyzed in this study. Although the seeds of the analyzed taxa were generally reniform, S. tenuiflora and S. koycegizensis from the section Behenantha were clearly distinct from other taxa, while subspecies of S. dichotoma and S. euxina in the section Dichotomae showed differences. Pollen grains are periporate and spheroidal and ornamentation is generally spinulate-microperforate in all taxa. However, ornamentation is spinulate in S. euxina and semireticulate in S. koycegizensis. While the exine structure is generally tectate, it is semitectate in S. koycegizensis. …

Responding To Soil Fungal Communities: A Look At Interactions Between Arbuscular Mycorrhizal Fungi And The Common Yellow Monkeyflower, Mariah Mcintosh

Undergraduate Theses, Professional Papers, and Capstone Artifacts

The obligate fungal mutualists arbuscular mycorrhizal fungi (AMF) colonize the roots approximately 80% of vascular plants, generally thought to provide mineral nutrition, pathogen protection, or drought resistance to plants in exchange for photosynthetic carbon. Because of the ecological and evolutionary significance of these interactions, much work has been done to understand this symbiosis at the community level. However, much remains to be understood about how AMF affect plant fitness on an individual level. In this study, we took advantage of the tractability of the emerging model species Mimulus guttatus, the common yellow monkeyflower, to identify genetic differences in how …

Treating Human Breast Cancer Cell Lines With The Use Of Plants, Shaylee Green

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

An Annotated Checklist Of The Vascular Plants Of Oklahoma, James P. Smith Jr

Botanical Studies

No abstract provided.

Invasion Dynamics Of The Exotic Liana Euonymus Fortunei (Turcz.) Hand.-Mazz. (Wintercreeper), Todd J. Rounsaville

Theses and Dissertations--Biology

Elevated atmospheric CO₂ has been implicated as a driver of increased liana abundance worldwide. Known as disturbance creators and beneficiaries, lianas possess the potential to significantly influence forest ecosystems. I investigated the early-invasion dynamics of Euonymus fortunei (wintercreeper), an evergreen liana that is invading forests in eastern North America, disrupting native plant communities and ecosystem functions.

Wintercreeper is widely cultivated as an ornamental groundcover, frequently invading natural areas via asexual stem growth. Invasion of remote natural areas is dependent upon seed transport and may occur less frequently. I examined the mechanisms of seed dormancy by conducting a ‘move-along’ experiment …

Using Exogenous Hormone Application To Suppress Axillary Shoot Development In Tobacco, W. Jesse Carmack

Theses and Dissertations--Plant and Soil Sciences

The variability in the number of basal axillary shoots (ground suckers) among all tobacco (Nicotiana tabacum L.) varieties, has increased since the hydroponic transplant production system became the standard. The larger root ball of hydroponically produced transplants compared to traditionally produced transplants potentially generates a difference in the ratio of auxin (inhibits axillary shoot formation) to cytokinin (promotes lateral branching), that induces basal axillary shoot development. Starting in 2014, studies were conducted to investigate whether the addition of synthetic auxins or cytokinins to hydroponic transplant production could prevent ground sucker formation. Different tobacco cultivars, with high or low ground sucker …

Genes Linked To Production Of Secondary Metabolites In Talaromyces Atroroseus Revealed Using Crispr-Cas9, Maria Lund Nielsen, Thomas Isbrandt, Kasper Bøwig Rasmussen, Ulf Thrane, Jakob Blæsbjerg Hoof, Thomas Ostenfeld Larsen, Uffe Hasbro Mortensen

Department of Plant Pathology: Faculty Publications

The full potential of fungal secondary metabolism has until recently been impeded by the lack of universal genetic tools for most species. However, the emergence of several CRISPR-Cas9-based genome editing systems adapted for several genera of filamentous fungi have now opened the doors for future efforts in discovery of novel natural products and elucidation and engineering of their biosynthetic pathways in fungi where no genetic tools are in place. So far, most studies have focused on demonstrating the performance of CRISPR-Cas9 in various fungal model species, and recently we presented a versatile CRISPR-Cas9 system that can be successfully applied in …

Muti Site Screening Identifies And Verifies Levels Of Resistance To White Mold In Common Bean In 2016, Robert Higgins, James R. Steadman

Department of Plant Pathology: Faculty Publications

The development of common bean cultivars with partial resistance and/ or avoidance to white mold (WM) caused by Sclerotinia sclerotiorum would benefit producers by reducing yield loss and reducing input costs for fungicides. Our main objective in this study is to identify bean germplasm supplied by bean breeders from across the USA and Belgium with levels of partial resistance to WM. Breeders sent seed of 9 bean lines for field testing and 25 bean lines for greenhouse testing with putative sources of resistance to our laboratory. The seeds were divided in equal amounts for field (400g/line) and/or greenhouse (25 seeds/ …

Wheat Streak Mosaic Virus Coat Protein Is A Host-Specific Long-Distance Transport Determinant In Oat, Satyanarayana Tatineni

Department of Plant Pathology: Faculty Publications

Viral determinants involved in systemic infection of hosts by monocot-infecting plant viruses are poorly understood. Wheat streak mosaic virus (WSMV, genus Tritimovirus, family Potyviridae) exclusively infects monocotyledonous crops such as wheat, oat, barley, maize, triticale, and rye. Previously, we reported that WSMV CP amino acids 36–84 are expendable for systemic infection of wheat, maize, barley and rye. In this study, the role of coat protein (CP) in systemic infection of oat by WSMV was examined by using a series of viable deletion mutants. WSMV bearing deletions within or encompassing all of amino acids 36–57 efficiently infected oat, indicating that …

Understanding Fungicide Resistance, Tamra A. Jackson-Ziems, Loren J. Giesler, Anthony O. Adesemoye, Robert M. Harveson, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

Fungicide resistance has developed in some diseases of row crops as well as specialty crops. This implies that fungicide applications to control such diseases may no longer be effective. Scientific studies have shown that fungicide resistance develops through natural selection of a mutant strain of a pathogen in a population that is resistant to fungicides. Resistance is very difficult to eliminate but can be delayed through appropriate management practices. The availability of inexpensive options with single mode of action products being available makes this an important issue so we do not repeat what was done in weed management.

Introduction

Frogeye …

Population Structure And Phenotypic Variation Of Sclerotinia Sclerotiorum From Dry Bean (Phaseolus Vulgaris) In The United States, Zhian N. Kamvar, Bimal Sajeewa Amaradasa, Rachana Jhala, Serena Mccoy, James R. Steadman, Sydney Everhart

Department of Plant Pathology: Faculty Publications

The ascomycete pathogen Sclerotinia sclerotiorum is a necrotrophic pathogen on over 400 known host plants, and is the causal agent of white mold on dry bean. Currently, there are no known cultivars of dry bean with complete resistance to white mold. For more than 20 years, bean breeders have been using white mold screening nurseries (wmn) with natural populations of S. sclerotiorum to screen new cultivars for resistance. It is thus important to know if the genetic diversity in populations of S. sclerotiorum within these nurseries (a) reflect the genetic diversity of the populations in the surrounding region and (b) …

Stress-Responsive Pathways And Small Rna Changes Distinguish Variable Developmental Phenotypes Caused By Msh1 Loss, Mon-Ray Shao, Sunil Kumar Kenchanmane Raju, John D. Laurie, Robersy Sanchez, Sally A. Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

Background: Proper regulation of nuclear-encoded, organelle-targeted genes is crucial for plastid and mitochondrial function. Among these genes, MutS Homolog 1 (MSH1) is notable for generating an assortment of mutant phenotypes with varying degrees of penetrance and pleiotropy. Stronger phenotypes have been connected to stress tolerance and epigenetic changes, and in Arabidopsis T-DNA mutants, two generations of homozygosity with the msh1 insertion are required before severe phenotypes begin to emerge. These observations prompted us to examine how msh1 mutants contrast according to generation and phenotype by profiling their respective transcriptomes and small RNA populations.

Results: Using RNA-seq, we analyze …

Patterns Of Gene Expression In Western Corn Rootworm (Diabrotica Virgifera Virgifera) Neonates, Challenged With Cry34ab1, Cry35ab1 And Cry34/35ab1, Based On Next-Generation Sequencing, Haichuan Wang, Seong-Il Eyun, Kanika Arora, Sek Yee Tan, Premchand Gandra, Etsuko N. Moriyama, Chitvan Khajuria, Jessica D. Jurzenski, Huarong Li, Maia Donahue, Kenneth E. Narva, Blair Siegfried

Department of Agronomy and Horticulture: Faculty Publications

With Next Generation Sequencing technologies, high-throughput RNA sequencing (RNAseq) was conducted to examine gene expression in neonates of Diabrotica virgifera virgifera (LeConte) (Western Corn Rootworm, WCR) challenged with individual proteins of the binary Bacillus thuringiensis insecticidal proteins, Cry34Ab1 and Cry35Ab1, and the combination of Cry34/Cry35Ab1, which together are active against rootworm larvae. Integrated results of three different statistical comparisons identified 114 and 1300 differentially expressed transcripts (DETs) in the Cry34Ab1 and Cry34/35Ab1 treatment, respectively, as compared to the control. No DETs were identified in the Cry35Ab1 treatment. Putative Bt binding receptors previously identified in other insect species were not identified …