Plant Pathology Commons^™

A Coordinated Effort To Manage Soybean Rust In North America: A Success Story In Soybean Disease Monitoring, E. J. Sikora, T. W. Allen, K. A. Wise, G. Bergstrom, C. A. Bradley, J. Bond, D. Brown-Rytlewski, M. Chilvers, J. Damicone, E. Dewolf, Ohio State University Dorrance, N. Dufault, P. Esker, T. R. Faske, L. Giesler, N. Goldberg, J. Golod, I. R. G. Gomez, C. Grau, A. Grybauskas, G. Franc, R. Hammerschmidt, G. L. Hartman, R. A. Henn, D. Hershman, C. Hollier, T. Isakeit, S. Isard, B. Jacobsen, D. Jardine, R. Kemerait, S. Koenning, M. Langham, D. Malvick, S. Markell, J. J. Marois, S. Monfort, D. S. Mueller, J. Mueller, R. Mulrooney, M. Newman, L. Osborne, G. B. Padgett, B. E. Ruden, J. Rupe, R. Schneider, H. Schwartz, G. Shaner, S. Singh, E. Stromberg, L. Sweets, A. Tenuta, S. Vaiciunas, X. B. Yang, H. Young-Kelly, J. Zidek

Department of Plant Pathology: Faculty Publications

Existing crop monitoring programs determine the incidence and distribution of plant diseases and pathogens and assess the damage caused within a crop production region. These programs have traditionally used observed or predicted disease and pathogen data and environmental information to prescribe management practices that minimize crop loss (3,69). Monitoring programs are especially important for crops with broad geographic distribution or for diseases that can cause rapid and great economic losses. Successful monitoring programs have been developed for several plant diseases, including downy mildew of cucurbits, Fusarium head blight of wheat, potato late blight, and rusts of cereal crops (13,36,51,80).

Expression Of Chlorovirus Mt325 Aquaglyceroporin (Aqpv1) In Tobacco And Its Role In Mitigating Drought Stress, Saadia Bihmidine, Mingxia Cao, Ming Kang, Tala Awada, James L. Van Etten, David Dunigan, Thomas E. Clemente

James Van Etten Publications

Main conclusions A Chlorovirus aquaglyceroporin expressed in tobacco is localized to the plastid and plasma membranes. Transgenic events display improved response to water deficit. Necrosis in adult stage plants is observed.

Aquaglyceroporins are a subclass of the water channel aquaporin proteins (AQPs) that transport glycerol along with other small molecules transcellular in addition to water. In the studies communicated herein, we analyzed the expression of the aquaglyceroporin gene designated, aqpv1, from Chlorovirus MT325, in tobacco (Nicotiana tabacum), along with phenotypic changes induced by aqpv1 expression in planta. Interestingly, aqpv1 expression under control of either a constitutive or …

Coordinated And Distinct Functions Of Velvet Proteins In Fusarium Verticillioides, Nan Lan, Hanxing Zhang, Chengcheng Hu, Wenzhao Wang, Ana M. Calvo, Steven D. Harris, She Chen, Shaojie Li

Department of Plant Pathology: Faculty Publications

Velvet-domain-containing proteins are broadly distributed within the fungal kingdom. In the corn pathogen Fusarium verticillioides, previous studies showed that the velvet protein F. verticillioides VE1 (FvVE1) is critical for morphological development, colony hydrophobicity, toxin production, and pathogenicity. In this study, tandem affinity purification of FvVE1 revealed that FvVE1 can form a complex with the velvet proteins F. verticillioides VelB (FvVelB) and FvVelC. Phenotypic characterization of gene knockout mutants showed that, as in the case of FvVE1, FvVelB regulated conidial size, hyphal hydrophobicity, fumonisin production, and oxidant resistance, while FvVelC was dispensable for these biological processes. Comparative transcriptional analysis of …

Pattern And Rate Of Decline Of A Population Of Carolina Hemlock (Tsuga Caroliniana Engelm.) In North Carolina, Foster Levy, Elaine S. Walker

ETSU Faculty Works

We monitored a population of Carolina Hemlocks in northwestern North Carolina for four years to examine the rate and pattern of decline in response to infestation by Adelges tsugae (Hemlock Woolly Adelgid). Our yearly census of hemlock condition and severity of the adelgid infestation included trees of all sizes. We estimated declines in condition as the portions of the leaf canopy that were lost. Initially, infestation occurred throughout the population but was severe in only a small cluster of individuals. Within 1 year, the area of severe infestation increased in size to encompass 48% of the population. In another region …

Management Of Root Knot Nematode (Meloidogyne Incognita ) In Indiana Soybeans, David Edgardo Perla Martinez

Open Access Theses

The aim of this project was to evaluate different strategies for management of Root Knot Nematode (RKN) on soybean and tomato in Indiana. Seed treatments were evaluated under field and greenhouse conditions, but no effect on RKN populations was observed. Soybean lines evaluated for resistance to RKN under greenhouse conditions showed that six lines may be resistant to RKN. Four different commercial mustard cover crops were evaluated for their bio-fumigant impact on RKN populations in the production of tomato. Euruca sativa, Cv. Nemat was a poor host of RKN. A positive impact on the vigor of the tomato plants followed …

Potential Susceptibility Of Canna Flaccida And Two Canna Hybrids To Five Species Of Phytophthora, Kristin Van Kampen

All Theses

The costs and need for clean water are increasing for greenhouse, nursery, and agricultural businesses. Runoff from irrigated agriculture and specialty crops also can take a toll on the surrounding environment, because irrigation runoff water can contain high amounts of nutrients, contaminants, and plant pathogens. To assuage the pollution contributed to runoff water and reduce the overall volume of water used, nurseries are starting to reuse irrigation runoff water. For this to be possible, the water first should be treated before reuse. Constructed wetlands are a biological treatment option that employs vegetation to collect, filter, and store runoff water. Some …

Surface-Soil Properties Of Alder Balds With Respect To Grassy And Rhododendron Balds On Roan Mountain, North Carolina—Tennessee, James T. Donaldson, Zachary C. Dinkins, Foster Levy, Arpita Nandi

ETSU Faculty Works

We analyzed soils in Alder Bald, Grassy Bald, and Rhododendron Bald communities on Roan Mountain to infer the influence of vegetation on soil and to help guide management strategies. In all vegetation types, soils were acid (pH = 4–5) sandy loams. We found vegetation-associated differences for organic content, cation exchange capacity, acidity, two plant macronutrients (K, Mg), and three cations (Fe, Na, Zn). We predicted that nitrogen compounds would be highest in the Alder Bald because Alnus viridis ssp. crispa (Green Alder) can harbor nitrogen-fixing bacteria. Organic content was highest at the alder-bald sites, ammonium was similar among vegetation types, …

Biology And Control Of Rice False Smut Caused By Ustilaginoidea Virens (Teleomorph Villosiclava Virens), Andrew Clayton Jecmen

Graduate Theses and Dissertations

Rice false smut (FS), a disease caused by Ustilaginoidea virens (Cke.) Takahashi (1896), was first reported in northeastern Arkansas counties in 1997. The first objective of this research was to establish a collection of U. virens isolates from geographically diverse regions of Arkansas. Three U. virens isolates and chlamydospores from `Templeton' and `Clearfield-151' rice cultivars were used to determine the effects of temperature and pH on mycelial growth and germination. A nested-PCR protocol and histological methods were used to determine if U. virens infects and colonizes rice seedlings and spikelets on panicles. The sensitivity of three U. virens isolates was …

Relationship Between 1,3-Dichloropropene And Nitrogen Fertility In Cotton In The Presence Of Root-Knot And Reniform Nematodes, Amanda Michelle Greer

Graduate Theses and Dissertations

The use of soil fumigation for nematode management in cotton (Gossypium hirsutum) has become increasingly popular in recent years in the absence of effective resistant cultivars. While soil fumigation is relatively expensive, lint yields have consistently been improved to make this practice profitable in fields with severe nematode pressure. Growers in southern Arkansas have observed changes in cotton growth patterns when severely infested fields are fumigated. The most noticeable change has been excessive (rank) growth resulting in an increased need for growth regulators, especially where the nitrogen fertilization exceeds standard recommendations. Field studies were conducted between 2007 and 2010 to …

Population Dynamics Of Triticum Mosaic Virus In Various Host Species, Melissa S. Bartels

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

It has been established that RNA viruses should be genetically diverse, due to the high error rate of their RNA-dependent RNA polymerases and the lack of proof-reading capabilities. Plant RNA viruses are not as genetically diverse as expected. Evolutionary factors, such as purifying selection and bottlenecks that favor genetic stability, might be affecting plant viral populations. Otherwise RNA virus populations, with their potential for extreme diversity, might acquire a lethal number of mutations leading to the collapse of the population.

Triticum mosaic virus (TriMV) populations maintained in a controlled greenhouse environment displayed genetic stability. The mutation frequency per nucleotide of …

Impact Of Early Infestation Of Two-Spotted Spider Mites (Tetranychus Urticae) On Cotton Growth And Yield, Luis Orellana Jimenez

Graduate Theses and Dissertations

Two-spotted spider mites (Tetranychus urticae Koch, 1836) are pests of vegetables, ornamentals, and row crops around the world. Two-spotted spider mites have become an important long-season pests of cotton, causing injury to cotton from an early vegetative stage. In the past eight years, Arkansas cotton acreage treated for spider mites has more than doubled and most of the increase has been attributed to early season infestations. Yield losses of up to 30% have been observed in other studies where spider mite infestation started at third true leaf. Because of the apparent change in this pest's population dynamics, particularly at …

Fungicide Resistance In Botrytis Cinerea From Strawberry - Molecular Mechanisms And Management, Anja Grabke

All Theses

The United States is the largest producer of strawberries worldwide, generating approximately $2.4 billion worth of fruit each year. Strawberry production, however, is often threatened by pathogens. One of the most destructive fungal pathogens is Botrytis cinerea, the causal agent of gray mold disease. The control of gray mold in commercial fields is largely dependent on the application of fungicides, including the dicarboximide iprodione and the hydroxyanilide fenhexamid. Because both fungicides are prone to resistance development, a survey was conducted to determine the occurrence and prevalence of fungicide resistance. Single-spore isolates were collected from strawberry fields in Florida (for …

Efficacy Of Rice Insecticide Seed Treatments At Selected Nitrogen Rates For Control Of The Rice Water Weevil, Lissorhoptrus Oryzophilus Kuschel, Mallory Elise Everett

Graduate Theses and Dissertations

Seed-applied insecticides are the standard control method used to prevent rice water weevil (Lissorhoptrus oryzophilus Kuschel) injury to rice (Oryza sativa L.) roots, and often results in greater yields than rice that receives no seed-applied insecticide. Yield increases from seed-applied insecticides often occur even when insect pressure is low and should not cause yield loss. The research objective was to evaluate the effect of urea-nitrogen rate and seed-applied insecticide on number of rice water weevil larvae, nitrogen uptake and rice grain yield. Six trials were conducted at the Pine Tree Research Station (PTRS) and the Rice Research Extension Center (RREC) …

Noncanonical Role For The Host Vps4 Aaa+ Atpase Escrt Protein In The Formation Of Tomato Bushy Stunt Virus Replicase, Daniel Barajas, Isabel Fernández De Castro Martín, Judit Pogany, Cristina Risco, Peter D. Nagy

Plant Pathology Faculty Publications

Assembling of the membrane-bound viral replicase complexes (VRCs) consisting of viral- and host-encoded proteins is a key step during the replication of positive-stranded RNA viruses in the infected cells. Previous genome-wide screens with Tomato bushy stunt tombusvirus (TBSV) in a yeast model host have revealed the involvement of eleven cellular ESCRT (endosomal sorting complexes required for transport) proteins in viral replication. The ESCRT proteins are involved in endosomal sorting of cellular membrane proteins by forming multiprotein complexes, deforming membranes away from the cytosol and, ultimately, pinching off vesicles into the lumen of the endosomes. In this paper, we show an …

The Expanding Functions Of Cellular Helicases: The Tombusvirus Rna Replication Enhancer Co-Opts The Plant Eif4aiii-Like Atrh2 And The Ddx5-Like Atrh5 Dead-Box Rna Helicases To Promote Viral Asymmetric Rna Replication, Nikolay Kovalev, Peter D. Nagy

Plant Pathology Faculty Publications

Replication of plus-strand RNA viruses depends on recruited host factors that aid several critical steps during replication. Several of the co-opted host factors bind to the viral RNA, which plays multiple roles, including mRNA function, as an assembly platform for the viral replicase (VRC), template for RNA synthesis, and encapsidation during infection. It is likely that remodeling of the viral RNAs and RNA-protein complexes during the switch from one step to another requires RNA helicases. In this paper, we have discovered a second group of cellular RNA helicases, including the eIF4AIII-like yeast Fal1p and the DDX5-like Dbp3p and the orthologous …

Characterization Of Microorganisms From Alfalfa Seeds Inoculants, Benedicte Diatta, Kalianna Kennoy, Silvia Rossbach

Research and Creative Activities Poster Day

Atmospheric nitrogen fixation can be accomplished by free living microorganisms or by symbiosis between legume plants and rhizobia. The symbiosis between the alfalfa plant and Sinorhizobium meliloti is one example of the symbiotic relationship between legume plants and rhizobia. During the symbiosis, the rhizobia fix nitrogen for the plant and the plant in return provides carbohydrates for the bacteria. In order to maximize the plant’s yield in agriculture, recent technologies used include seed inoculants. Seed inoculation methods rely on coating the seeds with plant-growth promoting bacteria. Besides nitrogen-fixing bacteria, the seeds may also be coated with microorganisms aiding in mineral …

Application And Timing Effects Of Qoi And Dmi Fungicides And A Foliar Fertilizer On Overall Plant Health And Grain Yield In Corn, Jason Phillip Geis

Open Access Theses

The use of fungicides on corn has recently increased as a result of higher grain market prices, changes in cropping practices, higher disease incidence and severity, and the availability and marketing claims of new fungicides. Some of the marketed potential "plant health(TM)" benefits include improved tolerance to drought and heat, improved N utilization, and increased stalk strength. Previous studies have displayed delayed canopy senescence, changes in water use efficiency, and reduced ozone damage in controlled environments. Foliar fertilization has also increased in popularity in recent years due to an increase in grain prices, manufacturer claims, and product availability.

Large-scale field …

Investigation Of Macrophomina Phaseolina On Soybeans From A Regional Perspective, Zachary Forbes Sexton

Open Access Theses

The fungal pathogen, Macrophomina phaseolina, causes the disease charcoal rot (CR), which greatly impacts soybean production. Host resistance to CR is the primary means of managing this disease, yet resistance in commercial soybean cultivars in Maturity Groups (MG) I-III is currently unknown. Thirty (30) and sixty-seven (67) entries to the 2012 Wisconsin (MG I-II) and Indiana (MG II-III) Soybean Variety Trials, respectively, were evaluated for resistance to CR using a cut-stem assay. Disease was characterized as an area under the disease progress curve (AUDPC) based on lesion development and resistance assessed in relation to the resistant check (DT97-4290). In each …

Effects Of Wheat Grain Moisture: Quality, Germination, And Relationship To Accumulated Growing Degree Days, Kirsten Thomas

Open Access Theses

Bread wheat (Triticum aestivum L.) is a cereal crop of global importance. As global demand increases, it is essential to increase the quality and efficiency of crop production. Harvesting wheat early provides an opportunity for increased grain quality, and it may also allow the grower to double-crop soybean ( Glycine max L.) after wheat more effectively. Our objectives were to determine if harvesting grain early, at high moisture would, 1) increase milling and baking quality and 2) improve germination potential. As a result of these objectives, we will develop a model to predict dry-down of wheat. Five soft red …

Quality Changes In Hermetically Stored Corn Caused By Fungi And Sitophilus Zeamais, Nda-Agyima Addae-Mensah K

Open Access Theses

Hermetic storage has been shown to be effective in controlling insect pests and maintaining grain quality of dry grains at 13% moisture and below. However, the feasibility and use of hermetic storage for grains at intermediate mid-moisture levels under the influence of the sub-Saharan African weather conditions is relatively unknown. Hermetic storage experiments were conducted on grade 1 "6297 and 6333 VT RIB" hybrid corn under controlled temperature conditions at 10 degrees centigrade and 25 degrees centigrade at target approximate moisture content levels of 11, 15, 18 and 21% wet basis for a total storage period of 6 months. Corn …

Characterization Of Glomerella Strains Recovered From Anthracnose Lesions On Common Bean Plants In Brazil, Quélen L. Barcelos, Joyce M.A. Pinto, Lisa J. Vaillancourt, Elaine A. Souza

Plant Pathology Faculty Publications

Anthracnose caused by Colletotrichum lindemuthianum is an important disease of common bean, resulting in major economic losses worldwide. Genetic diversity of the C. lindemuthianum population contributes to its ability to adapt rapidly to new sources of host resistance. The origin of this diversity is unknown, but sexual recombination, via the Glomerella teleomorph, is one possibility. This study tested the hypothesis that Glomerella strains that are frequently recovered from bean anthracnose lesions represent the teleomorph of C. lindemuthianum. A large collection of Glomerella isolates could be separated into two groups based on phylogenetic analysis, morphology, and pathogenicity to beans. Both …

Proceedings Of The 41st Annual Meeting, Southern Soybean Disease Workers (March 5-6, 2014, Pensacola Beach, Florida), Edward Sikora, Clayton A. Hollier, Craig Rothrock, Myra Purvis, Danise Beadle, Stephen R. Koenning

Southern Soybean Disease Workers: Conference Proceedings

Contents

Schedule

Southern United Station Soybean Disease Loss Estimates for 2013. Compiled by SR Koenning

Graduate student paper competition (Ed Sikora, moderator)

Association of Phomopsis longicolla and Macrophomina phaseolina with zone lines in soybean roots at maturity. ML Zaccaron, JC Rupe, and RT Holland

Molecular Phylogenetic Redefinition of Cercospora kikuchii. S Albu, P Price, V Doyle, and R Schneider

The effects of salinity on Pythium rot of soybean. TJ Stetina, CS Rothrock, and JC Rupe

Distribution of Cercospora sojina and sensitivity to Qol fungicides in Mississippi soybean fields. J Standish, M Tomaso-Peterson, TW Allen, S Sabanadzovic, N Aboughanem-Sabanadzovic

Effect …

First Report Of The Root-Knot Nematode Meloidogyne Enterolobii Parasitizing Watermelon From Veracruz, Mexico, A. Ramírez-Suárez, L. Rosas-Hernández, S. Alcasio-Rangel, Guillermo Pérez Valenzuela, T. O. Powers

Department of Plant Pathology: Faculty Publications

In early April 2012, a sampling of watermelon crop Citrullus lanatus (Thunb.) Matsum & Nakai, 1916 cv. Sunsugar took place as part of the National System of Epidemiological Phytosanitary Surveillance (SINAVEF-MEX). This sampling was conducted at Riachuelos locality, Tecolutla, Veracruz, located at the geographic coordinates: 20.42008° N and 96.9627° W, within 50 meters of the Gulf of Mexico. Plants showed yellowing, stunting, and high levels of infection expressed by extensive galling on the roots. These symptoms were reproduced in the greenhouse on watermelon cv. Sunsugar. Egg masses were extracted to obtain juveniles (J2). Female necks and perineal patterns were mounted …

The Pythium Suppressive Ability Of Glomus Intraradices In Cherry Tomato Propagation, Stanley Graham

Biological Sciences

No abstract provided.

Inactivation Of The Host Lipin Gene Accelerates Rna Virus Replication Through Viral Exploitation Of The Expanded Endoplasmic Reticulum Membrane, Chingkai Chuang, Daniel Barajas, Jun Qin, Peter D. Nagy

Plant Pathology Faculty Publications

RNA viruses take advantage of cellular resources, such as membranes and lipids, to assemble viral replicase complexes (VRCs) that drive viral replication. The host lipins (phosphatidate phosphatases) are particularly interesting because these proteins play key roles in cellular decisions about membrane biogenesis versus lipid storage. Therefore, we examined the relationship between host lipins and tombusviruses, based on yeast model host. We show that deletion of PAH1 (phosphatidic acid phosphohydrolase), which is the single yeast homolog of the lipin gene family of phosphatidate phosphatases, whose inactivation is responsible for proliferation and expansion of the endoplasmic reticulum (ER) membrane, facilitates robust RNA …

No 1 2013 Eggplant Variety Trial, Rebecca Brown

University of Rhode Island Vegetable Production Research Reports

Descriptions of eggplant varieties trialed at the Gardiner Crop Research Farm of URI, Kingston, RI

No3 2013 Melon Variety Trial, Rebecca Brown

University of Rhode Island Vegetable Production Research Reports

Descriptions of melon varieties, including disease ratings, trialed at the Gardiner Crop Research Farm of URI, Kingston, RI

The C-Terminus Of Wheat Streak Mosaic Virus Coat Protein Is Involved In Differential Infection Of Wheat And Maize Through Host-Specific Long-Distance Transport, Satyanarayana Tatineni, Roy French

Department of Plant Pathology: Faculty Publications

Viral determinants and mechanisms involved in extension of host range of monocot-infecting viruses are poorly understood. Viral coat proteins (CP) serve many functions in almost every aspect of the virus life cycle. The role of the Cterminal region of Wheat streak mosaic virus (WSMV) CP in virus biology was examined by mutating six negatively charged aspartic acid residues at positions 216, 289, 290, 326, 333, and 334. All of these amino acid residues are dispensable for virion assembly, and aspartic acid residues at positions 216, 333, and 334 are expendable for normal infection of wheat and maize. However, mutants D …

Unprecedented Heterogeneity In The Synonymous Substitution Rate Within A Plant Genome, Andan Zhu, Wenhu Guo, Kanika Jain, Jeffrey P. Mower

Center for Plant Science Innovation: Faculty Publications

The synonymous substitution rate varies widely among species, but it is generally quite stable within a genome due to the absence of strong selective pressures. In plants, plastid genes tend to evolve faster than mitochondrial genes, rate variation among species generally correlates between the mitochondrial and plastid genomes, and few examples of intragenomic rate heterogeneity exist. To study the extent of substitution rate variation between and within plant organellar genomes, we sequenced the complete mitochondrial and plastid genomes from the bugleweed, Ajuga reptans, which was previously shown to exhibit rate heterogeneity for several mitochondrial genes. Substitution rates were accelerated specifically …

Evaluation Of Constitutive Iron Reductase (Atfro2) Expression On Mineral Accumulation And Distribution In Soybean (Glycine Max. L), Marta W. Vasconcelos, Thomas E. Clemente, Michael A. Grusak

Center for Plant Science Innovation: Faculty Publications

Iron is an important micronutrient in human and plant nutrition. Adequate iron nutrition during crop production is central for assuring appropriate iron concentrations in the harvestable organs, for human food or animal feed. The whole-plant movement of iron involves several processes, including the reduction of ferric to ferrous iron at several locations throughout the plant, prior to transmembrane trafficking of ferrous iron. In this study, soybean plants that constitutively expressed the AtFRO2 iron reductase gene were analyzed for leaf iron reductase activity, as well as the effect of this transgene's expression on root, leaf, pod wall, and seed mineral concentrations. …