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Articles 271 - 300 of 467

Full-Text Articles in Plant Pathology

Spatial Patterns Of Brown Rot Epidemics And Development Of Microsatellite Markers For Analyzing Fine-Scale Genetic Structure Of Monilinia Fructicola Populations Within Peach Tree Canopies, Sydney E. Everhart, A. Askew, L. Seymour, T. C. Glenn, H. Scherm Jan 2012

Spatial Patterns Of Brown Rot Epidemics And Development Of Microsatellite Markers For Analyzing Fine-Scale Genetic Structure Of Monilinia Fructicola Populations Within Peach Tree Canopies, Sydney E. Everhart, A. Askew, L. Seymour, T. C. Glenn, H. Scherm

Department of Plant Pathology: Faculty Publications

To better understand the fine-scale spatial dynamics of brown rot disease and corresponding fungal genotypes, we analyzed three-dimensional spatial patterns of pre-harvest fruit rot caused by Monilinia fructicola in individual peach tree canopies and developed microsatellite markers for canopy-level population genetics analyses. Using a magnetic digitizer, high-resolution maps of fruit rot development in five representative trees were generated, and M. fructicola was isolated from each affected fruit. To characterize disease aggregation, nearest-neighbor distances among symptomatic fruit were calculated and compared with appropriate random simulations. Within-canopy disease aggregation correlated negatively with the number of diseased fruit per tree (r = −0.827, …


Prothioconazole Tolerant Cryptococcus Flavescens Strains For Biological Control Of Fusarium Head Blight, David A. Schisler, Michael J. Boehm Jan 2012

Prothioconazole Tolerant Cryptococcus Flavescens Strains For Biological Control Of Fusarium Head Blight, David A. Schisler, Michael J. Boehm

Department of Plant Pathology: Faculty Publications

Strains of Cryptococcus flavescens which are superior antagonists of F. graminearum for suppression and control of FHB in cereals, particularly in wheat and barley, are described. The strains are prothioconazole tolerant variants of previously described C. flavescens OH 182.9 (NRRL Y-30216). Moreover, these prothioconazole tolerant variants exhibit significantly increased efficacy against F. graminearum in comparison to the parent strain OH 182.9.


Product Comparison Of Foliar Fungicide Efficacy On Diseases Of Field Corn In Nebraska, 2011, C. M. Schleicher, T. A. Jackson Jan 2012

Product Comparison Of Foliar Fungicide Efficacy On Diseases Of Field Corn In Nebraska, 2011, C. M. Schleicher, T. A. Jackson

Department of Plant Pathology: Faculty Publications

foliar fungicide efficacy trial was conducted at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, NE. Dekalb corn hybrid DKC 62-54, rating of “good” (6 out of 9) for gray leaf spot (GLS) and “excellent” (2 out of 9) for common rust (CR), was planted on 3 May in 30-in. rows with a target population of 32,000 plants/A. The trial area was disked with soybean as the previous year’s crop. On 9 May before plant emergence, a herbicide program of Roundup (1 pt/A), Verdict (16 fl oz/A) and Atrazine (1 lb/A) was applied to the trial site. …


Efficacy Evaluation Of Foliar Fungicide Application Timing On Diseases Of Field Corn In Nebraska, 2011, C. M. Schleicher, T. A. Jackson Jan 2012

Efficacy Evaluation Of Foliar Fungicide Application Timing On Diseases Of Field Corn In Nebraska, 2011, C. M. Schleicher, T. A. Jackson

Department of Plant Pathology: Faculty Publications

foliar fungicide efficacy timing trial was conducted at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, NE. Dekalb corn hybrid DKC 62-54, rating of “good” (6 out of 9) for gray leaf spot (GLS) and “excellent” (2 out of 9) for common rust (CR), was planted on 3 May in 30-in. rows with a target population of 32,000 plants/A. The trial area was disked with soybean as the previous year’s crop. On 9 May before plant emergence, a herbicide program of Roundup (1 pt/A), Verdict (16 fl oz/A) and Atrazine (1 lb/A) was applied to the trial …


Evaluation Of Foliar Fungicide Efficacy On Sorghum In Nebraska, 2011, C. M. Schleicher, T. A. Jackson-Ziems Jan 2012

Evaluation Of Foliar Fungicide Efficacy On Sorghum In Nebraska, 2011, C. M. Schleicher, T. A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

A foliar fungicide efficacy trial was conducted at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, NE. DeKalb sorghum hybrid DKS 36-06 was planted on 23 May in 30-in. rows with a target population of approximately 120,000 plants/A. The trial area was disked with soybean as the previous year’s crop. Four treatments and a nontreated control were replicated six times in a randomized complete block design. Each plot was four rows (10 ft) wide by 40 ft in length. . . . There were significant differences in GLS AUDPC among treatments. The nontreated control exhibited the largest …


Application Timing On Foliar Fungicide Efficacy On Sorghum In Nebraska, 2009, C. M. Schleicher, T. A. Jackson Jan 2012

Application Timing On Foliar Fungicide Efficacy On Sorghum In Nebraska, 2009, C. M. Schleicher, T. A. Jackson

Department of Plant Pathology: Faculty Publications

A foliar fungicide efficacy trial was established at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, NE. Grain sorghum hybrid NC+ 7R83 was planted on 18 May in 30-in. rows with a target population of 90,000 plants/A. The trial area was disked with a crop history of five years of continuous corn. Eight treatments and a non-treated control were replicated six times in a randomized complete block design. Each plot was four rows (10 ft) wide by 40 ft in length. . . . There were no significant differences in stay green. Stay green percentages ranged from …


Effects Of Crop Injury On Disease Development, Tamra A. Jackson, Loren J. Giesler, Robert M. Harveson Jan 2012

Effects Of Crop Injury On Disease Development, Tamra A. Jackson, Loren J. Giesler, Robert M. Harveson

Department of Plant Pathology: Faculty Publications

The effect of damage caused by blowing soil and leaf contact with high speed winds and hail will all create a similar level of wounding that is often sufficient for pathogens that require wounds to enter (infect) plants. As we look at the level of disease and crop damage we can identify several examples in the corn and soybean disease systems when this can be a factor that could lead to significant disease development and possibly trigger a disease management action.

Hail and wind damage can result in an open canopy which can affect the microclimate and impact disease development. …


What's New In Plant Pathology: Resistance: Mystery And Misunderstandings, Amy D. Timmerman, Loren J. Giesler, Robert M. Harveson, Tamra Jackson-Ziems, Stephen N. Wegulo Jan 2012

What's New In Plant Pathology: Resistance: Mystery And Misunderstandings, Amy D. Timmerman, Loren J. Giesler, Robert M. Harveson, Tamra Jackson-Ziems, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

One of the most common management recommendations for plant diseases is the use of resistant or tolerant varieties/hybrids in your production system. However, there is common confusion on the definition and differentiation of susceptible, tolerant, and resistant varieties/hybrids from a plant pathology viewpoint. A susceptible variety/hybrid allows the pathogen to reproduce and causes significant disease development and in turn compromises the productivity of the plant (i.e., yield). A tolerant variety/hybrid allows the pathogen to reproduce and cause disease at the same or at a slightly reduced rate as a susceptible variety/cultivar; however, there is no noticeable reduction in the plant’s …


The N-Terminal Region Of Wheat Streak Mosaic Virus Coat Protein Is A Host- And Strain-Specific Long-Distance Transport Factor, Satyanarayana Tatineni, David H. Van Winkle, Roy French Feb 2011

The N-Terminal Region Of Wheat Streak Mosaic Virus Coat Protein Is A Host- And Strain-Specific Long-Distance Transport Factor, Satyanarayana Tatineni, David H. Van Winkle, Roy French

Department of Plant Pathology: Faculty Publications

Understanding the genetics underlying host range differences among plant virus strains can provide valuable insights into viral gene functions and virus-host interactions. In this study, we examined viral determinants and mechanisms of differential infection of Zea mays inbred line SDp2 by Wheat streak mosaic virus (WSMV) isolates. WSMV isolates Sidney 81 (WSMV-S81) and Type (WSMV-T) share 98.7% polyprotein sequence identity but differentially infect SDp2: WSMV-S81 induces a systemic infection, but WSMV-T does not. Coinoculation and sequential inoculation of SDp2 with WSMV-T and/or WSMV-S81 did not affect systemic infection by WSMV-S81, suggesting that WSMV-T does not induce a restrictive defense response …


Co-Culture Of Yeast Antagonists Of Fusarium Head Blight And Their Effect On Disease Development In Wheat, D. A. Schisler, P. J. Slininger, Michael J. Boehm, P. A. Paul Jan 2011

Co-Culture Of Yeast Antagonists Of Fusarium Head Blight And Their Effect On Disease Development In Wheat, D. A. Schisler, P. J. Slininger, Michael J. Boehm, P. A. Paul

Department of Plant Pathology: Faculty Publications

Multistrain mixtures of biocontrol agents which can reduce plant disease to a greater extent than the individual strains of the mixture, commonly, are prepared by blending separately produced fermentation products. Co-cultivation of strains to equivalent biomass yields would provide mixture advantages without incurring the cost disadvantages of multiple fermentation and processing protocols. Fusariwn Head Blight (FHB) antagonists Cryptococcus flavescens OR 182.9 (NRRL Y-302l6), C. aureus OH 181.1 (NRRL Y-302l5) and C. aureus OR 181.1 (NRRL Y -30215), were grown in two- and three-strain co-cultures to assess the quality and efficacy of the fermentation end products produced. Final cell counts of …


The Gc-Rich Mitochondrial And Plastid Genomes Of The Green Alga Coccomyxa Give Insight Into The Evolution Of Organelle Dna Nucleotide Landscape, David Roy Smith, Fabien Burki, Takashi Burki, Jane Grimwood, Igor V, Grigoriev, James L. Van Etten, Patrick J. Keeling Jan 2011

The Gc-Rich Mitochondrial And Plastid Genomes Of The Green Alga Coccomyxa Give Insight Into The Evolution Of Organelle Dna Nucleotide Landscape, David Roy Smith, Fabien Burki, Takashi Burki, Jane Grimwood, Igor V, Grigoriev, James L. Van Etten, Patrick J. Keeling

Department of Plant Pathology: Faculty Publications

Most of the available mitochondrial and plastid genome sequences are biased towards adenine and thymine (AT) over guanine and cytosine (GC). Examples of GC-rich organelle DNAs are limited to a small but eclectic list of species, including certain green algae. Here, to gain insight in the evolution of organelle nucleotide landscape, we present the GC-rich mitochondrial and plastid DNAs from the trebouxiophyte green alga Coccomyxa sp. C-169. We compare these sequences with other GC-rich organelle DNAs and argue that the forces biasing them towards G and C are nonadaptive and linked to the metabolic and/or life history features of this …


Efficient And Stable Expression Of Gfp Through Wheat Streak Mosaic Virus-Based Vectors In Cereal Hosts Using A Range Of Cleavage Sites: Formation Of Dense Fluorescent Aggregates For Sensitive Virus Tracking, Satyanarayana Tatineni, Anthony J. Mcmechan, Gary L. Hein, Roy French Jan 2011

Efficient And Stable Expression Of Gfp Through Wheat Streak Mosaic Virus-Based Vectors In Cereal Hosts Using A Range Of Cleavage Sites: Formation Of Dense Fluorescent Aggregates For Sensitive Virus Tracking, Satyanarayana Tatineni, Anthony J. Mcmechan, Gary L. Hein, Roy French

Department of Plant Pathology: Faculty Publications

A series of Wheat streak mosaic virus (WSMV)-based expression vectors were developed by engineering a cycle 3 GFP (GFP) cistron between P1 and HC-Pro cistrons with several catalytic/cleavage peptides at the Cterminus of GFP. WSMV-GFP vectors with the Foot-and-mouth disease virus 1D/2A or 2A catalytic peptides cleaved GFP from HC-Pro but expressed GFP inefficiently. WSMV-GFP vectors with homologous NIa-Pro heptapeptide cleavage sites did not release GFP from HC-Pro, but efficiently expressed GFP as dense fluorescent aggregates. However, insertion of one or two spacer amino acids on either side of NIb/CP heptapeptide cleavage site or deletion in HC-Pro cistron improved processing …


Another Really, Really Big Virus, James L. Van Etten Jan 2011

Another Really, Really Big Virus, James L. Van Etten

Department of Plant Pathology: Faculty Publications

Viruses with genomes larger than 300 kb and up to 1.2 Mb, which encode hundreds of proteins, are being discovered and characterized with increasing frequency. Most, but not all, of these large viruses (often referred to as giruses) infect protists that live in aqueous environments. Bioinformatic analyses of metagenomes of aqueous samples indicate that large DNA viruses are quite common in nature and await discovery. One issue that is perhaps not appreciated by the virology community is that large viruses, even those classified in the same family, can differ significantly in morphology, lifestyle, and gene complement. This brief commentary, which …


Motus, Morphology, And Biodiversity Estimation: A Case Study Using Nematodes Of The Suborder Criconematina And A Conserved 18s Dna Barcode, Thomas O. Powers, Timothy Harris, Rebecca Higgins, Peter Mullin, Lisa Sutton, Kirsten Powers Jan 2011

Motus, Morphology, And Biodiversity Estimation: A Case Study Using Nematodes Of The Suborder Criconematina And A Conserved 18s Dna Barcode, Thomas O. Powers, Timothy Harris, Rebecca Higgins, Peter Mullin, Lisa Sutton, Kirsten Powers

Department of Plant Pathology: Faculty Publications

DNA barcodes are increasingly used to provide an estimate of biodiversity for small, cryptic organisms like nematodes. Nucleotide sequences generated by the barcoding process are often grouped, based on similarity, into molecular operational taxonomic units (MOTUs). In order to get a better understanding of the taxonomic resolution of a 3’ 592-bp 18S rDNA barcode, we have analyzed 100 MOTUs generated from 214 specimens in the nematode suborder Criconematina. Previous research has demonstrated that the primer set for this barcode reliably amplifies all nematodes in the Phylum Nematoda. Included among the Criconematina specimens were 25 morphologically described species representing 12 genera. …


Presence Of Fusarium Spp. In Air And Soil Associated With Sorghum Fields, Deanna L. Funnell-Harris, Jeffrey F. Pedersen Jan 2011

Presence Of Fusarium Spp. In Air And Soil Associated With Sorghum Fields, Deanna L. Funnell-Harris, Jeffrey F. Pedersen

Department of Plant Pathology: Faculty Publications

Sorghum grain, valuable for feed, food, and bioenergy, can be colonized by several Fusarium spp.; therefore, it was of interest to identify possible sources of conidia. Analysis of air and soil samples provided evidence for the presence of propagules from Fusarium genotypes that may cause grain infections. Soil population estimates of members of the Gibberella fujikuroi species complex, that includes sorghum pathogens and other Fusarium spp., suggested that adequate inoculum for systemic infections was present. Conidia in air samples within two sorghum fields were collected by passive trapping for 2 years. Subsampled Fusarium isolates indicated that numbers of G. fujikuroi …


First Report Of Goss's Bacterial Wilt And Leaf Blight (Clavibacter Michiganensis Subsp. Nebraskensis) Of Corn In Texas, K. A. Korus, A. D. Timmerman, R. D. French-Monar, T. A. Jackson Jan 2011

First Report Of Goss's Bacterial Wilt And Leaf Blight (Clavibacter Michiganensis Subsp. Nebraskensis) Of Corn In Texas, K. A. Korus, A. D. Timmerman, R. D. French-Monar, T. A. Jackson

Department of Plant Pathology: Faculty Publications

In September 2009, the University of Nebraska–Lincoln Plant and Pest Diagnostic Clinic received leaf samples of hybrid corn (Zea mays L.) displaying long, necrotic lesions with wavy margins. The lesions had discontinuous water-soaked spots that are indicative of Goss's bacterial wilt and leaf blight. The symptomatic leaves were submitted from Dallam County, located in the Texas Panhandle (northwest Texas). According to the USDA Farm Service Agency and the National Agricultural Statistics Service, in 2009 Dallam County had 54,025 ha planted to corn. This is approximately 19% of the total corn planted in the 26 counties in the Texas Panhandle …


Effects Of Integrating Cultivar Resistance And Fungicide Application On Fusarium Head Blight And Deoxynivalenol In Winter Wheat, Stephen N. Wegulo, William W. Bockus, John Hernandez Nopsa, Erick D. De Wolf, Kent M. Eskridge, Kamaranga H. S. Peiris, Floyd E. Dowell Jan 2011

Effects Of Integrating Cultivar Resistance And Fungicide Application On Fusarium Head Blight And Deoxynivalenol In Winter Wheat, Stephen N. Wegulo, William W. Bockus, John Hernandez Nopsa, Erick D. De Wolf, Kent M. Eskridge, Kamaranga H. S. Peiris, Floyd E. Dowell

Department of Plant Pathology: Faculty Publications

Fusarium head blight (FHB) or scab, incited by Fusarium graminearum, can cause significant economic losses in small grain production. Five field experiments were conducted from 2007 to 2009 to determine the effects on FHB and the associated mycotoxin deoxynivalenol (DON) of integrating winter wheat cultivar resistance and fungicide application. Other variables measured were yield and the percentage of Fusarium-damaged kernels (FDK). The fungicides prothioconazole + tebuconazole (formulated as Prosaro 421 SC) were applied at the rate of 0.475 liters/ha, or not applied, to three cultivars (experiments 1 to 3) or six cultivars (experiments 4 and 5) differing in their …


Characterization Of Three-Dimensional Spatial Aggregation And Association Patterns Of Brown Rot Symptoms Within Intensively Mapped Sour Cherry Trees, Sydney E. Everhart, Ashley Askew, Lynne Seymour, Imre J. Holb, Harald Scherm Jan 2011

Characterization Of Three-Dimensional Spatial Aggregation And Association Patterns Of Brown Rot Symptoms Within Intensively Mapped Sour Cherry Trees, Sydney E. Everhart, Ashley Askew, Lynne Seymour, Imre J. Holb, Harald Scherm

Department of Plant Pathology: Faculty Publications

Characterization of spatial patterns of plant disease can provide insights into important epidemiological processes such as sources of inoculum, mechanisms of dissemination, and reproductive strategies of the pathogen population. While two-dimensional patterns of disease (among plants within fields) have been studied extensively, there is limited information on three-dimensional patterns within individual plant canopies. Reported here are the detailed mapping of different symptom types of brown rot (caused by Monilinia laxa) in individual sour cherry tree (Prunus cerasus) canopies, and the application of spatial statistics to the resulting data points to de-termine patterns of symptom aggregation and association. …


Control Of Glucosylceramide Production And Morphogenesis By The Bar1 Ceramide Synthase In Fusarium Graminearum, William B. Rittenour, Ming Chen, Edgar B. Cahoon, Steven D. Harris Jan 2011

Control Of Glucosylceramide Production And Morphogenesis By The Bar1 Ceramide Synthase In Fusarium Graminearum, William B. Rittenour, Ming Chen, Edgar B. Cahoon, Steven D. Harris

Department of Plant Pathology: Faculty Publications

The contribution of plasma membrane proteins to the virulence of plant pathogenic fungi is poorly understood. Accordingly, the objective of this study was to characterize the acyl-CoA dependent ceramide synthase Bar1 (previously implicated in plasma membrane organization) in the wheat pathogen Fusarium graminearum. The role of Bar1 in mediating cell membrane organization was confirmed as DBAR1 mutants failed to display a distinct sterol-rich domain at the hyphal tip. The DBAR1 mutants were non-pathogenic when inoculated onto wheat heads, and their in vitro growth also was severely perturbed. DBAR1 mutants were incapable of producing perithecia (sexual fruiting structures) and only produced …


The Sugar Sensor, Trehalose-6-Phosphate Synthase (Tps1), Regulates Primary And Secondary Metabolism During Infection By The Rice Blast Fungus: Will Magnaporthe Oryzae’S “Sweet Tooth” Become Its “Achilles’ Heel”?, Jesse Fernandez, Richard Wilson Jan 2011

The Sugar Sensor, Trehalose-6-Phosphate Synthase (Tps1), Regulates Primary And Secondary Metabolism During Infection By The Rice Blast Fungus: Will Magnaporthe Oryzae’S “Sweet Tooth” Become Its “Achilles’ Heel”?, Jesse Fernandez, Richard Wilson

Department of Plant Pathology: Faculty Publications

Rice blast disease is considered one of the most serious diseases of cultivated rice and is mediated by the causal agent, Magnaporthe oryzae. During infection, dome-shaped fungal cells, called appressoria, form on the surface of the leaf and generate turgor through the accumulation of glycerol. This enormous pressure is directed down onto a thin penetration hypha emerging from the base of the cell, forcing it through the surface of the rice leaf and allowing fungal colonization of the plant interior. The non-reducing disaccharide, trehalose, is present in conidia of M. oryzae and is mobilized during appressorium formation. The first …


Mechanisms Of Contact-Mediated Killing Of Yeast Cells On Dry Metallic Copper Surfaces, Davide Quaranta, Travis Krans, Christophe Espirito Santo, Christian Elowsky, Dylan W. Domaille, Christopher J. Chang, Gregor Grass Jan 2011

Mechanisms Of Contact-Mediated Killing Of Yeast Cells On Dry Metallic Copper Surfaces, Davide Quaranta, Travis Krans, Christophe Espirito Santo, Christian Elowsky, Dylan W. Domaille, Christopher J. Chang, Gregor Grass

Department of Plant Pathology: Faculty Publications

Surfaces made of copper or its alloys have strong antimicrobial properties against a wide variety of microorganisms. However, the molecular mode of action responsible for the antimicrobial efficacy of metallic copper is not known. Here, we show that dry copper surfaces inactivate Candida albicans and Saccharomyces cerevisiae within minutes in a process called contact-mediated killing. Cellular copper ion homeostasis systems influenced the kinetics of contact-mediated killing in both organisms. Deregulated copper ion uptake through a hyperactive S. cerevisiae Ctr1p (ScCtr1p) copper uptake transporter in Saccharomyces resulted in faster inactivation of mutant cells than of wild-type cells. Similarly, lack of the …


Regalia-Induced Resistance In Powdery Mildew-Infected Grapevine Plants Correlates With The Induction Of Chalcone Synthase, Thomas Crottogini Dec 2010

Regalia-Induced Resistance In Powdery Mildew-Infected Grapevine Plants Correlates With The Induction Of Chalcone Synthase, Thomas Crottogini

Horticulture and Crop Science

No abstract provided.


Increased Plant Uptake Of Nitrogen From 15N-Depleted Fertilizer Using Plant Growth-Promoting Rhizobacteria, A. O. Adesemoye, H. A. Torbert, J. W. Kloepper Sep 2010

Increased Plant Uptake Of Nitrogen From 15N-Depleted Fertilizer Using Plant Growth-Promoting Rhizobacteria, A. O. Adesemoye, H. A. Torbert, J. W. Kloepper

Department of Plant Pathology: Faculty Publications

Harmful environmental effects resulting from fertilizer use have spurred research into integrated nutrient management strategies which can include the use of specific microorganisms to enhance nutrient use efficiency by plants. Some strains of plant growth-promoting rhizobacteria (PGPR) have been reported to enhance nutrient uptake by plants, but no studies with PGPR have used 15N isotope techniques to prove that the increased N in plant tissues came from the N applied as fertilizer. The current study was conducted to demonstrate that a model PGPR system can enhance plant uptake of fertilizer N applied to the soil using different rates of …


Unique Functionality Of 22 Nt Mirnas In Triggering Rdr6-Dependent Sirna Biogenesis From Target Transcripts In Arabidopsis, Josh T. Cuperus, Alberto Carbonell, Noah Fahlgren, Hernan Garcia-Ruiz, Russell T. Burke, Atsushi Takeda, Christopher M. Sullivan, Sunny D. Gilbert, Taiowa A. Montgomery, James C. Carrington Aug 2010

Unique Functionality Of 22 Nt Mirnas In Triggering Rdr6-Dependent Sirna Biogenesis From Target Transcripts In Arabidopsis, Josh T. Cuperus, Alberto Carbonell, Noah Fahlgren, Hernan Garcia-Ruiz, Russell T. Burke, Atsushi Takeda, Christopher M. Sullivan, Sunny D. Gilbert, Taiowa A. Montgomery, James C. Carrington

Department of Plant Pathology: Faculty Publications

RNA interference pathways may involve amplification of secondary siRNAs by RNA-dependent RNA polymerases. In plants, RDR6-dependent secondary siRNAs arise from transcripts targeted by some microRNA (miRNA). Here, Arabidopsis thaliana secondary siRNA from mRNA, and trans-acting siRNA, are shown to be triggered through initial targeting by 22 nt miRNA that associate with AGO1. In contrast to canonical 21 nt miRNA, 22 nt miRNA primarily arise from foldback precursors containing asymmetric bulges. Using artificial miRNA constructs, conversion of asymmetric foldbacks to symmetric foldbacks resulted in production of 21 nt forms of miR173, miR472 and miR828. Both 21 and 22 nt forms associated …


Heterokaryotic Nuclear Conditions And A Heterogeneous Nuclear Population Are Observed By Flow Cytometry In Phytophthora Infestans, Mursel Catal, Louis King, Pavani Tumbalam, Prissana Wiriyajitsomboon, William W. Kirk, Gerard C. Adams Aug 2010

Heterokaryotic Nuclear Conditions And A Heterogeneous Nuclear Population Are Observed By Flow Cytometry In Phytophthora Infestans, Mursel Catal, Louis King, Pavani Tumbalam, Prissana Wiriyajitsomboon, William W. Kirk, Gerard C. Adams

Department of Plant Pathology: Faculty Publications

A simple and reliable method for preparation of whole nuclei of a common oomycete, Phytophthora infestans, is described for laser flow cytometry. The ease of preparation, the absence of detectable debris and aggregates, and the precision in determinations of DNA content per nucleus improve interpretation and understanding of the genetics of the organism. Phytophthora infestans is the pathogen that causes potato and tomato late blight. The genetic flexibility of P. infestans and other oomycete pathogens has complicated understanding of the mechanisms of variation contributing to shifts in race structure and virulence profiles on important agricultural crops. Significant phenotypic and …


Alteration In Lignin Biosynthesis Restricts Growth Of Fusarium Spp. In Brown Midrib Sorghum, Deanna L. Funnell-Harris, Jeffrey F. Pedersen, Scott E. Sattler Jul 2010

Alteration In Lignin Biosynthesis Restricts Growth Of Fusarium Spp. In Brown Midrib Sorghum, Deanna L. Funnell-Harris, Jeffrey F. Pedersen, Scott E. Sattler

Department of Plant Pathology: Faculty Publications

To improve sorghum for bioenergy and forage uses, brown midrib (bmr)6 and -12 near-isogenic genotypes were developed in different sorghum backgrounds. The bmr6 and bmr12 grain had significantly reduced colonization by members of the Gibberella fujikuroi species complex compared with the wild type, as detected on two semiselective media. Fusarium spp. were identified using sequence analysis of a portion of the translation elongation factor (TEF) 1-α gene. The pathogens Fusarium thapsinum, F. proliferatum, and F. verticillioides, G. fujikuroi members, were commonly recovered. Other frequently isolated Fusarium spp. likely colonize sorghum asymptomatically. The χ2 analyses showed that the …


Overall Growth Of Tomato (Lycopersicon Esculentum L. Cv. Glacier) Inoculated With Species Of Glomus And Trichoderma Growing Under Greenhouse Conditions, Brian J. Adkins Jun 2010

Overall Growth Of Tomato (Lycopersicon Esculentum L. Cv. Glacier) Inoculated With Species Of Glomus And Trichoderma Growing Under Greenhouse Conditions, Brian J. Adkins

Horticulture and Crop Science

The overall plant growth of tomato (Lycopersicon esculentum L. cv. Glacier) cultivated in greenhouse conditions along with inoculation treatments of beneficial fungi species were observed. This study included 2 brand name products containing species of fungi which include: 1)Botanicare Guardian TR containing Trichoderma harzianum 10,000,000 CFU/g, T. hamatum 10,000,000 CFU/g, T. koningii 10,000,000 CFU/g; and 2)Botanicare Guardian MY containing Glomus intraradices 57 propagules/g;G. fasiculatum 57 propagules/g; G. etunicatum 57 propagules/g; G. clarum 57 propagules/g. Treatments include: Treatments: 1) 2g Botanicare Guardian TR; 2) 2g Botanicare Guardian MY; 3) 1g Botanicare Guardian TR + 1g Botanicare Guardian MY; and …


Vittatidera Zeaphila (Nematoda: Heteroderidae), A New Genus And Species Of Cyst Nematode Parasitic On Corn (Zea Mays), Ernest C. Bernard, Zafar A. Handoo, Thomas O. Powers, Patricia A. Donald, Robert D. Heinz Jun 2010

Vittatidera Zeaphila (Nematoda: Heteroderidae), A New Genus And Species Of Cyst Nematode Parasitic On Corn (Zea Mays), Ernest C. Bernard, Zafar A. Handoo, Thomas O. Powers, Patricia A. Donald, Robert D. Heinz

Department of Plant Pathology: Faculty Publications

A new genus and species of cyst nematode, Vittatidera zeaphila, is described from Tennessee. The new genus is superficially similar to Cactodera but is distinguished from other cyst-forming taxa in having a persistent lateral field in females and cysts, persistent vulval lips covering a circumfenestrate vulva, and subventral gland nuclei of the female contained in a separate small lobe. Infective juveniles (J2) are distinguished from all previously described Cactodera spp. by the short stylet in the second-stage juvenile (14-17 mm); J2 of Cactodera spp. have stylets at least 18 mm long. The new species also is unusual in that …


Wheat Cultivar-Specific Disease Synergism And Alteration Of Virus Accumulation During Co-Infection With Wheat Streak Mosaic Virus And Triticum Mosaic Virus, Satyanarayana Tatineni, Robert A. Graybosch, Gary L. Hein, Stephen N. Wegulo, Roy French Mar 2010

Wheat Cultivar-Specific Disease Synergism And Alteration Of Virus Accumulation During Co-Infection With Wheat Streak Mosaic Virus And Triticum Mosaic Virus, Satyanarayana Tatineni, Robert A. Graybosch, Gary L. Hein, Stephen N. Wegulo, Roy French

Department of Plant Pathology: Faculty Publications

Triticum mosaic virus (TriMV), the type member of the newly proposed Poacevirus genus, and Wheat streak mosaic virus (WSMV), the type member of Tritimovirus genus of the family Potyviridae, infect wheat naturally in the Great Plains and are transmitted by wheat curl mites. In this study, we examined the ability of these viruses to infect selected cereal hosts, and found several differential hosts between TriMV and WSMV. Additionally, we examined the interaction between WSMV and TriMV in three wheat cultivars at two temperature regimens (19 and 20 to 26°C), and quantified the virus concentration in single and double infections …


Crop Updates 2010 - Farming Systems, Christopher R. Newman, Jonathan England, Stephen Gherardi, Mohammad Amjad, David Ferris, Phil Ward, Roger Lawes, Tim Wiley, Perry Dolling, Philip Barrett-Lennard, John Kirkegaard, Susan Sprague, Hugh Dove, Walter Kelman, Peter Hamblin, Brad Nutt, Angelo Loi, Wayne Parker, Glen Riethmuller, Ken Flowers, Neil Cordingley, Shane Micin, Senthold Asseng, Peter Mcintosh, Mike Pook, James Risbey, Guomin Wang, Oscar Alves, Ian Foster, Imma Farre, Nirav Khimashia, W. Anderson, D. Beard, J. Blake, R. Grieve, M. Lang, J. Lemon, R. Mctaggart, D. Gray, M. Price, D. Stephens, P. Carmody, Doug Abrecht, Greg Kirk, Peter Rowe, Comeron Weeks, Peter Tozer, Derk Bakker, Frank D'Emden, Quenten Knight, Luke Marquis, Roger Mandel Feb 2010

Crop Updates 2010 - Farming Systems, Christopher R. Newman, Jonathan England, Stephen Gherardi, Mohammad Amjad, David Ferris, Phil Ward, Roger Lawes, Tim Wiley, Perry Dolling, Philip Barrett-Lennard, John Kirkegaard, Susan Sprague, Hugh Dove, Walter Kelman, Peter Hamblin, Brad Nutt, Angelo Loi, Wayne Parker, Glen Riethmuller, Ken Flowers, Neil Cordingley, Shane Micin, Senthold Asseng, Peter Mcintosh, Mike Pook, James Risbey, Guomin Wang, Oscar Alves, Ian Foster, Imma Farre, Nirav Khimashia, W. Anderson, D. Beard, J. Blake, R. Grieve, M. Lang, J. Lemon, R. Mctaggart, D. Gray, M. Price, D. Stephens, P. Carmody, Doug Abrecht, Greg Kirk, Peter Rowe, Comeron Weeks, Peter Tozer, Derk Bakker, Frank D'Emden, Quenten Knight, Luke Marquis, Roger Mandel

Crop Updates

This session covers twenty papers from different authors:

Pests and Disease

1. Preserving phosphine for use in Grain Storage Industry, Christopher R Newman, Department of Agriculture and Food

Farming Systems Research

2. Demonstrating the benefits of grazing canola in Western Australia, Jonathan England, Stephen Gherardi and Mohammad Amjad, Department of Agriculture and Food

3. Buloke barley yield when pasture-cropped across subtropical perennial pastures, David Ferris, Department of Agriculture and Food, Phil Ward and Roger Lawes, CSIRO

4. Is pasture cropping viable in WA? Grower perceptions and EverCrop initiatives to evaluate, David Ferris, Tim Wiley, Perry Dolling …