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Plant Pathology Commons

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University of Nebraska - Lincoln

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Articles 841 - 870 of 1125

Full-Text Articles in Plant Pathology

Selected Soybean Plant Introductions With Partial Resistance To Sclerotinia Sclerotiorum, D. D. Hoffman, B. W. Diers, G. L. Hartman, C. D. Nickell, R. L. Nelson, W. L. Pedersen, E. R. Cober, George L. Graef, J. R. Steadman, C. R. Grau, B. D. Nelson, L. E. Del Rio, T. Helms, T. Anderson, V. Poysa, University Of Guelph, W. C. Stienstra Jan 2002

Selected Soybean Plant Introductions With Partial Resistance To Sclerotinia Sclerotiorum, D. D. Hoffman, B. W. Diers, G. L. Hartman, C. D. Nickell, R. L. Nelson, W. L. Pedersen, E. R. Cober, George L. Graef, J. R. Steadman, C. R. Grau, B. D. Nelson, L. E. Del Rio, T. Helms, T. Anderson, V. Poysa, University Of Guelph, W. C. Stienstra

Department of Plant Pathology: Faculty Publications

Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, is a major soybean (Glycine max) disease in north-central regions of the United States and throughout the world. Current sources of resistance to Sclerotinia stem rot express partial resistance, and are limited in number within soybean germ plasm. A total of 6,520 maturity group (MG) 0 to IV plant introductions (PIs) were evaluated for Sclerotinia stem rot resistance in the United States and Canada in small plots or in the greenhouse from 1995 to 1997. Selected PIs with the most resistance were evaluated for resistance in the United States and …


Greenhouse And Field Evaluation Of Biological Control Of Fusarium Head Blight On Durum Wheat, D. A. Schisler, N. I. Khan, Michael J. Boehm, P. J. Slininger Jan 2002

Greenhouse And Field Evaluation Of Biological Control Of Fusarium Head Blight On Durum Wheat, D. A. Schisler, N. I. Khan, Michael J. Boehm, P. J. Slininger

Department of Plant Pathology: Faculty Publications

Fusarium head blight (FHB) is a devastating disease that causes extensive yield and quality losses to wheat and barley. In durum wheat, the pathogen-produced toxin deoxynivalenol (DON) is retained in semolina at ~50%, and the causal agent of FHB, Gibberella zeae, has a strong adverse effect on pasta color. Two bacteria and two yeast strains with known efficacy against G. zeae on hexaploid wheats were produced in liquid culture and assayed on two cultivars of durum wheat in greenhouse bioassays. All antagonists reduced FHB severity on cultivar Renville, and three of the four reduced severity on cultivar Ben, with …


Genomewide Identification Of Proteins Secreted By The Hrp Type Iii Protein Secretion System Of Pseudomonas Syringae Pv. Tomato Dc3000, Tanja Petnicki-Ocwieja, David J. Schneider, Vincent C. Tam, Scott T. Chancey, Libo Shan, Yashitola Jamir, Lisa M. Schechter, Misty Janes, C. Robin Buell, Xiaoyan Tang, Alan Collmer, James R. Alfano Jan 2002

Genomewide Identification Of Proteins Secreted By The Hrp Type Iii Protein Secretion System Of Pseudomonas Syringae Pv. Tomato Dc3000, Tanja Petnicki-Ocwieja, David J. Schneider, Vincent C. Tam, Scott T. Chancey, Libo Shan, Yashitola Jamir, Lisa M. Schechter, Misty Janes, C. Robin Buell, Xiaoyan Tang, Alan Collmer, James R. Alfano

Department of Plant Pathology: Faculty Publications

The ability of Pseudomonas syringae pv. tomato DC3000 to be pathogenic on plants depends on the Hrp (hypersensitive response and pathogenicity) type III protein secretion system and the effector proteins it translocates into plant cells. Through iterative application of experimental and computational techniques, the DC3000 effector inventory has been substantially enlarged. Five homologs of known avirulence (Avr) proteins and five effector candidates, encoded by genes with putative Hrp promoters and signatures of horizontal acquisition, were demonstrated to be secreted in culture and/or translocated into Arabidopsis in a Hrp-dependent manner. These 10 Hrp-dependent outer proteins (Hops) were designated HopPtoC (Avr- PpiC2 …


The P23 Protein Of Citrus Tristeza Virus Controls Asymmetrical Rna Accumulation, Satyanarayana Tatineni, Siddarame Gowda, Maria A. Ayllon, Maria R. Albiach-Marti, Shailaja Rabindran, William O. Dawson Jan 2002

The P23 Protein Of Citrus Tristeza Virus Controls Asymmetrical Rna Accumulation, Satyanarayana Tatineni, Siddarame Gowda, Maria A. Ayllon, Maria R. Albiach-Marti, Shailaja Rabindran, William O. Dawson

Department of Plant Pathology: Faculty Publications

Citrus tristeza virus (CTV), a member of the Closteroviridae, has a 19.3-kb positive-stranded RNA genome that is organized into 12 open reading frames (ORFs) with the 10 3' genes expressed via a nested set of nine or ten 3'-coterminal subgenomic mRNAs (sgRNAs). Relatively large amounts of negative-stranded RNAs complementary to both genomic and sgRNAs accumulate in infected cells. As is characteristic of RNA viruses, wild-type CTV produced more positive than negative strands, with the plus-to-minus ratios of genomic and sgRNAs estimated at 10 to 20:1 and 40 to 50:1, respectively. However, a mutant with all of the 3' genes …


Septum Formation In Aspergillus Nidulans, Steven D. Harris Dec 2001

Septum Formation In Aspergillus Nidulans, Steven D. Harris

Department of Plant Pathology: Faculty Publications

Filamentous fungi form multicellular hyphae that are partitioned by septa. In A. nidulans, septum formation requires the assembly of a septal band following the completion of mitosis. Recent observations show that this band is a dynamic structure composed of actin, a septin and a formin. In addition, assembly is dependent upon a conserved protein kinase cascade that regulates mitotic exit and septation in yeast. Hyphal differentiation may reflect the regulation of this cascade by cyclin-dependent kinase activity. In this review, the dynamics and regulation underlying the assembly of the septal band are discussed.


The Ns5a Protein Of Bovine Viral Diarrhoea Virus Interacts With The Α Subunit Of Translation Elongation Factor-1, Craig M. Johnson, Daniel R. Perez, Roy C. French, William C. Merrick, Ruben O. Donis Nov 2001

The Ns5a Protein Of Bovine Viral Diarrhoea Virus Interacts With The Α Subunit Of Translation Elongation Factor-1, Craig M. Johnson, Daniel R. Perez, Roy C. French, William C. Merrick, Ruben O. Donis

Department of Plant Pathology: Faculty Publications

A cellular protein that interacts with the NS5A polypeptide of bovine viral diarrhoea virus (BVDV) was identified in a yeast two-hybrid screen. The NS5A interactor was identified as the a subunit of bovine translation elongation factor 1A (eEF1A). Cell-free binding studies were performed with chimeric NS5A fused to glutathione S-transferase (GST–NS5A) expressed in bacteria. GST–NS5A bound specifically to both in vitro-translated and mammalian cell-expressed eEF1A. Moreover, purified eEF1A bound specifically to GST–NS5A attached to a solid phase. Conservation of this interaction was then analysed using a set of NS5A proteins derived from divergent BVDV strains encompassing known biotypes and genotypes. …


Structure And Temporal Dynamics Of Populations Within Wheat Streak Mosaic Virus Isolates, Jeffrey S. Hall, Roy C. French, Thomas Jack Morris, Drake C. Stenger Nov 2001

Structure And Temporal Dynamics Of Populations Within Wheat Streak Mosaic Virus Isolates, Jeffrey S. Hall, Roy C. French, Thomas Jack Morris, Drake C. Stenger

Department of Plant Pathology: Faculty Publications

Variation within the Type and Sidney 81 strains of wheat streak mosaic virus was assessed by single-strand conformation polymorphism (SSCP) analysis and confirmed by nucleotide sequencing. Limiting-dilution subisolates (LDSIs) of each strain were evaluated for polymorphism in the P1, P3, NIa, and CP cistrons. Different SSCP patterns among LDSIs of a strain were associated with single-nucleotide substitutions. Sidney 81 LDSI-S10 was used as founding inoculum to establish three lineages each in wheat, corn, and barley. The P1, HC-Pro, P3, CI, NIa, NIb, and CP cistrons of LDSI-S10 and each lineage at passages 1, 3, 6, and 9 were evaluated for …


First Report Of Columbia Root Knot Nematode (Meloidogyne Chitwoodi) In Potato In Texas, A. L. Szalanski, P. G. Mullin, T. S. Harris, T. O. Powers Apr 2001

First Report Of Columbia Root Knot Nematode (Meloidogyne Chitwoodi) In Potato In Texas, A. L. Szalanski, P. G. Mullin, T. S. Harris, T. O. Powers

Department of Plant Pathology: Faculty Publications

Columbia root-knot nematode, Meloidogyne chitwoodi Golden et al. (1) was identified from potatoes, Solanum tuberosum L., collected from Dallam County, Texas in October 2000. Seed potatoes are the most likely source for this introduction. This nematode is currently found infecting potatoes grown in California, Colorado, Idaho, New Mexico, Nevada, Oregon, Utah, and Washington. Some countries prohibit import of both seed and table stock potatoes originating in states known to harbor M. chitwoodi. Lesions on the potatoes had discrete brown coloration with white central spots in the outer 1 cm of the tuber flesh. Female nematode densities averaged 3 per square …


Contributions Of Genetic Drift And Negative Selection On The Evolution Of Three Strains Of Wheat Streak Mosaic Tritimovirus, I.-R. Choi, J.S. Hall, M. Henry, Lingyu Zhang, G. L. Hein, Roy C. French, D.C. Stenger Mar 2001

Contributions Of Genetic Drift And Negative Selection On The Evolution Of Three Strains Of Wheat Streak Mosaic Tritimovirus, I.-R. Choi, J.S. Hall, M. Henry, Lingyu Zhang, G. L. Hein, Roy C. French, D.C. Stenger

Department of Plant Pathology: Faculty Publications

Genome sequences of three Wheat streak mosaic virus (WSMV) strains were compared. The Type and Sidney 81 strains of WSMV from the American Great Plains were closely related, with sequence identities of 97.6% (nucleotide) and 98.7% (amino acid). In contrast, the El Batán 3 strain from central Mexico was divergent, and shared only 79.2–79.3% (nucleotide) and 90.3–90.5% (amino acid) sequence identity with Type and Sidney 81. All threeWSMVstrains were serologically related, however the El Batán 3 capsid protein (CP) had 15 fewer amino acid residues. Phylogenetic analysis of the CP cistron indicated that Type, Sidney 81, and nine other American …


Virulence Of Puccinia Triticina On Wheat In Nebraska During 1997 And 1998, J. E. Watkins, J. Schimelfenig, P. Stephen Baenziger, Kent M. Eskridge Feb 2001

Virulence Of Puccinia Triticina On Wheat In Nebraska During 1997 And 1998, J. E. Watkins, J. Schimelfenig, P. Stephen Baenziger, Kent M. Eskridge

Department of Plant Pathology: Faculty Publications

Urediniospore isolates of Puccinia triticina were obtained from wheat leaf collections made in three wheat-growing regions in Nebraska in 1997 and in four regions in 1998. Using 16 Thatcher lines that are near-isogenic for leaf rust resistance, 17 virulence phenotypes were found among 121 single uredinial isolates in 1997, and 42 virulence phenotypes were found among 178 isolates in 1998. The most prevalent phenotype in 1997 was MDRR (virulent on Lr1, 3, 3ka, 10, 11, 18, 23, 24, and 30). In 1998, virulence phenotypes MDRR and MDRM (virulent on Lr1, 3, 3ka, 10, 11, 23, 24, and 30 …


Use Of Flow Cytometry, Fluorescence Microscopy, And Pcr-Based Techniques To Assess Intraspecific And Interspecific Matings Of Armillaria Species, Mee-Sook Kim, Ned B. Klopfenstein, Geral I. Mcdonald, Kathiravetpillai Arumuganathan, Anne K. Vidaver Feb 2001

Use Of Flow Cytometry, Fluorescence Microscopy, And Pcr-Based Techniques To Assess Intraspecific And Interspecific Matings Of Armillaria Species, Mee-Sook Kim, Ned B. Klopfenstein, Geral I. Mcdonald, Kathiravetpillai Arumuganathan, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

For assessments of intraspecific mating using flow cytometry and fluorescence microscopy, two compatible basidiospore-derived isolates were selected from each of four parental basidiomata of North American Biological Species (NABS) X. The nuclear status in NABS X varied with basidiospore-derived isolates. Nuclei within basidiospore-derived isolates existed as haploids, diploids (doubled haploids), or a mixture of haploids and diploids (doubled haploids). Depending on the nuclear status of the basidiospore-derived lines of NABS X, intraspecifically mated cultures can exist as diploids or tetraploids, and possibly triploids or aneuploids under in vitro conditions. Based on previous in vitro mating studies, seven basidiospore isolates were …


Abrogation Of Disease Development In Plants Expressing Animal Antiapoptotic Genes, M. B. Dickman, Y. K. Park, T. Oltersdorf, W. Li, T. Clemente, Roy C. French Jan 2001

Abrogation Of Disease Development In Plants Expressing Animal Antiapoptotic Genes, M. B. Dickman, Y. K. Park, T. Oltersdorf, W. Li, T. Clemente, Roy C. French

Department of Plant Pathology: Faculty Publications

An emerging topic in plant biology is whether plants display analogous elements of mammalian programmed cell death during development and defense against pathogen attack. In many plant– pathogen interactions, plant cell death occurs in both susceptible and resistant host responses. For example, specific recognition responses in plants trigger formation of the hypersensitive response and activation of host defense mechanisms, resulting in restriction of pathogen growth and disease development. Several studies indicate that cell death during hypersensitive response involves activation of a plant-encoded pathway for cell death. Many susceptible interactions also result in host cell death, although it is not clear …


Three Distinct Mechanisms Facilitate Genetic Isolation Of Sympatric Wheat Streak Mosaic Virus Lineages, Jeffrey Hall, Roy C. French, Gary L. Hein, Thomas Jack Morris, Drake Stenger Jan 2001

Three Distinct Mechanisms Facilitate Genetic Isolation Of Sympatric Wheat Streak Mosaic Virus Lineages, Jeffrey Hall, Roy C. French, Gary L. Hein, Thomas Jack Morris, Drake Stenger

Department of Plant Pathology: Faculty Publications

Cross-protection and vector transmission bottlenecks have been proposed as mechanisms facilitating genetic isolation of sympatric viral lineages. Molecular markers were used to monitor establishment and resolution of mixed infections with genetically defined strains of wheat streak mosaic virus (WSMV). Two closely related WSMV strains from the U.S. (Type and Sidney 81) exhibited reciprocal cross-protection in wheat, confirming this classic phenomenon as a mechanism of genetic isolation. In contrast, cross-protection between either U.S. strain and the divergent El Batan 3 strain from Mexico was unilateral, erratic, and only partially effective. Distribution of WSMV strains within individual leaves of plants supporting a …


Accumulation Of Barley Stripe Mosaic Virus Is Significantly Reduced In Transgenic Wheat Plants Expressing A Bacterial Ribonuclease, Lingyu Zhang, Roy C. French, Willem G. Langenberg, Amitava Mitra Jan 2001

Accumulation Of Barley Stripe Mosaic Virus Is Significantly Reduced In Transgenic Wheat Plants Expressing A Bacterial Ribonuclease, Lingyu Zhang, Roy C. French, Willem G. Langenberg, Amitava Mitra

Department of Plant Pathology: Faculty Publications

Anrnc70 gene encoding a mutant bacterial ribonuclease III (RNase III) was introduced into wheat (Triticum aestivum cv. Bobwhite) by microprojectile bombardment. T1, T2, and T3 plants regenerated from three transgenic callus lines were challenged with barley stripe mosaic virus. Plants expressing RNase III exhibited a high level of resistance to the virus infection. This resistance was evidenced by the absence of virus symptoms and reduced accumulation of virions in these plants. The result demonstrates that this pathogen-targeted resistance strategy can be effectively employed in conferring resistance to viral diseases of cereal crops.


Chitinases From The Plant Disease Biocontrol Agent, Stenotrophomonas Maltophilia C3, Z. Zhang, Gary Yuen, Gautam Sarath, A. R. Penheiter Jan 2001

Chitinases From The Plant Disease Biocontrol Agent, Stenotrophomonas Maltophilia C3, Z. Zhang, Gary Yuen, Gautam Sarath, A. R. Penheiter

Department of Plant Pathology: Faculty Publications

Stenotrophomonas maltophilia strain C3, a biocontrol agent of Bipolaris sorokiniana in turfgrass, produced chitinases in broth media containing chitin. Chitinases were partially purified from culture fluid by ammonium sulfate precipitation and chitin affinity chromatography. The chromatography fraction with the highest specific chitinase activity was inhibitory to conidial germination and germ-tube elongation of B. sorokiniana, but it was less inhibitory than the protein fraction or the raw culture filtrate. The fraction exhibited strong exochitinase and weak endochitinase activity. Optimum temperature and pH for chitinase activity were 45 to 50°C and 4.5 to 5.0, respectively. Chitinase activity was inhibited by Hg …


Identification Of Seed Gall Nematodes Of Agronomic And Regulatory Concern With Pcr-Rflp Of Its1, Thomas O. Powers, Allen L. Szalanski, P. G. Mullin, T. S. Harris, T. Bertozzi, J. A. Griesbach Jan 2001

Identification Of Seed Gall Nematodes Of Agronomic And Regulatory Concern With Pcr-Rflp Of Its1, Thomas O. Powers, Allen L. Szalanski, P. G. Mullin, T. S. Harris, T. Bertozzi, J. A. Griesbach

Department of Plant Pathology: Faculty Publications

A molecular analysis of eight described species of seed gall nematode, along with six undescribed isolates from different hosts, has revealed a strong association between nucleotide sequence polymorphism and host status. Each anguinid nematode associated with a unique host produced a unique PCR-RFLP pattern for the ITS1 region. Anguina species that had been synonymized in the past, Anguina agrostis, A. funesta, and A. wevelli (Afrina wevelli), were readily discriminated. Two undescribed species from northern New South Wales and southeastern South Australia, reported to be vectors of Rathyaibacter toxicus in the disease called ‘‘floodplain staggers,’’ were differentiated …


Bacillus Species For Reducing Fusarium Head Blight In Cereals, David A. Schisler, Naseem I. Khan, Michael J. Boehm Jan 2001

Bacillus Species For Reducing Fusarium Head Blight In Cereals, David A. Schisler, Naseem I. Khan, Michael J. Boehm

Department of Plant Pathology: Faculty Publications

Microbial antagonists that will suppress Fusarium head blight (head scab) in cereals, particularly in wheat and barley have been identified. Two superior antagonists include NRRL B-30210 and NRRL B-30211.


Selection And Evaluation Of Microorganisms For Biocontrol Of Fusarium Head Blight Of Wheat Incited By Gibberella Zeae, N. I. Khan, D. A. Schisler, Michael J. Boehm, P. J. Slininger, R. J. Bothast Jan 2001

Selection And Evaluation Of Microorganisms For Biocontrol Of Fusarium Head Blight Of Wheat Incited By Gibberella Zeae, N. I. Khan, D. A. Schisler, Michael J. Boehm, P. J. Slininger, R. J. Bothast

Department of Plant Pathology: Faculty Publications

Gibberella zeae incites Fusarium head blight (FHB), a devastating disease that causes extensive yield and quality losses to wheat and barley. Of over 700 microbial strains obtained from wheat anthers, 54 were able to utilize tartaric acid as a carbon source when the compound was supplied as choline bitartrate in liquid culture. Four tartaric acid–utilizing and three nonutilizing strains reduced FHB in initial tests and were selected for further assays. Antagonists were effective against three different isolates of G. zeae when single wheat florets were inoculated with pathogen and antagonist inoculum. All seven antagonists increased 100-kernel weight when applied simultaneously …


Fungal Symbiosis From Mutualism To Parasitism: Who Controls The Outcome, Host Or Invader?, Regina S. Redman, David Dunigan, Rusty J. Rodriguez Jan 2001

Fungal Symbiosis From Mutualism To Parasitism: Who Controls The Outcome, Host Or Invader?, Regina S. Redman, David Dunigan, Rusty J. Rodriguez

Department of Plant Pathology: Faculty Publications

• Plant symbiotic fungi are generally thought to express a single lifestyle that might increase (mutualism), decrease (parasitism), or have no influence (commensalism) on host fitness. However, data are presented here demonstrating that plant pathogenic Colletotrichum species are able to asymptomatically colonize plants and express nonpathogenic lifestyles.

• Experiments were conducted in growth chambers and plant colonization was assessed by emergence of fungi from surface sterilized plant tissues. Expression of symbiotic lifestyles was assessed by monitoring the ability of fungi to confer disease resistance, drought tolerance and growth enhancement.

• Several pathogenic Colletotrichum species expressed either mutualistic or commensal lifestyles …


The Aspergillus Nidulans Snt Genes Are Required For The Regulation Of Septum Formation And Cell Cycle Checkpoints, Peter R. Kraus, Steven D. Harris Jan 2001

The Aspergillus Nidulans Snt Genes Are Required For The Regulation Of Septum Formation And Cell Cycle Checkpoints, Peter R. Kraus, Steven D. Harris

Department of Plant Pathology: Faculty Publications

In Aspergillus nidulans, germinating conidia undergo multiple rounds of nuclear division before forming a septum. Previous genetic results suggest that the ability to separate nuclear division and septum formation depends upon a threshold level of activity of the cyclin-dependent kinase NIMXcdk1. Mutations in nimX and nimT, the gene encoding the NIMXcdk1-activating phosphatase, have revealed that Tyr-15 phosphorylation is important for determining the timing of the formation of the first septum. Here, we describe a screen for suppressors of nimT23 (snt), designed to identify additional components of the pathway regulating septum formation. We show that a subset …


Age-Related Resistance In Bell Pepper To Cucumber Mosaic Virus , Hernan Garcia-Ruiz, John F. Murphy Jan 2001

Age-Related Resistance In Bell Pepper To Cucumber Mosaic Virus , Hernan Garcia-Ruiz, John F. Murphy

Department of Plant Pathology: Faculty Publications

We demonstrated the occurrence of mature plant resistance in Capsicum annuum 'Early Calwonder' to Cucumber mosaic virus (CMV) under greenhouse conditions. When Early Cal wonder plants were sown at 10 day intervals and transplanted to 10-cm square pots, three distinct plant sizes were identified that were designated small, medium and large. Trials conducted during each season showed that CMV accumulated in inoculated leaves of all plants of each size category. All small plants (with the exception of the winter trial) developed a systemic infection that included accumulation of CMV in uninoculated leaves and severe systemic symptoms. Medium plants had a …


Cultivar-Dependent Expression Of A Maize Lipoxygenase Responsive To Seed Infesting Fungi, Richard A. Wilson, Harold W. Gardner, Nancy P. Keller Jan 2001

Cultivar-Dependent Expression Of A Maize Lipoxygenase Responsive To Seed Infesting Fungi, Richard A. Wilson, Harold W. Gardner, Nancy P. Keller

Fungal Molecular Plant-Microbe Interactions

Maize kernels are highly susceptible to Aspergillus spp. infection and aflatoxin (AF) contamination. Fatty acid signaling molecules appear to mediate the plant–fungal interaction by affecting the growth, development, and AF production of the fungus. In particular, fatty acid derivatives of the plant lipoxygenase (LOX) pathway are implicated in the Aspergillus spp.-seed interaction. The 9(S)-hydroperoxide derivative of linoleic acid promotes transcription of AF genes, whereas the 13(S)-hydroperoxide derivative decreases AF gene expression and production; both are sporulation factors. Our goal was to identify LOX genes responsive to Aspergillus spp. colonization and determine their specificities, 9(S)- …


'Earlibrite' Strawberry, C. K. Chandler, D. E. Legard, David Dunigan, T. E. Crocker, C. A. Sims Dec 2000

'Earlibrite' Strawberry, C. K. Chandler, D. E. Legard, David Dunigan, T. E. Crocker, C. A. Sims

Department of Plant Pathology: Faculty Publications

There is a need in west central Florida and other winter strawberry (Fragaria xananassa Duchesne) production areas for an early ripening cultivar to replace or be an alternative to 'Sweetcharlie' (Chandleretal., 1997a). 'Sweet Charlie' has benefitted the Florida strawberry industry through its relatively high production of fruit early in the season, when market prices are generally high. But the average fruit size is small, and the texture of its fruit is often soft, making shipment and shelf life of 'Sweet Charlie' problematic. 'Earlibrite' strawberry has produced high early-season (December through February) yields of large, flavorful fruit at the Univ. …


‘Strawberry Festival’ Strawberry, C. K. Chandler, D. E. Legard, David Dunigan, T. E. Crocker, C. A. Sims Dec 2000

‘Strawberry Festival’ Strawberry, C. K. Chandler, D. E. Legard, David Dunigan, T. E. Crocker, C. A. Sims

Department of Plant Pathology: Faculty Publications

Most of the strawberries (Fragaria xananassa Duchesne) produced in Florida are shipped fresh to locations throughout the eastern United States and Canada (Florida Agricultural Statistics [www.nass.usda.gov/ fl]). Therefore, Florida growers need cultivars that produce fruit that are attractive and flavorful, and maintain these qualities during and after long-distance shipment. 'Strawberry Festival' strawberry has produced commercially acceptable yields of firm, attractive, and flavorful fruit in trials at the Univ. of Florida's Gulf Coast Research and Education Center in Dover (GCREC-Dover) and in two commercial fields in west central Florida. It is recommended for trial in areas where strawberries are grown …


Sequences Of Citrus Tristeza Virus Separated In Time And Space Are Essentially Identical, Maria R. Albiach-Marti, Munir Mawassi, Siddarame Gowda, Satyanarayana Tatineni, Mark E. Hilf, Savita Shanker, Ernesto C. Almira, Maria C. Vives, Carmelo Lopez, Jose Guerri, Ricardo Flores, Pedro Moreno, Steve M. Garnsey, William O. Dawson Aug 2000

Sequences Of Citrus Tristeza Virus Separated In Time And Space Are Essentially Identical, Maria R. Albiach-Marti, Munir Mawassi, Siddarame Gowda, Satyanarayana Tatineni, Mark E. Hilf, Savita Shanker, Ernesto C. Almira, Maria C. Vives, Carmelo Lopez, Jose Guerri, Ricardo Flores, Pedro Moreno, Steve M. Garnsey, William O. Dawson

Department of Plant Pathology: Faculty Publications

The first Citrus tristeza virus (CTV) genomes completely sequenced (19.3-kb positive-sense RNA), from four biologically distinct isolates, are unexpectedly divergent in nucleotide sequence (up to 60% divergence). Understanding of whether these large sequence differences resulted from recent evolution is important for the design of disease management strategies, particularly the use of genetically engineered mild (essentially symptomless)-strain cross protection and RNA-mediated transgenic resistance. The complete sequence of a mild isolate (T30) which has been endemic in Florida for about a century was found to be nearly identical to the genomic sequence of a mild isolate (T385) from Spain. Moreover, samples of …


Pseudomonas Syringae Hrp Type Iii Secretion System And Effector Proteins, Alan Collmer, Jorge L. Badel, Amy O. Charkowski, Wen-Ling Deng, Derrick E. Fouts, Adela R. Ramos, Amos H. Rehm, Deborah M. Anderson, Olaf Schneewind, Karin V. Van Dijk, James R. Alfano Aug 2000

Pseudomonas Syringae Hrp Type Iii Secretion System And Effector Proteins, Alan Collmer, Jorge L. Badel, Amy O. Charkowski, Wen-Ling Deng, Derrick E. Fouts, Adela R. Ramos, Amos H. Rehm, Deborah M. Anderson, Olaf Schneewind, Karin V. Van Dijk, James R. Alfano

Center for Plant Science Innovation: Faculty Publications

Pseudomonas syringae is a member of an important group of Gram-negative bacterial pathogens of plants and animals that depend on a type III secretion system to inject virulence effector proteins into host cells. In P. syringae, hrpyhrc genes encode the Hrp (type III secretion) system, and avirulence (avr) and Hrpdependent outer protein (hop) genes encode effector proteins. The hrpyhrc genes of P. syringae pv syringae 61, P. syringae pv syringae B728a, and P. syringae pv tomato DC3000 are flanked by an exchangeable effector locus and …


Nuclear Localization Of Turnip Crinkle Virus Movement Protein P8, Yuval Cohen, Feng Qu, Andreas Gisel, Thomas Jack Morris, Patricia Zambryski Aug 2000

Nuclear Localization Of Turnip Crinkle Virus Movement Protein P8, Yuval Cohen, Feng Qu, Andreas Gisel, Thomas Jack Morris, Patricia Zambryski

Department of Plant Pathology: Faculty Publications

Turnip crinkle virus (TCV) is a single-stranded positive-sense RNA virus of the Carmovirus genus. Two of its five open reading frames (ORFs), encoding proteins of 8 and 9 kDa, are required for cell-to-cell movement of the virus. These movement proteins (MPs) were fused to green fluorescent protein (GFP) to determine their cellular localization. In protoplasts, p9-GFP, like GFP itself, is found throughout the cytoplasm, as well as in cell nuclei. In contrast, p8-GFP was confined to the cell nucleus. Similar localization patterns were observed when specific small peptide epitopes were fused to p8 and p9 proteins instead of GFP. The …


Utility Of The Mitochondrial Cytochrome Oxidase Ii Gene For Resolving Relationships Among Black Flies (Diptera: Simuliidae), K. P. Pruess, B. J. Adams, T. J. Parsons, X. Zhu, Thomas O. Powers Aug 2000

Utility Of The Mitochondrial Cytochrome Oxidase Ii Gene For Resolving Relationships Among Black Flies (Diptera: Simuliidae), K. P. Pruess, B. J. Adams, T. J. Parsons, X. Zhu, Thomas O. Powers

Department of Plant Pathology: Faculty Publications

The complete mitochondrial cytochrome oxidase II gene was sequenced from 17 black flies, representing 13 putative species, and used to infer phylogenetic relationships. A midge (Paratanytarsus sp.) and three mosquitoes (Aedes aegypti, Anopheles quadrimaculatus, and Culex quinquefasciatus) were used as outgroup taxa. All outgroup taxa were highly divergent from black flies. Phylogenetic trees based on weighted parsimony (a priori and a posteriori), maximum likelihood, and neighbor-joining (log-determinant distances) differed topologically, with deeper nodes being the least well-supported. All analyses supported current classification into species groups but relationships among those groups were poorly resolved. The majority of phylogenetic …


A Plant Virus Vector For Systemic Expression Of Foreign Genes In Cereals, Il-Ryong Choi, Drake C. Stenger, Thomas Jack Morris, Roy C. French Aug 2000

A Plant Virus Vector For Systemic Expression Of Foreign Genes In Cereals, Il-Ryong Choi, Drake C. Stenger, Thomas Jack Morris, Roy C. French

Department of Plant Pathology: Faculty Publications

Inserts bearing the coding sequences of NPTll and P-glucuronidase (GUS) were placed between the nuclear inclusion b (Nlb) and coat protein (CP) domains of the wheat streak mosaic virus (WSMV) polyprotein ORF. The WSMV Nlb-CP junction containing the nuclear inclusion a (Nla) protease cleavage site was duplicated, permitting excision of foreign protein domains from the viral polyprotein. Wheat, barley, oat and maize seedlings supported systemic infection of WSMV bearing NPTII. The NPTII insert was stable for at least 18-30 days post-inoculation and had little effect on WSMV CP accumulation. Histochemical assays indicated the presence of functional GUS protein in systemically …


The Open Reading Frame 5a Of Foxtail Mosaic Virus Is Expressed In Vivo And Is Dispensable For Systemic Infection, N.L. Robertson, Roy C. French, Thomas Jack Morris Jul 2000

The Open Reading Frame 5a Of Foxtail Mosaic Virus Is Expressed In Vivo And Is Dispensable For Systemic Infection, N.L. Robertson, Roy C. French, Thomas Jack Morris

Department of Plant Pathology: Faculty Publications

Infectious transcripts were successfully derived from full-length cDNA clones of foxtail mosaic potexvirus (FoMV). Full-length clones were constructed by RT-PCR whereby 50 and 30 genomic segments of 2.7 and 3.4 kb, respectively, were ligated into Bluescript II KS. The in vitro RNA transcripts were infectious to moncotyledonous (barley) and dicotyledonous (Chenopodium amaranticolor) plant species. Individual mutation studies on clones of each of the five major ORFs confirmed predicted gene function for the polymerase, TGB (triple gene block), and coat protein (CP) genes. Protoplast studies on expression of a unique open reading frame, ORF 5A, which initiates 143 nts …