Digital Commons Network^™

Whole-Genome Expression Profiling Defines The Hrpl Regulon Of Pseudomonas Syringae Pv. Tomato Dc3000, Allows De Novo Reconstruction Of The Hrp Cis Element, And Identifies Novel Coregulated Genes, Adriana O. Ferreira, Christopher R. Myers, Jeffrey S. Gordon, Gregory B. Martin, Monica Vencato, Alan Collmer, Misty D. Wehling, James R. Alfano, Gabriel Moreno-Hagelsieb, Warren F. Lamboy, Geneviene Declerck, David J. Schneider, Samuel W. Cartinhour

Department of Plant Pathology: Faculty Publications

Pseudomonas syringae pv. tomato DC3000 is a model pathogen of tomato and Arabidopsis that uses a hypersensitive response and pathogenicity (Hrp) type III secretion system (T3SS) to deliver virulence effector proteins into host cells. Expression of the Hrp system and many effector genes is activated by the HrpL alternative sigma factor. Here, an open reading frame-specific whole-genome microarray was constructed for DC3000 and used to comprehensively identify genes that are differentially expressed in wild-type and ΔhrpL strains. Among the genes whose differential regulation was statistically significant, 119 were upregulated and 76 were downregulated in the wild-type compared with the ΔhrpL …

Microbial Content Of Abattoir Wastewater And Its Contaminated Soil In Lagos, Nigeria, A. O. Adesemoye, B. O. Opere, S. C. O. Makinde

Department of Plant Pathology: Faculty Publications

Microbial content of wastewater in two abattoirs and the impact on microbial population of receiving soil was studied in Agege and Ojo Local Government Areas in Lagos State, Nigeria. Wastewater samples were collected from each of the abattoirs over three months period and examined for microbial content. Soil samples contaminated with the wastewaters were also collected and analyzed for microbial content as compared to soil without wastewater contamination in the neighborhood (control). Some physico-chemical parameters of the samples such as total dissolved solid, chemical oxygen demand, etc., were examined. The wastewater samples from both abattoirs were highly contaminated; Agege abattoir …

Cloning Of Nt.Cviqii Nicking Endonuclease And Its Cognate Methyltransferase: M.Cviqii Methylates Ag Sequence, Siu-Hong Chan, Zhenyu Zhu, David Dunigan, James L. Van Etten, Shuang-Yong Xu

Department of Plant Pathology: Faculty Publications

Chlorella virus NY-2A has a large, highly methylated dsDNA genome (45% of the cytosines are 5-methylcytosine and 37% of the adenines are N⁶-methyladenine). Here, we report the cloning, expression, and characterization of the NY-2A-encoded CviQII nicking-modification (N-M) system. The nicking endonuclease, Nt.CviQII, recognizes R ↓ AG (R = A or G, ↓ indicating cleavage site) sequences and cleaves the phosphodiester bond 5′ to the adenosine. Because of the difficulty in cloning and expressing the wild-type Nt.CviQII, C-terminal truncation mutants were generated and full-length Nt.CviQII was reconstructed by intein-mediated peptide ligation. The truncation mutants and the reconstructed full-length Nt.CviQII …

Pseudomonas SyringaeHrpj Is A Type Iii Secreted Protein That Is Required For Plant Pathogenesis, Injection Of Effectors,And Secretion Of The Hrpz1 Harpin, Zheng Qing Fu, Ming Guo, James R. Alfano

Center for Plant Science Innovation: Faculty Publications

The bacterial plant pathogen Pseudomonas syringae requires a type III protein secretion system (TTSS) to cause disease. The P. syringae TTSS is encoded by the hrp-hrc gene cluster. One of the genes within this cluster, hrpJ, encodes a protein with weak similarity to YopN, a type III secreted protein from the animal pathogenic Yersinia species. Here, we show that HrpJ is secreted in culture and translocated into plant cells by the P. syringae pv. tomato DC3000 TTSS. A DC3000 hrpJ mutant, UNL140, was greatly reduced in its ability to cause disease symptoms and multiply in Arabidopsis thaliana …

Inducible Yeast System For Viral Rna Recombination Reveals Requirement For An Rna Replication Signal On Both Parental Rnas, Hernan Garcia-Ruiz, Paul Ahlquist

Department of Plant Pathology: Faculty Publications

To facilitate RNA recombination studies, we tested whether Saccharomyces cerevisiae, which supports brome mosaic virus (BMV) replication, also supports BMV RNA recombination. Yeast strains expressing BMV RNA replication proteins 1a and 2a^pol were engineered to transiently coexpress two independently inducible, overlapping, nonreplicating derivatives of BMV genomic RNA3. B33' lacked the coat protein gene and negative-strand RNA promoter. B35' lacked the positive-strand RNA promoter and had the coat gene replaced by the selectable URA3 gene. After 12 to 72 h of induction, B33' and B35' transcription was repressed and Ura⁺ yeast cells were selected. All Ura⁺ cells …

Sheep Updates 2006 - Part 2, Darryl Smith, Kathryn Kemper, David Rutley, R. R. Woolaston, D. J. Brown, K. D. Atkins, A. E. Casey, A. J. Ball, David Hopkins, David Stanley, Leonie Martin, Arthur Gilmour, Remy Van De Ven, Geoff Duddy, Steve Semple, David Kessell, Andrew Thompson

Sheep Updates

This session covers six papers from different authors:

GENETICS

1. Novel selection traits - what are the possible side effects?, Darryl Smith, Kathryn Kemper, South Australian Research and Development Institute, David Rutley, University of Adelaide.

2. Genetic Changes in the Australian Merino since 1900, Sheep Genetics Australia Technical Committee, R.R. Woolaston Pullenvale, Queensland, D.J. Brown, Animal Genetics and Breeding Unit*, University of New England, K.D. Atkins, A.E. Casey, NSW Department of Primary Industries, A.J. Ball, Meat and Livestock Australia, University of New England

3. Influence of Sire Growth Estimated Breeding Value (EBV0 on Progeny Growth, David Hopkins, David Stanley, Leonie …

Nested Deletion Analysis Of Wheat Streak Mosaic Virus Hc-Pro: Mapping Of Domains Affecting Polyprotein Processing And Eriophyid Mite Transmission, Drake C. Stenger, Gary L. Hein, Roy C. French

Department of Plant Pathology: Faculty Publications

A series of in-frame and nested deletion mutations which progressively removed 5′-proximal sequences of the Wheat streak mosaic virus (WSMV) HC-Pro coding region (1152 nucleotides) was constructed and evaluated for pathogenicity to wheat. WSMV HC-Pro mutants with 5′- proximal deletions of 12 to 720 nucleotides systemically infected wheat. Boundary sequences flanking the deletions were stable and unaltered by passage through plants for all deletion mutants except HCD12 (lacking HC-Pro codons 3–6) that exhibited strong bias for G to A substitution at nucleotide 1190 in HC-Pro codon 2 (aspartic acid to asparagine). HC-Pro mutants with 5′-proximal deletions of up to 720 …

Functional Characterization Of Aspergillus Nidulans Homologues Of Saccharomyces Cerevisiae Spa2 And Bud6, Aleksandra Virag, Steven D. Harris

Department of Plant Pathology: Faculty Publications

The importance of polarized growth for fungi has elicited significant effort directed at better understanding underlying mechanisms of polarization, with a focus on yeast systems. At sites of tip growth, multiple protein complexes assemble and coordinate to ensure that incoming building material reaches the appropriate destination sites, and polarized growth is maintained. One of these complexes is the polarisome that consists of Spa2, Bud6, Pea2, and Bni1 in Saccharomyces cerevisiae. Filamentous hyphae differ in their development and life style from yeasts and likely regulate polarized growth in a different way. This is expected to reflect on the composition and …

An Assessment Model For Rating High-Threat Crop Pathogens, N. W. Schaad, J. Abrams, L. V. Madden, R. D. Frederick, D. G. Luster, V. D. Damsteegt, A. K. Vidaver

Department of Plant Pathology: Faculty Publications

Natural, accidental, and deliberate introductions of nonindigenous crop pathogens have become increasingly recognized as threats to the U.S. economy. Given the large number of pathogens that could be introduced, development of rapid detection methods and control strategies for every potential agent would be extremely difficult and costly. Thus, to ensure the most effective direction of resources a list of high-threat pathogens is needed. We address development of a pathogen threat assessment model based on the analytic hierarchy process (AHP) that can be applied worldwide, using the United States as an illustrative example. Previously, the AHP has been shown to work …

New Outbreaks Of Bacterial Wilt Of Dry Bean In Nebraska Observed From Field Infections, R. M. Harveson, H. F. Schwartz, A. K. Vidaver, Patricia A. Lambrecht, K. L. Otto

Department of Plant Pathology: Faculty Publications

Bacterial wilt caused by Curtobacterium flaccumfaciens pv. flaccumfaciens was one of the more problematic diseases of dry bean (Phaseolus vulgaris L.) throughout the irrigated High Plains (Colorado, Nebraska, and Wyoming) in the 1960s and early 1970s, but has not been observed since that time. However, in August of 2003, plants exhibiting wilting and irregular, interveinal necrotic foliar lesions surrounded by a bright yellow border were found in three dry bean fields (market class Great Northern) in Scotts Bluff County, Nebraska. During 2004, plants exhibiting identical symptoms were additionally found occurring in more than 40 dry bean fields in western …

Phycodnaviruses: A Peek At Genetic Diversity, David Dunigan, Lisa A. Fitzgerald, James L. Van Etten

Department of Plant Pathology: Faculty Publications

The family Phycodnaviridae encompasses a diverse collection of large icosahedral, dsDNA viruses infecting algae. These viruses have genomes ranging from 160 to 560 kb. The family consists of six genera based initially on host range and supported by sequence comparisons. The family is monophyletic with branches for each genus, but the phycodnaviruses have evolutionary roots that connect with several other families of large DNA viruses, referred to as the nucleocytoplasmic large DNA viruses (NCLDV). The genomes of members in three genera in the Phycodnaviridae have recently been sequenced and the purpose of this manuscript is to summarize these data. The …

Potassium Ion Channels Of Chlorella Viruses Cause Rapid Depolarization Of Host Cells During Infection, Florian Frohns, Anja Kasmann, Detlef Kramer, Britta Schafer, Mario Mehmel, Ming Kang, James L. Van Etten, Sabrina Gazzarrini, Ana Morino, Gerhard Thiel

Department of Plant Pathology: Faculty Publications

revious studies have established that chlorella viruses encode K⁺ channels with different structural and functional properties. In the current study, we exploit the different sensitivities of these channels to Cs⁺ to determine if the membrane depolarization observed during virus infection is caused by the activities of these channels. Infection of Chlorella NC64A with four viruses caused rapid membrane depolarization of similar amplitudes, but with different kinetics. Depolarization was fastest after infection with virus SC-1A (half time [t_1/2], about 9 min) and slowest with virus NY-2A (t_1/2, about 12 min). Cs⁺ inhibited …

Polarity In Plants - Annual Plant Reviews, Volume 12, Steven D. Harris

Department of Plant Pathology: Faculty Publications

Polarity is a fundamental property of all cells. The molecular mechanisms that underlies the establishment and maintenance of cellular polarity have been intensively studied in animal cells and yeast-like fungi. These studies reveal an emerging general principle whereby positional information is relayed to the cytoskeleton and other morphogenetic functions by conserved signaling pathways. Comparatively less attention has been directed toward the molecular basis of polarized growth in plant cells and tissues. This volume, Polarity in Plants, provides a comprehensive review of the topic that should satisfy both hardcore aficionados of plant cell and developmental biology as well as curious investigators …

Bacillus Species Nrrl B-30212 For Reducing Fusarium Head Blight In Cereals, David A. Schisler, Naseem L. Khan, Michael J. Boehm

Department of Plant Pathology: Faculty Publications

Four yeasts (NRRL Y-30213, NRRL Y-30214, NRRL Y-30215, and NRRL Y-30216) and 1 bacterium (NRRL B-30212) have been identified as being superior antagonists capable of suppressing Fusarium head blight (head scab) in cereals, particularly in wheat and barley. Fusarium head blight is primarily caused by the fungus Gibberella zeae (anamorph=Fusarium graminearum).

Crop Updates 2006 - Weeds, Alexandra Douglas, Thomas M. Wolf, Harm Van Rees, Bill Gordon, Peter Newman, Glenn Adam, Aik Lee, Siew Lee, Katherine Hollaway, Brad Rayner, John Peirce, Rick Llewellyn, Frank D'Emden, Michelle Owen, Stephen Powles, Michael Walsh, Emma Glasfurd, Kathryn Steadman, David Ferris, Bevan Addison, Aik Cheam, Dave Nicholson, Ruben Vargas, Shahab Pathan, Abul Hashem, Nerys Wilkins, Catherine Borger, Bob French, Kari-Lee Falconer, Martin Harries, Chris Matthews, Vikki Osten, Harnohinder Dhammu, David Nicholson, Richard Quinlan, Debbie Allen, Mark Seymour, Pam Burgess, Owen Coppen, Chris Roberts, Christiaan Valentine, A. K. Basandrai, W. J. Macleod, John Moore, Neil Rothnie, Russell Speed, John Andrew Simons, Ted Spadek, Daya Patabendige, Michael Renton, Sally Peltzer, Art Diggle

Crop Updates

This session covers thirty seven papers from different authors:

1. ACKNOWLEDGEMENTS, Alexandra Douglas, CONVENOR – WEEDS DEPARTMENT OF AGRICULTURE

SPRAY TECHNOLOGY

2. Meeting the variable application goals with new application technology, Thomas M. Wolf, Agriculture and Agri-Food Canada, Saskatoon Research Centre

3. Spray nozzles for grass weed control, Harm van Rees, BCG (Birchip Cropping Group)

4. Boom sprayer setups – achieving coarse droplets with different operating parameters, Bill Gordon, Bill Gordon Consulting

5. Complying with product label requirements, Bill Gordon, Bill Gordon Consulting

6. IWM a proven performer over 5 years in 33 focus paddocks, Peter Newman and …

Crop Updates 2006 - Lupins And Pulses, Peter White, Mark Seymour, Amelia Mclarty, Wayne Parker, Ian Pritchard, Bob French, Rodger Beermier, Bevan Buirchell, Mark Sweetingham, Jon Clements, Geoff Thomas, Roger Jones, Sofia Sipsas, John Quealy, Leigh Smith, Gordon Francis, Huaan Yang, Jeffrey Boersma, Margaret Pallotta, Chengdao Li, Krishnapillai Sivasithamparam, M. Nelson, H. Phan, S. Ellwood, P, Moolhuijzen, M. Bellgard, J. Hane, A. Williams, J. Fos-Nyarko, B. Wolko, M. Książkiewicz, M. Cakir, M. Jones, M. Scobie, C. O'Lone, S. J. Barker, R. Oliver, W. Cowling, Laurie Maiolo, Martin Harries, Jo Walker, Murray Blyth, Stephen Cosh, Dirranie Kirby, Kedar Adhikari, Patrizia Guantini, Katie Bell, Ken Adcock, Ciara Beard, Anne Smith, Tim Maling, Art Diggle, Debbie Thackray, Kadambot Siddique, Ping Si, Huaan Yang, Vijay Jayasena, Florence Kartawinata, Ranil Coorey, Ken Dods, Kerry Regan, Tanveer Khan, Jenny Garlinge, Rod Hunter, Pam Burges, Eric Armstrong, Glen Riethmuller, Greg Shea, Moin Salam, Jean Galloway, Pip Payne, Bill Macleod, Brenda Coutts, Pooran Gaur, Heather Clarke, Stuart Morgan, Alan Harris, Ted Knights, Kristy Hobson, Chris Matthews, Colin Hanbury, Tim Pope, Mike Baker, Leanne Young, Syed Muhammad Nasar-Abbas, Julie Plummer, D. Harris, Phill Chambers, Michael Materne, Dennis Van Gool, Huyen Phan, Simon Ellwood, J. Hane, Angela Williams, R. Ford, S. Thomas, R. Oliver, Rory Coffey, Chris Poole, Theo Pfaff, Judith Lichtenzveig, Lars Kamphuis, Nola D'Souza, Emma Groves, Karam Singh

Crop Updates

This session covers sixty six papers from different authors:

2005 LUPIN AND PULSE INDUSTRY HIGHLIGHTS

1. Lupin Peter White, Department of Agriculture

2. Pulses Mark Seymour, Department of Agriculture

3. Monthly rainfall at experimental sites in 2005

4. Acknowledgements Amelia McLarty EDITOR

5. Contributors

6. Background Peter White, Department of Agriculture

2005 REGIONAL ROUNDUP

7. Northern agricultural region Wayne Parker, Department of Agriculture

8. Central agricultural region Ian Pritchard and Bob French, Department of Agriculture

9. Great southern and lakes Rodger Beermier, Department of Agriculture

10. South east region Mark Seymour, Department of …

Crop Updates 2006 - Oilseeds, Graham Walton, Fiona Martin, Anne Wilkins, Nathan Hancock, Matthew Nelson, Marieclaire Castello, Linda Thompson, Anouska Cousin, Guijun Yan, Wallace Cowling, Moin Salam, Bill Mcloud, Ravjit Khangura, Jean Galloway, Art Diggle, R. F. Brennan, M. D. A. Bolland, P. M. Damon, Z. Rengel, Terry Rose, Qifu Ma, Dave Eksteen

Crop Updates

This session covers thirteen papers from different authors:

1. INTRODUCTION, Graham Walton, CONVENOR, Department of Agriculture

2. The performance of new TT canola varieties in National Variety Testing (NVT) WA, Fiona Martin, Research Agronomist, Agritech Crop Research

3. Comparison of TT Canola Varieties in Oilseeds WA Trials – 2005, Collated by G.H. Walton, Department of Agriculture, WA, from a collaboration between Oilseeds WA, Seed Companies, Agronomists and Growers

4. An overview of the potential for a Biofuels Industry in Western Australia, Anne Wilkins and Nathan Hancock, Department of Agriculture

5. Retrieval of fertile progeny from interspecific …

Crop Updates 2006 - Cereals, Roger Jones, Nichole Burges, Mohommad Amjad, Ben Curtis, Wal Anderson, Darren Chitty, Brianna Peake, Harm Van Rees, Cherie Reilly, James Hunt, Dean Holzworth, Zvi Hochman, Allan Peake, Neal Dalgliesh, Stephen Van Rees, Trudy Mccann, Peter Carberry, Raj Malik, Kelly Winfield, Brenda Shackley, Judith Devenish, Darshan Sharma, Steve Penny Jr, Christine Zaicou-Kunesch, Mike Bolland, Ross Brennan, Paul Damon, Zed Rengel, Jeremy Lemon, Perry Poulton, Nick Poole, Brooke Thompson, Stephen Loss, Jeff Russell, Angie Roe, James Eyres, Narelle Simpson, Ron Mctaggart, Lionel Martin, Dave Allen, Hossein Golzar, Manisha Shankar, Robert Loughman, John Majewski, Donna Foster, Jamie Piotrowski, Nicole Harry, Geoff Thomas, Kith Jayasena, Svetlana Micic, Paul Matson, Tony Dore, Thomas (Ben) Biddulph, Daryl Mares, Julie Plummer, Tim Setter, Garren Knell, Steve Curtin, Wade Longmuir, Nigel Metz, Tina Botwright Acuña, Len Wade, Cindy Mills, Peter Stone

Crop Updates

This session covers twenty nine papers from different authors:

PLENARY

1. The 2005 wheat streak mosaic virus epidemic in New South Wales and the threat posed to the Western Australian wheat industry, Roger Jones and Nichole Burges, Department of Agriculture

SOUTH COAST AGRONOMY

2. South coast wheat variety trial results and best options for 2006, Mohammad Amjad, Ben Curtis and Wal Anderson, Department of Agriculture

3. Dual purpose winter wheats to improve productivity, Mohammad Amjad and Ben Curtis, Department of Agriculture

4. South coast large-scale premium wheat variety trials, Mohammad Amjad and Ben Curtis, Department of Agriculture …

Chlorella Virus Mt325 Encodes Water And Potassium Channels That Interact Synergistically, Sabrina Gazzarrini, Ming Kang, Svetlana Epimashko, James L. Van Etten, Jack Dainty, Gerhard Thiel, Anna Moroni

James Van Etten Publications

Fast and selective transport of water through cell membranes is facilitated by water channels. Water channels belonging to the major intrinsic proteins (MIPs) family have been found in all three domains of life, Archaea, Bacteria, and Eukarya. Here we show that Chlorella virus MT325 has a water channel gene, aqpv1, that forms a functional aquaglyceroporin in oocytes. aqpv1 is transcribed during infection together with MT325 kcv, a gene encoding a previously undescribed type of viral potassium channel. Coexpression of AQPV1 and MT325-Kcv in Xenopus oocytes synergistically increases water transport, suggesting a possible concerted action of the two channels in …

Farnesol-Induced Apoptosis In Aspergillus Nidulans Reveals A Possible Mechanism For Antagonistic Interactions Between Fungi, Camile P. Semighini, Jacob M. Hornby, Raluca Dumitru, Kenneth W. Nickerson, Steven D. Harris

Department of Plant Pathology: Faculty Publications

The dimorphic fungus Candida albicans secretes farnesol, which acts as a quorum-sensing molecule and prevents the yeast to mycelium conversion. In this study we examined the effect of farnesol in the filamentous fungus Aspergillus nidulans. We show that externally added farnesol has no effect on hyphal morphogenesis; instead, it triggers morphological features characteristic of apoptosis. Additional experiments suggest that mitochondria and reactive oxygen species (ROS) participate in farnesol-induced apoptosis. Moreover, the effects of farnesol appear to be mediated by the FadA heterotrimeric G protein complex. Because A. nidulans does not secrete detectable amounts of farnesol, we propose that it …

Chlorella Viruses, Takashi Yamada, Hideki Onimatsu, James L. Van Etten

James Van Etten Publications

Chlorella viruses or chloroviruses are large, icosahedral, plaque‐forming, double‐stranded‐DNA— containing viruses that replicate in certain strains of the unicellular green alga Chlorella. DNA sequence analysis of the 330‐kbp genome of Paramecium bursaria chlorella virus 1 (PBCV‐1), the prototype of this virus family (Phycodnaviridae), predict ∼366 protein‐encoding genes and 11 tRNA genes. The predicted gene products of ∼50% of these genes resemble proteins of known function, including many that are completely unexpected for a virus. In addition, the chlorella viruses have several features and encode many gene products that distinguish them from most viruses. These products include: (1) multiple …

Carbon-To-Nitrogen Ratio And Carbon Loading Of Production Media Influence Freeze-Drying Survival And Biocontrol Efficacy Of Cryptococcus Nodaensis Oh 182.9, Shouan Zhang, David A. Schisler, Michael J. Boehm, Patricia J. Slininger

Department of Plant Pathology: Faculty Publications

Fusarium head blight (FHB), caused by Gibberella zeae, is a devastating disease of wheat worldwide. Cryptococcus nodaensis OH 182.9 is an effective biocontrol agent for this disease. Development of a dried product of OH 182.9 would have potential advantages of ease of handling, favorable economics, and acceptance by end users. Isolate OH 182.9 was grown for 48 and 72 h in semi-defined complete liquid (SDCL) medium with carbon-to-nitrogen (C/N) ratios of 6.5:1, 9:1, 11:1, 15:1, and 30:1, and in SDCL C/N 30:1 media with varied carbon loadings of 7, 14, 21, and 28 g/liter. Total biomass production and cell …

A Highly Efficient Transient Protoplast System For Analyzing Defence Gene Expression And Protein–Protein Interactions In Rice, Songbiao Chen, Lizen Tao, Lirong Zeng, Miguel E. Vega-Zanchez, Kenji Umemura, Guo-Liang Wang

Center for Plant Science Innovation: Faculty Publications

The transient assay system based on mesophyll or cultured cell-derived protoplasts has been exploited in several plant species and has become a powerful tool for rapid gene functional analysis and biochemical manipulations. However, the system has not been widely used in rice owing to the difficulties in large-scale isolation of viable rice protoplasts from leaves or suspension-cultured cells. Here, we describe a significantly improved method to isolate a large number of protoplasts from stem and sheath tissues of both young and mature plants. High-level coexpression of multiple constructs and efficient suppression of exogenous and endogenous genes were observed in the …

Influence Of Lysobacter Enzymogenes Strain C3 On Nematodes, J. Chen, W. H. Moore, Gary Yuen, D. Kobayashi, E.P. Caswell-Chen

Department of Plant Pathology: Faculty Publications

Chitinolytic microflora may contribute to biological control of plant-parasitic nematodes by causing decreased egg viability through degradation of egg shells. Here, the influence of Lysobacter enzymogenes strain C3 on Caenorhabditis elegans, Heterodera schachtii, Meloidogyne javanica, Pratylenchus penetrans, and Aphelenchoides fragariae is described. Exposure of C. elegans to L. enzymogenes strain C3 on agar resulted in almost complete elimination of egg production and death of 94% of hatched juveniles after 2 d. Hatch of H. schachtii eggs was about 50% on a lawn of L. enzymogenes strain C3 on agar as compared to 80% on a lawn of E. coli …

First Report Of Sudden Death Syndrome Of Soybean Caused By Fusarium Solani F. Sp. Glycines In Nebraska, A. D. Ziems, L. J. Giesler, G. Y. Yuen

Department of Plant Pathology: Faculty Publications

During August of 2004, soybean (Glycine max (L.) Merr.) plants exhibiting symptoms typical of sudden death syndrome (SDS) caused by Fusarium solani (Mart.) Sacc. f. sp. glycines (= Fusarium virguliforme Akoi, O'Donnell, Homma, & Lattanzi) (1) were observed in Nemaha and Pierce counties in eastern Nebraska. Leaf symptoms ranged from small chlorotic spots to prominent interveinal necrosis on plants at R5-R6 growth stages. Taproots of symptomatic plants were plated on potato dextrose agar (PDA) amended with hymexazol, ampicillin, and rifampicin (HAR). Resulting fungal isolates grew slowly and developed masses of blue macroconidia, characteristic of F. solani f. sp. glycines …

Avenacin Production In Creeping Bentgrass (Agrostis Stolonifera) And Its Influence On The Host Range Of Gaeumannomyces Graminis, S. L. Thomas, P. Bonello, P. E. Lipps, Michael J. Boehm

Department of Plant Pathology: Faculty Publications

Avenacinase activity has been shown to be a key factor determining the host range of Gaeumannomyces graminis on oats (Avena sativa). G. graminis var. avenae produces avenacinase, which detoxifies the oat root saponin avenacin, enabling it to infect oats. G. graminis var. tritici does not produce avenacinase and is unable to infect oats. G. graminis var. avenae is also reported to incite take-all patch on creeping bentgrass (Agrostis stolonifera). It is unknown whether creeping bentgrass produces avenacin and if the avenacin-avenacinase interaction influences G. graminis pathogenicity on creeping bentgrass. The root extracts of six creeping bentgrass …

Fungicide Sensitivity Of Sclerotinia Homoeocarpa From Golf Courses In Ohio, Young-Ki Jo, Amy L. Niver, Joseph W. Rimelspach, Michael J. Boehm

Department of Plant Pathology: Faculty Publications

Managing dollar spot, the most common and chronic disease on intensively cultivated turfgrass, relies on the judicious use of fungicides. The heavy use of fungicides has led to the development of isolates of Sclerotinia homoeocarpa insensitive to several classes of fungicides, including benzimidazoles, demethylation-inhibitors, and dicarboximides. In vitro fungicide sensitivity assays using single discriminatory concentrations of thiophanate-methyl, propiconazole, and iprodione were developed in this study for evaluating field efficacy of these fungicides and the prevalence of fungicide insensitivity within S. homoeocarpa isolated from golf courses throughout Ohio. Discriminatory concentrations for these fungicides were determined to be: thiophanate-methyl = 1,000 μg …

Assessing Heterodera Glycines-Resistant And Susceptible Cultivar Yield Response, P. A. Donald, P. E. Pierson, S. K. St. Martin, P. R. Sellers, G. R. Noel, A. E. Macguidwin, J. Faghihi, V. R. Ferris, C. R. Grau, D. J. Jardine, H, Melakeberhan, T. L. Niblack, W. C. Stienstra, G. L. Tylka, T. A. Wheeler, D. S. Wysong

Department of Plant Pathology: Faculty Publications

The soybean cyst nematode Heterodera glycines (SCN) is of major economic importance and widely distributed throughout soybean production regions of the United States where different maturity groups with the same sources of SCN resistance are grown. The objective of this study was to assess SCN-resistant and -susceptible soybean yield responses in infested soils across the northcentral region. In 1994 and 1995, eight SCN-resistant and eight SCN-susceptible public soybean cultivars representing maturity groups (MG) I to IV were planted in 63 fields, either infested or noninfested, in 10 states in the north-central United States. Soil samples were taken to determine initial …

Sentinel Nematodes Of Land-Use Change And Restoration In Tallgrass Prairie, T. C. Todd, T. O. Powers, P.G. Mullin

Department of Plant Pathology: Faculty Publications

Changes in land use and the associated changes in land cover are recognized as the most important component of human-induced global change. Much attention has been focused on deforestation, but grasslands are among the most endangered ecosystems on Earth. The North American tallgrass prairie is a dramatic example, exhibiting a greater than 95% decline in historical area. Renewed interest in prairie conservation and restoration has highlighted the need for ecological indicators of disturbance and recovery in native systems, including the below ground component. The tallgrass prairie differs from the agricultural systems that have replaced it in having greater diversity and …

A Position Paper On The Electronic Publication Of Nematode Taxonomic Manuscripts, Eyualem Abebe, James G. Baldwin, Byron Adams, Duane Hope, Scott Gardner, Robin Huettel, Peter Mullin, Thomas O. Powers, Jyotsna Sharma, Weimin Ye, William K. Thomas

Department of Plant Pathology: Faculty Publications

Several nematode species have now attained ‘model organism’ status, yet there remain many niches in basic biological inquiry for which nematodes would be ideal model systems of study. However, furthering the model system approach is hindered by lack of information on nematode biodiversity. The shortage of taxonomic resources to inventory and characterize biodiversity hinders research programs in invasion biology, ecosystem functioning, conservation biology, and many others. The disproportion between numbers of species to be described and numbers of available taxonomic specialists is greater for Nematoda than for any other metazoan phylum. A partial solution to the taxonomic impediment is the …