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Plant Biology

2006

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Articles 1 - 30 of 56

Full-Text Articles in Life Sciences

Lake Mead National Recreation Area Vegetation Monitoring And Management: Quarterly Progress Report, Period Ending December 31, 2006, Margaret N. Rees Dec 2006

Lake Mead National Recreation Area Vegetation Monitoring And Management: Quarterly Progress Report, Period Ending December 31, 2006, Margaret N. Rees

Vegetation Monitoring

Executive Summary

  • Two new Weed Sentry research assistants were hired.
  • Weed Sentry staff surveyed for exotic species on 89 miles of roads on NPS and BLM land and treated more than 21,000 exotic plants in incipient populations.
  • A grid-based rare plant monitoring method was tested this quarter.
  • A manuscript detailing vegetation succession on a water pipeline at Lake Mead NRA was submitted for review to the journal Crossosoma.
  • New integrative projects undertaken this quarter included establishing a competition study between a native grass and the exotic Sahara mustard, salvaging plants for research purposes from private sites with permission from ...


Insect-Mediated Seed-Set Evaluation Of 21 Soybean Lines Segregating For Male Sterility At 10 Different Loci, E. Ortiz-Perez, Harry T. Horner, S. J. Hanlin, R. G. Palmer Dec 2006

Insect-Mediated Seed-Set Evaluation Of 21 Soybean Lines Segregating For Male Sterility At 10 Different Loci, E. Ortiz-Perez, Harry T. Horner, S. J. Hanlin, R. G. Palmer

Genetics, Development and Cell Biology Publications

The first requirement to establish a successful hybrid soybean program is the availability of a stable male-sterile, female-fertile system. Male sterility has been an important tool in soybean breeding programs to improve traits such as yield, seed-protein and seed-oil content, and seed size. However, improvement of seed-set per se on male-sterile plants has not been an important breeding objective. The evaluation of the out-crossing potential of the available male-sterile, female-fertile soybean lines is crucial to determine the future of hybrid soybean. The objective of this study was to evaluate seed-set among 21 soybean lines segregating for male sterility at 10 ...


Nuclec Acds Encoding Pseudomonas Hop Proteins And Use Thereof, Alan Collmer, James R. Alfano, Xiaoyan Tang, C. Robin Buell, Gregory B. Martin Nov 2006

Nuclec Acds Encoding Pseudomonas Hop Proteins And Use Thereof, Alan Collmer, James R. Alfano, Xiaoyan Tang, C. Robin Buell, Gregory B. Martin

Papers in Plant Pathology

The present invention relates to isolated nucleic acid mol ecules encoding a type III—secreted bacterial protein capable of modifying a cell death pathway in a plant cell. One aspect of the present invention involves an isolated nucleic acid molecule having a nucleotide sequence that encodes the HopPtol)2 protein of Pseudomonas syringae pv. syringae DC 3000. Expression vectors, host cells, and transgenic plants which include the DNA molecules of the present invention are also disclosed. The nucleic acid mol ecules of the present invention can be used to impart disease resistance to a plant and to make a plant ...


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 Nov 2006

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

Papers in Plant Pathology

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 ...


The Exoribonuclease Xrn4 Is A Component Of The Ethylene Response Pathway In Arabidopsis, Brad Binder, Thomas Potuschak, Amérin Vansiri, Esther Lechner, Richard Vierstra, Pascal Genschik Oct 2006

The Exoribonuclease Xrn4 Is A Component Of The Ethylene Response Pathway In Arabidopsis, Brad Binder, Thomas Potuschak, Amérin Vansiri, Esther Lechner, Richard Vierstra, Pascal Genschik

Brad M. Binder

EXORIBONUCLEASE4 (XRN4), the Arabidopsis thaliana homolog of yeast XRN1, is involved in the degradation of several unstable mRNAs. Although a role for XRN4 in RNA silencing of certain transgenes has been reported, xrn4 mutant plants were found to lack any apparent visible phenotype. Here, we show that XRN4 is allelic to the unidentified components of the ethylene response pathway ETHYLENE-INSENSITIVE5/ACC-INSENSITIVE1 (EIN5/AIN1) and EIN7. xrn4 mutant seedlings are ethylene-insensitive as a consequence of the upregulation of EIN3 BINDING F-BOX PROTEIN1 (EBF1) and EBF2 mRNA levels, which encode related F-box proteins involved in the turnover of EIN3 protein, a crucial ...


Ethylene-Stimulated Nutations Do Not Require Etr1 Receptor Histidine Kinase Activity, Brad Binder Oct 2006

Ethylene-Stimulated Nutations Do Not Require Etr1 Receptor Histidine Kinase Activity, Brad Binder

Brad M. Binder

Ethylene influences the growth and development of plants through the action of receptors that have homology to bacterial two-component receptors. In bacteria these receptors function via autophosphorylation of a His residue in the kinase domain followed by phosphotransfer to a conserved Asp residue in a response regulator protein. In Arabidopsis, two of the five receptor isoforms are capable of His kinase activity. However, the role of His kinase activity and phosphotransfer is unclear in ethylene signaling. A previous study showed that ethylene stimulates nutations of the hypocotyl in etiolated Arabidopsis seedlings that are dependent on the ETR1 receptor isoform. The ...


Microbial Content Of Abattoir Wastewater And Its Contaminated Soil In Lagos, Nigeria, A. O. Adesemoye, B. O. Opere, S. C. O. Makinde Oct 2006

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

Papers in Plant Pathology

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 ...


Lake Mead National Recreation Area Vegetation Monitoring And Management: Final Close-Out Report, Time Period: October 1, 2005 To September 30, 2006, Margaret N. Rees Sep 2006

Lake Mead National Recreation Area Vegetation Monitoring And Management: Final Close-Out Report, Time Period: October 1, 2005 To September 30, 2006, Margaret N. Rees

Vegetation Monitoring

The National Park Service (NPS) at Lake Mead National Recreation Area (LAME) entered into a cooperative agreement with the University of Nevada, Las Vegas (UNLV) to accomplish vegetation monitoring and management activities. This report summarizes activities that took place by UNLV under this task agreement between October 1, 2005, and September 30, 2006. The activities included:

  • Weed Sentry mapping and treating incipient populations of exotic invasive plants throughout Clark County, including along shorelines of Lakes Mead and Mohave;
  • Monitoring of targeted rare native plant species;
  • Sahara mustard research; and
  • Providing technical assistance upon request to the NPS vegetation manager.

In ...


Inducible Yeast System For Viral Rna Recombination Reveals Requirement For An Rna Replication Signal On Both Parental Rnas, Hernan Garcia-Ruiz, Paul Ahlquist Sep 2006

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

Papers in Plant Pathology

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 2apol 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 contained recombinant RNA3 ...


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 Sep 2006

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

Faculty Publications from the Center for Plant Science Innovation

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. UNL140 exhibited ...


Latex Of Sciadopitys Verticillata (Thunb.) Siebold And Zuccarini: Antibiotic Properties, Phytochemistry, And Inhibition Of Adventitious Rooting Of Stem Cuttings., David Ira Yates Aug 2006

Latex Of Sciadopitys Verticillata (Thunb.) Siebold And Zuccarini: Antibiotic Properties, Phytochemistry, And Inhibition Of Adventitious Rooting Of Stem Cuttings., David Ira Yates

Electronic Theses and Dissertations

Sciadopitys verticillata was subjected to three propagation treatments designed to inhibit coagulation of its latex-like sap at the cut ends of the stem cuttings. Twenty-four hour soaking in water prior to rooting hormone application significantly enhanced production of adventitious roots. Old wood stem cuttings from shade-grown trees rooted at higher proportions than stem cuttings collected from sun-grown trees. Height, age, and place of origin of the source trees were not important factors in successful rooting. Antibacterial activity against some human pathogens and soil bacterial species was detected in latex application trials but the antibiotic activity was not related to the ...


Gene Expression Programs During Shoot, Root, And Callus Development In Arabidopsis Tissue Culture, Ping Che, Sonia Lall, Dan Nettleton, Stephen H. Howell Jun 2006

Gene Expression Programs During Shoot, Root, And Callus Development In Arabidopsis Tissue Culture, Ping Che, Sonia Lall, Dan Nettleton, Stephen H. Howell

Statistics Publications

Shoots can be regenerated from Arabidopsis (Arabidopsis thaliana) root explants in tissue culture through a two-step process requiring preincubation on an auxin-rich callus induction medium. Regenerating tissues can be directed along different developmental pathways leading to the formation of shoots, new roots, or callus by transferring to the appropriate organ induction medium. Using gene-profiling methods, we identified groups of genes that serve as molecular signatures of the different developmental processes, i.e. genes that were specifically up- or down-regulated on one developmental pathway, but not on others. One transcription factor gene that was up-regulated during early shoot development was RAP2 ...


Evaluation Of Insect-Mediated Seed Set Among Soybean Lines Segregating For Male Sterility At The Ms6 Locus, E. Ortiz-Perez, Harry T. Horner, S. J. Hanlin, R. G. Palmer Jun 2006

Evaluation Of Insect-Mediated Seed Set Among Soybean Lines Segregating For Male Sterility At The Ms6 Locus, E. Ortiz-Perez, Harry T. Horner, S. J. Hanlin, R. G. Palmer

Genetics, Development and Cell Biology Publications

Currently, there is no economical way to produce large quantities of F1 hybrid soybean seed in the USA. One of the fundamental requirements for hybrid seed production is the availability of a stable male-sterile, female-fertile system. However, the more challenging barrier is the efficient transfer of pollen from the male parent to the female parent. This could potentially be achieved through pollinator insects. Our observations suggested that seed set on male-sterile, female-fertile plants is a good indicator of insect attraction. The objective of this study was to evaluate seed set among male-sterile, female-fertile lines segregating for male-sterile, female-fertile ms6 ...


Effects Of Smoke And Fire-Related Cues On Panstemon Barbatus Seeds, Scott R. Abella Apr 2006

Effects Of Smoke And Fire-Related Cues On Panstemon Barbatus Seeds, Scott R. Abella

Public Policy and Leadership Faculty Publications

Previous research has found that exposure to fire-related cues enhances germination of some plant species, and such species may exist in frequent-fire southwestern United States Pinus ponderosa forests. I performed four greenhouse experiments with Penstemon barbatus, a perennial forb common in P. ponderosa forests, testing seed responses to liquid and air smoke, charred P. ponderosa wood and leachate, heat and emergence substrates. Liquid smoke increased P. barbatus emergence to as high as 63%, 44% greater than controls, and enhanced emergence in all 4 experiments. Air smoke produced by burning P. ponderosa litter for 15 min appeared to increase emergence similar ...


The Importance Of Maltose In Transitory Starch Breakdown, Yan Lu, Thomas Sharkey Feb 2006

The Importance Of Maltose In Transitory Starch Breakdown, Yan Lu, Thomas Sharkey

Yan Lu

No abstract provided.


Bacillus Species Nrrl B-30212 For Reducing Fusarium Head Blight In Cereals, David A. Schisler, Naseem L. Khan, Michael J. Boehm Feb 2006

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

Papers in Plant Pathology

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 - Oilseeds, Graham Walton, Fiona Martin, Anne Wilkins, Nathan Hancock, Matthew Nelson, Marie-Claire 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 Feb 2006

Crop Updates 2006 - Oilseeds, Graham Walton, Fiona Martin, Anne Wilkins, Nathan Hancock, Matthew Nelson, Marie-Claire 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 crosses between Brassica napus ...


Crop Updates 2006 - Weeds, Alexandra Douglas, Thomas M. Wolf, Harm Van Rees, Bill Gordon, Peter Newman, Glen 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 Simons, Ted Spadek, Daya Patabendige, Michael Renton, Sally Peltzer, Art Diggle Feb 2006

Crop Updates 2006 - Weeds, Alexandra Douglas, Thomas M. Wolf, Harm Van Rees, Bill Gordon, Peter Newman, Glen 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 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 Glenn Adam, Department of ...


Iron Bioavailability Of Hemoglobin From Soy Root Nodules Using A Caco-2 Cell Culture Model, Amy K. Proulx, Manju B. Reddy Jan 2006

Iron Bioavailability Of Hemoglobin From Soy Root Nodules Using A Caco-2 Cell Culture Model, Amy K. Proulx, Manju B. Reddy

Food Science and Human Nutrition Publications

Heme iron has been identified in many plant sourcesmost commonly in the root nodules of leguminous plants, such as soy. Our objective was to test the effectiveness of soy root nodule (SRN) and purified soy hemoglobin (LHb) in improving iron bioavailability using an in vitro Caco-2 cell model, with ferritin response as the bioavailability index. We assessed bioavailability of iron from LHb (either partially purified (LHbA) or purified (LHbD)) with and without food matrix and compared it with that from bovine hemoglobin (BHb), ferrous sulfate (FeSO4), or SRN. Bioavailability of each treatment was normalized to 100% of the FeSO4 treatment ...


Variation In Shoot Anatomy And Rooting Behaviour Of Stem Cuttings In Relation To Age Of Donor Plants In Teak (Tectona Grandis Linn. F.), Azamal Husen Dr., Mohinder Pal Jan 2006

Variation In Shoot Anatomy And Rooting Behaviour Of Stem Cuttings In Relation To Age Of Donor Plants In Teak (Tectona Grandis Linn. F.), Azamal Husen Dr., Mohinder Pal

Dr. Azamal Husen

No abstract provided.


Bioinformatics-Enabled Identification Of The Hrpl Regulon And Type Iii Secretion System Effector Proteins Of Pseudomonas Syringae Pv. Phaseolicola 1448a, Monica Vencato, Fang Tian, James R. Alfano, C. Robin Buell, Samuel Cartinhour, Genevieve A. Declerck, David S. Guttman, John Stavrinides, Vinita Joardar, Magdalen Lindeberg, Philip A. Bronstein, John W. Mansfield, Christopher R. Myers, Alan Collmer, David J. Schneider Jan 2006

Bioinformatics-Enabled Identification Of The Hrpl Regulon And Type Iii Secretion System Effector Proteins Of Pseudomonas Syringae Pv. Phaseolicola 1448a, Monica Vencato, Fang Tian, James R. Alfano, C. Robin Buell, Samuel Cartinhour, Genevieve A. Declerck, David S. Guttman, John Stavrinides, Vinita Joardar, Magdalen Lindeberg, Philip A. Bronstein, John W. Mansfield, Christopher R. Myers, Alan Collmer, David J. Schneider

Papers in Plant Pathology

The ability of Pseudomonas syringae pv. phaseolicola to cause halo blight of bean is dependent on its ability to translocate effector proteins into host cells via the hypersensitive response and pathogenicity (Hrp) type III secretion system (T3SS). To identify genes encoding type III effectors and other potential virulence factors that are regulated by the HrpL alternative sigma factor, we used a hidden Markov model, weight matrix model, and type III targeting-associated patterns to search the genome of P. syringae pv. phaseolicola 1448A, which recently was sequenced to completion. We identified 44 high-probability putative Hrp promoters upstream of genes encoding the ...


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 Jan 2006

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

Papers in Plant Pathology

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. Sorghum seed ...


First Report Of Leaf Spot Of Smooth Bromegrass Caused By Pithomyces Chartarum In Nebraska, C. Eken, C. C. Jochum, G. Y. Yuen Jan 2006

First Report Of Leaf Spot Of Smooth Bromegrass Caused By Pithomyces Chartarum In Nebraska, C. Eken, C. C. Jochum, G. Y. Yuen

Papers in Plant Pathology

Smooth bromegrass (Bromus inermis Leyss.) is the most common perennial grass species cultivated for forage in North America. During late fall of 2004, smooth bromegrass plants in Lincoln, NE were observed to have brown lesions on leaf midveins that were several centimeters long. Symptomatic leaves were surface disinfested for 1 min in 2% NaOCl and incubated at 25°C on potato dextrose agar (PDA) and water agar. The fungus, Pithomyces chartarum (Berk. & Curt) Ellis, was isolated consistently and identified on the basis of morphological characteristics (1). Colonies were effused and black on PDA. Conidiophores measured 3.5 to 8 × 1 ...


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 Jan 2006

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

Papers in Plant Pathology

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 cultivars were analyzed by ...


Fungicide Sensitivity Of Sclerotinia Homoeocarpa From Golf Courses In Ohio, Young-Ki Jo, Amy L. Niver, Joseph W. Rimelspach, Michael J. Boehm Jan 2006

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

Papers in Plant Pathology

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 ...


The Role Of Increased Sea Surface Temperature On Eelgrass Leaf Dynamics: Onset Of El Nin˜ O As A Proxy For Global Climate Change In San Quintı´N Bay, Baja California, Hector A. Echavarria-Heras, Elena Solana-Arellano, Ernesto Franco-Vizcaino Jan 2006

The Role Of Increased Sea Surface Temperature On Eelgrass Leaf Dynamics: Onset Of El Nin˜ O As A Proxy For Global Climate Change In San Quintı´N Bay, Baja California, Hector A. Echavarria-Heras, Elena Solana-Arellano, Ernesto Franco-Vizcaino

Bulletin of the Southern California Academy of Sciences

We present a quantitative study of the effects of sea surface temperatures on eelgrass productivity variables. We compared standing stock variables for Zostera marina for the strong El Nin˜o event of 1986–1987, previously published by other workers for San Quintı´n Bay, Baja California, to our previously unpublished data for the ‘‘normal year’’ of 1992–1993. We found significant differences for most of the variables measured, which included Leaf Area Index, leaf length, width, dry weight and area, biomass, shoot density, and number of leaves per shoot. Inspection of the multivariate ENSO index (MEI) and sea surface temperature ...


Function Of Autophagy In Development And Abiotic Stress Tolerance In Arabidopsis Thaliana , Yan Xiong Jan 2006

Function Of Autophagy In Development And Abiotic Stress Tolerance In Arabidopsis Thaliana , Yan Xiong

Retrospective Theses and Dissertations

Autophagy is a process in which cytoplasmic components are degraded in the vacuole. It occurs when organisms are subjected to environmental stress conditions or during certain stages of development. Upon induction of autophagy, a portion of cytoplasm is surrounded by a double membrane structure to form an autophagosome. The outer membrane of the autophagosome then fuses with the vacuole and the inner membrane and its contents are degraded by vacuolar hydrolases. The morphological characteristics of autophagy have been observed in plants for decades and several autophagy defective mutants have been isolated recently; however, little is known about the molecular mechanism ...


Relationship Between Concentration Of Isoflavones In Soybean Grain And Potassium Fertilization , Mario Valadez Ramirez Jan 2006

Relationship Between Concentration Of Isoflavones In Soybean Grain And Potassium Fertilization , Mario Valadez Ramirez

Retrospective Theses and Dissertations

Soybean grain contains isoflavones that may prevent various human diseases. Previous studies in Canada found that K fertilization and high grain K concentration can result in increased isoflavones concentration in grain, but effects were inconsistent across sites and soil-test K (STK) levels. The objective of this study was to assess (1) effects of K fertilization on the concentration of isoflavones and K in soybean grain and (2) relationships between soybean grains K concentration, isoflavone concentration, and yield. The study was based on analyses of grain collected from selected treatments and years of six Iowa long-term experiments that investigated effects of ...


Adventitious Shoot Propagation And Cultural Inputs In Nursery Production Of A Primocane-Fruiting Blackberry Selection, Kimberley Dennis, John R. Clark, James A. Robbins Jan 2006

Adventitious Shoot Propagation And Cultural Inputs In Nursery Production Of A Primocane-Fruiting Blackberry Selection, Kimberley Dennis, John R. Clark, James A. Robbins

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Studies were conducted from January to October 2005 to determine the effect of root-cutting length on adventitious shoot yield and the management practices necessary to produce nurseryquality primocane-fruiting blackberry plants. The first portion of the study measured the average number of shoots produced from 7.6 cm- and 15.2 cm-long root cuttings of APF-44 blackberry—a primocane-fruiting genotype from the University of Arkansas breeding program. Cuttings were forced in a shallow bin containing a soilless potting medium. The average number of shoots per root cutting from 7.6 cm- and 15.2 cm- long root cuttings averaged 1.6 ...


The Role Of Herbaceous Woodland Perennial Diversity For Improving Nutrient Uptake Capacity Of Riparian Areas, Cathy Mabry Mcmullen, Jan Thompson Jan 2006

The Role Of Herbaceous Woodland Perennial Diversity For Improving Nutrient Uptake Capacity Of Riparian Areas, Cathy Mabry Mcmullen, Jan Thompson

Leopold Center Completed Grant Reports

This project investigated the roles of forest understory perennial plant communities in storing nutrients and preventing pollution of surface waters.