scholarly journals Determination of Virulence Phenotypes of Plasmopara halstedii in the United States

Plant Disease ◽  
2020 ◽  
Vol 104 (11) ◽  
pp. 2823-2831 ◽  
Author(s):  
Michelle A. Gilley ◽  
Thomas J. Gulya ◽  
Gerald J. Seiler ◽  
William Underwood ◽  
Brent S. Hulke ◽  
...  
Keyword(s):  
Disease Management ◽  
Great Plains ◽  
Resistance Genes ◽  
Genetic Resistance ◽  
The United States ◽  
Management Tool ◽  
Plasmopara Halstedii ◽  
Pathogen Virulence ◽  
Standard Set ◽  
The U.S

Downy mildew, caused by Plasmopara halstedii (Farl.) Berl. and de Toni, is an economically important disease in cultivated sunflowers, Helianthus annuus L. Resistance genes incorporated into commercial hybrids are used as an effective disease management tool, but the duration of effectiveness is limited as virulence evolves in the pathogen population. A comprehensive assessment of pathogen virulence was conducted in 2014 and 2015 in the U.S. Great Plains states of North Dakota and South Dakota, where approximately 75% of the U.S. sunflower is produced annually. The virulence phenotypes (and races) of 185 isolates were determined using the U.S. standard set of nine differentials. Additionally, the virulence phenotypes of 61 to 185 isolates were determined on 13 additional lines that have been used to evaluate pathogen virulence in North America and/or internationally. Although widespread virulence was identified on several genes, new virulence was identified on the Pl8 resistance gene, and no virulence was observed on the PlArg, Pl15, Pl17 and Pl18 genes. Results of this study suggest that three additional lines should be used as differentials and agree with previous studies that six lines proposed as differentials should be used in two internationally accepted differential sets. For effective disease management using genetic resistance, it is critical that virulence data be relevant and timely. This is best accomplished when pathogen virulence is determined frequently and by using genetic lines containing resistance genes actively incorporated into commercial cultivars.

Survey of Ochratoxin A in Freshly Harvested Durum and Hard Red Spring Wheat in the United States, 2011 and 2012

2014 ◽  
Vol 77 (6) ◽  
pp. 1005-1009 ◽  
Author(s):  
JULIE A. KURUC ◽  
FRANK MANTHEY ◽  
SENAY SIMSEK ◽  
CHARLENE WOLF-HALL
Keyword(s):  
Durum Wheat ◽  
Ochratoxin A ◽  
Great Plains ◽  
High Performance ◽  
The United States ◽  
Cereal Grains ◽  
Hard Red Spring Wheat ◽  
The World ◽  
Food And Feed ◽  
The U.S

Ochratoxin A (OTA) is a toxin produced by some Penicillium and Aspergillus species around the world in a variety of food and feed, especially cereal grains, before harvest but primarily during storage. Durum and hard red spring (HRS) wheat samples were collected right after harvest as part of the U.S. regional crop quality survey in both 2011 (n = 560) and 2012 (n = 654) from the upper Great Plains. All samples were analyzed for OTA contamination using high-performance liquid chromatography with fluorescence detection. Overall, 2.1% of the samples were positive for OTA. In 2011, OTA was detected in 1.0% of the durum wheat samples but was not found in HRS wheat. In 2012, 8.3 and 1.4% of the durum and HRS wheat samples, respectively, were positive for OTA. Of the 25 samples that had detectable OTA, 3 samples (12%), all of which were durum wheat, had OTA that exceeded 5 ng/g.

Status of a broadly distributed endangered species: results and implications of the second International Piping Plover Census

2000 ◽  
Vol 78 (1) ◽  
pp. 128-139 ◽  
Author(s):  
Jonathan H Plissner ◽  
Susan M Haig
Keyword(s):  
Endangered Species ◽  
Great Plains ◽  
Atlantic Coast ◽  
The United States ◽  
Greater Antilles ◽  
Piping Plover ◽  
Canadian Prairie ◽  
Wintering Birds ◽  
The U.S ◽  
Second International

Methods for monitoring progress toward recovery goals are highly variable and may be problematic for endangered species that are mobile and widely distributed. Recovery objectives for Piping Plovers (Charadrius melodus) include attainment of minimum population sizes within specified recovery units, as determined by two U.S. and two Canadian recovery teams. To assess progress toward these goals, complete surveys of the species' winter and breeding ranges in Canada, the United States, Mexico, the Bahamas, and the Greater Antilles are conducted every 5 years. In 1996, 1200 biologists and volunteers participated in the second International Piping Plover Census, tallying 2515 wintering birds and 5913 adults (2668 breeding pairs) during the breeding census. Winter numbers were 27% lower than those of the first international census conducted in 1991, with substantially fewer wintering birds along the Gulf of Mexico and an overall increase in numbers along the Atlantic Coast. Large numbers of wintering plovers remain undetected. In 1996, the total number of breeding adults was 7.7% higher than in 1991. Regionally, breeding numbers were 31% higher along the Atlantic Coast and 20% higher in the small Great Lakes population, but declined by 5% in the U.S. Great Plains and the Canadian Prairie. Target recovery numbers were met only for Saskatchewan but were approached in Alberta and New England. The results suggest that Piping Plover distribution and habitat use in the U.S. Great Plains/Canadian Prairie region may shift dramatically with water conditions.

scholarly journals Physiologic Specialization of Puccinia triticina on Wheat in the United States in 2004

Plant Disease ◽  
2006 ◽  
Vol 90 (9) ◽  
pp. 1219-1224 ◽  
Author(s):  
J. A. Kolmer ◽  
D. L. Long ◽  
M. E. Hughes
Keyword(s):  
United States ◽  
Leaf Rust ◽  
Great Plains ◽  
Resistance Genes ◽  
Durable Resistance ◽  
Puccinia Triticina ◽  
Leaf Rust Resistance ◽  
The United States ◽  
Virulence Phenotype ◽  
Common Phenotype

Collections of Puccinia triticina were obtained from rust-infected wheat leaves by cooperators throughout the United States and from surveys of wheat fields and nurseries in the Great Plains, Ohio Valley, southeast, California, and Pacific Northwest, in order to determine the virulence of the wheat leaf rust population in 2004. Single uredinial isolates (757 in total) were derived from the collections and tested for virulence phenotype on lines of Thatcher wheat that are near-isogenic for leaf rust resistance genes Lr1, Lr2a, Lr2c, Lr3a, Lr9, Lr16, Lr24, Lr26, Lr3ka, Lr11, Lr17a, Lr30, LrB, Lr10, Lr14a, Lr18, Lr21, and Lr28, and winter wheat lines with genes Lr41 and Lr42. In the United States in 2004, 52 virulence phenotypes of P. triticina were found. Virulence phenotype MCDSB, selected by virulence to resistance genes Lr17a and Lr26, was the most common phenotype in the United States and was found in all wheat growing areas. Virulence phenotype TBBGG, with virulence to Lr2a, was the second most common phenotype and was found primarily in the spring wheat region of the north-central states. Virulence phenotype MBDSB, which has virulence to Lr17a, was the third most common phenotype and was found in all wheat growing areas except California. Phenotype TNRJJ, with virulence to genes Lr9, Lr24, and Lr41, was the fourth most common phenotype and occurred in the southeastern states and throughout the Great Plains region. Virulence phenotypes avirulent to a second gene in the Thatcher differential line with Lr1 increased in frequency in the United States in 2004. The highly diverse population of P. triticina in the United States will continue to present a challenge for the development of wheat cultivars with effective durable resistance.

MEXUS GULF EXERCISE 2004*

2005 ◽  
Vol 2005 (1) ◽  
pp. 715-718 ◽  
Author(s):  
Warren T. (Tommy) Hutto ◽  
David Pertuz
Keyword(s):  
The United States ◽  
Lessons Learned ◽  
Coast Guard ◽  
Hazardous Substances ◽  
Management Tool ◽  
Management Service ◽  
Exploration And Production ◽  
Bilateral Cooperation ◽  
Production Company ◽  
The U.S

ABSTRACT The Agreement of Cooperation Between the United States of American and the United Mexican States Regarding Pollution of the Marine Environment by Discharges of Hydrocarbons and Other Hazardous Substances signed in February 2000 by the U.S. Coast Guard and the Secretaria de Marina-Armada de Mexico, established the beginning of a successful bilateral cooperation between both countries for the preparation and response to pollution incidents that could affect the coastal waters of both countries. The agreement calls for joint pollution response exercises to be conducted to exercise the bilateral coordination and joint response system. In May 2004, the Shell Exploration and Production Company acted as the Responsible Party in such a joint exercise, denominated MEXUS GULF 2004. The exercise was conducted in Matamoros, Tamaulipas, Mexico May 25–27, 2004. Building on a previously conducted exercise in 2002, the objectives of the 2004 exercise were to exercise and identify joint response procedures following a significant impact to the shared shorelines. Specifically, the four identified objectives included:Identify Natural Resources Damage Assessment (NRDA) Procedures in Mexico.Address transboundary movement Procedures of collected waste and contaminated equipment with emphasis on movement from Mexico to the U.S.Identify joint procedures for clean-up and rehabilitation of oiled wildlife.Exercise Joint Command and Control Procedures including transboundary and field communications Shell Exploration and Production Company (SEPCo), working jointly with the U.S. Coast Guard, and the Mexican Secretaria de Marina—Armada de Mexico and with outstanding support from the National Ocaanographic and Atmospheric Administration, The U.S. Fish and Wildlife Service, the Minerals Management Service and the Texas General Land Office designed and executed an outstanding exercise well lessons learned were captured and shared. This paper will cover the planning, logistical considerations, execution and lessons learned from the joint exercise as well as the successful use of the Incident Command System as an incident response management tool for bilateral cooperation.

scholarly journals Drought and Pluvial Dipole Events within the Great Plains of the United States

2015 ◽  
Vol 54 (9) ◽  
pp. 1886-1898 ◽  
Author(s):  
Jordan Christian ◽  
Katarina Christian ◽  
Jeffrey B. Basara
Keyword(s):  
United States ◽  
Standard Deviation ◽  
Great Plains ◽  
Spatial Scales ◽  
The United States ◽  
Northern Great Plains ◽  
High Plains ◽  
Southern Great Plains ◽  
One Year ◽  
The U.S

AbstractThe purpose of this study was to quantify dipole events (a drought year followed by a pluvial year) for various spatial scales including the nine Oklahoma climate divisions and the author-defined regions of the U.S. Southern Great Plains (SGP), High Plains (HP), and Northern Great Plains (NGP). Analyses revealed that, on average, over twice as many standard deviation (STDEV) dipoles existed in the latter half of the dataset (1955–2013) relative to the first half (1896–1954), suggesting that dramatic increases in precipitation from one year to the next within the Oklahoma climate divisions are increasing with time. For the larger regions within the Great Plains of the United States, the percent chance of a significant pluvial year following a significant drought year was approximately 25% of the time for the SGP and NGP and approximately 16% of the time for the HP. The STDEV dipole analyses further revealed that the frequency of dipoles was consistent between the first and second half of the dataset for the NGP and HP but was increasing with time in the SGP. The temporal periods of anomalous precipitation during relative pluvial years within the STDEV dipole events were unique for each region whereby October occurred most frequently (70%) within the SGP, September occurred most frequently (60%) within the HP, and May occurred most frequently (62%) within the NGP.

scholarly journals A compilation of and typology for abundance-, phylogenetic- and functional-based diversity metrics

2019 ◽  
Author(s):  
Samuel M. Scheiner
Keyword(s):  
National Science Foundation ◽  
The United States ◽  
United States Government ◽  
States Government ◽  
National Science ◽  
Standard Set ◽  
Similarities And Differences ◽  
Work Done ◽  
The U.S ◽  
Diversity Metrics

AbstractEcologists are faced with an over-abundance of ways to measure biodiversity. In this paper, I provide a compilation of and guide through this ticket of diversity metrics. I present a typology for diversity metrics that encompasses the three commonly considered categories of information: abundance, phylogenetic relationships, and traits (i.e., function). I update and expand previous summaries of diversity metrics. The formulas of those 117 metrics are presented in a standard notation and format that makes it easy to see the mathematical similarities and differences among the metrics. Finally, I propose a standard set of symbols for many of the metrics that makes their properties immediately obvious. This compilation will make it easier for researchers to identify the metric(s) most suited to their needs and will help guide future metric development.DisclaimerThis manuscript is based on work done while serving at (and furloughed from) the U.S. National Science Foundation. The views expressed in this paper do not necessarily reflect those of the National Science Foundation or the United States Government.

scholarly journals Virulence in Oat Crown Rust (Puccinia coronata f. sp. avenae) in the United States from 2006 through 2009

Plant Disease ◽  
2011 ◽  
Vol 95 (12) ◽  
pp. 1528-1534 ◽  
Author(s):  
M. L. Carson
Keyword(s):  
United States ◽  
Resistance Genes ◽  
The United States ◽  
Crown Rust ◽  
Puccinia Coronata ◽  
The North ◽  
Oat Crown Rust ◽  
Primary Means ◽  
Oat Cultivars ◽  
The U.S

The use of race-specific seedling genes for resistance is the primary means of controlling crown rust of oat (Puccinia coronata f. sp. avenae) in the United States. To better utilize those resistance genes, knowledge of the occurrence and frequency of corresponding virulence in the population of P. coronata f. sp. avenae in the United States is essential. In total, 571 single-pustule isolates of oat crown rust were collected from cultivated and wild oat (Avena sativa and A. fatua, respectively) in the major oat production areas of the United States from 2006 through 2009. They were tested for virulence on seedlings of 31 differential oat lines in the greenhouse. In all, 201 races were found among the 357 isolates from the spring oat region of the north-central United States, and 140 races were found among 214 isolates from the southern winter oat region. The crown rust populations from the winter and spring oat regions were clearly differentiated from one another, differing in the frequency of virulence for 24 of the 31 differentials. Some virulence associations previously reported in the U.S. oat crown rust population were also found in both regions in this survey, even when the dataset was clone corrected. Associations between virulence to the Pc genes were predominately positive in both regions but both positive and negative associations occurred more frequently in the winter oat region, where sexual reproduction does not occur. Some of the virulence diversity in the oat crown rust population in the United States can be related to the deployment of resistance genes in commercial oat cultivars and virulence associations existing in the oat crown rust population. When data from a previous report covering 2001 through 2005 is combined with data reported in this article, the mean virulence of the U.S. populations of crown rust continued to increase from 2001 to 2009. Virulence to Pc38, Pc39, Pc45, Pc48, Pc52, Pc55, Pc56, Pc57, Pc59, Pc62, Pc63, Pc64, Pc68, and Pc96 significantly increased in one or both regions during this time period. No significant declines in virulence frequency were found in either region. Genes for crown rust resistance derived from A. sterilis appear to be as rapidly defeated as has happened to Pc genes from A. sativa. There is an urgent need to find additional sources of effective resistance to P. coronata f. sp. avenae and introgress it into adapted oat cultivars.

scholarly journals Genome-Enabled Phylogeographic Investigation of the Quarantine Pathogen Ralstonia solanacearum Race 3 Biovar 2 and Screening for Sources of Resistance Against Its Core Effectors

2015 ◽  
Vol 105 (5) ◽  
pp. 597-607 ◽  
Author(s):  
Christopher R. Clarke ◽  
David J. Studholme ◽  
Byron Hayes ◽  
Brendan Runde ◽  
Alexandra Weisberg ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Ralstonia Solanacearum ◽  
Genetic Resistance ◽  
Brown Rot ◽  
The United States ◽  
South American ◽  
Sources Of Resistance ◽  
Quarantine Pathogen ◽  
Potato Brown Rot ◽  
Core Effectors

Phylogeographic studies inform about routes of pathogen dissemination and are instrumental for improving import/export controls. Genomes of 17 isolates of the bacterial wilt and potato brown rot pathogen Ralstonia solanacearum race 3 biovar 2 (R3bv2), a Select Agent in the United States, were thus analyzed to get insight into the phylogeography of this pathogen. Thirteen of fourteen isolates from Europe, Africa, and Asia were found to belong to a single clonal lineage while isolates from South America were genetically diverse and tended to carry ancestral alleles at the analyzed genomic loci consistent with a South American origin of R3bv2. The R3bv2 isolates share a core repertoire of 31 type III-secreted effector genes representing excellent candidates to be targeted with resistance genes in breeding programs to develop durable disease resistance. Toward this goal, 27 R3bv2 effectors were tested in eggplant, tomato, pepper, tobacco, and lettuce for induction of a hypersensitive-like response indicative of recognition by cognate resistance receptors. Fifteen effectors, eight of them core effectors, triggered a response in one or more plant species. These genotypes may harbor resistance genes that could be identified and mapped, cloned, and expressed in tomato or potato, for which sources of genetic resistance to R3bv2 are extremely limited.

scholarly journals Understanding Hailstone Temporal Variability and Contributing Factors over the U.S. Southern Great Plains

2020 ◽  
Vol 33 (10) ◽  
pp. 3947-3966
Author(s):  
Jong-Hoon Jeong ◽  
Jiwen Fan ◽  
Cameron R. Homeyer ◽  
Zhangshuan Hou
Keyword(s):  
Great Plains ◽  
Temporal Variability ◽  
Southern Oscillation ◽  
The United States ◽  
Economic Losses ◽  
Physical Factors ◽  
Contributing Factors ◽  
Southern Great Plains ◽  
Aerosol Loading ◽  
The U.S

AbstractHailstones are a natural hazard that pose a significant threat to property and are responsible for significant economic losses each year in the United States. Detailed understanding of their characteristics is essential to mitigate their impact. Identifying the dynamic and physical factors contributing to hail formation and hailstone sizes is of great importance to weather and climate prediction and policymakers. In this study, we have analyzed the temporal and spatial variabilities of severe hail occurrences over the U.S. southern Great Plains (SGP) states from 2004 to 2016 using two hail datasets: hail reports from the Storm Prediction Center and the newly developed radar-retrieved maximum expected size of hail (MESH). It is found that severe and significant severe hail occurrences have a considerable year-to-year temporal variability in the SGP region. The interannual variabilities have a strong correspondence with sea surface temperature anomalies over the northern Gulf of Mexico and there is no outlier. The year 2016 is identified as an outlier for the correlations with both El Niño–Southern Oscillation (ENSO) and aerosol loading. The correlations with ENSO and aerosol loading are not statistically robust to inclusion of the outlier 2016. Statistical analysis without the outlier 2016 shows that 1) aerosols that may be mainly from northern Mexico have the largest correlation with hail interannual variability among the three factors and 2) meteorological covariation does not significantly contribute to the high correlation. These analyses warrant further investigations of aerosol impacts on hail occurrence.

scholarly journals Physiologic Specialization of Puccinia triticina on Wheat in the United States in 2001

Plant Disease ◽  
2003 ◽  
Vol 87 (7) ◽  
pp. 859-866 ◽  
Author(s):  
J. A. Kolmer ◽  
D. L. Long ◽  
E. Kosman ◽  
M. E. Hughes
Keyword(s):  
United States ◽  
Leaf Rust ◽  
Great Plains ◽  
Resistance Genes ◽  
Puccinia Triticina ◽  
Leaf Rust Resistance ◽  
The United States ◽  
Ohio Valley ◽  
Virulence Phenotype ◽  
Common Phenotype

Collections of Puccinia triticina were obtained from rust-infected wheat leaves by cooperators throughout the United States and from surveys of wheat fields and nurseries in the Great Plains, Ohio Valley, Gulf Coast, California, Pacific Northwest, and Atlantic Coast States in order to determine the virulence of the wheat leaf rust fungus in 2001. Single uredinial isolates (477 in total) were derived from the wheat leaf rust collections and tested for virulence phenotype on lines of Thatcher wheat that are near-isogenic for leaf rust resistance genes Lr1, Lr2a, Lr2c, Lr3, Lr9, Lr16, Lr24, Lr26, Lr3ka, Lr11, Lr17, Lr30, LrB, Lr10, Lr14a, and Lr18. The isolates also were tested for virulence on adult plants with leaf rust resistance genes Lr12, Lr13, Lr22a, Lr22b, Lr34, Lr35, and Lr37. In the United States in 2001, 44 virulence phenotypes of P. triticina were found. Virulence phenotype MBDS, which is virulent to resistance gene Lr17, was the most common phenotype in the United States. MBDS was found in the Southeast, Great Plains, and Ohio Valley regions. Virulence phenotype THBJ, which is virulent to Lr16 and Lr26, was the second most common phenotype, and occurred almost exclusively in the north-central Great Plains region. Phenotype MCDS, which is virulent to Lr17 and Lr26, was the third most common phenotype and was found primarily in the Southeast, Ohio Valley, and Great Plains regions. The Southeast and Ohio Valley regions differed from the Great Plains region for predominant virulence phenotypes, which indicate that populations of P. triticina in those areas are not closely connected. The northern and southern areas of the Great Plains region differed for phenotypes with virulence to Lr16; however, the two areas had other phenotypes in common. Virulence to the adult plant resistance genes Lr35 and Lr37 was detected for the first time in North America in the MBDS, MCJS, and MCDS phenotypes.

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