scholarly journals A Standardized Inoculation Protocol to Test Wheat Cultivars for Reaction to Head Blast Caused by Magnaporthe oryzae (Triticum pathotype)

2016 ◽  
Vol 17 (3) ◽  
pp. 186-187 ◽  
Author(s):  
C. D. Cruz ◽  
W. W. Bockus ◽  
J. P. Stack ◽  
B. Valent ◽  
J. N. Maciel ◽  
...  

Wheat blast, caused by the Triticum pathotype of Magnaporthe oryzae, poses a significant threat to wheat production worldwide. Because this pathotype does not occur in the United States, it is important to prepare for its possible introduction. As part of this preparation, over 500 U.S. wheat cultivars were tested for susceptibility or resistance to head blast. Inoculations were conducted under biosafety level 3 conditions. However, the protocols to phenotype wheat cultivars vary among researchers, and head blast inoculation protocols need to be standardized so that results can be easily interpreted and shared internationally. The protocol presented, based on several years' experience, is recommended for common use to facilitate direct comparison of disease phenotyping results among researchers. Accepted for publication 12 August 2016.

Plant Disease ◽  
2016 ◽  
Vol 100 (10) ◽  
pp. 1979-1987 ◽  
Author(s):  
Christian D. Cruz ◽  
Roger D. Magarey ◽  
David N. Christie ◽  
Glenn A. Fowler ◽  
Jose M. Fernandes ◽  
...  

Wheat blast, caused by the Triticum pathotype of Magnaporthe oryzae, is an emerging disease considered to be a limiting factor to wheat production in various countries. Given the importance of wheat blast as a high-consequence plant disease, weather-based infection models were used to estimate the probabilities of M. oryzae Triticum establishment and wheat blast outbreaks in the United States. The models identified significant disease risk in some areas. With the threshold levels used, the models predicted that the climate was adequate for maintaining M. oryzae Triticum populations in 40% of winter wheat production areas of the United States. Disease outbreak threshold levels were only reached in 25% of the country. In Louisiana, Mississippi, and Florida, the probability of years suitable for outbreaks was greater than 70%. The models generated in this study should provide the foundation for more advanced models in the future, and the results reported could be used to prioritize research efforts regarding the biology of M. oryzae Triticum and the epidemiology of the wheat blast disease.


2013 ◽  
Vol 14 (1) ◽  
pp. 2-10 ◽  
Author(s):  
S. C. Olsen

AbstractRegulations in the United States require animal biosafety level 3 (ABSL-3) or biosafety level 3 agriculture (BSL-3-Ag) containment for many endemic zoonotic pathogens and etiologic agents of foreign animal diseases. In an effort to protect public health, billions of dollars were invested in regulatory programs over many years to reduce the prevalence of zoonotic pathogens such as Brucella and Mycobacterium bovis in domestic livestock. In addition to research needs in domestic livestock hosts, the establishment of brucellosis and tuberculosis in wildlife in the United States has created a need for research studies addressing these zoonotic diseases. As guidelines in the Biosafety in Microbiological and Biomedical Laboratories (BMBL, 2009) for BSL-3 and BSL-3-Ag facilities are primarily directed toward laboratory or vivarium facilities, additional issues should be considered in designing large animal containment facilities for domestic livestock and/or wildlife. Flight distance, herd orientation, social needs, aggressiveness, and predictability are all factors we considered on a species by species basis for designing our containment facilities and for work practices with large ruminants. Although safety risk cannot be completely eliminated when working with large animals, studies in natural hosts are critical for advancing vaccine and diagnostic development, and providing basic knowledge of disease pathogenesis in natural hosts. Data gathered in these types of studies are vital for state and national regulatory personnel in their efforts to design strategies to control or eradicate diseases such as brucellosis and tuberculosis in their natural hosts, whether it is domestic livestock or wildlife. It is likely that failure to address the prevalence of disease in wildlife reservoirs will lead to re-emergence in domestic livestock. The overall benefit of these studies is to protect public health, provide economic benefits to producers, and protect the economic investment made in regulatory programs.


Plant Disease ◽  
2017 ◽  
Vol 101 (5) ◽  
pp. 684-692 ◽  
Author(s):  
Mark Farman ◽  
Gary Peterson ◽  
Li Chen ◽  
John Starnes ◽  
Barbara Valent ◽  
...  

Wheat blast is a devastating disease that was first identified in Brazil and has subsequently spread to surrounding countries in South America. In May 2011, disease scouting in a University of Kentucky wheat trial plot in Princeton, KY identified a single plant with disease symptoms that differed from the Fusarium head blight that was present in surrounding wheat. The plant in question bore a single diseased head that was bleached yellow from a point about one-third up the rachis to the tip. A gray mycelial mass was observed at the boundary of the healthy tissue and microscopic examination of this material revealed pyriform spores consistent with a Magnaporthe sp. The pathogen was subsequently identified as Magnaporthe oryzae through amplification and sequencing of molecular markers, and genome sequencing revealed that the U.S. wheat blast isolate was most closely related to an M. oryzae strain isolated from annual ryegrass in 2002 and quite distantly related to M. oryzae strains causing wheat blast in South America. The suspect isolate was pathogenic to wheat, as indicated by growth chamber inoculation tests. We conclude that this first occurrence of wheat blast in the United States was most likely caused by a strain that evolved from an endemic Lolium-infecting pathogen and not by an exotic introduction from South America. Moreover, we show that M. oryzae strains capable of infecting wheat have existed in the United States for at least 16 years. Finally, evidence is presented that the environmental conditions in Princeton during the spring of 2011 were unusually conducive to the early production of blast inoculum.


2021 ◽  
pp. PHP-11-20-0101-
Author(s):  
Barbara Valent ◽  
Giovana Cruppe ◽  
James P. Stack ◽  
C. D. Cruz ◽  
Mark L. Farman ◽  
...  

Wheat blast is an explosive new fungal disease of wheat caused by an Magnaporthe oryzae (synonym of Pyricularia oryzae) host-adapted subpopulation, the M. oryzae Triticum pathotype (MoT). MoT has been found in South America, South Asia, and Africa, but not in the United States. Wheat blast caused by the MoT fungus was first reported in Brazil in 1985 and subsequently spread to Bolivia, Paraguay, and Argentina in the 1990s and 2000s. The disease first appeared in Bangladesh in 2016 and in Zambia in 2017. The MoT fungus is seedborne, and the most likely route for movement across oceans was though grain trade. Wheat head (spike) blast is the predominant form of the disease in the field, although foliar and stem blast also occurs. The disease has proven hard to control when weather conditions are conducive, often resulting in devastating yield and quality losses. The only currently effective resistance, contained in the 2NvS translocation from the wild wheat relative Aegilops ventricosa, confers partial resistance that is variable depending on the genetic background of the specific wheat variety. Fungicides are not fully effective in controlling wheat head blast if warm, humid weather occurs during the heading stage. A major disease management strategy in areas where the disease occurs involves timing the wheat planting date so that heading does not coincide with warm rainy weather. A climate suitability model for the United States indicates that all of U.S. soft red winter wheat and about half of the hard red winter wheat are at risk.


Plant Disease ◽  
2007 ◽  
Vol 91 (5) ◽  
pp. 517-524 ◽  
Author(s):  
Y. Tosa ◽  
W. Uddin ◽  
G. Viji ◽  
S. Kang ◽  
S. Mayama

Gray leaf spot caused by Magnaporthe oryzae is a serious disease of perennial ryegrass (Lolium perenne) turf in golf course fairways in the United States and Japan. Genetic relationships among M. oryzae isolates from perennial ryegrass (prg) isolates within and between the two countries were examined using the repetitive DNA elements MGR586, Pot2, and MAGGY as DNA fingerprinting probes. In all, 82 isolates of M. oryzae, including 57 prg isolates from the United States collected from 1995 to 2001, 1 annual ryegrass (Lolium multiflorum) isolate from the United States collected in 1972, and 24 prg isolates from Japan collected from 1996 to 1999 were analyzed in this study. Hybridization with the MGR586 probe resulted in approximately 30 DNA fragments in 75 isolates (designated major MGR586 group) and less than 15 fragments in the remaining 7 isolates (designated minor MGR586 group). Both groups were represented among the 24 isolates from Japan. All isolates from the United States, with the exception of one isolate from Maryland, belonged to the major MGR586 group. Some isolates from Japan exhibited MGR586 fingerprints that were identical to several isolates collected in Pennsylvania. Similarly, fingerprinting analysis with the Pot2 probe also indicated the presence of two distinct groups: isolates in the major MGR586 group showed fingerprinting profiles comprising 20 to 25 bands, whereas the isolates in the minor MGR586 group had less than 10 fragments. When MAGGY was used as a probe, two distinct fingerprint types, one exhibiting more than 30 hybridizing bands (type I) and the other with only 2 to 4 bands (type II), were identified. Although isolates of both types were present in the major MGR586 group, only the type II isolates were identified in the minor MGR586 group. The parsimony tree obtained from combined MGR586 and Pot2 data showed that 71 of the 82 isolates belonged to a single lineage, 5 isolates formed four different lineages, and the remaining 6 (from Japan) formed a separate lineage. This study indicates that the predominant groups of M. oryzae associated with the recent outbreaks of gray leaf spot in Japan and the United States belong to the same genetic lineage.


Author(s):  
Matthew W Parker ◽  
Diana Sobieraj ◽  
Mary Beth Farrell ◽  
Craig I Coleman

Background: Little has been published on the practice of echocardiography (echo) in the United States. We used the Intersocietal Accreditation Commission-Echocardiography (IAC-Echo) applications database to describe the personnel in echo laboratories seeking accreditation. Methods: We used de-identified data provided on IAC-Echo applications to characterize facilities by hospital association, census region, annual volume, number of sites, previous accreditation, and numbers of physicians and sonographers as well as National Board of Echocardiography (NBE) testamur status of physicians and registered credential status of sonographers. We categorized Medical Directors by board certification in cardiovascular diseases, internal medicine, other specialty, or none. Medical Director echo training could be formal Level 2 or 3 or experiential by ≥3 years of practice. Frequencies, means, and medians were compared between groups using the chi-square test, t-test, or Mann Whitney test, respectively. Results: From 2011 to 2013, 1926 echo labs representing 10618 physicians and 6870 sonographers applied for IAC-Echo accreditation or re-accreditation. The majority of medical directors were board certified in cardiovascular diseases and 34.1% of medical directors and 27.2% of staff physicians held NBE testamur status; 79.5% of sonographers held registered credentials. Most echo labs were in the Northeast or South census regions, have an average of 1.75 sites, and are based outside of hospitals (Table). Compared to nonhospital echo labs, medical directors of hospital-based echo labs were more likely to be Level 3 trained (19.8% versus 30.8%, p<0.01) and be NBE testamurs (28.9% versus 45.6%, p<0.01). Markers of echo lab size, region, previous accreditation, and credentialed sonographers were associated with accreditation versus delay decisions; there was a trend toward accreditation among facilities with NBE medical directors. Conclusion: Among facilities seeking IAC-Echo accreditation, the minority of echo physicians hold NBE testamur status. Hospital and nonhospital facilities are different in the credentials of their personnel.


2019 ◽  
Vol 11 (4) ◽  
pp. 350-354
Author(s):  
Matthew C. Hess ◽  
Zachary Devilbiss ◽  
Garry Wai Keung Ho ◽  
Raymond Thal

Context:Lyme disease is the most common tick-borne illness in North America and Europe, and Lyme arthritis is a frequent late-stage manifestation in the United States. However, Lyme arthritis has rarely been reported as a postoperative complication.Evidence Acquisition:The PubMed database was queried through June 2018, and restricted to the English language, in search of relevant articles.Study Design:Clinical review.Level of Evidence:Level 3.Results:A total of 5 cases of Lyme arthritis as a postoperative complication have been reported in the literature.Conclusion:These cases highlight the importance for providers practicing in Lyme-endemic regions to keep such an infection in mind when evaluating postoperative joint pain and swelling. We propose herein an algorithm for the workup of potential postoperative Lyme arthritis.Strength of Recommendation Taxonomy (SORT):C


Plant Disease ◽  
2017 ◽  
Vol 101 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Anmin Wan ◽  
Kebede T. Muleta ◽  
Habtemariam Zegeye ◽  
Bekele Hundie ◽  
Michael O. Pumphrey ◽  
...  

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most important diseases of wheat in Ethiopia. In total, 97 isolates were recovered from stripe rust samples collected in Ethiopia in 2013 and 2014. These isolates were tested on a set of 18 Yr single-gene differentials for characterization of races and 7 supplementary differentials for additional information of virulence. Of 18 P. striiformis f. sp. tritici races identified, the 5 most predominant races were PSTv-105 (21.7%), PSTv-106 (17.5%), PSTv-107 (11.3%), PSTv-76 (10.3%), and PSTv-41 (6.2%). High frequencies (>40%) were detected for virulence to resistance genes Yr1, Yr2, Yr6, Yr7, Yr8, Yr9, Yr17, Yr25, Yr27, Yr28, Yr31, Yr43, Yr44, YrExp2, and YrA. Low frequencies (<40%) were detected for virulence to Yr10, Yr24, Yr32, YrTr1, Hybrid 46, and Vilmorin 23. None of the isolates were virulent to Yr5, Yr15, YrSP, and YrTye. Among the six collection regions, Arsi Robe and Tiyo had the highest virulence diversities, followed by Bekoji, while Bale and Holeta had the lowest. Evaluation of 178 Ethiopian wheat cultivars and landraces with two of the Ethiopian races and three races from the United States indicated that the Ethiopian races were more virulent on the germplasm than the predominant races of the United States. Thirteen wheat cultivars or landraces that were resistant or moderately resistant to all five tested races should be useful for breeding wheat cultivars with resistance to stripe rust in both countries.


Author(s):  
Chandra Shekhar Biswas ◽  
Afsana Hannan ◽  
Abul Monsur ◽  
G H M Sagor

Global food security is seriously threatened due to increased frequency and occurrence of fungal diseases. One example is wheat blast caused by Magnaporthe oryzae is a fungal diseases of rice, wheat, and other grasses, that can destroy the whole food production to sustain millions of people. Wheat blast was first detected in february 2016 with a serious outbreak in Asia. Assessment of the available germplasms to stress tolerant/resistant is one of the best options for developing stress tolerant crop varieties. In this study, a total of sixteen wheat cultivars were collected and test their disease severity to blast pathogen Magnaporthe oryzae pv. Triticum (MoT). Among the varieties, BARI Gom 33 exhibited partially resistance against blast pathogen, whereas all other genotypes become susceptible to MoT. Different yield and yield contributing characters of both resistant and susceptible cultivars were also evaluated and found no significant differences among them. To understand the underlying mechanism of resistance in BARI Gom 33, antioxidant enzyme activity, concentration of reactive oxygen species and cellular damage after fungal infection were also evaluated and found that activities of ascorbate peroxidase (APX), catalase (CAT) and peroxidase (POD) were higher in BARI Gom 33 than BARI Gom 25 and BARI Gom 31. The hydrogen peroxide (H2O2) and malondealdehyde (MDA) content in BARI Gom 33 was low compare to BARI Gom 25 and BARI Gom 31, which may due to greater increase of the APX, CAT and POD in resistant genotypes. Thus, it may suggest that a more efficient antioxidative defense system in BARI Gom 33 during the infection process of M. oryzae restricts the cell damage caused by the fungus. The identified genotypes can either be used directly in the blast prone area or as a source of resistance to further development of blast resistance high yielding wheat variety.


Plant Disease ◽  
2018 ◽  
Vol 102 (6) ◽  
pp. 1066-1071 ◽  
Author(s):  
J. A. Kolmer ◽  
M. E. Hughes

Leaves of wheat infected with the leaf rust fungus Puccinia triticina were obtained from farm fields and breeding plots at experimental stations in the Great Plains, Ohio River Valley, and southeastern states in 2016 in order to identify virulence phenotypes prevalent in the United States in different wheat-growing regions. In total, 496 single uredinial isolates derived from the leaf rust collections were tested for virulence to 20 lines of Thatcher wheat that differ for single leaf rust resistance genes. In total, 71 virulence phenotypes were described in the United States in 2016. The three most common virulence phenotypes across the United States were MBTNB, MBDSD, and TNBJJ. Phenotype MBTNB is virulent to Lr11, and was most common in the soft red winter wheat region of the southeastern states and Ohio Valley. Phenotype MBDSD is virulent to Lr17 and Lr39, and was most common in the hard red winter wheat area of the southern Great Plains. Phenotype TNBJJ is virulent to Lr24 and Lr39, which are present in the hard red winter wheat cultivars. The P. triticina population in the United States was characterized by two major regional groups of virulence phenotypes in the Great Plains region where hard red winter and spring wheat cultivars are grown, and in the southeastern states and Ohio Valley region where soft red winter wheat cultivars are grown. Isolates from New York State differed the most for virulence compared with the other two major regions.


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