scholarly journals Characterization of the Black Shank Pathogen, Phytophthora nicotianae, Across North Carolina Tobacco Production Areas

Plant Disease ◽  
2018 ◽  
Vol 102 (6) ◽  
pp. 1108-1114 ◽  
Author(s):  
Courtney A. Gallup ◽  
Kestrel L. McCorkle ◽  
Kelly L. Ivors ◽  
David Shew
Keyword(s):  
North Carolina ◽  
Natural Populations ◽  
Hyphal Growth ◽  
The United States ◽  
The State ◽  
Phytophthora Nicotianae ◽  
Mating Types ◽  
Black Shank ◽  
Nuclear Regions

Black shank disease of tobacco, caused by the oomycete Phytophthora nicotianae, is a major threat to production in the United States and tobacco-producing areas worldwide. In a statewide survey of North Carolina, the rapid shift from race 0 to race 1 was documented. Collected pathogen isolates were characterized phenotypically for mating type and mefenoxam sensitivity, and genotypically by comparing sequences from three cytoplasmic and two nuclear regions. Both the A1 and A2 mating types were found throughout the state. When both mating types were recovered from the same field, pairings of isolates yielded viable oospores, indicating for the first time the potential for sexual sporulation by P. nicotianae in natural populations. Because the loss of complete resistance required a renewed use of the fungicide mefenoxam, a subset of the survey isolates was screened for sensitivity to the fungicide. All isolates were sensitive, with a mean effective concentration to inhibit 50% of hyphal growth of 0.4 μg/ml that was similar across mating types and races. Molecular characterization of 226 isolates revealed that the pathogen exists as multiple clonal types within the state. Genetic diversity among the pathogen population and the potential for sexual recombination may help explain the ability of the pathogen to rapidly adapt to host resistance genes.

scholarly journals Characterization of Phytophthora spp. on Floriculture Crops in North Carolina

Plant Disease ◽  
2011 ◽  
Vol 95 (8) ◽  
pp. 1013-1020 ◽  
Author(s):  
H. A. Olson ◽  
D. M. Benson
Keyword(s):  
North Carolina ◽  
Growth Inhibition ◽  
Mating Type ◽  
Host Species ◽  
Effective Concentration ◽  
Phytophthora Nicotianae ◽  
Mating Types ◽  
Previous Survey ◽  
Phytophthora Spp

Isolates of Phytophthora in floriculture crops were collected from North Carolina commercial greenhouse facilities in 2007 and 2008, identified, and characterized for mating type and mefenoxam sensitivity. In all, 163 isolates from 13 host species at 11 locations were identified primarily as Phytophthora nicotianae (59%), P. drechsleri (23%), P. cryptogea (9%), and P. tropicalis (4%). Multiple Phytophthora spp. were found at five locations. DNA sequencing was more reliable for differentiating P. cryptogea and P. drechsleri. Only the A1 mating type of P. drechsleri was collected; however, both mating types of P. nicotianae, P. cryptogea, and P. tropicalis were found. Overall, 66% of Phytophthora isolates were resistant or intermediate in resistance to mefenoxam at 1 μg a.i./ml. Three groups of P. drechsleri isolates had effective concentration of mefenoxam providing 50% growth inhibition (EC50) estimates over 700 μg a.i./ml. EC50 estimates for P. nicotianae ranged from 246 to 435 μg a.i./ml. Isolates of P. nicotianae exhibited phenotypic heterogeneity at several locations, suggesting multiple separate introductions to the facilities. In contrast, P. nicotianae and P. drechsleri isolates from two locations were phenotypically identical to a previous survey, suggesting that the facilities have Phytophthora spp. established onsite.

scholarly journals Phenotypic Characterization of Recent Clonal Lineages of Phytophthora infestans in the United States

Plant Disease ◽  
2013 ◽  
Vol 97 (7) ◽  
pp. 873-881 ◽  
Author(s):  
G. Danies ◽  
I. M. Small ◽  
K. Myers ◽  
R. Childers ◽  
W. E. Fry
Keyword(s):  
United States ◽  
Late Blight ◽  
Phytophthora Infestans ◽  
The United States ◽  
Phenotypic Characterization ◽  
Phenotypic Traits ◽  
Mating Types ◽  
Late Blight Disease ◽  
Blight Disease

Phytophthora infestans, the causal agent of late blight disease, has been reported in the United States and Canada since the mid-nineteenth century. Due to the lack of or very limited sexual reproduction, the populations of P. infestans in the United States are primarily reproducing asexually and, thus, show a simple genetic structure. The emergence of new clonal lineages of P. infestans (US-22, US-23, and US-24) responsible for the late blight epidemics in the northeastern region of the United States in the summers of 2009 and 2010 stimulated an investigation into phenotypic traits associated with these genotypes. Mating type, differences in sensitivity to mefenoxam, differences in pathogenicity on potato and tomato, and differences in rate of germination were studied for clonal lineages US-8, US-22, US-23, and US-24. Both A1 and A2 mating types were detected. Lineages US-22, US-23, and US-24 were generally sensitive to mefenoxam while US-8 was resistant. US-8 and US-24 were primarily pathogenic on potato while US-22 and US-23 were pathogenic on both potato and tomato. Indirect germination was favored at lower temperatures (5 and 10°C) whereas direct germination, though uncommon, was favored at higher temperatures (20 and 25°C). Sporangia of US-24 released zoospores more rapidly than did sporangia of US-22 and US-23. The association of characteristic phenotypic traits with genotype enables the prediction of phenotypic traits from rapid genotypic analyses for improved disease management.

Education and the University of North Carolina Pre-Flight School

Home Front ◽  
2017 ◽  
Keyword(s):  
United States ◽  
North Carolina ◽  
Military Training ◽  
The United States ◽  
Colleges And Universities ◽  
The State ◽  
Chapel Hill ◽  
Trained Teachers ◽  
The University ◽  
The U.S

Primary and secondary schools were hard hit by the war, with a dearth of supplies and trained teachers. Many colleges and universities, vacated by men off to war, would have had to close were it not for the U.S. military training units at the schools. Each institution in the state had some sort of government activity on their campuses, but the preeminent center was the Navy Pre-Fight School at UNC-Chapel Hill, where two future presidents of the United States, George H. W. Bush and Gerald Ford trained.

scholarly journals Epizootiology and transmission of a newly discovered baculovirus from the mosquitoes Culex nigripalpus and C. quinquefasciatus

2001 ◽  
Vol 82 (2) ◽  
pp. 275-282 ◽  
Author(s):  
James J. Becnel ◽  
Susan E. White ◽  
Bettina A. Moser ◽  
Tokuo Fukuda ◽  
Margaret J. Rotstein ◽  
...  
Keyword(s):  
Divalent Cations ◽  
Mosquito Species ◽  
Great Part ◽  
Natural Populations ◽  
Virus Transmission ◽  
The United States ◽  
Culex Nigripalpus ◽  
Life Threatening ◽  
Laboratory Bioassays

Reports of mosquito baculoviruses are extremely uncommon and epizootics in field populations are rarely observed. We describe a baculovirus that was responsible for repeated and extended epizootics in field populations of Culex nigripalpus and C. quinquefasciatus over a 2 year period. These mosquito species are important vectors of St Louis and Eastern equine encephalitis in the United States. Our initial attempts to transmit this baculovirus to mosquitoes in the laboratory were unsuccessful. A salt mixture similar to that found in water supporting infection in the field was used in laboratory bioassays and indicated that certain salts were crucial to transmission of the virus. Further investigations revealed conclusively that transmission is mediated by divalent cations: magnesium is essential, whereas calcium inhibits virus transmission. These findings represent a major advancement in our understanding of the transmission of baculoviruses in mosquitoes and will allow characterization of the virus in the laboratory. In addition, they can explain, in great part, conditions that support epizootics in natural populations of mosquitoes that vector life-threatening diseases of man and animals.

scholarly journals GENOTYPE CHARACTERIZATION OF Leishmania (Viannia) braziliensis ISOLATED FROM HUMAN AND CANINE BIOPSIES WITH AMERICAN CUTANEOUS LEISHMANIASIS

2015 ◽  
Vol 57 (3) ◽  
pp. 257-262
Author(s):  
Lasaro Teixeira FERREIRA ◽  
Aparecida Helena de Souza GOMES ◽  
Vera Lucia PEREIRA-CHIOCCOLA
Keyword(s):  
Genetic Diversity ◽  
Natural Populations ◽  
Sao Paulo ◽  
The State ◽  
Internal Transcribed Spacers ◽  
São Paulo ◽  
Three Samples ◽  
Two Samples ◽  
American Tegumentary Leishmaniasis

Introduction: American tegumentary leishmaniasis (ATL) can be caused by Leishmania (Viannia) braziliensis complex. The evolution of ATL initially results in lesions and can develop into disseminated or diffuse forms. The genetic diversity of L. (V.) braziliensis in some endemic areas of Brazil has been poorly studied, such as in the state of São Paulo. This study analyzed the genetic diversity of L. (V.) braziliensis isolates collected from patients and dogs with LTA from the state of São Paulo. Methods: Leishmaniasis diagnosis was determined by PCR. The 132 biopsies were collected in different regions of Sao Paulo State, Brazil (36 municipalities). The genetic characterization of L. (V.) braziliensis isolates was tested by RFLP-PCR using DNA extracted from biopsies. The primer set amplified a specific region of Leishmania internal transcribed spacers of the ribosomal DNA locus. Results: Of the 132 samples, 52 (40%) were completely genotyped by RFLP-PCR (44 from human patients and eight from dogs). The results showed nine distinct patterns. The majority of the genotyped samples were from Sorocaba (30), and the others were distributed among 14 other municipalities. The first pattern was more frequent (29 samples), followed by pattern 2 (nine samples) and pattern 3 (three samples). Patterns 4, 6, 7, 8 and 9 were composed of two samples each and pattern 5 of one sample. Conclusion: These results suggest that polymorphic strains of L. (V.) braziliensis circulate in the state of São Paulo. These data agree with studies from other regions of Brazil, showing great variability among the natural populations of endemic foci.

Nat Turner’s Rebellion

2021 ◽  
Author(s):  
Patrick Breen
Keyword(s):  
United States ◽  
North Carolina ◽  
State Legislatures ◽  
The United States ◽  
The State ◽  
Southern State ◽  
Slave Revolt ◽  
Nat Turner's Rebellion ◽  
History Of ◽  
Women And Children

In Southampton County, Virginia, Nat Turner and six other men launched the deadliest slave revolt in the history of the United States. The revolt began in the middle of the night, August 21–22, 1831, and by the middle of the day on August 22 the rebels had killed nearly five dozen whites, including many women and children. Whites responded in many ways. Many panicked, and some rallied to oppose the rebels. Some of these irregular white forces stumbled upon Turner and his men at James Parker’s farm, not far from Jerusalem, Southampton’s county seat. The encounter ended quickly and indecisively, but the whites had stopped the rebel advance. Following this first battle, Turner tried to rally his men, something that became increasingly hard to do as more and more whites from nearby counties in Virginia and North Carolina came to Southampton. By the morning of August 23, the rebels were defeated at a series of engagements and the organized phase of the revolt ended. Whites quickly and brutally reasserted their control over Southampton, torturing many of the accused and killing roughly three dozen black suspects without trials. Worried about the possibility of a more extensive bloodbath, white leaders in Southampton, who knew that owners were compensated for the value of their slaves who had been condemned by the state, soon clamped down on the extralegal massacre of suspected rebels. On August 31, 1831, trials of suspect rebels began. By the time that the trials were finished the following spring, thirty slaves and one free black had been condemned to death. Of these people, nineteen were executed in Southampton, and twelve had their sentences commuted to transportation from the state of Virginia. Turner himself, one of the condemned, was hanged on November 11, 1831, although not before Thomas R. Gray, a lawyer who was defense council for other slave rebels, interviewed the jailed rebel leader. Gray published this transcript as The Confessions of Nat Turner, which presented Turner’s religious motivations. Immediately after the revolt, several southern state legislatures took up laws regulating slavery; the Virginia legislature also considered and rejected a gradual emancipation scheme. Since the revolt, Nat Turner and his legacy have been contested by many, including scholars, novelists, artists, and filmmakers.

scholarly journals Population Structure, Mating Type, and Mefenoxam Sensitivity of Phytophthora nicotianae in Virginia Tobacco Fields

Plant Disease ◽  
2010 ◽  
Vol 94 (11) ◽  
pp. 1361-1365 ◽  
Author(s):  
V. Parkunan ◽  
C. S. Johnson ◽  
B. C. Bowman ◽  
C. X. Hong
Keyword(s):  
United States ◽  
Population Structure ◽  
Mating Type ◽  
Single Gene ◽  
The United States ◽  
Phytophthora Nicotianae ◽  
Species Identity ◽  
Single Strand Conformational Polymorphism ◽  
Black Shank ◽  
Major Mechanism

Black shank is an important disease of tobacco (Nicotiana tabacum) caused by the fungus-like organism, Phytophthora nicotianae. Three physiological races (0, 1, and 3) have been documented in the United States. Shifts in the pathogen population structure have become a concern due to the widespread use of cultivars possessing resistance to race 0 arising from a single gene (Php or Phl). A comprehensive statewide survey conducted throughout major tobacco-growing areas during summer 2006 and supplemented by additional isolates in 2007 and 2008 yielded 217 isolates from flue-cured, burley, and dark fire-cured tobacco fields. After determining species identity using a single-strand conformational polymorphism fingerprinting technique, the race identity of isolates was assessed via greenhouse tests using three differential cultivars (Hicks, L8, and NC1071). Approximately 76% of the isolates belonged to race 1, 21% to race 0, and the remaining 3% were race 3. This race structure was comparable with those in the other tobacco-producing states in the United States. Approximately 94% of isolates belonged to A2 mating type and merely 6% were A1. These data suggest that it is unlikely that sexual recombination serves as a major mechanism enhancing the genetic diversity of the pathogen in Virginia. All isolates were also evaluated against mefenoxam at 5 μg/ml. None were insensitive; 98% of isolates were either highly sensitive or sensitive and the remaining 2% were intermediately sensitive. These results indicate that mefenoxam remains effective for control of black shank in Virginia. The results of this study can assist breeders to develop cultivars possessing the most appropriate set of disease resistance traits, as well as extension specialists, county agents, and tobacco growers in their decision-making process to manage tobacco black shank in Virginia.

scholarly journals The Tobacco Trichome Exudate Z-abienol and Its Relationship With Plant Resistance to Phytophthora nicotianae

Plant Disease ◽  
2017 ◽  
Vol 101 (7) ◽  
pp. 1214-1221 ◽  
Author(s):  
William T. Steede ◽  
Justin M. Ma ◽  
David P. Eickholt ◽  
Katherine E. Drake-Stowe ◽  
Sheri P. Kernodle ◽  
...  
Keyword(s):  
Close Association ◽  
Hyphal Growth ◽  
Field Resistance ◽  
Phytophthora Nicotianae ◽  
In Vitro Assays ◽  
Black Shank ◽  
Plant Parts ◽  
Tobacco Cultivar ◽  
High Level

In previous research, we discovered a favorable quantitative trait locus (QTL) in cigar tobacco cultivar ‘Beinhart 1000’ designated as Phn15.1, which provides a high level of partial resistance to the black shank disease caused by Phytophthora nicotianae. A very close genetic association was also found between Phn15.1 and the ability to biosynthesize Z-abienol, a labdanoid diterpene exuded by the trichomes onto above-ground plant parts, and that imparts flavor and aroma characteristics to Oriental and some cigar tobacco types. Because accumulation of Z-abienol is considered to be undesirable for cultivars of other tobacco types, we herein describe a series of experiments to gain insight on whether this close association is due to genetic linkage or pleiotropy. First, in an in vitro bioassay, we observed Z-abienol and related diterpenes to inhibit hyphal growth of P. nicotianae at concentrations between 0.01 and 100 ppm. Secondly, we field-tested transgenic versions of Beinhart 1000 carrying RNAi constructs for downregulating NtCPS2 or NtABS, two genes involved in the biosynthesis of Z-abienol. Thirdly, we also field tested a recombinant inbred line population segregating for a truncation mutation in NtCPS2 leading to an interrupted Z-abienol pathway. We observed no correlation between field resistance to P. nicotianae and the ability to accumulate Z-abienol in either the transgenic materials or the mapping population. Results suggest that, although Z-abienol may affect P. nicotianae when applied at high concentrations in in vitro assays, the compound has little effect on black shank disease development under natural field conditions. Thus, it should be possible to disassociate Phn15.1-mediated black shank resistance identified in cigar tobacco cultivar Beinhart 1000 from the ability to accumulate Z-abienol, an undesirable secondary metabolite for burley and flue-cured tobacco cultivars.

scholarly journals Characterization of Phytophthora nicotianae Resistance Conferred by the Introgressed Nicotiana rustica Region, Wz, in Flue-Cured Tobacco

Plant Disease ◽  
2018 ◽  
Vol 102 (2) ◽  
pp. 309-317 ◽  
Author(s):  
Kestrel L. McCorkle ◽  
Katherine Drake-Stowe ◽  
Ramsey S. Lewis ◽  
David Shew
Keyword(s):  
Lesion Size ◽  
Resistance Mechanisms ◽  
Phytophthora Nicotianae ◽  
Slight Reduction ◽  
Additional Source ◽  
Black Shank ◽  
Initial Inoculum ◽  
Complete Resistance ◽  
Host Generation

Black shank, caused by Phytophthora nicotianae, is one of the most important diseases affecting tobacco worldwide and is primarily managed through use of host resistance. An additional source of resistance to P. nicotianae, designated as Wz, has been introgressed into Nicotiana tabacum from N. rustica. The Wz gene region confers high levels of resistance to all races, but has not been characterized. Our study found Wz-mediated resistance is most highly expressed in the roots, with only a slight reduction in stem-lesion size in Wz genotypes compared with susceptible controls. No substantial relationships were observed between initial inoculum levels and disease development on Wz genotypes, which is generally consistent with qualitative or complete resistance. Isolates of P. nicotianae adapted for five host generations on plants with the Wz gene caused higher disease severity than isolates adapted on Wz plants for only one host generation. Wz-adapted isolates did not exhibit increased aggressiveness on genotypes with other sources of partial resistance, suggesting pathogen adaptation was specific to the Wz gene. To reduce potential for pathogen population shifts with virulence on Wz genotypes, Wz should be combined with other resistance sources and rotation of varying black shank resistance mechanisms is also recommended.

scholarly journals Commissioning Innocence and Restoring Confidence: the North Carolina Innocence Inquiry Commission and the Missing Deliberative Citizen

2018 ◽  
Author(s):  
Mary Kelly Tate
Keyword(s):  
United States ◽  
North Carolina ◽  
The United States ◽  
The State ◽  
State Agency ◽  
Actual Number ◽  
Important Work ◽  
Wrongful Convictions ◽  
National Crisis ◽  
The North

Since 1989, the United States has witnessed 289 DNA exonerations, with exonerees serving an average of thirteen years in prison. Although DNA and its unmatched power for conclusive results is what brought popular attention to wrongful convictions, the scope of the problem is vastly larger than the number of known DNA exonerations. The actual number of convicted individuals who are factually innocent is unknown. The state of North Carolina has recently responded to this national crisis via a newly created state agency. This essay applauds North Carolina's response, but urges that ordinary citizens, qua jurors, be active participants in its important work.

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