scholarly journals Spatial and Temporal Distribution of Mutations Conferring QoI and SDHI Resistance in Alternaria solani Across the United States

Plant Disease ◽  
2018 ◽  
Vol 102 (2) ◽  
pp. 349-358 ◽  
Author(s):  
Mitchell J. Bauske ◽  
Ipsita Mallik ◽  
S. K. R. Yellareddygari ◽  
Neil C. Gudmestad
Keyword(s):  
Temporal Frequency ◽  
Point Mutations ◽  
Temporal Distribution ◽  
Alternaria Solani ◽  
The United States ◽  
Future Research ◽  
Wide Range ◽  
Parasitic Fitness ◽  
Polymerase Chain ◽  
Prevalent Mutation

The application of succinate dehydrogenase inhibiting (SDHI) and quinone outside inhibiting (QoI) fungicide chemistries is a primary tactic in the management of early blight of potato, caused by Alternaria solani. Resistance to QoIs in A. solani has been attributed to the F129L mutation, while resistance to SDHIs is conferred by five different known point mutations on three AsSdh genes. In total, 1,323 isolates were collected from 2013 through 2015 across 11 states to determine spatial and temporal frequency distribution of these mutations. A real-time polymerase chain reaction (PCR) was used to detect the presence of the F129L mutation. Molecular detection of SDHI-resistant isolates was performed using SDH multiplex PCR specific for point mutations in AsSdhB, AsSdhC, or AsSdhD genes and mismatch amplification analysis PCR detecting the point mutations in AsSdhB. Previous work in our research group determined that substitutions of histidine for tyrosine (H278Y) or arginine (H278R) at codon 278 on the AsSdhB gene were the most prevalent mutations, detected in 46 and 21% of A. solani isolates, respectively, collected in 2011 to 2012, and uniformly distributed among six sampled states. In contrast, the substitution of histidine for arginine (H134R) at codon 134 in the AsSdhC gene was the most prevalent mutation in 2013 through 2015, identified in 36% of isolates, compared with 7.5% of isolates recovered in 2011 to 2012. Substitutions of histidine for arginine (H133R) at codon 133 and aspartic acid for glutamic acid (D123E) at codon 123 in the AsSdhD gene were detected in 16 and 12%, respectively, in the A. solani population by 2015 and were recovered across a wide range of states, compared with 15 and 1.5% of isolates collected in 2011 to 2012, respectively. Overall, SDHI- and QoI-resistant isolates were detected at high frequencies across all years, with evidence of significant spatial variability. Future research will investigate whether these results are due to differences in parasitic fitness.

scholarly journals Parasitic Fitness of Fungicide-Resistant and -Sensitive Isolates of Alternaria solani

Plant Disease ◽  
2018 ◽  
Vol 102 (3) ◽  
pp. 666-673 ◽  
Author(s):  
Mitchell J. Bauske ◽  
Neil C. Gudmestad
Keyword(s):  
Spore Germination ◽  
Point Mutations ◽  
Alternaria Solani ◽  
The United States ◽  
Wild Type ◽  
Parasitic Fitness ◽  
Fitness Parameters ◽  
Multiple Chemical

Resistance to chemistries of the succinate dehydrogenase inhibiting (SDHI) and quinone outside inhibiting (QoI) fungicides has developed rapidly in populations of Alternaria solani, the cause of early blight of potato. Reduced sensitivity to the anilinopyrimidine (AP) fungicide pyrimethanil has also been identified recently, determining that resistance to three chemical classes of fungicides is present within the A. solani population. Although no mutations have been characterized to confer resistance to APs, in A. solani five point mutations on three AsSdh genes have been determined to convey resistance to SDHIs, and the substitution of phenylalanine with leucine at position 129 (F129L) in the cytb gene confers resistance to QoIs. The objective of this study was to investigate the parasitic fitness of A. solani isolates with resistance to one or more of these chemical classes. A total of 120 A. solani isolates collected from various geographical locations around the United States were chosen for in vitro assessment, and 60 of these isolates were further evaluated in vivo. Fitness parameters measured were (i) spore germination in vitro, (ii) mycelial expansion in vitro, and (iii) aggressiveness in vivo. No significant differences in spore germination or mycelial expansion (P = 0.44 and 0.51, respectively) were observed among wild-type and fungicide-resistant isolates in vitro. Only A. solani isolates possessing the D123E mutation were shown to be significantly more aggressive in vivo (P < 0.0001) compared with wild-type isolates. These results indicate that fungicide-resistant A. solani isolates have no significant fitness penalties compared with sensitive isolates under the parameters evaluated regardless of the presence or absence of reduced sensitivity to multiple chemical classes. Results of these studies suggest that A. solani isolates with multiple fungicide resistances may compete successfully with wild-type isolates under field conditions.

scholarly journals Population structure of Drosophila suzukii and signals of multiple invasions into the continental United States

2021 ◽  
Author(s):  
Kyle M Lewald ◽  
Antoine Abrieux ◽  
Derek A Wilson ◽  
Yoosook Lee ◽  
William R Conner ◽  
...  
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Population Structure ◽  
Weather Conditions ◽  
The United States ◽  
Future Research ◽  
Drosophila Suzukii ◽  
Significant Damage ◽  
Wide Range ◽  
Multiple Invasions

Drosophila suzukii, or spotted-wing drosophila, is now an established pest in many parts of the world, causing significant damage to numerous fruit crop industries. Native to East Asia, D. suzukii infestations started in the United States a decade ago, occupying a wide range of climates. To better understand invasion ecology of this pest, knowledge of past migration events, population structure, and genetic diversity is needed. To improve on previous studies examining genetic structure of D. suzukii, we sequenced whole genomes of 237 individual flies collected across the continental U.S., as well as several representative sites in Europe, Brazil, and Asia, to identify hundreds of thousands of genetic markers for analysis. We analyzed these markers to detect population structure, to reconstruct migration events, and to estimate genetic diversity and differentiation within and among the continents. We observed strong population structure between West and East Coast populations in the U.S., but no evidence of any population structure North to South, suggesting there is no broad-scale adaptations occurring in response to the large differences in regional weather conditions. We also find evidence of repeated migration events from Asia into North America have provided increased levels of genetic diversity, which does not appear to be the case for Brazil or Europe. This large genomic dataset will spur future research into genomic adaptations underlying D. suzukii pest activity and development of novel control methods for this agricultural pest.

Norwalk-like Virus Sequences Detected by Reverse Transcription-Polymerase Chain Reaction in Mineral Waters Imported into or Bottled in Switzerland

2000 ◽  
Vol 63 (11) ◽  
pp. 1576-1582 ◽  
Author(s):  
CHRISTIAN BEURET ◽  
DOROTHE KOHLER ◽  
THOMAS LÜTHI
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcription ◽  
Carbonic Acid ◽  
Point Mutations ◽  
Chemical Properties ◽  
The United States ◽  
Mineral Waters ◽  
Nucleotide Sequence Analysis ◽  
Chain Reaction ◽  
Polymerase Chain

Norwalk-like viruses (NLVs) is a genus belonging to the Caliciviridae. NLVs are transmitted by the fecal-oral and the aerosol route and are the most common cause of outbreaks of nonbacterial gastroenteritis. NLVs are responsible for an estimated 67% of all illnesses caused by known foodborne pathogens and for 96% of nonbacterial gastroenteritis in the United States. Many outbreaks could be associated with the consumption of primarily or secondarily contaminated foods. To our knowledge, no epidemic arising from contaminated mineral water has been reported. We investigated the presence of NLV sequences in 63 mineral waters of 29 different brands that were imported into or bottled in Switzerland. NLV sequences were detected in 21 mineral waters by reverse transcription-seminested polymerase chain reaction. Specimens of two NLV genogroups (gg), gg I and gg II, were randomly present in the contaminated samples. The presence of NLV sequences could not be correlated either with bottle characteristics or with chemical properties like mineralization, pH, or the presence of carbonic acid. Nucleotide sequence analysis of 12 NLV-positive samples revealed several point mutations. All isolated NLV gg I strains have a similarity of 70 to 87% with the common Desert Shield virus (UO4469), and all isolated NLV gg II strains have a similarity of 89 to 93% with the Camberwell virus (U46500). Possible reasons for the presence of NLV sequences in mineral waters are discussed.

scholarly journals Industrial hemp and its potential

2020 ◽  
Author(s):  
ARNAB BHOWMIK
Keyword(s):  
Contaminated Soils ◽  
Management Practices ◽  
Cannabis Sativa ◽  
Emerging Market ◽  
The United States ◽  
Future Research ◽  
Research Needs ◽  
Hemp Fiber ◽  
Hemp Seed ◽  
Wide Range

Hemp (Cannabis sativa L.) is an emerging high-value specialty crop that can be cultivated foreither fiber, seed, or cannabidiol (CBD). The demand for hemp and its products has been consistently onthe rise in the 21st century. The United States of America has reintroduced hemp and legalizedits production as an agricultural commodity through the 2018 Federal Farm Bill. Although thereis a renewed interest in the adoption of hemp due to the emerging market, its production in theUnited States remains limited partly because of unclear agronomic guidance and fertilizationrecommendations. This review article provides information on the current agronomic managementpractices that are available in the literature and identifies the future research needs for cultivating thismultipurpose crop to address the growing market demands. Hemp production could be beneficialif managed properly. Hemp fertilizer requirements vary in accordance with the type of hempgrown (seed, fiber, or CBD), soil, environmental conditions and requires a wide range of macro- andmicronutrients. Integrating management practices in hemp cultivation intended to build soil health ispromising since the hemp cropping system is suitable for crop rotation, cover cropping, and livestockintegration through animal waste applications. Hemp also has significant environmental benefitssince it has the potential to remediate contaminated soils through phytoremediation, convert highamounts of atmospheric CO2 to biomass through bio-sequestration, and hemp biomass for bioenergyproduction. This review identifies that most of the agronomic research in the past has been limitedto hemp fiber and, to some extent, hemp seed but not CBD hemp. With the increase in the globalmarkets for hemp products, more research needs to be conducted to provide agronomic guidelinesfor sustainable hemp production.

scholarly journals Population genomics of Drosophila suzukii reveal longitudinal population structure and signals of migrations in and out of the continental United States

2021 ◽  
Author(s):  
Kyle M Lewald ◽  
Antoine Abrieux ◽  
Derek A Wilson ◽  
Yoosook Lee ◽  
William R Conner ◽  
...  
Keyword(s):  
United States ◽  
Population Structure ◽  
Population Genomics ◽  
The United States ◽  
Future Research ◽  
Drosophila Suzukii ◽  
Genomic Dataset ◽  
Significant Damage ◽  
Wide Range ◽  
Whole Genomes

Abstract Drosophila suzukii, or spotted-wing drosophila, is now an established pest in many parts of the world, causing significant damage to numerous fruit crop industries. Native to East Asia, D. suzukii infestations started in the United States (U.S.) a decade ago, occupying a wide range of climates. To better understand invasion ecology of this pest, knowledge of past migration events, population structure, and genetic diversity is needed. In this study, we sequenced whole genomes of 237 individual flies collected across the continental U.S., as well as several sites in Europe, Brazil, and Asia, to identify and analyze hundreds of thousands of genetic markers. We observed strong population structure between Western and Eastern U.S. populations, but no evidence of any population structure between different latitudes within the continental U.S., suggesting there is no broad-scale adaptations occurring in response to differences in winter climates. We detect admixture from Hawaii to the Western U.S. and from the Eastern U.S. to Europe, in agreement with previously identified introduction routes inferred from microsatellite analysis. We also detect potential signals of admixture from the Western U.S. back to Asia, which could have important implications for shipping and quarantine policies for exported agriculture. We anticipate this large genomic dataset will spur future research into the genomic adaptations underlying D. suzukii pest activity and development of novel control methods for this agricultural pest.

scholarly journals Advances in Research on Phytophthora capsici on Vegetable Crops in The United States

Plant Disease ◽  
2012 ◽  
Vol 96 (11) ◽  
pp. 1588-1600 ◽  
Author(s):  
Leah L. Granke ◽  
Lina Quesada-Ocampo ◽  
Kurt Lamour ◽  
Mary K. Hausbeck
Keyword(s):  
Host Range ◽  
Phytophthora Capsici ◽  
The United States ◽  
Fruit Rot ◽  
Economic Losses ◽  
Future Research ◽  
Vegetable Crops ◽  
Long Distance ◽  
Term Survival ◽  
Wide Range

Since L. H. Leonian's first description of Phytophthora capsici as a pathogen of chile pepper in 1922, we have made many advances in our understanding of this pathogen's biology, host range, dissemination, and management. P. capsici causes foliar blighting, damping-off, wilting, and root, stem, and fruit rot of susceptible hosts, and economic losses are experienced annually in vegetable crops including cucurbits and peppers. Symptoms of P. capsici infection may manifest as stunting, girdling, or cankers for some cultivars or crops that are less susceptible. P. capsici continues to be a constraint on production, and implementation of an aggressive integrated management scheme can still result in insufficient control when weather is favorable for disease. Management of diseases caused by P. capsici is currently limited by the long-term survival of the pathogen as oospores in the soil, a wide host range, long-distance movement of the pathogen in surface water used for irrigation, the presence of fungicide-resistant pathogen populations, and a lack of commercially acceptable resistant host varieties. P. capsici can infect a wide range of hosts under laboratory and greenhouse conditions including cultivated crops, ornamentals, and native plants belonging to diverse plant families. As our understanding of P. capsici continues to grow, future research should focus on developing novel and effective solutions to manage this pathogen and prevent economic losses due to the diseases it causes.

scholarly journals Trends in global research on Sanitation: A 30-year perspective from 1990 to 2019

2020 ◽  
Author(s):  
li huang ◽  
mi zhou
Keyword(s):  
Developed Countries ◽  
The United States ◽  
The Body ◽  
Future Research ◽  
Knowledge Mapping ◽  
Scientific Publications ◽  
Bibliometric Method ◽  
Wide Range ◽  
Depth Analysis ◽  
Research Hotspots

Abstract Background Sanitation issues have aroused widespread concern around the world, and scholars began research in this area as early as the 1920s. After decades of development, there is a great amount of research on this topic, and the body of research continues to grow rapidly. Methods Based on the Web of Science Core Collection databases from 1990–2019, this paper applies the bibliometric method to analyze the research characteristics and developments of scientific publications about sanitation. Visualized knowledge mapping is employed to investigate development status, scientific collaboration, involved disciplines, research hotspots and emerging trends of this field. Results The breadth and depth of sanitation studies has improved significantly as the number of related publications increases rapidly in the 21st century. The strength of developed countries is greater than that of developing countries; the comprehensive strength of the United States ranks first in the field, followed by England and Switzerland. This field is a highly interdisciplinary field that covers a wide range of interests, and institutional collaboration is increasing in this field. Keyword clustering analysis shows that the main research topics in the domain of sanitation could be summarized as: (a) drinking water; (b) sustainability; (c) biofilm; (d) epidemiology; and (e) WaSH. Meanwhile, keyword bursts analysis showed that the new research hotspots and research frontiers mainly concentrated on: (a) Sustainable development of sanitation services adapting to climate change; (b) Main determinants affecting child malnutrition; (c) Multinational research and model innovation; and (d) Evaluations on various aspects of performance. Conclusions Through in-depth analysis of sanitation research, this paper provides a better understanding of trends that have emerged over the past 30 years, and can serve as a reference for future research.

Tooth Retention and Tooth Loss in the Permanent Dentition of Adults: United States, 1988–1991

1996 ◽  
Vol 75 (2_suppl) ◽  
pp. 684-695 ◽  
Author(s):  
S.E. Marcus ◽  
T.F. Drury ◽  
L.J. Brown ◽  
G.R. Zion
Keyword(s):  
United States ◽  
Mexican Americans ◽  
Tooth Loss ◽  
The United States ◽  
Future Research ◽  
Anterior Teeth ◽  
Wide Range ◽  
Race Ethnicity ◽  
Tooth Retention ◽  
Lower Arch

While the overall prevalence of tooth loss and edentulism has been declining in the United States over the past several decades, important variations remain among subgroups of the population. Data from Phase 1 of the Third National Health and Nutrition Examination Survey (NHANES III) provide the most current estimates of the prevalence and distribution of tooth retention and tooth loss in the United States. Weighted analyses were conducted for all adults 18+ years of age (n = 8,366) and for selected age, gender, and race-ethnicity groups. In 1988–91, 89.5% of the population was dentate, and 30.5% had retained all 28 teeth. The mean number of teeth retained was 21.1 for all adults and 23.5 for dentate persons. The most commonly retained teeth in the mouth were the six anterior teeth in the lower arch. Conversely, 10.5% of the population was edentulous. Partial edentulism was much more common in the upper arch than in the lower arch. The most commonly missing teeth were the first and second molars. Age was strongly related to every measure of tooth retention and tooth loss. Gender was not related to any of these measures, after adjustment for age. Race-ethnicity was consistently related to these measures, after adjustment for age and gender. In general, Mexican-Americans had the lowest and black non-Hispanics the highest rates of tooth loss. Future research needs to examine a wide range of potential correlates of tooth retention and tooth loss before we can understand the complex interplay among the personal, dental, and environmental factors influencing tooth retention and tooth loss in the United States.

scholarly journals Use of Irrigation Technologies for Citrus Trees in Florida

2010 ◽  
Vol 20 (1) ◽  
pp. 74-81 ◽  
Author(s):  
Kelly T. Morgan ◽  
Lincoln Zotarelli ◽  
Michael D. Dukes
Keyword(s):  
Control Systems ◽  
Research Priorities ◽  
Soil Nutrient ◽  
The United States ◽  
Irrigation Scheduling ◽  
Future Research ◽  
Factors Affecting ◽  
Wide Range ◽  
Evapotranspiration Estimation ◽  
Irrigation Technologies

Florida is the most important center of processed citrus (Citrus spp.) production in the United States, and all of the crop is irrigated. Irrigation systems include low-volume microirrigation, sprinkler systems, and subsurface irrigation. This review details the relative irrigation efficiencies and factors affecting irrigation uniformity such as design and maintenance. A wide range of soil moisture sensors (e.g., tensiometers, granular matrix, and capacitance) are currently being used for citrus in the state. The use of these sensors and crop evapotranspiration estimation using weather information from the Florida Automated Weather Network in irrigation scheduling are discussed. Current examples of scheduling tools and automated control systems being used on selected fruit crops in Florida are provided. Research data on the effect of irrigation scheduling, soluble fertilizer injection, and soil nutrient movement, particularly nitrate and the use of reclaimed water in Florida, are also reviewed. Concluding this review is a discussion of the potential for adoption of irrigation scheduling and control systems for citrus by Florida growers and future research priorities.

scholarly journals The Association of E-cigarette Flavors With Satisfaction, Enjoyment, and Trying to Quit or Stay Abstinent From Smoking Among Regular Adult Vapers From Canada and the United States: Findings From the 2018 ITC Four Country Smoking and Vaping Survey

2020 ◽  
Vol 22 (10) ◽  
pp. 1831-1841 ◽  
Author(s):  
Shannon Gravely ◽  
K Michael Cummings ◽  
David Hammond ◽  
Eric Lindblom ◽  
Danielle M Smith ◽  
...  
Keyword(s):  
United States ◽  
The United States ◽  
Cross Sectional Study ◽  
Future Research ◽  
Cross Sectional ◽  
Quit Attempt ◽  
Quit Smoking ◽  
Wide Range ◽  
The Us ◽  
Former Smokers

Abstract Aims This study examined whether nontobacco flavors are more commonly used by vapers (e-cigarette users) compared with tobacco flavor, described which flavors are most popular, and tested whether flavors are associated with: vaping satisfaction relative to smoking, level of enjoyment with vaping, reasons for using e-cigarettes, and making an attempt to quit smoking by smokers. Methods This cross-sectional study included 1603 adults from Canada and the United States who vaped at least weekly, and were either current smokers (concurrent users) or former smokers (exclusive vapers). Respondents were categorized into one of seven flavors they used most in the last month: tobacco, tobacco–menthol, unflavored, or one of the nontobacco flavors: menthol/mint, fruit, candy, or “other” (eg, coffee). Results Vapers use a wide range of flavors, with 63.1% using a nontobacco flavor. The most common flavor categories were fruit (29.4%) and tobacco (28.7%), followed by mint/menthol (14.4%) and candy (13.5%). Vapers using candy (41.0%, p &lt; .0001) or fruit flavors (26.0%, p = .01) found vaping more satisfying (compared with smoking) than vapers using tobacco flavor (15.5%) and rated vaping as very/extremely enjoyable (fruit: 50.9%; candy: 60.9%) than those using tobacco flavor (39.4%). Among concurrent users, those using fruit (74.6%, p = .04) or candy flavors (81.1%, p = .003) were more likely than tobacco flavor users (63.5%) to vape in order to quit smoking. Flavor category was not associated with the likelihood of a quit attempt (p = .46). Among exclusive vapers, tobacco and nontobacco flavors were popular; however, those using tobacco (99.0%) were more likely than those using candy (72.8%, p = .002) or unflavored (42.5%, p = .005) to vape in order to stay quit. Conclusions A majority of regular vapers in Canada and the US use nontobacco flavors. Greater satisfaction and enjoyment with vaping are higher among fruit and candy flavor users. While it does not appear that certain flavors are associated with a greater propensity to attempt to quit smoking among concurrent users, nontobacco flavors are popular among former smokers who are exclusively vaping. Future research should determine the likely impact of flavor bans on those who are vaping to quit smoking or to stay quit. Implications Recent concerns about the attractiveness of e-cigarette flavors among youth have resulted in flavor restrictions in some jurisdictions of the United States and Canada. However, little is known about the possible consequences for current and former smokers if they no longer have access to their preferred flavors. This study shows that a variety of nontobacco flavors, especially fruit, are popular among adult vapers, particularly among those who have quit smoking and are now exclusively vaping. Limiting access to flavors may therefore reduce the appeal of e-cigarettes among adults who are trying to quit smoking or stay quit.

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