scholarly journals Geographical Distribution of Fungal Plant Pathogens in Dust Across the United States

2019 ◽  
Vol 7 ◽  
Author(s):  
Kristin Dietzel ◽  
Denis Valle ◽  
Noah Fierer ◽  
Jana M. U'Ren ◽  
Albert Barberán
Keyword(s):  
United States ◽  
Geographical Distribution ◽  
Plant Pathogens ◽  
The United States ◽  
Fungal Plant Pathogens

scholarly journals First Report of Gaeumannomyces graminis var. graminis on Seashore Paspalum in the United States

Plant Disease ◽  
2002 ◽  
Vol 86 (12) ◽  
pp. 1405-1405 ◽  
Author(s):  
W. C. Elmore ◽  
M. D. Gooch ◽  
C. M. Stiles
Keyword(s):  
United States ◽  
Plant Pathogens ◽  
Warm Season ◽  
The United States ◽  
Gaeumannomyces Graminis ◽  
Sterile Soil ◽  
Seashore Paspalum ◽  
First Report ◽  
Fungal Plant Pathogens ◽  
Rot Disease

Gaeumannomyces graminis var. graminis is an ectotrophic, root-infecting fungus found on some warm-season turfgrass species (1). A sample of seashore paspalum (Paspalum vaginatum) exhibiting rotted roots and stolons was taken from dying patches of turf in a home lawn in Hernando County, FL, and submitted to the Florida Extension Plant Disease Clinic, Gainesville, in October 2001. The lawn had been established within the previous year. Strongly lobed hyphopodia typical of G. graminis var. graminis (3,4) were present on diseased roots and stolons, and no other fungal plant pathogens were detected in the sample. Diseased roots and stolons with lobed hyphopodia were surface-sterilized and placed on one-quarter-strength potato dextrose agar (PDA) amended with rifampicin and streptomycin. One isolate produced structures characteristic of G. graminis var. graminis (3,4), including dark, strongly lobed hyphopodia, and perithecia and ascospores in PDA after incubation. The isolate (PDC 2965) was grown on a sterile ryegrass seed substrate at 25°C for 4 weeks to produce inoculum (2). The isolate was used to inoculate pots of ‘Sea Isle 1’ seashore paspalum grown in sterile soil from sprigs. An inoculum layer, 1 to 2 cm deep, was placed 2 to 4 cm below each sprig and covered with an overlay of sterile soil prior to sprigging (2). Following 4 weeks of plant growth in a greenhouse, dark, necrotic lesions appeared on leaf bases. Very dark lesions developed on roots, and brown runner hyphae and strongly lobed hyphopodia were observed on root and shoot tissues. Selected pieces of symptomatic root and shoot tissue were surface-sterilized and placed on PDA. One week later, dark mycelia and deeply lobed hyphopodia were observed growing from roots and shoots on the PDA. After 1 month, black, flask-shaped perithecia, 156 to 234 μm in body width, developed in cultures. Hyaline, filiform, septate ascospores ranged from 75 to 100 μm (mean = 89 μm; n = 250) long and were approximately 2.5 μm wide. Hyphopodia, perithecia, and ascospores were characteristic of G. graminis var. graminis (3,4). To our knowledge, this is the first report of take-all root rot disease due to G. graminis var. graminis on seashore paspalum in the United States. References: (1) L. E. Datnoff et al. Plant Dis. 81:1127, 1997. (2) M. L. Elliott. Plant Dis. 79:699, 1995. (3) M. L. Elliott and P. J. Landschoot. Plant Dis. 75:238, 1991. (4) P. J. Landschoot. Taxonomy and biology of ectotrophic root-infecting fungi associated with patch diseases of turfgrasses. Pages 41–71 in: Turfgrass Patch Diseases. B. B. Clarke and A. B. Gould, eds. American Phytopathological Society, St. Paul, MN, 1997.

scholarly journals Population Genomics Trace Clonal Diversification and Intercontinental Migration of an Emerging Fungal Pathogen of Boxwood

2020 ◽  
pp. PHYTO-06-20-021
Author(s):  
Nicholas LeBlanc ◽  
Marc A. Cubeta ◽  
Jo Anne Crouch
Keyword(s):  
United States ◽  
Plant Pathogens ◽  
Population Genomics ◽  
The United States ◽  
Sister Species ◽  
Evolutionary Divergence ◽  
Nucleotide Polymorphisms ◽  
Disease Emergence ◽  
Fungal Plant Pathogens ◽  
Genetic Clusters

Boxwood blight was first documented in Europe, prior to its recent colonization of North America, where it continues to have significant negative impacts on the ornamental industry. Due to near genetic uniformity in the two sister species of fungal plant pathogens that cause boxwood blight, understanding historical disease emergence and predicting future outbreaks is limited. The goal of this research was to apply population genomics to understand the role of pathogen diversification and migration in disease emergence. Specifically, we tested whether the primary pathogen species Calonectria pseudonaviculata has remained genetically isolated from its European-limited sister species C. henricotiae, while diversifying into clonal lineages that have migrated among continents. Whole-genome sequencing identified 1,608 single-nucleotide polymorphisms (SNPs) in 67 C. pseudonaviculata isolates from four continents and 1,017 SNPs in 13 C. henricotiae isolates from Europe. Interspecific genetic differentiation and an absence of shared polymorphisms indicated lack of gene flow between the sister species. Tests for intraspecific genetic structure in C. pseudonaviculata identified four genetic clusters, three of which corresponded to monophyletic phylogenetic clades. Comparison of evolutionary divergence scenarios among the four genetic clusters using approximate Bayesian computation indicated that the two C. pseudonaviculata genetic clusters currently found in the United States were derived from different sources, one from the first genetic cluster found in Europe and the second from an unidentified population. Evidence for multiple introductions of this pathogen into the United States and intercontinental migration indicates that future introductions are likely to occur and should be considered in plant disease quarantine regulation.

scholarly journals Assessing the Phytosanitary Risk Posed by an Intraspecific Invasion of Cryphonectria parasitica in Europe

2019 ◽  
Vol 109 (12) ◽  
pp. 2055-2063 ◽  
Author(s):  
Francesca Dennert ◽  
Joana Beatrice Meyer ◽  
Daniel Rigling ◽  
Simone Prospero
Keyword(s):  
United States ◽  
South Korea ◽  
Plant Pathogens ◽  
Castanea Sativa ◽  
The United States ◽  
Cryphonectria Parasitica ◽  
Seedling Mortality ◽  
New Host ◽  
Phytosanitary Measures

Intraspecific cryptic invasions may occur when new strains of an invasive species are introduced into an area where this species had already been introduced previously. In plant pathogens, such invasions are not well studied, even if, potentially, they can have severe consequences. Here, we investigated the effects of a potential intraspecific invasion in Europe of Cryphonectria parasitica, the causal agent of chestnut blight. Specifically, we tested the hypotheses that (i) non-European strains are more virulent on Castanea sativa than those already present in Europe because they have never encountered this new host, and (ii) the variation in virulence among strains is higher within native than within introduced populations. In a greenhouse, 2-year-old C. sativa seedlings were inoculated with Cryphonectria parasitica strains from South Korea, the United States, and Switzerland, and lesion development and seedling mortality were recorded weekly. Additionally, growth and sporulation of the strains were measured in vitro on agar medium at 15 and 24°C. Although lesion growth was similar for all strains, seedlings inoculated with strains from South Korea and Switzerland died faster than seedlings inoculated with strains from the United States. Moreover, in vitro strains from South Korea grew faster and produced more spores at both temperatures than the strains from the other two countries. In conclusion, our results did not support the two hypotheses. All strains, regardless of their origin, were found to be highly virulent on the inoculated chestnut seedlings. Nevertheless, current phytosanitary measures to avoid the introduction of new genotypes of C. parasitica into Europe should be further implemented.

A review of the biology and ecology of Florida beggarweed (Desmodium tortuosum)

Weed Science ◽  
2004 ◽  
Vol 52 (2) ◽  
pp. 185-200 ◽  
Author(s):  
Theodore M. Webster ◽  
John Cardina
Keyword(s):  
United States ◽  
Plant Pathogens ◽  
Cultural Practices ◽  
The United States ◽  
Western Hemisphere ◽  
Southern United States ◽  
Southeast United States ◽  
Forage Crop ◽  
Disturbed Areas ◽  
The World

Florida beggarweed is native to the Western Hemisphere but is naturalized around the world. During the last century, the mechanization of agriculture has transitioned Florida beggarweed from an important forage component to a weed of significance in the coastal plain of the southeast United States. This herbaceous annual is naturalized and found in fields and disturbed areas throughout the southern United States. The characteristics that made Florida beggarweed a good forage crop also make it a formidable weed. This review describes the importance of Florida beggarweed as a weed in the southern United States and the taxonomy of this species and details the distribution throughout the world and within the United States. The ecology of Florida beggarweed and its interactions with crop plants, insects, nematodes, and plant pathogens also are summarized. Finally, management of Florida beggarweed in agricultural systems using cultural practices and herbicides is reviewed.

Uromyces appendiculatus. [Descriptions of Fungi and Bacteria].

1965 ◽  
Author(s):  
G. F. Laundon
Keyword(s):  
United States ◽  
Sierra Leone ◽  
Geographical Distribution ◽  
World Wide ◽  
Indirect Evidence ◽  
Severe Infection ◽  
The United States ◽  
Total Loss ◽  
Uromyces Appendiculatus

Abstract A description is provided for Uromyces appendiculatus. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Dolichos, Phaseolus and Vigna species. DISEASE: Rust on leaves of French, Lima, and Scarlet Runner beans, and other Phaseolus spp., and cowpeas. The reddish-brown, circular sori may be surrounded by a yellow halo in some varieties. Complete defoliation and total loss of crop results in seasons favouring severe infection. GEOGRAPHICAL DISTRIBUTION: World-wide wherever beans are grown (CMI Map 290, Ed. 2, 1964). TRANSMISSION: By urediospores disseminated by wind, and through contact with animals including man and his implements. Indirect evidence of the possibility of introduction into Sierra Leone on seed imported from Ghana and S. Africa has been given by Deighton (25: 253). Some 40% of urediospores stored for 2 yr. at -60°C, and 16% stored more than 600 days at -18°C, have survived with virulence unimpaired, and it is thought that the rust is thus able to overwinter on bean trash and trellis poles in the United States (42: 167; 43, 299).

scholarly journals Application of Epidemiological Geographic Information System: An Open-Source Spatial Analysis Tool Based on the OMOP Common Data Model

2020 ◽  
Vol 17 (21) ◽  
pp. 7824
Author(s):  
Jaehyeong Cho ◽  
Seng Chan You ◽  
Seongwon Lee ◽  
DongSu Park ◽  
Bumhee Park ◽  
...  
Keyword(s):  
United States ◽  
Information System ◽  
Geographic Information System ◽  
Spatial Analysis ◽  
Health Outcomes ◽  
Open Source ◽  
Geographical Distribution ◽  
The United States ◽  
Geographic Information ◽  
Common Data Model

Background: Spatial epidemiology is used to evaluate geographical variations and disparities in health outcomes; however, constructing geographic statistical models requires a labor-intensive process that limits the overall utility. We developed an open-source software for spatial epidemiological analysis and demonstrated its applicability and quality. Methods: Based on standardized geocode and observational health data, the Application of Epidemiological Geographic Information System (AEGIS) provides two spatial analysis methods: disease mapping and detecting clustered medical conditions and outcomes. The AEGIS assesses the geographical distribution of incidences and health outcomes in Korea and the United States, specifically incidence of cancers and their mortality rates, endemic malarial areas, and heart diseases (only the United States). Results: The AEGIS-generated spatial distribution of incident cancer in Korea was consistent with previous reports. The incidence of liver cancer in women with the highest Moran’s I (0.44; p < 0.001) was 17.4 (10.3–26.9). The malarial endemic cluster was identified in Paju-si, Korea (p < 0.001). When the AEGIS was applied to the database of the United States, a heart disease cluster was appropriately identified (p < 0.001). Conclusions: As an open-source, cross-country, spatial analytics solution, AEGIS may globally assess the differences in geographical distribution of health outcomes through the use of standardized geocode and observational health databases.

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