scholarly journals First Report of Leaf Spot of Smooth Bromegrass Caused by Pithomyces chartarum in Nebraska

Plant Disease ◽  
2006 ◽  
Vol 90 (1) ◽  
pp. 108-108 ◽  
Author(s):  
C. Eken ◽  
C. C. Jochum ◽  
G. Y. Yuen
Keyword(s):  
United States ◽  
Relative Humidity ◽  
Morphological Characteristics ◽  
The United States ◽  
Grass Species ◽  
Commonwealth Mycological Institute ◽  
Conidial Suspension ◽  
Smooth Bromegrass ◽  
Decay Fungi ◽  
Wide Range

Smooth bromegrass (Bromus inermis Leyss.) is the most common perennial grass species cultivated for forage in North America. During late fall of 2004, smooth bromegrass plants in Lincoln, NE were observed to have brown lesions on leaf midveins that were several centimeters long. Symptomatic leaves were surface disinfested for 1 min in 2% NaOCl and incubated at 25°C on potato dextrose agar (PDA) and water agar. The fungus, Pithomyces chartarum (Berk. & Curt) Ellis, was isolated consistently and identified on the basis of morphological characteristics (1). Colonies were effused and black on PDA. Conidiophores measured 3.5 to 8 × 1.9 to 3.9 μm and were smooth and single. Conidia (7 to 25 × 9.5 to 14 μm) were broadly ellipsoidal, pale brown to dark brown, verrucose with mainly three transverse septa and one to two longitudinal septa. Pathogenicity tests were conducted on 50-day-old plants by spraying with a conidial suspension (2.5 × 105 spores per ml). Control plants were sprayed with sterile water. All plants were kept in a moist chamber (100% relative humidity) for 3 days and then transferred to a greenhouse (25°C, >70% relative humidity, and a 12-h photoperiod). One week after spraying, elongated lesions developed on leaf midveins of inoculated plants from which P. chartarum was consistently reisolated. No symptoms were observed on control plants. While P. chartarum has been described as a saprotroph or a parasite on a wide range of plants primarily in the tropics and subtropics, including the southern United States (2), it was reported previously on B. inermis only in Canada (3). This report expands the distribution and host range of P. chartarum as a pathogen in the United States. References: (1) M. B. Ellis. Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew, Surrey, England, 1971. (2) D. F. Farr et al. Fungal Databases, Systematic Botany and Mycology Laboratory, On-line publication. ARS, USDA, 2005. (3) J. H. Ginns. Compendium of Plant Disease and Decay Fungi in Canada 1960-1980. Res. Br. Can. Agric. Publ. 1813, 1986.

scholarly journals First Report of Pithomyces chartarum Causing a Leaf Blight of Miscanthus × giganteus in Kentucky

Plant Disease ◽  
2010 ◽  
Vol 94 (4) ◽  
pp. 480-480 ◽  
Author(s):  
M. O. Ahonsi ◽  
B. O. Agindotan ◽  
D. W. Williams ◽  
R. Arundale ◽  
M. E. Gray ◽  
...  
Keyword(s):  
Morphological Characteristics ◽  
The United States ◽  
Leaf Blight ◽  
Nuclear Ribosomal Dna ◽  
Growth Chamber ◽  
Commonwealth Mycological Institute ◽  
Conidial Suspension ◽  
First Report ◽  
Miscanthus Giganteus ◽  
Wide Range

Miscanthus × giganteus is a warm-season perennial grass, native to eastern Asia. Brought into the United States as a landscape plant, it is currently being considered as a potential biomass fuel crop. In August 2009, a newly established and a 2-year-old M. × giganteus field research trial near Lexington, KY were found to have 100% incidence of severe leaf blight. Brown, mosaic-like, coalesced necrotic lesions covered leaf blades and sheaths on every stand, ultimately killing some leaves and tillers. The disease was more destructive in the newly established trial where 4- to 5-month-old M. × giganteus tillers were killed. No fruiting bodies were found immediately on diseased leaves. However, surface-disinfested diseased leaf tissue produced a sooty black mass of conidia after 1 week following incubation in a petri dish moisture chamber at 25°C in the dark. Single conidia isolations were made on half-strength potato dextrose agar (HSPDA) amended with 25 mg/liter of rifamycin and incubated at 25°C. Morphological characteristics of the fungus fit those originally described for Pithomyces chartarum (Berk. & Curt.) M.B. Ellis (2). Colonies were fast growing on HSPDA, at first hyaline, then shortly punctiform, grayish black, up to 1-mm diameter, and then became confluent, producing several dark brown multicellular conidia on small peg-like denticles on branched conidiophores. Every detached conidium had a small piece of the denticle attached to its base. The conidia were echinulate, broadly ellipsoidal, pyriform, 18 to 29 × 11 to 18 μm, with three transverse septa, and a longitudinal septum constricted at the transverse septa. The identity of the fungus was confirmed by sequence analysis of the internal transcribed spacers (ITS) region of the nuclear ribosomal DNA. The 615-bp cloned and sequenced amplicon (Accession No. GU195649) was 99% identical to sequences from multiple isolates of Leptosphaerulina chartarum (anamorph Pithomyces chartarum) in the GenBank. Five potted M. × giganteus plants (45 days old) were spray inoculated with an aqueous conidial suspension (2 × 106 conidia/ml) and incubated in one tier of a two-tiered-growth chamber at 86 to 90% relative humidity. Initial incubation was in the dark at 26°C for 48 h, and thereafter at alternating 15 h of light (320 μmol) at 25°C and 9 h of darkness at 23°C. Control plants were sprayed with sterile water and incubated in the second tier of the same growth chamber. A week after inoculation, leaf blight developed on all inoculated plants, but not the controls. P. chartarum was reisolated from infected leaves 2 weeks after inoculation. To our knowledge, this is the first report of P. chartarum causing a disease on Miscanthus (3). The fungus is cosmopolitan, usually saprophytic, but can cause diseases on a wide range of plants as well as produce mycotoxins (3). It has been reported to cause a leaf spot of smooth bromegrass (Bromus inermis) in Nebraska (1) and a leaf blight of wheat (Triticum aestivum) in Hungary (4). The observed disease severity suggests P. chartarum could potentially limit M. × giganteus production as an ethanol feedstock. References: (1) C. Eken et al. Plant Dis. 90:108, 2006. (2) M. B. Ellis. Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew, Surrey, England, 1971. (3) D. F. Farr et al. Fungal Databases, Systematic Mycology and Microbiology Laboratory. Online publication. ARS, USDA, 2010. (4) B. Tóth et al. J. Plant Pathol. 89:405, 2007.

Taxonomy of the genusMyrionora, with a second species from South America

2013 ◽  
Vol 45 (2) ◽  
pp. 159-167 ◽  
Author(s):  
Zdeněk PALICE ◽  
Christian PRINTZEN ◽  
Toby SPRIBILLE ◽  
Måns SVENSSON ◽  
Tor TØNSBERG ◽  
...  
Keyword(s):  
United States ◽  
South America ◽  
Russian Federation ◽  
Morphological Characteristics ◽  
The United States ◽  
Deciduous Trees ◽  
Wide Range ◽  
The Russian Federation ◽  
Trees And Shrubs

AbstractA taxonomic and biogeographic overview of the genusMyrionorais provided. Two species are recognized,M. albidula(Willey) R. C. Harris andM. pseudocyphellariae(Etayo) S. Ekman & Palice comb. nov. The genus is characterized by polysporous asci, the presence of crystals in the hymenium and proper exciple that partly consist of lobaric acid, and a photobiont with large cells (mostly in the range 12–20 µm).Myrionora albidulais currently known from Germany, Norway, Sweden, the Russian Federation (Altayskiy Kray, Chelyabinskaya Oblast', Khabarovskiy Kray and Zabaykal'skiy Kray), and the United States (Alaska, Connecticut, Maine and Massachusetts). It inhabits bark of deciduous trees and shrubs and conifers over a wide range of latitudes.Myrionora pseudocyphellariaeis known from Chile and Ecuador, where it has been encountered on lichens and decaying bark. Based on morphological characteristics, we conclude thatMyrionorabelongs in theRamalinaceae.

scholarly journals First Report of Phytophthora syringae Causing Rot on Apples in Cold Storage in the United States

Plant Disease ◽  
2002 ◽  
Vol 86 (6) ◽  
pp. 693-693 ◽  
Author(s):  
R. A. Spotts ◽  
G. G. Grove
Keyword(s):  
United States ◽  
Cold Storage ◽  
The United States ◽  
River Valley ◽  
Fruit Rot ◽  
Commonwealth Mycological Institute ◽  
Postharvest Diseases ◽  
First Report ◽  
Postharvest Decay ◽  
Wide Range

A decay of ‘Granny Smith’ apples (Malus domestica Borkh.) was observed in 1988, 1990, and 1991 on fruit grown in the lower Hood River Valley of Oregon and stored at 0°C. Harvested fruit were drenched with thiabendazole and stored in October in all years. In mid-November, fruit were sized, drenched with sodium hypochlorite, and returned to cold storage. Decay was observed in January when fruit were removed from cold storage, sorted, and packed. Decayed areas were light brown and firm with a slightly indefinite margin. Losses were less than 1% of fruit packed. Diseased fruit were surface-disinfested with 95% ethanol, and tissue pieces were transferred aseptically to potato dextrose agar acidified with lactic acid and incubated at approximately 22°C. The fungus consistently isolated was identified as Phytophthora syringae (Kleb.) Kleb. based on morphological characters (3). Sporangia were persistent and averaged 60 μm long (range 59 to 69) × 40 μm wide (range 37 to 43). Antheridia were paragynous, and oospores averaged 37 μm (range 31 to 46). ‘Golden Delicious’, ‘Granny Smith’, and ‘Gala’ apples were inoculated with mycelial plugs from a 7-day-old culture of P. syringae and incubated 12 days at 5°C and 7 to 12 days at 22°C. Twenty fruit of each cultivar were used—ten were inoculated, and ten uninoculated fruit served as controls. Lesions developed on all inoculated fruit but not on uninoculated controls. Lesions were spherical, chocolate brown, and firm with no evidence of external mycelia. Lesion morphology was similar on all cultivars. P. syringae was reisolated from lesion margins of all infected fruit. This postharvest decay of apples has not been observed in the Hood River Valley since 1991. Fruit rot of apples caused by P. syringae is known in Canada (1) and is common in the United Kingdom (2), but has not been reported previously in the United States. To our knowledge, this is the first report of postharvest decay of apples by P. syringae in the United States. References: (1) R. G. Ross and C. O. Gourley. Can. Plant Dis. Surv. 49:33, 1969. (2) A. L. Snowdon. A Color Atlas of Postharvest Diseases. CRC Press, Inc., Boca Raton, FL, 1990. (3) G. M. Waterhouse. The Genus Phytophthora. Misc. Publ. 12. The Commonwealth Mycological Institute, Kew, Surrey, England, 1956.

scholarly journals First Report of Passalora Leaf Spot Caused by Passalora bougainvilleae on Bougainvillea in Mexico

Plant Disease ◽  
2011 ◽  
Vol 95 (6) ◽  
pp. 775-775 ◽  
Author(s):  
V. Ayala-Escobar ◽  
V. Santiago-Santiago ◽  
A. Madariaga-Navarrete ◽  
A. Castañeda-Vildozola ◽  
C. Nava-Diaz
Keyword(s):  
Uv Light ◽  
Disease Incidence ◽  
Morphological Characteristics ◽  
The United States ◽  
Pathogenicity Test ◽  
Commonwealth Mycological Institute ◽  
Conidial Suspension ◽  
Single Spore ◽  
First Report ◽  
Bougainvillea Spectabilis

Bougainvillea (Bougainvillea spectabilis Willd) growing in 28 gardens during 2009 showed 100% disease incidence and 3 to 7% disease severity. Bougainvilleas with white flowers were the most affected. Symptoms consisted of light brown spots with dark brown margins visible on adaxial and abaxial sides of the leaves. Spots were circular, 2 to 7 mm in diameter, often surrounded by a chlorotic halo, and delimited by major leaf veins. Single-spore cultures were incubated at 24°C under near UV light for 7 days to obtain conidia. Pathogenicity was confirmed by spraying a conidial suspension (1 × 104 spores/ml) on leaves of potted bougainvillea plants (white, red, yellow, and purple flowers), incubating the plants in a dew chamber for 48 h and maintaining them in a greenhouse (20 to 24°C). Identical symptoms to those observed at the residential gardens appeared on inoculated plants after 45 to 60 days. The fungus was reisolated from inoculated plants that showed typical symptoms. No symptoms developed on control plants treated with sterile distilled water. The fungus produced distinct stromata that were dark brown, spherical to irregular, and 20 to 24 μm in diameter. Conidiophores were simple, born from the stromata, loose to dense fascicles, brown, straight to curved, not branched, zero to two septate, 14 × 2 μm, with two to four conspicuous and darkened scars. The conidia formed singly, were brown, broad, ellipsoid, obclavate, straight to curved with three to four septa, 40 × 4 μm, and finely verrucous with thick hilum at the end. Fungal DNA from the single-spore cultures was obtained using a commercial DNA Extraction Kit (Qiagen, Valencia, CA); ribosomal DNA was amplified with ITS5 and ITS4 primers and sequenced. The sequence was deposited at the National Center for Biotechnology Information Database (GenBank Accession Nos. HQ231216 and HQ231217). The symptoms (4), morphological characteristics (1,2,4), and pathogenicity test confirm the identity of the fungus as Passalora bougainvilleae (Muntañola) Castañeda & Braun (= Cercosporidium bougainvilleae Muntañola). This pathogen has been reported from Argentina, Brazil, Brunei, China, Cuba, El Salvador, India, Indonesia, Jamaica, Japan, Thailand, the United States, and Venezuela (3). To our knowledge, this is the first report of this disease on B. spectabilis Willd in Mexico. P. bougainvilleae may become an important disease of bougainvillea plants in tropical and subtropical areas of Mexico. References: (1) U. Braun and R. R. Castañeda. Cryptogam. Bot. 2/3:289, 1991. (2) M. B. Ellis. More Dematiaceous Hypomycetes. Commonwealth Mycological Institute, Kew, Surrey, UK, 1976. (3) C. Nakashima et al. Fungal Divers. 26:257, 2007. (4) K. L. Nechet and B. A. Halfeld-Vieira. Acta Amazonica 38:585, 2008.

scholarly journals Distribution of a New Invasive Species, Sipha maydis (Heteroptera: Aphididae), on Cereals and Wild Grasses in the Southern Plains and Rocky Mountain States

2019 ◽  
Vol 112 (4) ◽  
pp. 1713-1721
Author(s):  
Gary J Puterka ◽  
Robert W Hammon ◽  
Melissa Franklin ◽  
Dolores W Mornhinweg ◽  
Tim Springer ◽  
...  
Keyword(s):  
United States ◽  
Host Range ◽  
Rocky Mountain ◽  
The United States ◽  
Grass Species ◽  
New Host ◽  
Southern Plains ◽  
Wide Range ◽  
Winter Temperatures ◽  
Sorghum Production

Abstract Sipha maydis Passerini (Heteroptera: Aphididae) is a cereal pest with an extensive geographical range that includes countries in Europe, Asia, Africa, and South America. Reports of S. maydis in the United States have been infrequent since it was first detected in California, 2007. Two studies, focused (NW CO) and multistate (OK, TX, NM, CO, UT, WY), were conducted to determine the distribution and host range of S. maydis in the Rocky Mountain and Southern Plains states over a 3-yr period, 2015–2017. In 2015, focused sampling in NW Colorado found S. maydis at 59% of the 37 sites, primarily on wheat. Sipha maydis did not survive extreme winter temperatures from late December 2015 to early January 2016 that ranged from −9.0 to −20.9°C over a 9-d period, which resulted in no aphids detected in 2016. In the multistate study, S. maydis occurred in 14.6% of 96 sites sampled in 2015, 8% of 123 sites in 2016, and 9% of 85 sites in 2017 at wide range of altitudes from 1,359 to 2,645 m. Sipha maydis occurred mainly in NW and SW Colorado and NE New Mexico along with a few sites in NE Colorado, SE Utah, and SE Wyoming. This aphid mainly infested wheat followed by a variety of eight wild grass species. No parasites, predators, sexual morphs, or significant plant damage occurred at the sites. Sipha maydis utilized 14 hosts in the United States including 8 new host records, which expands its host range to 52 plant species worldwide. Sipha maydis may be of concern to wheat, barley, and sorghum production in the United States if its populations continue to increase.

scholarly journals Occurrences of Diplodia Leaf Streak Caused by Stenocarpella macrospora on Corn (Zea mays) in Illinois

Plant Disease ◽  
2010 ◽  
Vol 94 (10) ◽  
pp. 1262-1262 ◽  
Author(s):  
C. A. Bradley ◽  
D. K. Pedersen ◽  
G. R. Zhang ◽  
N. R. Pataky
Keyword(s):  
United States ◽  
Zea Mays ◽  
Morphological Characteristics ◽  
The United States ◽  
Small Subunit ◽  
Minor Importance ◽  
United States Department ◽  
Conidial Suspension ◽  
Small Subunit Rdna ◽  
Corn Fields

In August 2008, long and narrow lesions were observed on leaves of corn (Zea mays L.) growing in a field in Pope County, Illinois. Lesions were 10 to 35 × 50 to 250 mm and were cream to tan. Dark pycnidia inside the lesions were immersed and approximately 350 μm in diameter. Affected leaves were collected and placed into a moist chamber to encourage the development of conidia. Conidia developed in cirri and were dark, one septate, and 7 to 11 × 59 to 87 μm. Cirri were streaked onto potato dextrose agar (PDA; Becton, Dickinson, and Company, Franklin Lakes, NJ) and cultures arising from single conidia were transferred and maintained. On the basis of the corn leaf symptoms and the morphological characteristics of the pycnidia and conidia, the fungus was tentatively identified as Stenocarpella macrospora (Earle) Sutton (1). To complete Koch's postulates, ‘Garst 84H80-3000GT’ corn was inoculated in the greenhouse. Conidia were produced by placing a S. macrospora isolate from Pope County, IL onto water agar containing autoclaved corn leaves and incubating at room temperature until pycnidia and conidia were produced (approximately 3 weeks). A conidial suspension was used to inoculate the leaf whorls of corn plants (approximately at the V4 growth stage). Control plants were mock inoculated with sterile water. The experiment was repeated once over time. Twenty days after inoculation, all plants inoculated with S. macrospora conidia developed lesions similar to those observed in the field, and mock-inoculated plants remained symptomless. The fungus was reisolated on PDA from the symptomatic leaves. In August 2009, symptomatic leaves similar to those observed in Pope County, IL in 2008 were observed and collected from corn fields in Gallatin and Vermillion counties. Pycnidia and conidia from these lesions were similar to those described above, and isolates from single conidia were obtained from these samples. To confirm the identity of all isolates collected, PCR amplification of the small subunit rDNA and internal transcribed spacer (ITS) region with primers EF3RCNL and ITS4 was conducted (3). The PCR product was sequenced with these primers at the Keck Biotechnology Center at the University of Illinois, Urbana. The resulting nucleotide sequence was compared with small subunit rDNA and ITS sequences deposited in the GenBank nucleotide database, which revealed 99% homology to sequences of S. macrospora. In total, six of our S. macrospora isolates from Gallatin, Pope, and Vermillion counties were submitted to the United States Department of Agriculture–Agriculture Research Service Culture Collection in Peoria, IL, where they have received NRRL Accession Nos. 54190–54195. To our knowledge, this is the first report of S. macrospora affecting corn in Illinois. Although not observed in the Illinois corn fields described above, S. macrospora has been reported to infect stalks and ears (2). Because of the large leaf lesions caused by S. macrospora and its reported aggressiveness in causing disease on leaves, ears, and stalks, this pathogen has the potential to cause severe yield and quality losses to corn in the United States (2). References: (1) M. L. Carson. Diseases of minor importance or limited occurrence. Page 23 in: Compendium of Corn Diseases. 3rd ed. The American Phytopathological Society, St. Paul, MN, 1999. (2) F. M. Latterell and A. E. Rossi. Plant Dis. 67:725, 1983. (3) N. S. Lord et al. FEMS Microbiol. Ecol. 42:327, 2002.

scholarly journals First Report of Pilidium concavum Causing Tan-brown Rot on Strawberry Nursery Stock in South Carolina

Plant Disease ◽  
2014 ◽  
Vol 98 (7) ◽  
pp. 1010-1010 ◽  
Author(s):  
D. Fernández-Ortuño ◽  
P. K. Bryson ◽  
G. Schnabel
Keyword(s):  
United States ◽  
South Carolina ◽  
Brown Rot ◽  
The United States ◽  
Conidial Suspension ◽  
Strawberry Fruit ◽  
Internal Transcribed Spacer Region ◽  
First Report ◽  
Nursery Stock ◽  
Wide Range

Pilidium concavum (Desm.) Höhn. [synanamorph: Hainesia lythri (Desm.) Höhn.] is an opportunistic pathogen that causes leaf spots and stem necrosis in a wide range of hosts, including strawberry (Fragaria ananassa) (1,2). In October 2013, 24 strawberry plug plants (cv. Chandler) with brown to dark brown necrotic lesions on stolons were obtained from a nursery in Easley, SC. The lesions were oval shaped and varied in length from 2 to 8 mm. The tips of stolons with larger spots had died. To isolate the causal agent, 3 to 5 cm of necrotic stolon tissue was surface disinfected for 1 min with 10% bleach, rinsed with sterile distilled water, air dried, and placed on potato dextrose agar (PDA). After 7 days of incubation at 22°C, pink-orange masses of spores emerged. Single spore colonies on PDA produced a gray to brown colony with whitish aerial mycelium. Numerous discoid to hemisphaerical conidiomata (0.3 to 2.2 mm in diameter) developed with a dark base and exuded a pink, slimy mass that contained many conidia. Conidiophores (10.2 to 47.8 × 0.8 to 2.0 μm) were hyaline, unicellular, cylindrical, and filiform. Conidia (3.0 to 8.5 × 1.0 to 2.9 μm) were aseptate, fusiform, hyaline, and canoe-shaped to allantoid. On the basis of morphology, the pathogen was identified as P. concavum (3). The internal transcribed spacer region ITS1-5.8S-ITS2 was amplified by PCR and sequenced with primers ITS1 and ITS4 (4). The sequence was submitted to GenBank (Accession No. KF911079) and showed 100% homology with sequences of P. concavum. Pathogenicity was examined on strawberry fruit and leaves. Our previous efforts to achieve infection without wounding failed, which is consistent with experiences of other scientists (not cited). Thus, 24 strawberry fruit were wounded (1 cm deep) with a needle once, and submerged for 3 min in a conidial suspension (2 × 106 conidia ml−1). Controls were wounded and submerged in sterile water. After 4 days of incubation at 22°C, characteristic symptoms were observed at the wound site only on inoculated fruit. Detached leaves (about 6 cm in diameter) from 3- to 4-week-old strawberry plants cv. Chandler were surface sterilized and placed right side up in petri dishes (one leaf per dish) containing water agar. Leaves were inoculated at one site with a 50 μl conidial suspension (2 × 106 conidia ml−1) after inflicting a scraping-type injury with a needle to the surface at the point of inoculation. Control leaves received just water. After 7 days of incubation at 22°C, only the inoculated leaves showed symptoms similar to those observed on strawberry stolons. The fungus was re-isolated from symptomatic fruit and leaf lesions and identity was confirmed based on morphological features. The experiments were repeated. To our knowledge, this is the first report of P. concavum causing tan-brown rot on strawberry tissue in South Carolina. Prior to this study, the pathogen has been described from different hosts and countries including Belgium, Brazil, China, France, Iran, Poland, and the United States. Contamination of strawberry nursery stock by P. concavum could become a plant health management issue in the United States, especially if the pathogen is transferred to strawberry production areas. Further information on in-field occurrence of P. concacum is needed. References: (1) J. Debode et al. Plant Dis. 95:1029, 2011. (2) W. L. Gen et al. Plant Dis. 96:1377, 2012. (3) A. Y. Rossman et al. Mycol. Prog. 3:275, 2004. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.

scholarly journals First Report of Verticillium Wilt Caused by Verticillium dahliae on Rudbeckia fulgida (Orange Coneflower) in Italy

Plant Disease ◽  
2008 ◽  
Vol 92 (9) ◽  
pp. 1367-1367 ◽  
Author(s):  
A. Garibaldi ◽  
D. Bertetti ◽  
M. L. Gullino
Keyword(s):  
United States ◽  
Verticillium Wilt ◽  
Verticillium Dahliae ◽  
Vascular Tissue ◽  
Morphological Characteristics ◽  
Its Region ◽  
The United States ◽  
Conidial Suspension ◽  
First Report ◽  
Initial Symptoms

Rudbeckia fulgida (common name orange coneflower) is an herbaceous perennial (Asteraceae) grown in full sun in perennial borders in gardens. At the end of the summer of 2007, in a public garden located in Turin (northern Italy), symptoms of vascular wilt and stunting were observed on approximately 80% of the plants grown in a mixed border. Initial symptoms were yellowing of external leaves and brown or black streaks in the vascular tissue of roots, crown, and leaves. A fungus was consistently and readily isolated on potato dextrose agar from symptomatic vascular tissue previously disinfested in 1% sodium hypochloride. Ovoid, dark microsclerotia, 41 to 108 μm, developed in hyaline hyphae after 10 days of growth at 23°C (12 h of light and 12 h of dark). Hyaline, elliptical, single-celled conidia, 3.2 to 7.3 × 2.1 to 3.7 (average 4.7 × 2.8) μm, developed on verticillate conidiophores. On the basis of these morphological characteristics, the fungus was identified as Verticillium dahliae (4). The internal transcribed spacer (ITS) region of rDNA was amplified using primers ITS4/ITS6 and sequenced. BLASTn analysis (1) of the 530 bp showed a 100% homology with the sequence of V. dahliae. The nucleotide sequence has been assigned GenBank Accession No. EU 627007. Healthy, 30-day-old R. fulgida plants were grown in a steam-disinfested mix of sphagnum peat:pomix:pine bark:clay (50:20:20:10) infested with a conidial suspension (1.5 × 106/ml) of three isolates of V. dahliae isolated from infected plants. Noninoculated plants served as controls. Plants (16 per treatment) were grown in pots (3 liter vol) and maintained in a glasshouse at temperatures between 22 and 25°C and relative humidity between 50 and 70%. First wilt symptoms and vascular discoloration in the roots, crown, and veins developed 17 days after inoculation. Noninoculated plants remained healthy. The pathogenicity tests were carried out twice. To our knowledge, this is the first report in Italy of Verticillium wilt on R. fulgida. Wilts caused by V. dahliae on R. laciniata in Poland (3) and V. albo-atrum on R. hirta in the United States (2) were previously reported. The importance and economic impact of this disease is currently limited but may increase because of the popularity of Rudbeckia spp. in private and public parks. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) D. F. Farr et al. Fungi on Plants and Their Products in the United States. The American Phytopathological Society, St Paul, MN, 1989. (3) B. Leski. Rocz. Nauk Roln. 253, 1974. (4) G. F. Pegg and B. L. Brady. Verticillium Wilts. CABI Publishing, Wallingford, UK, 2002.

The Politics of Precaution

2012 ◽  
Author(s):  
David Vogel
Keyword(s):  
United States ◽  
Animal Feed ◽  
The United States ◽  
Hazardous Substances ◽  
Risk Regulation ◽  
Scientific Certainty ◽  
European Public ◽  
Wide Range ◽  
Regulatory Controls ◽  
Milk Hormones

This book examines the politics of consumer and environmental risk regulation in the United States and Europe over the last five decades, explaining why America and Europe have often regulated a wide range of similar risks differently. It finds that between 1960 and 1990, American health, safety, and environmental regulations were more stringent, risk averse, comprehensive, and innovative than those adopted in Europe. But since around 1990 global regulatory leadership has shifted to Europe. What explains this striking reversal? This book takes an in-depth, comparative look at European and American policies toward a range of consumer and environmental risks, including vehicle air pollution, ozone depletion, climate change, beef and milk hormones, genetically modified agriculture, antibiotics in animal feed, pesticides, cosmetic safety, and hazardous substances in electronic products. The book traces how concerns over such risks—and pressure on political leaders to do something about them—have risen among the European public but declined among Americans. The book explores how policymakers in Europe have grown supportive of more stringent regulations while those in the United States have become sharply polarized along partisan lines. And as European policymakers have grown more willing to regulate risks on precautionary grounds, increasingly skeptical American policymakers have called for higher levels of scientific certainty before imposing additional regulatory controls on business.

scholarly journals Effects of trees, gardens, and nature trails on heat index and child health: design and methods of the Green Schoolyards Project

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kevin Lanza ◽  
Melody Alcazar ◽  
Deanna M. Hoelscher ◽  
Harold W. Kohl
Keyword(s):  
Physical Activity ◽  
United States ◽  
Relative Humidity ◽  
Air Temperature ◽  
The United States ◽  
Heat Index ◽  
Activity Levels ◽  
Natural Setting ◽  
Physical Activity Levels ◽  
Nature Trails

Abstract Background Latinx children in the United States are at high risk for nature-deficit disorder, heat-related illness, and physical inactivity. We developed the Green Schoolyards Project to investigate how green features—trees, gardens, and nature trails—in school parks impact heat index (i.e., air temperature and relative humidity) within parks, and physical activity levels and socioemotional well-being of these children. Herein, we present novel methods for a) observing children’s interaction with green features and b) measuring heat index and children’s behaviors in a natural setting, and a selection of baseline results. Methods During two September weeks (high temperature) and one November week (moderate temperature) in 2019, we examined three joint-use elementary school parks in Central Texas, United States, serving predominantly low-income Latinx families. To develop thermal profiles for each park, we installed 10 air temperature/relative humidity sensors per park, selecting sites based on land cover, land use, and even spatial coverage. We measured green features within a geographic information system. In a cross-sectional study, we used an adapted version of System for Observing Play and Recreation in Communities (SOPARC) to assess children’s physical activity levels and interactions with green features. In a cohort study, we equipped 30 3rd and 30 4th grade students per school during recess with accelerometers and Global Positioning System devices, and surveyed these students regarding their connection to nature. Baseline analyses included inverse distance weighting for thermal profiles and summing observed counts of children interacting with trees. Results In September 2019, average daily heat index ranged 2.0 °F among park sites, and maximum daily heat index ranged from 103.4 °F (air temperature = 33.8 °C; relative humidity = 55.2%) under tree canopy to 114.1 °F (air temperature = 37.9 °C; relative humidity = 45.2%) on an unshaded playground. 10.8% more girls and 25.4% more boys interacted with trees in September than in November. Conclusions We found extreme heat conditions at select sites within parks, and children positioning themselves under trees during periods of high heat index. These methods can be used by public health researchers and practitioners to inform the redesign of greenspaces in the face of climate change and health inequities.

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