scholarly journals First Report of Entyloma Polysporum on Sunflower (Helianthus annuus) in Southern California

Plant Disease ◽  
1999 ◽  
Vol 83 (4) ◽  
pp. 396-396 ◽  
Author(s):  
M. F. Dirac ◽  
P. Nolan ◽  
J. A. Menge ◽  
A. O. Paulus

During a period of wet weather from December 1996 to March 1997, commercial plantings of sunflower in San Diego County, CA, were infected by a leaf smut, Entyloma polysporum (Peck) Farl. The fungus was observed on sunflowers grown in a greenhouse in San Diego County and also on sunflowers from nurseries in Ventura and Riverside counties. Although the disease was first noticed in 1996, the infection was not of economic significance so no attempt was made to identify the causal agent. However, with continuous cropping of sunflowers year round significant losses were observed on seedlings that were systemically infected as they emerged. This is the first report of E. polysporum causing economic losses on sunflowers. The distinguishing characteristics of this fungus are masses of globose to subglobose spores, pale green to yellow green in color, approximately 12 μm in diameter, with a double wall consisting of an inner pale green wall and outer hyaline sheath. The spores occur in dense masses called sori that completely replace the leaf cells. Young spores are difficult to distinguish from leaf cells in a cursory examination. Older sori form discolored lesions in the leaf ranging from circular to irregular in shape and replace most of the chlorenchyma tissue in the infected lesions. Identification of species of smut fungi such as Entyloma is based on the location of the sori in the vegetative parts of the host, the identification of the host, and the spore morphology (4). Savile (3) reviewed the genus on North American composites and, based on morphological characteristics, concluded that almost all the pathogens were either E. compositarum or E. polysporum, with a few intermediate forms. E. polysporum is characterized by globose spores 10 to 17 μm in diameter, surrounded by cell walls 1 μm thick encased in a 1.5- to 2.5-μm thick smooth hyaline sheath (1). Spores of E. compositarum are smaller, 9 to 12 μm in diameter, thin walled (1 to 1.5 μm), smooth, and without a sheath (2). Vánky (4) lists 33 different species on composites according to their host. He believes E. polysporum only occurs on Ambrosia spp., and does not include E. compositarum in his list of Entyloma spp. Neither author mentions Entyloma infecting any species of Helianthus. Savile concluded that E. calendulae (Oudem.) de Bary, described in Europe, is very similar morphologically to E. polysporum, and is probably the same species. E. polysporum was first described in 1881 by Peck as Protomyces polysporus infecting Ambrosia trifida in New York State. In 1996, it was described on Ambrosia artemesifolia in Hungary (3). In the United States it has been reported on sunflowers in Montana (1,2). References: (1) D. F. Farr et al. 1989. Fungi on Plants and Plant Products in the United States. American Phytopathological Society, St. Paul, MN. (2) G. W. Fischer. 1953. Manual of the North American Smut Fungi. Ronald Press, New York. (3) D. B. O. Savile. Can. J. Res. 25(C):109, 1947. (4) K. Vánky. 1994. European Smut Fungi. Gustav Fischer, New York.

1993 ◽  
Vol 67 (1) ◽  
pp. 151-151
Author(s):  
R. William Orr ◽  
Richard H. Fluegeman

In 1990 (Fluegeman and Orr) the writers published a short study on known North American cyclocystoids. This enigmatic group is best represented in the United States Devonian by only two specimens, both illustrated in the 1990 report. Previously, the Cortland, New York, specimen initially described by Heaslip (1969) was housed at State University College at Cortland, New York, and the Logansport, Indiana, specimen was housed at Ball State University, Muncie, Indiana. Both institutions recognize the importance of permanently placing these rare specimens in a proper paleontologic repository with other cyclocystoids. Therefore, these two specimens have been transferred to the curated paleontologic collection at the University of Cincinnati Geological Museum where they can be readily studied by future workers in association with a good assemblage of Ordovician specimens of the Cyclocystoidea.


Plant Disease ◽  
2014 ◽  
Vol 98 (5) ◽  
pp. 696-696 ◽  
Author(s):  
J. A. Crouch ◽  
M. P. Ko ◽  
J. M. McKemy

Downy mildew of impatiens (Impatiens walleriana Hook.f.) was first reported from the continental United States in 2004. In 2011 to 2012, severe and widespread outbreaks were documented across the United States mainland, resulting in considerable economic losses. On May 5, 2013, downy mildew disease symptoms were observed from I. walleriana ‘Super Elfin’ at a retail nursery in Mililani, on the Hawai'ian island of Oahu. Throughout May and June 2013, additional sightings of the disease were documented from the islands of Oahu, Kauai, Maui, and Hawai'i from nurseries, home gardens, and botanical park and landscape plantings. Symptoms of infected plants initially showed downward leaf curl, followed by a stippled chlorotic appearance on the adaxial leaf surfaces. Abaxial leaf surfaces were covered with a layer of white mycelia. Affected plants exhibited defoliation, flower drop, and stem rot as the disease progressed. Based on morphological and molecular data, the organism was identified as Plasmopara obducens (J. Schröt.) J. Schröt. Microscopic observation disclosed coenocytic mycelium and hyaline, thin-walled, tree-like (monopodial branches), straight, 94.0 to 300.0 × 3.2 to 10.8 μm sporangiophores. Ovoid, hyaline sporangia measuring 11.0 to 14.6 × 12.2 to 16.2 (average 13.2 × 14.7) μm were borne on sterigma tips of rigid branchlets (8.0 to 15.0 μm) at right angle to the main axis of the sporangiophores (1,3). Molecular identification of the pathogen was conducted by removing hyphae from the surface of three heavily infected leaves using sterile tweezers, then extracting DNA using the QIAGEN Plant DNA kit (QIAGEN, Gaithersburg, MD). The nuclear rDNA internal transcribed spacer was sequenced from each of the three samples bidirectionally from Illustra EXOStar (GE Healthcare, Piscataway, NJ) purified amplicon generated from primers ITS1-O and LR-0R (4). Resultant sequences (GenBank KF366378 to 80) shared 99 to 100% nucleotide identity with P. obducens accession DQ665666 (4). A voucher specimen (BPI892676) was deposited in the U.S. National Fungus Collections, Beltsville, MD. Pathogenicity tests were performed by spraying 6-week-old impatiens plants (I. walleriana var. Super Elfin) grown singly in 4-inch pots with a suspension of 1 × 104 P. obducens sporangia/ml until runoff using a handheld atomizer. Control plants were sprayed with distilled water. The plants were kept in high humidity by covering with black plastic bags for 48 h at 20°C, and then maintained in the greenhouse (night/day temperature of 20/24°C). The first symptoms (downward curling and chlorotic stippling of leaves) and sporulation of the pathogen on under-leaf surfaces of the inoculated plants appeared at 10 days and 21 days after inoculation, respectively. Control plants remained healthy. Morphological features and measurements matched those of the original inoculum, thus fulfilling Koch's postulates. To our knowledge, this is the first report of downy mildew on I. walleriana in Hawai'i (2). The disease appears to be widespread throughout the islands and is likely to cause considerable losses in Hawai'ian landscapes and production settings. References: (1) O. Constantinescu. Mycologia 83:473, 1991. (2) D. F. Farr and A. Y. Rossman. Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ July 16, 2013. (3) P. A. Saccardo. Syllogue Fungorum 7:242, 1888. (4) M. Thines. Fungal Genet Biol 44:199, 2007.


Plant Disease ◽  
2007 ◽  
Vol 91 (7) ◽  
pp. 905-905 ◽  
Author(s):  
N. A. Mitkowski

In the fall of 2006, a golf course in Snoqualmie, WA renovated five putting greens with commercially produced Poa annua L. sod from British Columbia, Canada. Prior to the renovation, the greens had been planted with Agrostis stolonifera L. cv. Providence, which was removed during the renovation. In February of 2007, chlorotic patches were observed on the newly established P. annua greens. When the roots were examined, extensive galling was observed throughout plant roots. Galls were slender and twisted in appearance and less than one millimeter long. Upon dissection of washed galls, hundreds of eggs were exuded into the surrounding water droplet and both mature male and female nematodes were observed. Further morphometric examination of males, females, and juvenile nematodes demonstrated that they were Subanguina radicicola (Greef 1872) Paramanov 1967 (1). Amplification of nematode 18S, ITS1, and 5.8S regions, using previously published primers (2), resulted in a 100% sequence match with the publicly available sequence for S. radicicola, GenBank Accession No. AF396366. Each P. annua plant had an average of six galls (with a range of 1 to 8), primarily located within the top 2 cm of the soil. All five new P. annua putting greens at the golf course were infested with the nematode. Additionally, P. annua from two A. stolonifera cv. Providence greens that had not been renovated was infected, suggesting that the population occurred onsite and was not imported from the Canadian sod. S. radicicola has been identified as causing severe damage in New Brunswick, Canada on P. annua putting greens and in wild P. annua in the northwestern United States, but to our knowledge, this is the first report of the nematode affecting P. annua on a golf course in the United States. References: (1) E. L. Krall. Wheat and grass nematodes: Anguina, Subanguina, and related genera. Pages 721–760 in: Manual of Agricultural Nematology. Marcel Dekker, New York, 1991. (2) N. A. Mitkowski et al. Plant Dis. 86:840, 2002.


Plant Disease ◽  
2010 ◽  
Vol 94 (7) ◽  
pp. 924-924 ◽  
Author(s):  
C. Hernandez-Zepeda ◽  
T. Isakeit ◽  
A. Scott ◽  
J. K. Brown

During the okra growing season from August to November of 2009, symptoms reminiscent of geminivirus infection were observed on 75% of ‘Green Emerald’ Abelmoschus esculentus (L.) Moench, plants in a 0.2-km2 field in Hidalgo County, TX. Visible symptoms consisted of irregular yellow patches on leaves, distinctive yellow borders on leaf edges, and chlorosis of subsequently developing leaves. The whitefly vector of begomoviruses, Bemisia tabaci (Genn.), infested okra plants in the early growth stages during late July 2009. Total DNA was isolated from the leaves of three symptomatic okra plant samples (1) and used as the PCR template to amplify a 575-bp fragment of the coat protein gene (CP) using the universal begomovirus primers AV494 and AC1048 (2). PCR products of the expected size were cloned into the pGEM-T Easy (Promega, Madison, WI) and sequenced using the universal M13F and M13 R primers. ClustalV alignment indicated 99 to 100% shared nucleotide (nt) identity, and BLAST analysis revealed that the closest relative was Okra yellow mosaic Mexico virus - Tetekalitla (OkYMMV) (GenBank Accession No. EF591631) at 98%. To amplify the full-length DNA-A and a possible cognate DNA-B component, one plant that was positive by CP-PCR and DNA sequencing was selected for further analysis. Total DNA from this plant was used as template for a second detection method that consisted of rolling circle amplification (RCA) using the TempliPhi 100 Amplification System (GE Healthcare). RCA is a non-sequence-specific approach that permits amplification of circular DNA. The RCA products were linearized to release unit length ~2.6 kb DNA-A and DNA-B components using BamHI, and EcoRI, respectively. These products were cloned into pGEM3zf+ (Promega) and sequenced using M13F and M13 R primers and then by primer walking (>300 base overlap). Full-length DNA-A and DNA-B components were obtained, respectively, at 2,613 bp (GenBank Accession No. HM035059) and 2,594 bp (GenBank Accession No HM035060). Alignment of the DNA-A component using ClustalV (MegAlign, DNASTAR, Madison, WI) with begomoviral sequences available in GenBank indicated that it was 99% identical to OkYMMV DNA-A (GenBank Accession No. DQ022611). The closest relative to the DNA-B component (ClustalV) was Sida golden mosaic virus (SiGMV) (GenBank Accession No. AJ250731) at 73%. The nt identity of the 172-nt ‘common region’ present in the DNA-A and DNA-B components was 99%, and the iterons (predicted Rep binding motif) were identical for the two components, indicating that they are a cognate pair. The genome organization was typical of other New World bipartite begomoviruses. The economic losses due to infection by this virus could not be determined because an early freeze killed the plants. Hidalgo County is adjacent to Tamaulipas, Mexico, where ~50 km2 of okra are grown and the whitefly vector is also present. The identification of OkYMMV based on two independent detection methods, and the presence of begomovirus-like symptoms together with the whitefly vector, provide robust evidence for the association of OkYMMV-TX with diseased okra plants. To our knowledge, this is the first report of OkYMMV-TX infecting okra crops in Texas and in the continental United States. References: (1) J. J. Doyle and J. L. Doyle. Focus 12:13, 1990. (2) S. Wyatt and J. K. Brown. Phytopathology 86:1288, 1996.


PEDIATRICS ◽  
1974 ◽  
Vol 53 (1) ◽  
pp. 132-134
Author(s):  
Alex J. Steigman

This interesting volume is the result of a proper symposium rather than a collection of submitted reports. The authoritative findings are sprinkled generously with a free flowing discussion which brings sharply into focus what remains to be learned and how to go about it. The 22 well-qualified participants include 17 from Great Britain, 4 from the European continent, and 1 from the United States. Wisely included are the observations of a veterinarian-scientist; lessons learned from studies made primarily to prevent economic losses in animals may become useful to clinicians.


Author(s):  
Marlon Boarnet ◽  
Randall C. Crane

The facts, figures, and inferences in chapter 7 regarding municipal behavior toward transit-oriented housing opportunities illustrate many points. Still, there is much that even a careful statistical analysis might miss or misunderstand. For that reason, we also explored what we could learn by talking to real planners about these issues. The case of San Diego is interesting and useful for several reasons. First, the San Diego Trolley is the oldest of the current generation of light rail projects in the United States. Unlike many newer systems, the age of San Diego’s rail transit (the South Line opened in 1981) allows time for land use planning to respond to the fixed investment. Second, the San Diego system is no stranger to modern transit-based planning ideas. The San Diego City Council approved a land-use plan for their stations that includes many of the ideas promoted by transit-oriented development (TOD) advocates (City of San Diego, 1992). Third, the light rail transit (LRT) authority in San Diego County, the Metropolitan Transit Development Board (MTDB), is often regarded as one of the more successful municipal LRT agencies. The initial parts of the MTDB rail transit system were constructed strictly with state and local funds, using readily available, relatively low-cost technology (Demoro and Harder, 1989, p. 6). Portions of San Diego’s system have high fare-box recovery rates, including the South Line, which in its early years recovered as much as 90 percent of operating costs at the fare box (Gómez-Ibáñez, 1985). All of these factors make San Diego potentially a “best-case” example of TOD implementation. When generalizing from this case study, it is important to remember that the transit station area development process in San Diego is likely better developed than in many other urban areas in the United States. The results from San Diego County can illustrate general issues that, if they have not already been encountered, might soon become important in other urban areas with rail transit systems. Also, given San Diego County’s longer history of both LRT and TOD when compared with most other regions, any barriers identified in San Diego County might be even more important elsewhere.


1989 ◽  
Vol 45 (4) ◽  
pp. 443-460

Harris Gaylord Warren was, by common consent, the father of Paraguayan studies in the United States. His broad-ranging activities —from diplomatic undertakings in South America to military service in Italy to administrative and scholarly work at various North American universities—marked him as an historian of rare depth and insight. Not commonly known is that Dr. Warren began his career as a historian in the 1930s as a borderlands specialist. The Sword was their Passport: A History of American Filibustering in the Mexican Revolution (Baton Rouge, 1943) is yet recognized as the definitive work on North American adventurers in that turbulent era. As an officer in the United States Army in World War II he was selected for various military history projects. After the war Dr. Warren returned to teaching and then administration. At that time his publications ranged from texts to Herbert Hoover and the Great Depression, (New York, 1959).


1998 ◽  
Vol 36 (12) ◽  
pp. 3497-3504 ◽  
Author(s):  
D. Postic ◽  
N. Marti Ras ◽  
R. S. Lane ◽  
M. Hendson ◽  
G. Baranton

Up to now, the only species in the complex Borrelia burgdorferi sensu lato known to cause Lyme borreliosis in the United States has been B. burgdorferi sensu stricto. However, some atypical strains closely related to the previously designated genomic group DN127 have been isolated in the United States, mostly in California. To explore the diversity of B. burgdorferi sensu lato group DN127, we analyzed the nucleotide sequences of the rrf-rrl intergenic spacer regions from 19 atypical strains (18 from California and one from New York) and 13 North American B. burgdorferi sensu stricto strains (6 from California). The spacer region sequences from the entire B. burgdorferi sensu lato complex available in data banks were used for comparison. Phylogenetic analysis of sequences shows that the main species of the B. burgdorferi sensu lato complex (B. afzelii, B. garinii, B. andersonii,B. japonica, B. burgdorferi sensu stricto,B. valaisiana, and B. lusitaniae) each form a coherent cluster. A heterogeneous group comprising strains belonging to the previously designated group DN127 clustered separately fromB. burgdorferi sensu stricto. Within this cluster, the deep branches expressing the distances between the rrf-rrlsequences reflect a high level of divergence. This unexpected diversity contrasts with the monomorphism exhibited by B. burgdorferisensu stricto. To clarify the taxonomic status of this highly heterogeneous group, analysis of the rrs sequences of selected strains chosen from deeply separated branches was performed. The results show that these strains significantly diverge at a level that is compatible with several distinct genomic groups. We conclude that the taxonomy and phylogeny of North American B. burgdorferi sensu lato should be reevaluated. For now, we propose that the genomic group DN127 should be referred to as a new species,B. bissettii sp. nov., and that other related but distinct strains, which require further characterization, be referred to asBorrelia spp.


2012 ◽  
Vol 194 (23) ◽  
pp. 6620-6621 ◽  
Author(s):  
Rommel Thiago Jucá Ramos ◽  
Artur Silva ◽  
Adriana Ribeiro Carneiro ◽  
Anne Cybelle Pinto ◽  
Siomar de Castro Soares ◽  
...  

ABSTRACTThe bacteriumCorynebacterium pseudotuberculosisis of major veterinary importance because it affects livestock, particularly sheep, goats, and horses, in several countries, including Australia, Brazil, the United States, and Canada, resulting in significant economic losses. In the present study, we describe the complete genome of theCorynebacterium pseudotuberculosisCp316 strain, biovar equi, isolated from the abscess of a North American horse.


Plant Disease ◽  
2007 ◽  
Vol 91 (12) ◽  
pp. 1685-1685 ◽  
Author(s):  
J. Latinović ◽  
J. C. Batzer ◽  
K. B. Duttweiler ◽  
M. L. Gleason ◽  
G. Sun

The sooty blotch and flyspeck (SBFS) complex includes more than 30 fungi that blemish the cuticle of apple fruit, causing economic losses in humid regions worldwide (1). In August 2005, we sampled SBFS-infested wild plum (Prunus americana) fruit growing in hedgerows in Iowa. Colonies were categorized according to mycelial type (1), and isolates were made from representative colonies onto acidified water agar (AWA). Plum skins with SBFS signs were excised, pressed, and photographed. DNA was obtained from purified isolates and also from mycelium and fruiting bodies scraped directly from plum fruit skins. Extracted DNA was amplified using primer pair ITS1-F/Myc1-R (ACTCGTCGAAGGAGCTACG) and PCR products were sequenced using primer pair ITS-1F/ITS4. Six sequences were obtained from pure cultures and seven from colonies on plum fruit skin. BLAST analysis of the 470-bp sequences showed 100% homology to five known species in the SBFS complex: Zygophiala cryptogama, Zygophiala wisconsinensis, Pseudocercosporella sp. RH1, and Stomiopeltis spp. RS1 and RS2 (GenBank Accession Nos. AY598854, AY598853, AY5988645, AY598882, and AY598883, respectively). Observations of colony and fruiting structure morphology from cultures on potato dextrose agar (PDA) and colonies on plums confirmed species identity. A modified version of Koch's postulates was conducted to verify that these fungi caused the signs observed on plum and could also infest apple fruit. In June 2006, 1-month-old cultures on PDA were pulverized in a blender with sterile distilled water, passed through four layers of sterile cheesecloth, and transferred to sterile jars. Each isolate was inoculated onto 20 fruit on plum trees (P. americana) on the Iowa State University (ISU) campus and 20 fruit on cv. Golden Delicious apple trees at the ISU Research Station, Gilbert, IA. Each fruit was disinfested with 70% ethanol, air dried, swabbed with inoculum, and covered with a Fuji bag. At harvest, fungal colonies on fruit were reisolated onto AWA. DNA was extracted from pure cultures; when isolations on agar were unsuccessful, DNA was extracted directly from colonies on fruit. PCR was conducted using ITS1-F/Myc1-R, and PCR products were sequenced using ITS1-F/ITS4. All five species were reisolated and sequenced from apple. Pseudocercosporella sp. RH1 and Stomiopeltis sp. RS1 were sequenced from inoculated plums. Although flyspeck, presumably caused by Schizothyrium pomi, was reported on Japanese plum (P. salicina) in Japan (2) and black cherry (P. serotina) in the United States (3), to our knowledge this is the first report of SBFS fungi on plum in the United States and the first confirmation that fungi from plum can produce SBFS signs on apple fruit. Wild plum may therefore act as a reservoir host, providing inoculum for SBFS infestations on apple. References: (1) J. Batzer et al. Mycologia 97:1268, 2005. (2) H. Nasu and H. Kunoh. Plant Dis. 71:361, 1987. (3) T. B. Sutton. Plant Dis. 72:801, 1988.


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