scholarly journals First Report on White Smut of Gaillardia × grandiflora Caused by Entyloma polysporum in Virginia

Plant Disease ◽  
2003 ◽  
Vol 87 (3) ◽  
pp. 313-313 ◽  
Author(s):  
C. X. Hong ◽  
T. J. Banko

Disease samples of Gaillardia × grandiflora cvs. Goblin and Baby Cole were received at the Hampton Roads Agricultural Research and Extension Center in Virginia Beach in early April 2002. Samples were from a nursery in eastern Virginia, and most diseased plants had several to more than a dozen, round, flat, white to tan spots with indistinct margins up to 1 cm in diameter on their leaves. The spots later turned brown and necrotic, followed by necrosis of the entire leaf. Leaves of ‘Baby Cole’ were beginning to wilt and were more spotted than those of ‘Goblin’. Fungal fruiting bodies were not observed on the surface of diseased leaves. However, microscopic examination of internal leaf tissues revealed masses of round, double-walled, pale green-to-yellow spores approximately 12 μm in diameter and typical of the ustilospores of Entyloma polysporum (2,3). Inoculum for pathogenicity tests was prepared by blending 10 diseased leaves in 200 ml of sterile distilled water (SDW) for 2 min in a blender at low speed. The spore suspension was adjusted to 5 × 105 spores per ml with SDW. Healthy ‘Goblin’ gaillardia plants were obtained from a nursery where smut symptoms had never been seen. Four plants in one-gallon containers were inoculated by spraying them to runoff with the spore suspension. Four control plants were sprayed with SDW only. All plants were maintained in a greenhouse (15 to 35°C) and covered with a clean polyethylene plastic sheet overnight (14 h) to maintain high humidity and separated to avoid potential cross contamination. Inoculated and uninoculated plants were hand-watered separately, with application of water to the foliage to enhance spread of the disease. Typical white smut symptoms were observed on inoculated plants 2 weeks after inoculation, and numerous spores of E. polysporum were observed in the diseased tissues. No disease symptoms were seen on control plants. White smut has been reported on gaillardia in a few other states (1), but to our knowledge, this is the first report of the disease on gaillardia in Virginia. Growers at the affected nursery reported observing white smut symptoms on gaillardia in previous years, but in the spring of 2002, almost the entire gaillardia crop was destroyed. The disease has not been seen on gaillardia in any other nurseries, but it could have significant impact on production if it spreads. References: (1) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989. (2) W. Fischer. Manual of the North American Smut Fungi. Ronald Press, New York, 1953. (3) D. B. O. Savile. Can. J. Res. 25(C):109,1947.

EDIS ◽  
2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Mario H.M.L. Andrade ◽  
Rodrick Z. Mwatuwa ◽  
Christian T. Christensen ◽  
Pam Solano ◽  
Kathleen G. Haynes ◽  
...  

‘Peter Wilcox’ is a fresh market potato variety selected from progeny of a cross between B0810-1 and B0918-5 and tested under the pedigree B1816-5 by the United States Department of Agriculture. In 2007,  ‘Peter Wilcox’ was joint relesead with the North Carolina Agricultural Research Service, the Agricultural Experiment Stations of New Jersey, Pennsylvania, Florida, and New York, and the Maine Agricultural and Forest Experiment Station. In Florida, ‘Peter Wilcox’ demonstrates good tuber characteristics and high yields.  Tuber production and quality results provided in publication are from Florida Potato Variety Trials conducted at the UF/IFAS Hastings Agricultural Extension Center between 2001 and 2019.


Plant Disease ◽  
2001 ◽  
Vol 85 (1) ◽  
pp. 96-96 ◽  
Author(s):  
K. F. Chang ◽  
R. J. Howard ◽  
B. D. Gossen ◽  
S. F. Hwang

Intermediate wheatgrass (Thinopyrum intermedium [Host] Barkworth & D.R. Dewey) (syn. Agropyron intermedium [Host] Beauv.) is becoming an important forage grass species in Alberta, Canada. Severe losses in seed yield due to stem smut (Ustilago hypodytes [Schlecht.] Fr.) were noted in a 70-acre field near Warner, AB, in 1999. The crop had been established in 1993 and harvested for seed each year. Smut symptoms (5% incidence) were noted initially in 1997. Incidence, determined by counting the number of symptomatic stems, increased to 10% in 1998 and 50% in 1999. The symptoms usually appeared in the first week of June. Brown sori developed on infected stems, especially between the uppermost node and the leaf below the flag leaf, and gradually became black during the period of seed filling, which is characteristic of stem smut (1). Teliospores were smooth, spherical to oval, light to dark brown, and 4.5 to 5.0 × 5.0 to 6.8 μm in dimension, which is also consistent with previous descriptions of U. hypodytes. Infected stems occasionally flowered, but did not set seed, so seed yield losses were proportional to disease incidence. Plants infected with stem smut were often stunted. Tissues in the smutty stem often became sunken and stems became twisted and thinner than normal due to the propagation of sori in the stem over time. Stem smut has been reported on crested wheatgrass and slender wheatgrass in other parts of Canada (2) and on T. intermedium in the United States (3). This is the first report of stem smut affecting commercial grass seed production in Alberta, Canada. This disease could also have a significant impact on the seed production of intermediate wheatgrass elsewhere. References: (1) G. W. Fischer. 1953. Manual of the North American Smut Fungi. Ronald Press, New York. (2) B. D. Gossen and D. Regnier. Can. Plant Dis. Surv. 71:88–89, 1991. (3) J. F. Karn and J. M. Krupinsky. Phytopathology 73:1152–1155, 1983.


Plant Disease ◽  
2010 ◽  
Vol 94 (3) ◽  
pp. 381-381 ◽  
Author(s):  
R. L. Hirsch ◽  
D. O. TeBeest ◽  
B. H. Bluhm ◽  
C. P. West

In May 2007, switchgrass (Panicum virgatum L.) cv. Alamo and a breeding line, OSU-NSL 2001-1, were planted at the Arkansas Agricultural Research and Extension Center, Fayetteville. In August 2008, a high incidence of dark brown-to-black rectangular foliar lesions delineated by major veins was observed throughout plots of both lines. Lesions covered 25% to nearly 100% of total leaf tissue. Similar symptoms were also observed on unknown switchgrass cultivars in Benton County in northwest Arkansas and in St. Francis County in east-central Arkansas, suggesting that the disease was widely distributed throughout the state. The pathogen produced epiphyllous and adaxial masses of dark brown-to-black telia from erumpent fissures on leaf surfaces. Dark brown teliospores were observed under magnification and were two-celled, oblong to ellipsoid, and 33 ± 3.5 μm long with an apical cell width of 17.5 ± 2.7 μm and basal cell width of 16.2 ± 2.8 μm (reported as mean ± standard deviation, n = 25). Pedicles were colorless to light brown and measured 25.4 ± 9.2 μm (n = 25). In June 2009, at the Fayetteville Research and Extension Center, several second-year stands of switchgrass developed amphigenous and adaxial foliar lesions containing urediniospores. The uredia were globose and finely echinulate, measuring 23.1 ± 2.2 μm (n = 25) with brown cell walls. Teliospore and urediniospore morphology from all collections was consistent with Puccinia emaculata Schw. (2). Genomic DNA was extracted from a representative infected leaf of cv. Alamo, collected in Fayetteville, AR in June 2009, and amplified by PCR with primer sets PRITS1F (3) and ITS4B (1), which amplified an 803-bp fragment of rDNA encoding the first internal transcribed spacer (ITS1), 5.8S subunit, and second internal transcribed spacer (ITS2). The fragment was cloned into pGEM T Easy (Promega Corp, Madison, WI) and sequenced. A BLAST search of GenBank revealed that the fragment was most similar to the rDNA of P. emaculata (GenBank Accession No. EU915294.1; 755 of 758 bases matching; 99% identity) previously reported as a pathogen on switchgrass in Tennessee (3). The incidence and severity of rust on the widely planted switchgrass cv. Alamo is considerable cause for concern as efforts are made to increase acreage and production. Climatic conditions in St. Francis County are generally consistent with locations in Tennessee where switchgrass rust was previously reported (3). However, northwest Arkansas represents the eastern edge of the southwestern United States, suggesting that P. emaculata may affect switchgrass in geographically diverse areas of the United States. To our knowledge, this study represents the first report of rust on switchgrass in Arkansas. Managing this disease will be an important consideration for large-scale switchgrass cultivation in the state. References: (1) M. Gardes and T. D. Bruns. Mol. Ecol. 2:113, 1993. (2) P. Ramachar and G. Cummins. Mycopathol. Mycol. Appl. 25:7, 1965. (3) J. Zale et al. Plant. Dis. 92:1710, 2008.


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.


Author(s):  
Federico Varese

Organized crime is spreading like a global virus as mobs take advantage of open borders to establish local franchises at will. That at least is the fear, inspired by stories of Russian mobsters in New York, Chinese triads in London, and Italian mafias throughout the West. As this book explains, the truth is more complicated. The author has spent years researching mafia groups in Italy, Russia, the United States, and China, and argues that mafiosi often find themselves abroad against their will, rather than through a strategic plan to colonize new territories. Once there, they do not always succeed in establishing themselves. The book spells out the conditions that lead to their long-term success, namely sudden market expansion that is neither exploited by local rivals nor blocked by authorities. Ultimately the inability of the state to govern economic transformations gives mafias their opportunity. In a series of matched comparisons, the book charts the attempts of the Calabrese 'Ndrangheta to move to the north of Italy, and shows how the Sicilian mafia expanded to early twentieth-century New York, but failed around the same time to find a niche in Argentina. The book explains why the Russian mafia failed to penetrate Rome but succeeded in Hungary. A pioneering chapter on China examines the challenges that triads from Taiwan and Hong Kong find in branching out to the mainland. This book is both a compelling read and a sober assessment of the risks posed by globalization and immigration for the spread of mafias.


2005 ◽  
Vol 156 (8) ◽  
pp. 288-296
Author(s):  
Vittorio Magnago Lampugnani

In the first half of the 19th century scientific philosophers in the United States, such as Emerson and Thoreau, began to pursue the relationship between man and nature. Painters from the Hudson River School discovered the rural spaces to the north of New York and began to celebrate the American landscape in their paintings. In many places at this time garden societies were founded, which generated widespread support for the creation of park enclosures While the first such were cemeteries with the character of parks, housing developments on the peripheries of towns were later set in generous park landscapes. However, the centres of the growing American cities also need green spaces and the so-called «park movement»reached a first high point with New York's Central Park. It was not only an experimental field for modern urban elements, but even today is a force of social cohesion.


Plant Disease ◽  
2012 ◽  
Vol 96 (7) ◽  
pp. 1068-1068 ◽  
Author(s):  
Y. I. Chew-Madinaveitia ◽  
A. Gaytán-Mascorro ◽  
T. Herrera-Pérez

In 2009, 2010, and 2011, melon plants (Cucumis melo L.) exhibited vine decline in commercial fields in the Municipality of Viesca, State of Coahuila, in the north-central region of Mexico known as La Comarca Lagunera. Symptoms included wilting, leaf yellowing, and vine collapse prior to harvest. Diseased plants showed necrotic root lesions and loss of secondary and tertiary roots. Numerous perithecia containing asci and ascospores typical of Monosporascus cannonballus Pollack & Uecker (3) were found in the root system. M. cannonballus is a typical fungus of hot semiarid climates such as La Comarca Lagunera in which daytime temperatures above 40°C are frequent during the melon growing season. Small root pieces were disinfected with 1.5% sodium hypochlorite for 1 min and plated onto potato dextrose agar (PDA) medium with 0.5 g l–1 streptomycin sulfate and incubated for 7 days at 25°C under dark conditions. The mycelium of the fungus colony was initially white, turning gray about 3 weeks later and yielding black perithecia with one ascospore per asci. The internal transcribed spacer region of ribosomal DNA of isolate 4 was sequenced and submitted to GenBank with Accession No. JQ51935. Pathogenicity of this isolate was confirmed on melon plants (cv. Cruiser) in the greenhouse at 25 to 32°C. Fungus inoculum was produced in a sand-oat hull medium (0.5 l of sand, 45 g of oat hulls, and 100 ml of distilled water), and incubated at 25°C for 50 days (1). Melon seeds were sown in sterile sand in 20-cm diameter and 12-cm depth polyurethane containers, and the inoculum was added to produce a concentration of 20 CFU g–1. Sowing was done in five inoculated containers and thinned to two plants per container, each container representing a replication. Plants were also grown in five noninoculated containers that were used as controls. After 50 days under greenhouse conditions, plants were evaluated for disease symptoms. Melon plants inoculated with M. cannonballus exhibited root necrosis as opposed to healthy roots observed in noninoculated plants. M. cannonballus was reisolated from symptomatic plants, confirming Koch's postulates. M. cannonballus causes root rot and vine decline on melon and has been reported in Brazil, Guatemala, Honduras, India, Iran, Israel, Italy, Japan, Libya, the Netherlands (plants from Russia), Pakistan, Saudi Arabia, Spain, Taiwan, Tunisia, and the United States. M. cannonballus was reported in 1996 in southeastern Mexico in the State of Colima, where watermelon (Citrullus lanatus (Thunb.) Matsum.& Nakai) showed wilting and plant collapse prior to harvest (2). However, to our knowledge, this is the first report of M. cannonballus on melon in Mexico. This is relevant because La Comarca Lagunera region is one of the major melon producing areas in Mexico and M. cannonballus is a pathogen that may cause yield losses of up to 100%. References: (1) B. D. Bruton et al. Plant Dis. 84:907, 2000. (2) R. D. Martyn et al. Plant Dis. 80:1430, 1996. (3) F. G. Pollack and F. A. Uecker. Mycologia 66:346, 1974.


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 ◽  
2011 ◽  
Vol 95 (8) ◽  
pp. 1034-1034
Author(s):  
M. A. Delaney ◽  
E. J. Sikora ◽  
D. P. Delaney ◽  
M. E. Palm ◽  
J. Roscoe ◽  
...  

Soybean rust, caused by the fungus Phakopsora pachyrhizi, was detected on jicama (Pachyrhizus erosus L. Urban) for the first time in the United States in November 2009. The pathogen was observed on leaves of a single, potted jicama plant grown outdoors in a residential area and on leaves of all plants in a 12-m2 demonstration plot located at the Auburn University Teaching Garden in Auburn, AL. Symptoms on the upper leaf surfaces were isolated chlorotic areas near the leaf edges in the lower part of the canopy. The abaxial surface was first observed to exhibit brown lesions and subsequently produced volcano-shaped uredinia. These symptoms are consistent with a rust previously described on jicama in Mexico (1). Representative symptomatic plant tissue was sent to the USDA National Identification Services (Mycology) Laboratory in Beltsville, MD for diagnostic confirmation at both the Urbana, IL lab and the USDA National Plant Germplasm and Biotechnology Laboratory for DNA testing. From an infected leaf, samples of approximately 5 mm2 were excised from a microscopically observed rust lesion and an apparently noninfected area. Total DNA was purified with the FastDNA Spin Kit (MP Biomedicals, Solon, OH) followed by the E.Z.N.A. MicroElute DNA Clean-Up Kit (Omega Bio-tek, Inc, Doraville, GA) per manufacturer's instructions. Detection of P. pachyrhizi and P. meibomiae DNA was achieved by quantitative PCR using the method of Frederick et al. (2) and a DNA standard of previously prepared P. pachyrhizi spores. The observed rust pustule was found to contain P. pachyrhizi DNA in excess of 28,000 genomes, while no P. pachyrhizi DNA was observed from the asymptomatic sample. Both samples were negative for P. meibomiae. The fungal structures present were confirmed to be Phakopsora spp. DNA was extracted from sori aseptically removed from leaves with a Qiagen (Valencia, CA) DNeasy Plant Mini Kit and amplified with primers Ppa1 and NL4. The resulting partial ITS2 and 28S ribosomal RNA sequences were 100% identical to GenBank entry DQ354537 P. pachyrhizi internal transcribed spacer 2 and 28S ribosomal RNA gene, partial sequence. Sequences from jicama from Alabama were deposited in GenBank. Voucher specimens were deposited in the USDA Agricultural Research Service, National Fungus Collection (BPI). To our knowledge, this is the first report of the disease on jicama in the United States. References: (1) A. Cárcamo Rodriguez et al. Plant Dis. 90:1260, 2006. (2) R. D. Frederick et al. Phytopathology 92:217, 2002.


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