First Report of Curvularia trifolii Causing Curvularia Blight in Agrostis stolonifera in South of Portugal

Sclerotinia homoeocarpa is a fungal pathogen that causes dollar spot disease on more than 40 plant species, mostly in the family Poaceae (1), and is considered the most widespread pathogen of golf course turfgrasses in the St. Lawrence River Region. In June 2011, lesions were observed on tufted bulrush, Trichophorum cespitosum (Poales, Cyperaceae), on the sea shore near Peggys Cove, Nova Scotia, Canada. Single bunches had up to 40% of the leaves affected. The foliar symptoms resembled large hourglass lesions, up to 5 cm long, with a straw colored portion capped at two ends by dark zone lines on surrounding green foliar tissue. Leaf segments were taken, surface sterilized, and placed on potato dextrose agar (PDA). After 3 days of incubation at room temperature, white fluffy mycelia covered the entire petri dish. Brown columnar structures formed in the colony centers after 7 days and cultures became cinnamon colored after 14 days. Dark brown or black substratal stroma were formed on or in the agar, and cultures appeared dark brown from the bottom. DNA was extracted and amplified using primers ITS1 and ITS4 (2), and the amplicon sequenced (GenBank Accession No. KF447776). The sequence showed a top match of 522/524 bp identity with the ITS of an isolate of S. homoeocarpa, with the next 40 top matches also identified as S. homoeocarpa. Two-week-old seedlings of Agrostis stolonifera cv. Penncross, Poa pratensis cv. Touchdown, and Lolium perenne cv. Express were inoculated by placing 5-mm-diameter mycelial plugs from 5-day-old PDA cultures onto the leaves of plants grown in small containers, and incubating under enclosed humid conditions throughout the test. White aerial hyphae on the leaves and straw-colored leaf lesions were observed by 7 days after inoculation on P. pratensis and L. perenne, but no lesions or hyphal growth were observed on A. stolonifera. No signs or symptoms were observed on leaves where sterile agar plugs were used as inoculum. These tests were repeated three times with the same results, and a positive control was included by using an S. homoeocarpa isolate known to be pathogenic to A. stolonifera under the same test conditions. Disease was observed on A. stolonifera with the control isolate. S. homoeocarpa was re-isolated from the lesions on P. pratensis and L. perenne to satisfy Koch's postulates. To the best of our knowledge, this is the first report of S. homoeocarpa on T. cespitosum worldwide, an isolate that was found to cause disease on P. pratensis and L. perenne, but was not pathogenic to A. stolonifera in vitro. The original host was not used in pathogenicity tests because it is considered an endangered species in many locations. References: (1) B. Walsh et al. HortScience 34:13, 1999. (2) T. J. White et al. PCR protocols, a guide to methods and applications 18:315, 1990.

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First Report of Typhula Blight on Agrostis stolonifera and Poa annua in Italy

Plant Disease ◽

10.1094/pdis.2003.87.7.875c ◽

2003 ◽

Vol 87 (7) ◽

pp. 875-875 ◽

Cited By ~ 1

Author(s):

P. Titone ◽

M. Mocioni ◽

A. Garibaldi ◽

M. L. Gullino

Keyword(s):

Agrostis Stolonifera ◽

Northern Italy ◽

Potato Dextrose Agar ◽

Poa Annua ◽

Golf Course ◽

Pathogenicity Test ◽

Potato Dextrose Broth ◽

First Report ◽

Pathogenicity Tests ◽

Typhula Incarnata

During January 2002, Agrostis stolonifera and Poa annua turfgrasses on a golf course in Avigliana (northern Italy) exhibited 10- to 45-cm-diameter circular patches when the snow melted from the greens, tees, and fairways. Many patches coalesced to form large areas of strawcolored blighted turfgrass. At the patch margin, infected plants were covered with white-to-gray mycelium. Plants within patches were matted and appeared slimy with mycelium and sclerotia that were light pink, irregularly shaped, and less than 5 mm in diameter. Isolation from infected leaves on potato dextrose agar, supplemented with 100 mg/l of streptomycin sulfate, consistently yielded a fungus with mycelial, sclerotia, and cultural characteristics of Typhula incarnata (1). Pathogenicity tests were performed by spraying a suspension of mycelium and sclerotia, prepared by chopping mycelium and sclerotia produced in potato dextrose broth, onto 8-week-old A. stolonifera plants grown in plastic trays (45 × 30 cm). Trays were maintained at 0°C for 8 weeks in the dark. Blight symptoms developed on inoculated plants after 6 weeks. Non-inoculated plants remained healthy. The pathogen was reisolated from inoculated plants, and the pathogenicity test was repeated once. Typhula blight incited by T. incarnata was reported in Scandinavian countries and in several European countries including Holland, Germany, Austria, and Switzerland (1). To our knowledge, this is the first report of Typhula blight on turfgrass in Italy. Reference: (1) J. D. Smith et al. 1989. Fungal Diseases of Amenity Turf Grasses. E & FN Spong Ltd, London.

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First Report of Bentgrass Seed Gall Nematode, Anguina agrostis, in Virginia and Minnesota

Plant Disease ◽

10.1094/pd-90-1110c ◽

2006 ◽

Vol 90 (8) ◽

pp. 1110-1110 ◽

Cited By ~ 3

Author(s):

J. D. Eisenback ◽

C. W. Roane

Keyword(s):

Incidence Rate ◽

Creeping Bentgrass ◽

Virginia Tech ◽

Culture Collection ◽

Agrostis Stolonifera ◽

Construction Site ◽

First Report ◽

Voucher Specimens

On August 24, 2003, during a foray for grasses infected with fungi, redtop creeping bentgrass (Agrostis stolonifera L.) was collected on Butt Mountain Lookout near an abandoned fire tower with coordinates 80°37′40.3″ W and 37°22′14.0″N at an altitude of 1,284 m overlooking the New River between the towns of Pembroke and Ripplemead, VA. Seed heads with very elongated glumes, lemmas, and paleas were very common, and the incidence rate was nearly 95% on the basis of symptomatic plants in the immediate area surrounding the tower comprising more than 5 ha of a grassy meadow. Close examination revealed the occurrence of elongated, blackish galls replacing the ovaries and containing Anguina agrostis (Steinbuch, 1799) Filipjev, 1936. Nematode cultures were established and maintained on red top creeping bentgrass (A. stolonifera) in a greenhouse. Identification was based on morphology and measurements of juveniles L = 407 + 22 (376-418) μ, stylet L = 18.5 + 1.7 (17.0-21.3) μ males L = 351 + 17 (339-367) μm; and females L = 455 + 33. Examination of specimens collected previously by C. Roane revealed that another population of Anguina agrostis was also found on August 9, 1990 parasitizing the same host growing along Echo Trail near Big Lake Lodge Rd. in St. Louis County, MN. The infestation at the Virginia site may have been from sowing infested seeds at the disturbed construction site for the fire lookout tower and other buildings. However, the occurrence at the Minnesota site is less likely to be anthropogenic. Voucher specimens from both locations were placed in the Virginia Tech Nematode Collection, and voucher cultures are maintained in the Virginia Tech Nematode Culture Collection.

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First Report of Dollar Spot Caused by Clarireedia jacksonii and Brown Ring Patch Caused by Waitea circinata var. circinata on Agrostis stolonifera in Spain

Plant Disease ◽

10.1094/pdis-10-18-1816-pdn ◽

2019 ◽

Vol 103 (7) ◽

pp. 1771-1771

Author(s):

D. Gómez de Barreda ◽

V. De Luca ◽

A. Ramón-Albalat ◽

M. León ◽

J. Armengol

Keyword(s):

Agrostis Stolonifera ◽

Dollar Spot ◽

First Report ◽

Waitea Circinata

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First Report of Dollar Spot Disease, Caused by Sclerotinia Homoeocarpa, of Agrostis Stolonifera in Sweden

Crop Science ◽

10.2135/cropsci2016.10.0835 ◽

2017 ◽

Vol 57 (S1) ◽

Cited By ~ 2

Author(s):

Tatsiana Espevig ◽

May Bente Brurberg ◽

Marina Usoltseva ◽

Åslög Dahl ◽

Agnar Kvalbein ◽

...

Keyword(s):

Agrostis Stolonifera ◽

Sclerotinia Homoeocarpa ◽

Dollar Spot ◽

First Report ◽

Spot Disease

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First Report of a Bacterial Disease on Creeping Bentgrass (Agrostis stolonifera) Caused by Acidovorax spp. in the United States

Plant Disease ◽

10.1094/pdis-94-7-0922b ◽

2010 ◽

Vol 94 (7) ◽

pp. 922-922 ◽

Cited By ~ 8

Author(s):

P. R. Giordano ◽

J. M. Vargas ◽

A. R. Detweiler ◽

N. M. Dykema ◽

L. Yan

Keyword(s):

United States ◽

16S Rdna ◽

Creeping Bentgrass ◽

The United States ◽

Agrostis Stolonifera ◽

Bacterial Disease ◽

16S Rdna Sequencing ◽

First Report ◽

Rdna Sequencing ◽

Pure Cultures

In June of 2009, a golf course putting green sample of creeping bentgrass (Agrostis stolonifera L.) cv. Penn G-2 from a golf club in North Carolina was submitted to the Michigan State University Turfgrass Disease Diagnostic Laboratory for diagnosis. The sample exhibited symptoms of general wilt, decline, and characteristic necrosis from the leaf tips down. Fungal pathogens were ruled out when no phytopathogenic fungal structures were observed with microscopic examination of infected tissue. Symptoms appeared similar to those of annual bluegrass affected by bacterial wilt caused by Xanthomonas translucens pv. poae. Bacterial streaming was present in all of the cut infected tissue of the Penn G-2 bentgrass sample when observed with a microscope. To isolate the causal agent, cut leaf tissue (1- to 3-mm tips) exhibiting bacterial streaming was surface disinfected for 1 min in 10% sodium hypochlorite solution and rinsed for 1 min with sterile distilled water. Leaf blades were placed into Eppendorf microtubes with 20 μl of sterile phosphate-buffered saline (PBS) solution (pH 7) and macerated with a sterile scalpel. Serial dilutions up to 1 × 10–4 were performed in sterile PBS; 10 μl of each suspension was plated onto nutrient agar (NA) (Becton Dickinson, Sparks, MD) and incubated at room temperature for 5 days. Pure cultures of three commonly observed single bacterial colonies growing on plates from serial dilutions were made on NA medium. These pure cultures were grown for 5 days and used to inoculate three replicates of 5-week-old Penn G-2 plants that had uniformly filled in 8.5-cm-diameter pots grown under greenhouse conditions. Uninfected Penn G-2 creeping bentgrass plants were inoculated with 1 ml of 1.3 × 109 CFU/ml of bacterial suspension by adding drops of the suspension to blades of sterile scissors used to cut the healthy plants. Of the three different bacterial cultures selected to inoculate healthy plants, only one resulted in slight browning of leaf tips just 2 days after inoculation. The symptoms progressed, and by 5 days after inoculation, browning, twisting and leaf dieback to the sheath were observed. When leaf tips of the inoculated plants were cut, bacterial streaming was observed. Isolation of the bacterium from inoculated Penn G-2 plants was performed to fulfill Koch's postulates. Once isolated, a single bacterial colony was identified by 16S rDNA sequencing (Microcheck Inc. Northfield, VT). 16S rDNA sequencing results indicated that the causal agent of bacterial infection was a member of the Acidovorax genus, with a 100% sequence match to Acidovorax avenae subsp. avenae (2). The same nonflorescent, aerobic, gram-negative bacterium has been consistently isolated from inoculated plants exhibiting symptoms thus far. A member of the Acidovorax genus has also been identified as a pathogen of creeping bentgrass in Japan (1). To our knowledge, this is the first report of a bacterial disease affecting creeping bentgrass caused by Acidovorax spp. in the United States. References: (1) N. Furuya et al. J. Fac. Agric. Kyushu Univ. 54:13. 2009. (2) N. Schaad et al. Syst. Appl. Microbiol. 31:434. 2008.

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Occurrence of the Lance Nematode Hoplolaimus stephanus Infecting Bentgrass Agrostis stolonifera in Georgia, USA

Plant Health Progress ◽

10.1094/php-07-21-0104-rs ◽

2021 ◽

Author(s):

Ganpati B Jagdale ◽

Gema Takbir Takbir Nugraha ◽

Katherine Martin ◽

Alfredo D D Martinez-Espinoza ◽

Abolfazl Hajihassani

Keyword(s):

South Carolina ◽

Dna Sequence ◽

Creeping Bentgrass ◽

Agrostis Stolonifera ◽

High Population ◽

Specific Primer ◽

Sequence Analyses ◽

First Report ◽

Pcr Method ◽

Species Specific

A high population of lance nematodes Hoplolaimus spp. were found associated with creeping bentgrass (Agrostis stolonifera L.) in May 2019 in Georgia, USA. The nematode was pathogenic to bentgrass as its population increased by over 3-fold 180 days after inoculation under greenhouse conditions. Morphological measurements of body and stylet lengths of both mature females and males were similar to a grass population of H. stephanus from South Carolina. DNA sequence analyses of the D1-D3 expansion segments of the 28s gene identified the nematode as H. stephanus. The DNA sequence of the nematode was 99.7% identical to a H. stephanus isolate from South Carolina. Also, the PCR method using a species-specific primer set confirmed the identity of H. stephanus. To the best of our knowledge, this is the first report of H. stephanus Sher, 1963, infecting creeping bentgrass in Georgia.

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First Report of Brown Ring Patch Caused by Waitea circinata var. circinata on Poa annua and Agrostis stolonifera in New Jersey

Plant Disease ◽

10.1094/pdis-08-10-0606 ◽

2011 ◽

Vol 95 (1) ◽

pp. 78-78 ◽

Cited By ~ 1

Author(s):

E. N. Njambere ◽

B. B. Clarke ◽

S. A. Bonos ◽

J. A. Murphy ◽

R. Buckley ◽

...

Keyword(s):

New Jersey ◽

Creeping Bentgrass ◽

The United States ◽

Agrostis Stolonifera ◽

Poa Annua ◽

Its Sequencing ◽

First Report ◽

Annual Bluegrass ◽

Pathogenicity Tests ◽

Waitea Circinata

Waitea circinata var. circinata was first reported as the causal agent of brown ring patch on annual bluegrass (Poa annua L.) in the United States in 2007 (2). In early April to mid-June of 2009, circular to irregularly shaped yellow rings resembling symptoms of this disease were observed on an annual bluegrass putting green at Rutgers University in North Brunswick, NJ. Severely infected foliage eventually turned brown as the disease progressed. During the same time period, similar disease symptoms were observed on creeping bentgrass (Agrostis stolonifera L.) from a golf course in Bedminster Township, NJ. The disease reappeared in both locations in April of 2010. Five additional samples with similar symptoms on creeping bentgrass and annual bluegrass were received at Rutgers Diagnostic Laboratory from Paramus, Madison, Allamuchy, and Farmingdale, NJ between late April and early May of 2010. Portions of diseased leaf and sheath tissue that displayed symptoms of the disease were disinfested for 1 min in 0.5% NaOCl, rinsed with sterile distilled water, and plated on potato dextrose agar (PDA) amended with 50 mg/liter of streptomycin sulfate. At the first sign of fungal growth, single hyphal tips were transferred to PDA. After 1 week at 25°C, white-to-orange mycelial colonies formed in culture and eventually turned brown with age. Minute sclerotia (≤3 mm), which followed the same color development pattern, formed within 10 days. These features are consistent with those described of W. circinata var. circinata (2,3). The internal transcribed spacer (ITS) region of the ribosomal RNA gene was amplified using primer pair ITS1/ITS4 and sequenced with ITS4 (GenBank Accession Nos. HQ166065 to HQ166071). BLASTn analysis of the ITS sequences showed a 99 to 100% similarity to W. circinata var. circinata sequences deposited in GenBank (1,2). Pathogenicity tests were conducted in 2010 using 6-week-old creeping bentgrass seedlings cv. Declaration inoculated with colonized oat grain that had been autoclaved and then infested with the Bedminster Township isolate. Eight colonized oat grains were uniformly spread around the crowns of seedlings grown in 10-cm-diameter pots. Control plants were treated with autoclaved grain. Plants were incubated at 25°C and high humidity maintained by misting the plants three times per day. Within 3 days postinoculation, foliage near infested grain turned chlorotic. All foliage in pots became completely blighted and spherical orange-brown sclerotia were observed on leaf sheaths by the eighth day. W. circinata var. circinata was consistently reisolated from inoculated plants (as confirmed by isolate morphology and ITS sequencing) but not from control plants. The ITS sequence data, morphological characters of the isolates, and pathogenicity tests demonstrate that W. circinata var. circinata is present in New Jersey. To our knowledge, this is the first report of W. circinata var. circinata infecting turfgrass in New Jersey. References: (1) C. M. Chen et al. Plant Dis. 93:906, 2009. (2) K. A. de la Cerda et al. Plant Dis. 91:791, 2007. (3) T. Toda et al. Plant Dis. 89:536, 2005.

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First Report of Dollar Spot Caused by Sclerotinia homoeocarpa on Agrostis stolonifera in Argentina

Plant Disease ◽

10.1094/pdis.2004.88.12.1384b ◽

2004 ◽

Vol 88 (12) ◽

pp. 1384-1384 ◽

Cited By ~ 1

Author(s):

M. C. Rivera ◽

E. R. Wright ◽

L. V. Goldring ◽

B. A. Pérez ◽

D. Barreto

Keyword(s):

Substrate Surface ◽

Pathogenic Fungi ◽

Creeping Bentgrass ◽

Agrostis Stolonifera ◽

Fluorescent Light ◽

Infested Soil ◽

Sclerotinia Homoeocarpa ◽

Dollar Spot ◽

First Report ◽

Agar Plug

During the summer of 2000, circular, yellow-to-brown, blighted, 2- to 4-cm-diameter patches were observed on creeping bentgrass (Agrostis stolonifera) putting greens (cv. Pennlinks) maintained at a 4- to 5-mm height on a golf course in Pilar (Buenos Aires, Argentina). Symptomatic leaves had transverse chlorotic bands that sometimes extended to the tip with brown lesions inside the bands. A fungus was isolated from symptomatic tissue after surface sterilization with 2% bleach for 1 min and plating on 2% potato dextrose agar (PDA). The mycelium was fluffy and white. The culture turned olive to brown and developed black stromata on the lower side of the plate base after 2 weeks. Pathogenicity tests were performed on 2-month-old healthy plants of A. stolonifera (cv. Crenshaw) grown in sterilized sand. Recently cut, 14-mm-diameter plugs of A. stolonifera were placed in 22- × 17-cm plastic trays filled with a sterilized mixture of 50:50 soil/sand (vol/vol). Plants were maintained at a 7-mm height. Two sources of inoculum were prepared; one was cultured on PDA at 22 to 25°C for 10 days and the other was prepared by incubating in sterilized soil at room temperature for 14 days. Twenty pieces of 1-cm-diameter agar blocks containing mycelium were placed in each plug at the base of the plants. In the infested soil inoculation, 25 g of soil were distributed among the plants on the substrate surface. Control plants were treated with either sterile PDA pieces or noninfested soil. The trays were irrigated with sterilized distilled water, covered with polyethylene bags, and kept in a controlled environment chamber at 25°C with 12 h per day of fluorescent light for 30 days. Leaf chlorosis appeared 7 and 10 days after inoculation for the agar-plug and infested-soil methods, respectively. Leaf necrosis was observed at day 23. Controls remained asymptomatic. The inoculated fungus was reisolated from symptomatic leaf tissue. The pathogen was identified as Sclerotinia homoeocarpa (1,2). To our knowledge, this is the first report of Sclerotinia homoeocarpa causing dollar spot disease on Agrostis stolonifera in Argentina and the first report of a disease on golf courses in our country. References: (1) J. E. M. Mordue. Sclerotinia homoeocarpa. No. 618 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1979. (2) R. W. Smiley. Dollar Spot. Pages 14–16 in: Compendium of Turfgrass Diseases. The American Phytopathological Society, St. Paul, MN, 1983.

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First Report of Brown Ring Patch Caused by Waitea circinata var. circinata on Agrostis stolonifera and Poa pratensis in China

Plant Disease ◽

10.1094/pdis-04-12-0406-pdn ◽

2012 ◽

Vol 96 (12) ◽

pp. 1821-1821 ◽

Cited By ~ 2

Author(s):

X. X. Ni ◽

B. T. Li ◽

M. Cai ◽

X. L. Liu

Keyword(s):

Poa Pratensis ◽

Creeping Bentgrass ◽

Kentucky Bluegrass ◽

Agrostis Stolonifera ◽

Its Sequences ◽

Morphological Observation ◽

Golf Course ◽

First Report ◽

Turf Grass ◽

Waitea Circinata

Brown ring patch, caused by Waitea circinata var. circinata, is a recently described disease of turf grass (1,2). The disease was first reported in Japan in 2005 (2) and then in the United States (1). In late May to early September 2011, large yellow rings (20 to 30 cm in diameter) were observed on creeping bentgrass (Agrostis stolonifera) and Kentucky bluegrass (Poa pratensis) growing at the Qinghe Bay golf course, Beijing, China. Leaf blades turned from yellow to brown as the disease developed, and eventually died. The disease incidence was estimated at 20 to 30%. The rings became continuous on creeping bentgrass and Kentucky bluegrass in several putting greens. The same symptom was observed on the lawn of China Agricultural University. Symptomatic leaves were collected and incubated in high humidity at 25°C until mycelia developed. The leaves were then disinfested in 1% NaClO for 1 min, rinsed with sterile water three times, and placed on potato dextrose agar (PDA). Four isolates were obtained, including one isolate from the lawn of China Agricultural University (cau-1), and three from Qinghe Bay golf course (qhw-1, qhw-2, and qhw-3). The colonies that formed on PDA changed from white to orange over time, and minute orange to brown sclerotia (approx. 2 to 3 mm in diameter) formed after 2 weeks at 25°C. These characteristics were similar to W. circinata var. circinata (1,2). DNA was extracted from each isolate using a CTAB extraction method (3) and the internal transcribed spacer (ITS) regions were amplified with the ITS1/ITS4 universal primers. The ITS sequences of the isolated fungi (Accession Nos. JQ964235 and JQ964236) had 99 to 100% homology with the sequences of W. circinata in GenBank (Accession Nos. EU591763 and HQ207169). Pathogen inocula were prepared by inoculating autoclaved oat grains with strains qhw-1 and cau-1 respectively, followed by 4 days of incubation at 25°C. Each inoculum was placed in five spots in a uniform arrangement (5 g grain inoculum per spot) on soil in a 40 × 60 cm tray, followed by sowing bluegrass seed. In another experiment, 4-week-old bentgrass was transplanted into soil infested with 5 g grain inoculum in the middle of a 20-cm diameter pot (non-colonized grain was used as a control). There were five replicates for each isolate. Plants were then incubated in a growth chamber at 26°C and high relative humidity (>90%). After 5 to 6 days, the grass in the inoculated pots and trays began to turn yellow, and then became chlorotic and necrotic as the disease developed. Orange sclerotia were observed on the bluegrass leaves by the eighth day, and all the bentgrass turned chlorotic by the tenth day. After 2 weeks, brown ring patches formed in the trays with inoculated bluegrass. Waitea circinata var. circinata was reisolated from all inoculated plants and confirmed by morphological observation and the ITS sequences analysis as described above, while no symptoms were observed on the control plants and no isolate was obtained from them. To our knowledge, this is the first report of W. circinata var. circinata infecting turf grass in China. References: (1) K. A. De La Cerda et al. Plant Dis. 91:791, 2007. (2) T. Toda et al. Plant Dis. 89:536, 2005. (3) J. A. H. Van Burik et al. Med. Mycol. 36:299, 1998.

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