scholarly journals First Report of Gaeumannomyces graminicola Causing Bermudagrass Decline of Ultradwarf Bermudagrass Putting Greens in North Carolina

Plant Disease ◽  
2020 ◽  
Vol 104 (5) ◽  
pp. 1552-1552
Author(s):  
Cameron M. Stephens ◽  
James P. Kerns
Keyword(s):  
North Carolina ◽  
Putting Greens ◽  
First Report ◽  
Ultradwarf Bermudagrass

scholarly journals First Report of Meloidogyne marylandi Infecting Bermudagrass in Oklahoma

Plant Disease ◽  
2014 ◽  
Vol 98 (9) ◽  
pp. 1286-1286 ◽  
Author(s):  
N. Walker
Keyword(s):  
Cynodon Dactylon ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Similar Species ◽  
Root Knot Nematode ◽  
Putting Greens ◽  
Egg Masses ◽  
First Report ◽  
Mean Width ◽  
Ultradwarf Bermudagrass

Meloidogyne marylandi is a nematode commonly associated with turfgrasses and has been reported to occur in Texas and Arkansas (1,3). In the fall of 2013, a stand of ultradwarf bermudagrass (Cynodon dactylon × C. transvaalensis) plants in a sand-based, research putting green in Stillwater, Oklahoma, exhibited symptoms of decline. Roots of the affected plants had small galls and upon staining of the root system, numerous egg masses were evident. Egg masses were collected, placed in water, and the morphology of 20 hatched, second-stage juveniles were examined. The characteristics of the juveniles were: body length averaged 393.1 ± 19.87 (range: 361 to 425) μm, mean width averaged 16.6 ± 0.7 (15.6 to 17.8) μm, stylet lengths averaged 12.1 ± 0.7 (10.4 to 12.9) μm, dorsal gland orifice from stylet base averaged 2.9 ± 0.4 (2.5 to 3.6) μm, tail lengths averaged 53.7 ± 3.8 (46.2 to 60.4) μm, and the hyaline region of the tails averaged 10.4 ± 1.1 (8.4 to 12.7) μm. Genomic DNA was extracted from six females that were removed from roots. Amplification and sequencing of the mitochondrial DNA region between COII and 16S rRNA genes was performed with primers 1RNAF (5′-TACCTTTGACCAATCACGCT-3′) and CO11R (5′-GGTCAATGTTCAGAAATTTGTGG-3′) as previously described (2). A PCR product approximately 510 bp in length was obtained and sequenced at the Oklahoma State University Core Facility. Sequences were compared with those in NCBI's nucleotide database using BLAST and had 97% identity with two sequences from M. marylandi (KC473862.1 and KC473863.1) and the next most similar species being M. graminis (JN241898.1) with 83% identity. To our knowledge, this is the first report of the root-knot nematode M. marylandi in Oklahoma. As bermudagrass becomes more commonly used for putting greens in the turfgrass transition zone, M. marylandi may become a more common and damaging pathogen in the region. References: (1) A. A. Elmi et al. Grass For. Sci. 55:166, 2000. (2) M. A. McClure et al. Plant Dis. 96:635, 2012. (3) J. L. Starr et al. Nematrop. 37:43, 2007.

scholarly journals First Report of Subanguina radicicola, the Root-Gall Nematode Infecting Poa annua Putting Greens in Washington State

Plant Disease ◽  
2007 ◽  
Vol 91 (7) ◽  
pp. 905-905 ◽  
Author(s):  
N. A. Mitkowski
Keyword(s):  
United States ◽  
New York ◽  
The United States ◽  
Washington State ◽  
Poa Annua ◽  
Golf Course ◽  
Severe Damage ◽  
Surrounding Water ◽  
Putting Greens ◽  
First Report

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.

Characterization and aggressiveness of take-all root rot pathogens isolated from symptomatic bermudagrass putting greens

2021 ◽  
Author(s):  
Cameron Stephens ◽  
Travis W Gannon ◽  
Marc Cubeta ◽  
Tim L. Sit ◽  
Jim Kerns
Keyword(s):  
Plant Tissue ◽  
Root Rot ◽  
Pathogen Detection ◽  
Infected Plant ◽  
Gaeumannomyces Graminis ◽  
In Planta ◽  
High Resolution Melt ◽  
Putting Greens ◽  
Ultradwarf Bermudagrass ◽  
Take All

Take-all root rot is a disease of ultradwarf bermudagrass putting greens caused by Gaeumannomyces graminis (Gg), Gaeumannomyces sp. (Gx), Gaeumannomyces graminicola (Ggram), Candidacolonium cynodontis (Cc), and Magnaporthiopsis cynodontis (Mc). Many etiological and epidemiological components of this disease remain unknown. Improving pathogen identification and our understanding of the aggressiveness of these pathogens along with growth at different temperatures will advance our knowledge of disease development to optimize management strategies. Take-all root rot pathogens were isolated from symptomatic bermudagrass root and stolon pieces from 16 different golf courses. Isolates of Gg, Gx, Ggram, Cc, and Mc were used to inoculate ‘Champion’ bermudagrass in an in planta aggressiveness assay. Each pathogen was also evaluated at 10, 15, 20, 25, 30, and 35C to determine growth temperature optima. Infected plant tissue was used to develop a real-time PCR high resolution melt assay for pathogen detection. This assay was able to differentiate each pathogen directly from infected plant tissue using a single primer pair. In general, Ggram, Gg, and Gx were the most aggressive while Cc and Mc exhibited moderate aggressiveness. Pathogens were more aggressive when incubated at 30C compared to 20C. While they grew optimally between 24.4 and 27.8C, pathogens exhibited limited growth at 35C and no growth at 10C. These data provide important information on this disease and its causal agents that may improve take-all root rot management.

Mowing Pattern and Clip of the Reel Have Limited Effects on Green Speed of Ultradwarf Bermudagrass Putting Greens

cftm ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 1-3
Author(s):  
William D. Strunk ◽  
Kyley H. Dickson ◽  
John C. Sorochan
Keyword(s):  
Putting Greens ◽  
Ultradwarf Bermudagrass

scholarly journals First Report of Stem Blight Caused by Calonectria colhounii (Anamorph Cylindrocladium colhounii) on Greenhouse-Grown Blueberries in the United States

Plant Disease ◽  
2011 ◽  
Vol 95 (9) ◽  
pp. 1187-1187
Author(s):  
J. J. Sadowsky ◽  
T. D. Miles ◽  
A. M. C. Schilder
Keyword(s):  
United States ◽  
North Carolina ◽  
Root Rot ◽  
The United States ◽  
Vaccinium Corymbosum ◽  
Conidial Suspension ◽  
Centraalbureau Voor ◽  
First Report ◽  
Stem Lesions ◽  
Β Tubulin

Necrotic stems and leaves were observed on 2- to 4-month-old, rooted microshoot plants (Vaccinium corymbosum L. ‘Liberty’ and ‘Bluecrop’, V. angustifolium Aiton ‘Putte’, and V. corymbosum × V. angustifolium ‘Polaris’) in a Michigan greenhouse in 2008 and 2009. As the disease progressed, leaves fell off and 80 to 100% of the plants died in some cases. Root rot symptoms were also observed. A fungus was isolated from stem lesions. On potato dextrose agar (PDA), cultures first appeared light tan to orange, then rusty brown and zonate with irregular margins. Chains of orange-brown chlamydospores were abundant in the medium. Macroconidiophores were penicillately branched and had a stipe extension of 220 to 275 × 2.5 μm with a narrowly clavate vesicle, 3 to 4 μm wide at the tip. Conidia were hyaline and cylindrical with rounded ends, (1-)3-septate, 48 to 73 × 5 to 7 (average 60 × 5.5) μm and were held together in parallel clusters. Perithecia were globose to subglobose, yellow, 290 to 320 μm high, and 255 to 295 μm in diameter. Ascospores were hyaline, 2- to 3-septate, guttulate, fusoid with rounded ends, slightly curved, and 30 to 88 × 5 to 7.5 (average 57 × 5.3) μm. On the basis of morphology, the fungus was identified as Calonectria colhounii Peerally (anamorph Cylindrocladium colhounii Peerally) (1,2). The internal transcribed spacer region (ITS1 and ITS2) of the ribosomal DNA and the β-tubulin gene were sequenced (GenBank Accession Nos. HQ909028 and JF826867, respectively) and compared with existing sequences using BLASTn. The ITS sequence shared 99% maximum identity with that of Ca. colhounii CBS 293.79 (GQ280565) from Java, Indonesia, and the β-tubulin sequence shared 97% maximum identity with that of Ca. colhounii CBS 114036 (DQ190560) isolated from leaf spots on Rhododendron sp. in North Carolina. The isolate was submitted to the Centraalbureau voor Schimmelcultures in the Netherlands (CBS 129628). To confirm pathogenicity, 5 ml of a conidial suspension (1 × 105/ml) were applied as a foliar spray or soil drench to four healthy ‘Bluecrop’ plants each in 10-cm plastic pots. Two water-sprayed and two water-drenched plants served as controls. Plants were misted intermittently for 2 days after inoculation. After 7 days at 25 ± 3°C, drench-inoculated plants developed necrotic, sporulating stem lesions at the soil line, while spray-inoculated plants showed reddish brown leaf and stem lesions. At 28 days, three drench-inoculated and one spray-inoculated plant had died, while others showed stem necrosis and wilting. No symptoms were observed on control plants. Fungal colonies reisolated from surface-disinfested symptomatic stem, leaf, and root segments appeared identical to the original isolate. Cy. colhounii was reported to cause a leaf spot on blueberry plants in nurseries in China (3), while Ca. crotalariae (Loos) D.K. Bell & Sobers (= Ca. ilicicola Boedijn & Reitsma) causes stem and root rot of blueberries in North Carolina (4). To our knowledge, this is the first report of Ca. colhounii causing a disease of blueberry in Michigan or the United States. Because of its destructive potential, this pathogen may pose a significant threat in blueberry nurseries. References: (1) P. W. Crous. Taxonomy and Pathology of Cylindrocladium (Calonectria) and Allied Genera. The American Phytopathological Society, St. Paul, MN, 2002. (2) L. Lombard et al. Stud. Mycol. 66:31, 2010. (3) Y. S. Luan et al. Plant Dis. 90:1553, 2006. (4) R. D. Milholland. Phytopathology 64:831, 1974.

scholarly journals First Report of Anthracnose Caused by Colletotrichum fragariae on Cyclamen in North Carolina

Plant Disease ◽  
2011 ◽  
Vol 95 (11) ◽  
pp. 1480-1480 ◽  
Author(s):  
B. Liu ◽  
M. Munster ◽  
C. Johnson ◽  
F. J. Louws
Keyword(s):  
North Carolina ◽  
Sequence Analysis ◽  
Room Temperature ◽  
Plant Diseases ◽  
Pathogenicity Test ◽  
Conidial Suspension ◽  
Disease Symptoms ◽  
First Report ◽  
Leaf Spots ◽  
Colletotrichum Fragariae

In November 2009, cyclamen (Cyclamen persicum) plants with disease symptoms from a commercial greenhouse operation in the western part of North Carolina were sent to the Plant Diseases and Insect Clinic at North Carolina State University. Symptoms consisted of coalescing reddish and tan necrotic leaf spots with concentric circles. Other symptoms included darkened vascular tissue and decay of the corm, large roots, and petioles. Diseased leaves and stems were surface sterilized in 0.5% sodium hypochlorite for 3 min, air dried, and placed in petri dishes containing alkaline water agar. After 3 days of incubation at room temperature, fungal colonies were transferred to acidified potato dextrose agar. Isolation frequency after 5 days was 33% (three of nine pieces) and 16% (one of six pieces) from small leaf spots and petioles, respectively. Pure cultures of isolates were gray and black with abundant, aerial, gray whitish mycelia. Diseased plants were also incubated in a moist chamber at room temperature and sporulation was observed within 7 days. Conidia were tapered with rounded ends and produced in the acervulus and on the tips of setae, which is consistent with the morphology of described isolates of Colletotrichum fragariae. Similar setae were also observed directly on the fine roots of the original sample. The pathogenicity of single-spore cultures was tested by spraying four 2-month-old cyclamen plants with a conidial suspension (106 conidia/ml) and the plants were kept in a humid chamber for 24 h. Noninoculated controls (four plants) were sprayed with distilled water and subjected to the same conditions. The pathogenicity test was also repeated. Inoculated plants and controls were placed in a greenhouse with a temperature range from 22 to 25°C. After 7 to 10 days, symptomatic leaves and stems were observed on all the inoculated plants but not on the control plants. Fungi reisolated from 10 symptomatic leaf tissues had identical morphological features as the original isolates. Fungal DNA was extracted with DNeasy Plant Mini DNA Extraction Kits following the manufacturer's protocol (Qiagen Inc., Valencia, CA). Sequence analysis of the rRNA internal transcribed spacer (ITS) region of the cyclamen isolate (GenBank Accession No. HQ188923), based on the fragment amplified with ITS1 and ITS4 primers, showed 100% similarity to isolates of C. fragariae deposited in GenBank (Accession Nos. FJ172290 [ATCC MYA-4443 from cyclamen] and FJ810510 [ATCC MYA-4442 from silver date palm]) and Florida isolate C16 isolated from strawberry (1). In addition, the morphology and ITS sequences of the cyclamen isolate were identical to those of the C. fragariae voucher isolate from strawberry (GU174546). Results from disease symptoms, colony and spore morphology, pathogenicity tests, and ITS sequence analysis suggest that C. fragariae was the pathogen responsible for the disease symptoms on cyclamens. To our knowledge, this is the first report of a disease caused by C. fragariae on cyclamen in North Carolina and complements an earlier report from Florida (1). Reference: (1) S. J. MacKenzie et al. Plant Dis. 92:1432, 2008.

scholarly journals First Report of Sclerotium rolfsii on Common Chickweed in North Carolina

Plant Disease ◽  
2004 ◽  
Vol 88 (4) ◽  
pp. 426-426
Author(s):  
J. E. Hollowell ◽  
B. B. Shew
Keyword(s):  
North Carolina ◽  
Tap Water ◽  
Sclerotium Rolfsii ◽  
Control Treatment ◽  
Fungal Mycelium ◽  
Weed Species ◽  
Stellaria Media ◽  
Crop Species ◽  
First Report ◽  
Pure Cultures

Common chickweed (Stellaria media (L.) Cyrillo) is a common weed species found in agricultural fields of northeastern North Carolina. Symptomatic plants of common chickweed were observed during a March 2001 survey of winter annual weed species in Perquimans County, NC. The plants were growing in a harvested peanut field with a known history of southern stem rot caused by Sclerotium rolfsii Sacc. Water-soaked, bleached stems and chlorotic leaves were collected from plants and brought to the laboratory for isolation. Small portions (1 to 2 cm) of symptomatic stems and entire leaves were rinsed with tap water and placed on potato dextrose agar (PDA). Developing colonies were transferred to obtain pure cultures. The rapidly growing cultures had coarse, white mycelium typical of S. rolfsii and produced abundant, small, round, brown sclerotia approximately 2.0 mm in diameter on the surface of the culture. Clamp connections were observed with microscopic examination of mycelia. Pathogenicity of isolates was tested by placing 4-mm-diameter agar plugs of 2-day-old fungal mycelium on stems of three mature, nonsymptomatic chickweed plants. Agar plugs without fungal mycelium were used for the control treatment. Plugs were held in place with self-sticking bandage gauze. Plants were misted with water, enclosed in plastic bags, and incubated on a laboratory counter top at ambient temperature (24°C). Abundant mycelia developed, and water-soaked lesions and necrotic stems were observed. Noninoculated plants remained healthy and free of signs and symptoms during the incubation period. The fungus was reisolated on PDA, and pure cultures of S. rolfsii were obtained. Koch's postulates confirmed common chickweed was a host of S. rolfsii. To our knowledge, this is the first report of common chickweed as a host of S. rolfsii. Crop species commonly used in peanut rotations (corn, small grains, sorghum, and cotton) do not support populations of S. rolfsii. Many dicotyledonous weed species have been reported as hosts of S. rolfsii, but our observation of active disease on a winter weed species was unexpected. Colonization of winter weed, if prevalent, may enhance survival of S. rolfsii between crops of susceptible hosts such as peanut.

scholarly journals First Report of Fusarium Wilt of Blackberry Caused by Fusarium oxysporum f. sp. mori in North Carolina

Plant Disease ◽  
2020 ◽  
Vol 104 (3) ◽  
pp. 971 ◽  
Author(s):  
A. M. Pastrana ◽  
W. O. Cline ◽  
T. W. Wong ◽  
D. C. Watson ◽  
J. Mercier ◽  
...  
Keyword(s):  
North Carolina ◽  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
First Report

scholarly journals First Report of Pseudoperonospora cubensis Causing Downy Mildew on Momordica balsamina and M. charantia in North Carolina

Plant Disease ◽  
2014 ◽  
Vol 98 (9) ◽  
pp. 1279-1279 ◽  
Author(s):  
E. Wallace ◽  
M. Adams ◽  
K. Ivors ◽  
P. S. Ojiambo ◽  
L. M. Quesada-Ocampo
Keyword(s):  
United States ◽  
North Carolina ◽  
Downy Mildew ◽  
Leaf Surface ◽  
The United States ◽  
Pseudoperonospora Cubensis ◽  
Post Inoculation ◽  
Bitter Melon ◽  
First Report ◽  
C Cycle

Momordica balsamina (balsam apple) and M. charantia L. (bitter melon/bitter gourd/balsam pear) commonly grow in the wild in Africa and Asia; bitter melon is also cultivated for food and medicinal purposes in Asia (1). In the United States, these cucurbits grow as weeds or ornamentals. Both species are found in southern states and bitter melon is also found in Pennsylvania and Connecticut (3). Cucurbit downy mildew (CDM), caused by the oomycete Pseudoperonospora cubensis, was observed on bitter melon and balsam apple between August and October of 2013 in six North Carolina sentinel plots belonging to the CDM ipmPIPE program (2). Plots were located at research stations in Johnston, Sampson, Lenoir, Henderson, Rowan, and Haywood counties, and contained six different commercial cucurbit species including cucumbers, melons, and squashes in addition to the Momordica spp. Leaves with symptoms typical of CDM were collected from the Momordica spp. and symptoms varied from irregular chlorotic lesions to circular lesions with chlorotic halos on the adaxial leaf surface. Sporulation on the abaxial side of the leaves was observed and a compound microscope revealed sporangiophores (180 to 200 μm height) bearing lemon-shaped, dark sporangia (20 to 35 × 10 to 20 μm diameter) with papilla on one end. Genomic DNA was extracted from lesions and regions of the NADH dehydrogynase subunit 1 (Nad1), NADH dehydrogynase subunit 5 (Nad5), and internal transcribed spacer (ITS) ribosomal RNA genes were amplified and sequenced (4). BLAST analysis revealed 100% identity to P. cubensis Nad1 (HQ636552.1, HQ636551.1), Nad5 (HQ636556.1), and ITS (HQ636491.1) sequences in GenBank. Sequences from a downy mildew isolate from each Momordica spp. were deposited in GenBank as accession nos. KJ496339 through 44. To further confirm host susceptibility, vein junctions on the abaxial leaf surface of five detached leaves of lab-grown balsam apple and bitter melon were either inoculated with a sporangia suspension (10 μl, 104 sporangia/ml) of a P. cubensis isolate from Cucumis sativus (‘Vlaspik' cucumber), or with water as a control. Inoculated leaves were placed in humidity chambers to promote infection and incubated using a 12-h light (21°C) and dark (18°C) cycle. Seven days post inoculation, CDM symptoms and sporulation were observed on inoculated balsam apple and bitter melon leaves. P. cubensis has been reported as a pathogen of both hosts in Iowa (5). To our knowledge, this is the first report of P. cubensis infecting these Momordica spp. in NC in the field. Identifying these Momordica spp. as hosts for P. cubensis is important since these cucurbits may serve as a source of CDM inoculum and potentially an overwintering mechanism for P. cubensis. Further research is needed to establish the role of non-commercial cucurbits in the yearly CDM epidemic, which will aid the efforts of the CDM ipmPIPE to predict disease outbreaks. References: (1) L. K. Bharathi and K. J. John. Momordica Genus in Asia-An Overview. Springer, New Delhi, India, 2013. (2) P. S. Ojiambo et al. Plant Health Prog. doi:10.1094/PHP-2011-0411-01-RV, 2011. (3) PLANTS Database. Natural Resources Conservation Service, USDA. Retrieved from http://plants.usda.gov/ , 7 February 2014. (4) L. M. Quesada-Ocampo et al. Plant Dis. 96:1459, 2012. (5) USDA. Index of Plant Disease in the United States. Agricultural Handbook 165, 1960.

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