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

P. Titone; M. Mocioni; A. Garibaldi; M. L. Gullino

doi:10.1094/pdis.2003.87.7.875c

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 Rhizoctonia solani AG 4 on Lamb's Lettuce in Italy

Plant Disease ◽

10.1094/pd-90-1109c ◽

2006 ◽

Vol 90 (8) ◽

pp. 1109-1109 ◽

Cited By ~ 2

Author(s):

A. Garibaldi ◽

G. Gilardi ◽

M. L. Gullino

Keyword(s):

Rhizoctonia Solani ◽

Morphological Characteristics ◽

Northern Italy ◽

Crown Rot ◽

Pathogenicity Test ◽

First Report ◽

Pathogenicity Tests ◽

Hyphal Diameter ◽

Wheat Kernels ◽

Extensive Necrosis

Lamb's lettuce or corn salad (Valerianella olitoria) is increasingly grown in Italy and used primarily in the preparation of mixed processed salad. In the fall of 2005, plants of lamb's lettuce, cv Trophy, exhibiting a basal rot were observed in some commercial greenhouses near Bergamo in northern Italy. The crown of diseased plants showed extensive necrosis, progressing to the basal leaves, with plants eventually dying. The first symptoms, consisting of water-soaked zonate lesions on basal leaves, were observed on 30-day-old plants during the month of October when temperatures ranged between 15 and 22°C. Disease was uniformly distributed in the greenhouses, progressed rapidly in circles, and 50% of the plants were affected. Diseased tissue was disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar amended with 100 μg/liter of streptomycin sulfate. A fungus with the morphological characteristics of Rhizoctonia solani was consistently and readily isolated and maintained in pure culture after single-hyphal tipping (3). The five isolates of R. solani, obtained from affected plants successfully anastomosed with tester isolate AG 4, no. RT 31, received from R. Nicoletti of the Istituto Sperimentale per il Tabacco, Scafati, Italy (2). The hyphal diameter at the point of anastomosis was reduced, and cell death of adjacent cells occurred (1). Pairings were also made with AG 1, 2, 3, 5, 7, and 11 with no anastomoses observed between the five isolates and testers. For pathogenicity tests, the inoculum of R. solani (no. Rh. Vale 1) was grown on autoclaved wheat kernels at 25°C for 10 days. Plants of cv. Trophy were grown in 10-liter containers (20 × 50 cm, 15 plants per container) on a steam disinfested substrate (equal volume of peat and sand). Inoculations were made on 20-day-old plants by placing 2 g of infected wheat kernels at each corner of the container with 3 cm as the distance to the nearest plant. Plants inoculated with clean wheat kernels served as controls. Three replicates (containers) were used. Plants were maintained at 25°C in a growth chamber programmed for 12 h of irradiation at a relative humidity of 80%. The first symptoms, consisting of water-soaked lesions on the basal leaves, developed 5 days after inoculation with crown rot and plant kill in 2 weeks. Control plants remained healthy. R. solani was consistently reisolated from infected plants. The pathogenicity test was carried out twice with similar results. This is, to our knowledge, the first report of R. solani on lamb's lettuce in Italy as well as worldwide. The isolates were deposited at the AGROINNOVA fungal collection. The disease continues to spread in other greenhouses in northern Italy. References: (1) D. Carling. Rhizoctonia Species: Pages 37–47 in: Taxonomy, Molecular Biology, Ecology, Pathology and Disease Control. B. Sneh et al., eds. Kluwer Academic Publishers, the Netherlands, 1996. (2) J. Parmeter et al. Phytopathology, 59:1270, 1969. (3) B. Sneh et al. Identification of Rhizoctonia Species. The American Phytopathological Society, St. Paul, MN, 1996.

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First Report of Black Rot Caused by Phomopsis cucurbitae on Cantaloupe (Cucumis melo) in the Piedmont Region of Northern Italy

Plant Disease ◽

10.1094/pdis-06-11-0481 ◽

2011 ◽

Vol 95 (10) ◽

pp. 1317-1317

Author(s):

A. Garibaldi ◽

D. Bertetti ◽

A. Poli ◽

M. L. Gullino

Keyword(s):

Cucumis Melo ◽

Morphological Characteristics ◽

Its Region ◽

Northern Italy ◽

Pathogenicity Test ◽

First Report ◽

Sterile Needle ◽

Pathogenicity Tests ◽

Cucumis Melo L ◽

Piedmont Region

Cucumis melo L., belonging to the Cucurbitaceae family, is cultivated on more than 23,000 ha in Italy. Cantaloupe (C. melo L. var. cantalupensis Naudin) is the most popular variety. In summer 2010, a previously unknown rot was observed on fruits produced in Italy and marketed in the Piedmont Region of northern Italy. Early symptoms on fruit consisted of irregular, brown, soft, sunken lesions up to 10 cm in diameter. No surface mold was visible and pycnidia were not present. Internally, the decay is adjacent to the sunken area of the fruit's surface and is soft, water soaked, spongy, with a nearly circular margin, and easily separated from healthy tissues. Fragments (approximately 3 mm3) were taken from the margin of the internal diseased tissues, cultured on potato dextrose agar (PDA), and incubated at 24 ± 1°C, (16 h of light and 8 h of darkness). Fungal colonies initially appeared coarse, at first whitish then buff brown, and produced dark pycnidia 0.5 mm in diameter, which exuded numerous conidia belonging to two types. Type A conidia were hyaline, unicellular, ellipsoidal to fusiform, sometimes slightly constricted in the middle, and measured 5.6 to 10.3 × 1.7 to 2.6 (average 8.0 × 2.1) μm. Type B conidia were hyaline, long, slender, curved, and measured 17.1 to 26.6 × 0.7 to 1.4 (average 22.0 × 1.0) μm. Sclerotia were not produced. The morphological characteristics of the fungus corresponded to those of the genus Phomopsis (1). The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS1/ITS4 and sequenced. BLAST analysis of the 543-bp segment showed a 99% similarity with the sequence of a Phomopsis sp. (GenBank Accession No. HM999947). The nucleotide sequence has been assigned the GenBank Accession No. JN032733. Both Phomopsis cucurbitae and P. sclerotioides are pathogenic to Cucurbitaceae, however P. cucurbitae is identifiable by the production of B conidia and the absence of sclerotia. Therefore, P. cucurbitae has been considered the causal agent of the disease. Pathogenicity tests were performed by inoculating three wounded cantaloupe fruits after surface disinfesting in 1% sodium hypochlorite. Six wounds per fruit, 1 cm deep, were made with a sterile needle. Mycelial disks (10 mm in diameter), obtained from PDA cultures of one strain, were placed on each wound. Three control fruits were inoculated with PDA. Fruits were incubated at 16 ± 1°C in the dark. The first symptoms developed 4 days after the artificial inoculation. Two days later, the rot developed at all inoculation points and the pathogen was consistently reisolated. Noninoculated fruit remained healthy. The pathogenicity test was performed twice with similar results. P. cucurbitae has been reported on melon in many countries (2,3). To our knowledge, this is the first report of the disease in Italy. Currently, the relevance of the disease in the country is not yet well known. However, attention must be paid considering that the pathogen can be transmitted through seeds. References: (1) H. L. Barnett and B. B. Hunter. Illustrated Genera of Imperfect Fungi. Burgess Publishing Company, Minneapolis, MN, 1972. (2) L. Beraha and M. J. O'Brien. Phytopathol. Z. 94:199, 1979. (3) E. Punithalingam and P. Holliday. Phomopsis cucurbitae. IMI Descriptions of Fungi and Bacteria. 47, Sheet 469, 1975.

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First Report of Root Rot Incited by Thielaviopsis basicola on Lamb's Lettuce (Valerianella olitoria) in Europe

Plant Disease ◽

10.1094/pd-89-0205b ◽

2005 ◽

Vol 89 (2) ◽

pp. 205-205 ◽

Cited By ~ 1

Author(s):

A. Garibaldi ◽

G. Gilardi ◽

M. L. Gullino

Keyword(s):

Root Rot ◽

Morphological Characteristics ◽

The United States ◽

Northern Italy ◽

Potato Dextrose Agar ◽

Pathogenicity Test ◽

Thielaviopsis Basicola ◽

First Report ◽

Severe Stunting ◽

Extensive Necrosis

Lamb's lettuce (Valerianella olitoria) is increasingly grown in Italy and used in the preparation of processed salad. In the fall of 2003, plants of lamb's lettuce cvs. Trophy and Palmares showing symptoms of severe stunting were observed in several commercial plastic greenhouses near Bergamo in northern Italy. The distribution of the disease was generally uniform in the greenhouses and 10 to 30% of the plants were affected. The first symptoms, consisting of reduced growth of the plants and extensive chlorosis, developed in October at temperatures ranging between 10 and 20°C on 30-day-old plants. The roots of diseased plants showed extensive necrosis that extended to the crown of the plants. The diseased tissue was disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar amended with 100 µg/l streptomycin sulfate. A fungus with the morphological characteristics of Thielaviopsis basicola was consistently and readily isolated from symptomatic tissues (1). Catenulate, cylindrical, hyaline endoconidia and catenulate, subrectangular, thick-walled chlamydospores (aleuriospores) were observed. Ten-day-old plants of cvs. Trophy and Palmares were artificially inoculated by dipping three isolates of T. basicola obtained from infected plants for 15 min in a spore suspension (1 × 106 CFU/ml). Noninoculated plants served as control treatments. Each treatment consisted of 30 plants. Plants were maintained at 20°C in a growth chamber, with 12 h of light/day. Symptoms developed 25 days after the artificial inoculation on both cultivars, and T. basicola was consistently reisolated from diseased plants. The noninoculated plants remained healthy. The pathogenicity test was carried out twice. To our knowledge, this is the first report of T. basicola on lamb's lettuce in Italy as well as in the world. The same disease was described on corn salad (Valerianella locusta) in the United States (2). References: (1) D. E. Mathre and A.V. Ravenscroft. Phytopathology 56:337, 1966. (2) M. E. Stanghellini et al. Plant Dis. 74:81, 1990.

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First Report of Leaf Spot Caused by Phoma multirostrata on Fuchsia × hybrida in Italy

Plant Disease ◽

10.1094/pdis-94-3-0382a ◽

2010 ◽

Vol 94 (3) ◽

pp. 382-382 ◽

Cited By ~ 4

Author(s):

A. Garibaldi ◽

G. Gilardi ◽

M. L. Gullino

Keyword(s):

Leaf Surface ◽

Morphological Characteristics ◽

Its Region ◽

Northern Italy ◽

Pathogenicity Test ◽

First Report ◽

Plastic Bags ◽

Pathogenicity Tests ◽

Necrotic Spots ◽

Mycelial Suspension

Fuchsia × hybrida (Onagraceae) is widely used in gardens and very much appreciated as a potted plant. During the summer of 2008, a severe foliar disease was observed on 1- to 2-year-old plants in several gardens located near Biella (northern Italy). Small necrotic spots were observed on the upper and lower sides of infected leaves. Spots enlarged to form round areas of 2 to 12 mm in diameter and were well defined by a brown-purple margin at temperatures between 15 and 25°C. Severely infected leaves wilted and abscised as disease progressed. The disease occurred on 100% of the plants and at least 30% of the leaf surface was affected. Stems and flowers were not affected by the disease. A fungus was consistently isolated from infected leaves on potato dextrose agar amended with 25 mg/liter of streptomycin. The fungus was grown on leaf extract agar, including 30 g of autoclaved fuchsia leaves per liter, and maintained at 22°C (12-h light, 12-h dark). After 30 days, black pycnidia 150 to 450 μm in diameter developed, releasing abundant hyaline, elliptical, nonseptate conidia measuring 5.6 to 14.3 (10.3) × 1.9 to 5.6 (3.5) μm. On the basis of these morphological characteristics, the fungus was identified as a Phoma sp. (2). The internal transcribed spacer (ITS) region of rDNA of the isolate coded FuHy1 was amplified using primers ITS4/ITS6 (3) and sequenced. BLAST analysis (1) of the 488-bp segment obtained showed an E-value of 0.0 with Phoma multirostrata. The nucleotide sequence has been assigned GenBank Accession No. GU220539. Pathogenicity tests were performed by spraying leaves of healthy 6-month-old potted Fuchsia × hybrida plants with a spore and mycelial suspension (1 × 106 spores or mycelial fragments per milliliter). Noninoculated plants sprayed with water served as controls. Five plants were used for each treatment. Plants were covered with plastic bags for 5 days after inoculation and kept under greenhouse conditions at 20 to 24°C. Symptoms previously described developed on leaves 12 days after inoculation, whereas control plants remained healthy. The fungus was consistently reisolated from the lesions of the inoculated plants. The pathogenicity test was carried out twice. To our knowledge, this is the first report of the presence of P. multirostrata on fuchsia in Italy as well as worldwide. The importance of the disease is still limited in Italy. References: (1) S. F. Altschud et al. Nucleic Acids Res. 25:3389, 1997. (2) G. H. Boerema and G. J. Bollen. Persoonia 8:111, 1975. (3) D. E. L. Cooke and J. M. Duncan. Mycol. Res. 101:667, 1997.

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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 Leaf Spot of Wild (Diplotaxis tenuifolia) and Cultivated (Eruca vesicaria) Rocket Caused by Alternaria japonica in Italy

Plant Disease ◽

10.1094/pdis-04-11-0280 ◽

2011 ◽

Vol 95 (10) ◽

pp. 1316-1316 ◽

Cited By ~ 13

Author(s):

A. Garibaldi ◽

G. Gilardi ◽

C. Bertoldo ◽

M. L. Gullino

Keyword(s):

Morphological Characteristics ◽

Northern Italy ◽

Pathogenicity Test ◽

Academic Press ◽

First Report ◽

Plastic Bags ◽

Pcr Product ◽

Pathogenicity Tests ◽

Alternaria Sp ◽

Potential Impact

Wild (Diplotaxis tenuifolia) and cultivated (Eruca vesicaria) rocket, popular crops in Italy as well as in many Mediterranean areas, are grown for fresh consumption as well as for dish decoration. During fall and winter of 2010 to 2011, extensive necroses were observed on leaves of D. tenuifolia and E. vesicaria that were grown in commercial greenhouses in Piedmont and Liguria (northern Italy). The disease affected 30 to 40% of 60-day-old plants. First symptoms were usually black-brown lesions, 1 to 30 mm in diameter, which progressively turned black. Lesions usually started on the upper side of older leaves at the leaf margins and tips and developed a yellow halo. Eventually, lesions also affected leaf veins and stems. A fungus was consistently isolated from infected leaves on potato dextrose agar and was grown on water agar (15 g/liter) amended with autoclaved rocket tissues (100 g/liter). After 12 days of growth at 22°C and 12-h dark/12-h light, conidia that were produced were dark brown, obclavate, obpyriform, ovoid or ellipsoid, with beaks. Round conidia without beaks were also present. Conidia showed two to seven (average three to four) transverse and one to three longitudinal septa, and measured 17.7 to 56.2 (average 30.9) × 6.6 to 17.8 (average 10.8) μm. Conidia were produced singly or in short chains (two to three elements) and mostly presented a conical or cylindrical beak, 1.8 to 7.3 (average 3.6) μm, pale light brown to brown. On the basis of its morphological characteristics, the pathogen was identified as an Alternaria sp. (3). DNA was extracted with Terra PCR Direct Polymerase Mix (Clontech, Mountain View, CA) and PCR was carried out with ITS 1/ ITS 4 primer (4). A 553-bp PCR product was sequenced and a BLASTn search (1) confirmed that the sequence corresponded to Alternaria japonica. The nucleotide sequence has been assigned the GenBank Accession No. JP 742643. Pathogenicity tests were performed by spraying leaves of healthy 30-day-old wild and cultivated rocket plants with an aqueous 1 × 105 spore/ml suspension. The inoculum was obtained from cultures of the fungus grown on sterilized host leaves placed on water agar for 20 days in light/dark at 22 ± 1°C. Plants sprayed only with water served as controls. Three pots (four plants per pot) were used for each treatment. Plants were covered with plastic bags for 4 days after inoculation and maintained in a glasshouse at 22 ± 1°C. Lesions developed on leaves 7 days after inoculation with the spore suspension, whereas control plants remained healthy. A. japonica was consistently reisolated from these lesions. The pathogenicity test was carried out twice. The presence of A. japonica has been reported on several brassica hosts, such as Brassica napus, B. nigra, B. oleracea, and B. rapa (2). This is, to our knowledge, the first report of A. japonica on wild and cultivated rocket in Italy as well as in Europe. Because of the importance of rocket in many countries, the potential impact of this disease is high. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997 (2) J. C. David, IMI Description of Fungi and Bacteria. 144:1432, 2000. (3) E. G. Simmons. Alternaria. An Identification Manual. CBS Biodiversity Series 6, Utrecht, The Netherlands, 2007. (4) T. J. White et al. In: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, 1990.

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First Report of Petiole Rot of Pulmonaria longifolia Caused by Sclerotium rolfsii var. delphinii

Plant Disease ◽

10.1094/pdis.2003.87.3.313b ◽

2003 ◽

Vol 87 (3) ◽

pp. 313-313 ◽

Cited By ~ 1

Author(s):

B. A. Edmunds ◽

M. L. Gleason

Keyword(s):

Sclerotium Rolfsii ◽

Soil Surface ◽

Potato Dextrose Agar ◽

Pathogenicity Test ◽

First Report ◽

Plastic Bags ◽

Affected Tissue ◽

Pathogenicity Tests ◽

The Media ◽

Herbaceous Perennial

Sclerotium rolfsii var. delphinii was isolated from the bases of discolored petioles on wilted, yellow leaves of Pulmonaria longifolia (cultivar unknown), an herbaceous perennial growing in a landscape planting in Ames, IA. White mycelia and brick red, 2- to 3-mm-diameter sclerotia were found on affected tissue and nearby soil. The isolates were identified as S. rolfsii var. delphinii based on the formation of dark red, irregularly shaped, >2.0-mm-diameter sclerotia on potato dextrose agar (PDA) around the edge of the culture (1,2). Pathogenicity tests were conducted by inoculating 5-month-old P. longifolia cv. E. B. Anderson growing in 20-cm-diameter pots in a greenhouse at 25 to 30°C. Inoculum was produced by transferring plugs from a 1-week-old culture of the S. rolfsii var. delphinii isolate on PDA to autoclaved carrot disks. After 2 days of incubation, a mycelium-infested carrot disk was placed on the soil surface at the base of each plant. Six plants were inoculated and six plants served as uninoculated controls. All plants were enclosed in plastic bags to maintain high humidity. The pathogenicity test was repeated once. All inoculated plants developed characteristic symptoms within 10 days, whereas all control plants remained symptomless. Sclerotia developed on infected tissue and the media surface, and S. rolfsii var. delphinii was reisolated on PDA from symptomatic petioles. To our knowledge, this is the first report of petiole rot of P. longifolia caused by S. rolfsii var. delphinii. References: (1) Z. K. Punja. Annu. Rev. Phytopathol. 23:97, 1985. (2) Z. K. Punja and A. Damiani. Mycologia 88(5):694, 1996.

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

Plant Disease ◽

10.1094/pdis-91-7-0905c ◽

2007 ◽

Vol 91 (7) ◽

pp. 905-905 ◽

Cited By ~ 2

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.

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First Report of Occurrence of Eggplant Wilt Caused by Verticillium dahliae in Korea

Plant Disease ◽

10.1094/pdis.2000.84.10.1152a ◽

2000 ◽

Vol 84 (10) ◽

pp. 1152-1152

Author(s):

S. K. Kim ◽

S. S. Hong ◽

K. W. Kim ◽

E. W. Park

Keyword(s):

Verticillium Dahliae ◽

Solanum Melongena ◽

Morphological Characteristics ◽

Wilt Disease ◽

Potato Dextrose Agar ◽

First Report ◽

Vascular Tissues ◽

Fungal Isolates ◽

Pathogenicity Tests ◽

Root Cutting

A wilt disease occurred on greenhouse-grown eggplants (Solanum melongena L.) at Hanam and Yeojoo, Korea, in 1997. Lower leaves on the 2-month-old wilted eggplants exhibited gradual yellowing, interveinal necrosis, and marginal crinkling and dropped prematurely. Vascular tissues of diseased stems were discolored and turned black. Vertical sections of the stems revealed that the pith had been colonized by the fungus. The disease progressed from lower parts of the plants upward. Incidence of diseased eggplants in greenhouses was 5% on 23 May 1997. Although the incidence increased to 10% on 13 June, it remained constant through early July. Fungal isolates from discolored vascular tissues were initially whitish to cream color on potato-dextrose agar, which turned black due to the formation of microsclerotia. The fungus also produced abundant verticillate conidiophores with phialides and conidia. Based on these cultural and morphological characteristics, the fungus was identified as Verticillium dahliae Klebahn. Pathogenicity tests by root cutting, root dipping, or soil drenching resulted in similar symptoms observed in the naturally infected eggplants. Symptoms were first observed on lower leaves of each eggplant 3 weeks after inoculation. Isolation from symptomatic leaves of the inoculated eggplants yielded V. dahliae. This is the first report of occurrence of Verticillium wilt of eggplant in Korea.

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First Report of Guignardia psidii, an Ascigerous State of Phyllosticta psidiicola, Causing Fruit Rot on Guava in Venezuela

Plant Disease ◽

10.1094/pd-89-0773c ◽

2005 ◽

Vol 89 (7) ◽

pp. 773-773 ◽

Cited By ~ 1

Author(s):

M. S. González ◽

A. Rondón

Keyword(s):

Psidium Guajava ◽

Potato Dextrose Agar ◽

Fruit Rot ◽

Symptom Development ◽

First Report ◽

Guava Fruit ◽

Pathogenicity Tests ◽

Apical Appendage ◽

Ascigerous State ◽

Gelatinous Envelope

During August 2003, guava fruit (Psidium guajava L.) cv. Red Dominicana from Cojedes state in Venezuela showed circular, purple-to-brown lesions (0.5 to 1.0 cm) that spread over all surfaces and became black and shrunken on severely affected fruit. Symptomatic tissues were plated aseptically on potato dextrose agar (PDA). Colonies that were initially gray and turned black with age were consistently isolated. The fungus was characterized by dense, submerged, brown-to-black mycelium with septate hyphae. Ascocarps were perithecial, abundant, granulose, subglobose to cylindric obpyriform, solitary or aggregated, mostly unilocular with prominent long necks; ascocarp walls were stromatic, composed of several layers of cells, thick walled, and deeply pigmented on the outside. Asci were subclavate to cylindrical, stipitate, 44 to 84 × 7 to 9 μm, and eight-spored; asci walls were thick and bitunicate. Ascospores were unicellular, hyaline, guttulate, fusiform ellipsoid, widest in the mid-region with rounded ends and gelatinous plugs, and 12 to 17 × 4.5 μm. Conidiomata were pycnidial, intermixed among ascocarps, variable in shape, dark brown, solitary or aggregated, ostiolate, and with long necks up to 1 mm. Pycnidial walls were pseudoparenchymatic, multicellular, and composed of many layers of brown compressed cells. Conidiogenous cells were hyaline, subglobose to cylindrical, and smooth, and holoblastic. Conidia were hyaline, unicellular, obovate, 6 to 12 (7.5) × 5 to 8 μm, slightly truncate at the bases, rounded at apices, guttulate, and provided a gelatinous envelope and apical appendage. Appendages were hyaline, tubular, smooth, and 3.0 to 4.5 × 0.5 μm. The fungus is homothallic because single ascospores and single conidia developed ascigerous states. The ascigerous state was identified as Guignardia psidii (1) and the anamorph as Phyllosticta psidiicola (1,2). Pathogenicity tests were conducted on detached fruits inoculated with monosporic cultures. Pathogenesis and symptom development only occurred when a mixture of mycelium, ascospores, and conidia was used as inoculum. The fungus was reisolated from symptomatic fruit tissues. To our knowledge, this is the first report of Guignardia psidii, an ascigerous state of Phyllosticta psidiicola from guava fruits in Venezuela. References: (1) B. A. Ullasa and R. D. Rawal. Curr. Sci. 53:435, 1984. (2) H. A. van der Aa. Page 95 in: No. 5, Stud. Mycol., 1973.

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