First Report of Southern Blight Caused by Sclerotium rolfsii on St.-John's-Wort

Interest in commercial production of common St.-John's-wort (Hypericum perforatum L.), an herb that is dried, processed, and used as an anti-depressant medication, is increasing. In August 1998, St.-John's-wort growing in the field at Charleston, SC, showed blight symptoms. Leaves on prostrate branches turned reddish-yellow, then brown, and then abscised. As the disease progressed, branches and approximately 10% of the plants were killed. Coarse, white mycelia were present on the bases of dead branches. Segments cut from symptomatic branches were disinfested in 0.5% sodium hypochlorite and placed on potato dextrose agar (PDA) at 25°C. Sclerotium rolfsii Sacc. was isolated from one of 12 branches with discolored leaves and six of six dead branches. For pathogenicity tests, sclerotia were harvested from 6-week-old cultures on PDA. Ten-week-old St.-John's-wort plants, growing in potting mix in 10-cm pots, were inoculated by placing four sclerotia on the soil surface 1 to 1.5 cm from the main stem of each plant. Plants were grown in a greenhouse at 90% relative humidity and 25 to 35°C. Single blighted branches were observed on three plants 12 days after inoculation and all plants were blighted 28 days after inoculation. S. rolfsii was recovered from 10 and 9 of 10 plants inoculated with isolates of S. rolfsii from St.-John's-wort and tomato, respectively. All 10 noninoculated plants remained symptomless. The pathogenicity test was repeated and the results were similar. This is the first report of S. rolfsii causing Southern blight on St.-John's-wort in the United States.

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First Report of Southern Blight on Canadian Goldenrod (Solidago canadensis) Caused by Sclerotium rolfsii in China

Plant Disease ◽

10.1094/pdis-94-9-1172b ◽

2010 ◽

Vol 94 (9) ◽

pp. 1172-1172 ◽

Cited By ~ 7

Author(s):

W. Tang ◽

Y. Z. Zhu ◽

H. Q. He ◽

S. Qiang

Keyword(s):

Eastern China ◽

Sclerotium Rolfsii ◽

Soil Surface ◽

Pathogenicity Test ◽

Solidago Canadensis ◽

Uniform Size ◽

First Report ◽

Southern Blight ◽

Perennial Plant ◽

Nanjing City

Canadian goldenrod (Solidago canadensis L., Asteraceae) is a rhizomatous perennial plant native to North America that has invaded eastern China and continues to spread northward and westward. It is quite common on field borders, roadsides, and in undeveloped areas, posing a serious threat to native ecosystems and their biodiversity. During the late summers of 2007 and 2008, wilted Canadian goldenrod plants were occasionally found in invasive populations in the suburb of Nanjing city. Wilted plants were transplanted and maintained in a greenhouse at Nanjing Agricultural University. A white mass of fungal hyphae, which grew on the soil surface around the stem of the symptomatic S. canadesis plants and eventually covered the stem, was observed. Initially, the base of the stem became yellow, turned brown, and the light brown discoloration extended up the stem to a height of 3 to 7 cm. The leaves then collapsed, starting from the top until the entire plant wilted. The fungus produced numerous, small, roundish sclerotia of uniform size (0.7 to 2.0 mm in diameter), which were white at first and then became brown to dark brown. The fungus grew into the stems and downward into the rhizome area, but no sclerotia were detected inside the stem or root. Diseased tissue with sclerotia was disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar amended with 100 mg/liter of streptomycin sulfate. On the basis of sclerotia morphology and the presence of clamp connections at hyphal septa, the fungus was identified as Sclerotium rolfsii. Pathogenicity of the isolate was confirmed by inoculating 1-year-old S. canadensis plants (average 1.5 m high) grown in pots. The inoculum consisted of cottonseed hulls infested with mycelium and sclerotia of the pathogen and was placed on the soil surface around the base of each unwounded plant. Noninoculated plants served as controls. The pathogenicity test was conducted twice. After inoculation, the plants were maintained at high humidity and 30°C for 3 days and then transferred to a greenhouse. All inoculated plants developed symptoms of southern blight. Inoculated plants developed symptoms of wilting 5 to 7 days after inoculation and were completely wilted within 15 to 20 days. Symptoms of wilting were soon followed by the appearance of white-to-light brown sclerotia on the collar region. Control plants remained symptomless and Sclerotium rolfsii was reisolated from inoculated plants. To our knowledge, this is the first report of southern blight of Canadian goldenrod caused by Sclerotium rolfsii in China.

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First Report of Southern Blight Caused by Sclerotium rolfsii on Laurustinus

Plant Disease ◽

10.1094/pdis.2004.88.3.310b ◽

2004 ◽

Vol 88 (3) ◽

pp. 310-310

Author(s):

G. Polizzi ◽

A. Vitale ◽

G. Parlavecchio

Keyword(s):

Disease Incidence ◽

Sclerotium Rolfsii ◽

Soil Surface ◽

First Report ◽

Southern Blight ◽

Soil Line ◽

Sterile Needle ◽

Pathogenicity Tests ◽

On Line ◽

Polyethylene Bags

Laurustinus (Viburnum tinus L.), native to the Mediterranean Region, is an evergreen shrub commonly used as a specimen shrub or small tree or used in border plantings. During August 2003, a blight occurred on 2-year-old-plants of laurustinus growing in pots in a nursery in eastern Sicily (Italy). Disease incidence ranged from 2 to 5% across the field. Symptoms included 3 to 4 cm long lesions and the development of white mycelial strands and brown, 1.0 to 1.8 mm, nearly spherical sclerotia on the crown of plants at the soil line that are typical of Sclerotium rolfsii Sacc. The foliage of infected plants wilted, followed by a sudden collapse of the plant. The fungus was consistently isolated on acidified potato dextrose agar (PDA) (pH 4.5) by plating symptomatic tissues that were surface disinfested (1.2% NaOCl) for 1 min. and rinsed in sterile water. Pathogenicity tests were performed by sprinkling 50 sclerotia, obtained from infected oat kernels (2), on the soil surface around the collar of each of 10 healthy, potted 1-year-old plants of laurustinus. Five of the plants were previously wounded on the crown 1.5 cm above or below the soil line with a sterile needle. Five noninoculated plants served as controls. All plants were maintained at 25 ± 2°C and enclosed for 72 hr in polyethylene bags (90 to 95% relative humidity). Blight symptoms similar to those seen in nursery were observed on inoculated plants 20 to 25 days after inoculation, while no symptoms developed on control plants. Koch's postulates were fulfilled by reisolation of the fungus on acidified PDA from all infected laurustinus plants. S. rolfsii was previously recorded on Prague viburnum (Viburnum × pragense L.) as the causal agent of southern blight (1). To our knowledge, this is the first report of southern blight caused by S. rolfsii on laurustinus. References: (1) A. Hagan. Southern blight on flowers, shrubs, and trees. On-line publication ANR-1157. Alabama A & M, and Auburn University ( www.aces.edu/dept/extcomm/publications/html ). (2) R. Rodriguez-Kabana et al. Plant Dis. Rep. 59:5, 1975.

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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 Southern blight Incited by Sclerotium rolfsii on Dichondra repens in Italy

Plant Disease ◽

10.1094/pd-89-0203b ◽

2005 ◽

Vol 89 (2) ◽

pp. 203-203 ◽

Cited By ~ 1

Author(s):

A. Garibaldi ◽

A. Minuto ◽

M. L. Gullino

Keyword(s):

Sclerotium Rolfsii ◽

Soil Surface ◽

The United States ◽

First Report ◽

Southern Blight ◽

Inoculation Trial ◽

Leaf Yellowing ◽

White Mycelium ◽

Wheat Kernels ◽

Reddish Brown Color

Kidney weed (Dichondra repens) is increasingly used for low maintenance turf in Italy, particularly for gardens and parks in areas characterized by mild climate. During September 2003, on the D. repens turf of a private garden located near Imperia (northern Italy), yellow, circular areas as much as 60 cm in diameter appeared with the grass becoming chlorotic and thin. A ring of the patch at its periphery exhibited a reddish brown color and eventually died. An area of green grass remained in the center of the patch. Rings of dead grass enlarged rapidly during hot, humid weather. In the presence of abundant moisture, a white mycelium occurred on the dying grass at the periphery of the ring. White or light-to-dark brown sclerotia (1 to 3 mm in diameter) developed from mycelium on the dead grass. The diseased tissue was disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar amended with 100 mg/l of streptomycin sulphate. Sclerotium rolfsii was consistently isolated from infected plants. Pathogenicity of three isolates obtained from infected plants was confirmed by inoculating healthy D. repens turf (1 m2 plots and three replicates). Inoculum that consisted of wheat kernels infested with mycelium and sclerotia of each isolate was placed on the soil surface. Noninoculated plots served as controls. The inoculation trial was repeated once. Turf was covered with a plastic film for 7 days, kept at temperatures ranging between 22 and 25°C, and watered as needed. Inoculated plants developed symptoms of leaf yellowing within 11 days, soon followed by the appearance of white mycelium and sclerotia, and then eventually wilted. Control plants remained symptomless. Sclerotium rolfsii was re-isolated from inoculated plants. To our knowledge, this is the first report of S. rolfsii on D. repens in Italy. This disease has been reported on kidney weed in several countries such as the United States (3), Brazil (1), and India (2). References: (1) M. Menezes and J. A. A. Lima. Fitossanidade 1:18, 1974. (2) K. Ranganathan and N. Shanmugam. Indian Phytopathol, 27:113, 1974. (3) J. D. Smith et al. Fungal Diseases of Amenity Turf Grasses. E & F.N. Spon, London, 1989.

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First Report of Phytophthora citrophthora on Penstemon barbatus in Italy

Plant Disease ◽

10.1094/pd-90-1260a ◽

2006 ◽

Vol 90 (9) ◽

pp. 1260-1260 ◽

Cited By ~ 1

Author(s):

A. Garibaldi ◽

D. Bertetti ◽

D. Minerdi ◽

M. L. Gullino

Keyword(s):

Its Region ◽

The United States ◽

Phytophthora Species ◽

Crown Rot ◽

Pathogenicity Test ◽

Phytophthora Citrophthora ◽

First Report ◽

Blastn Analysis ◽

Root And Crown Rot ◽

Pathogenicity Tests

Penstemon barbatus (Cav.) Roth (synonym Chelone barbata), used in parks and gardens and sometimes grown in pots, is a plant belonging to the Scrophulariaceae family. During the summers of 2004 and 2005, symptoms of a root rot were observed in some private gardens located in Biella Province (northern Italy). The first symptoms resulted in stunting, leaf discoloration followed by wilt, root and crown rot, and eventually, plant death. The diseased tissue was disinfested for 1 min in 1% NaOCl and plated on a semiselective medium for Oomycetes (4). The microorganism consistently isolated from infected tissues, grown on V8 agar at 22°C, produced hyphae with a diameter ranging from 4.7 to 5.2 μm. Sporangia were papillate, hyaline, measuring 43.3 to 54.4 × 26.7 to 27.7 μm (average 47.8 × 27.4 μm). The papilla measured from 8.8 to 10.9 μm. These characteristics were indicative of a Phytophthora species. The ITS region (internal transcribed spacer) of rDNA was amplified using primers ITS4/ITS6 (3) and sequenced. BLASTn analysis (1) of the 800 bp obtained showed a 100% homology with Phytophthora citrophthora (R. & E. Sm.) Leonian. The nucleotide sequence has been assigned GenBank Accession No. DQ384611. For pathogenicity tests, the inoculum of P. citrophthora was prepared by growing the pathogen on autoclaved wheat and hemp kernels (2:1) at 25°C for 20 days. Healthy plants of P. barbatus cv. Nano Rondo, 6 months old, were grown in 3-liter pots (one plant per pot) using a steam disinfested substrate (peat/pomix/pine bark/clay 5:2:2:1) in which 200 g of kernels per liter of substrate were mixed. Noninoculated plants served as control treatments. Three replicates were used. Plants were maintained at 15 to 20°C in a glasshouse. The first symptoms, similar to those observed in the gardens, developed 21 days after inoculation, and P. citrophthora was consistently reisolated from infected plants. Noninoculated plants remained healthy. The pathogenicity test was carried out twice with similar results. A nonspecified root and crown rot of Penstemon spp. has been reported in the United States. (2). To our knowledge, this is the first report of P. citrophthora on P. barbatus in Italy as well as in Europe. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997 (2) F. E. Brooks and D. M. Ferrin. Plant Dis. 79:212, 1995. (3) D. E. L. Cooke and J. M. Duncan. Mycol. Res. 101:667, 1997. (4) H. Masago et al. Phytopathology 67:425, 1977.

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First Report of Postharvest Fruit Rot in Persimmon Caused by Phacidiopycnis washingtonensis in Italy

Plant Disease ◽

10.1094/pdis-94-6-0788b ◽

2010 ◽

Vol 94 (6) ◽

pp. 788-788 ◽

Cited By ~ 2

Author(s):

A. Garibaldi ◽

D. Bertetti ◽

M. T. Amatulli ◽

M. L. Gullino

Keyword(s):

United States ◽

Its Region ◽

The United States ◽

Fruit Rot ◽

Diospyros Kaki ◽

Pathogenicity Test ◽

Conidial Suspension ◽

First Report ◽

Pathogenicity Tests ◽

Phacidiopycnis Washingtonensis

Persimmon (Diospyros kaki L.) is widely grown in Italy, the leading producer in Europe. In the fall of 2009, a previously unknown rot was observed on 3% of fruit stored at temperatures between 5 and 15°C in Torino Province (northern Italy). The decayed area was elliptical, firm, and appeared light brown to dark olive-green. It was surrounded by a soft margin. The internal decayed area appeared rotten, brown, and surrounded by bleached tissue. On the decayed tissue, black pycnidia that were partially immersed and up to 0.5 mm in diameter were observed. Light gray conidia produced in the pycnidia were unicellular, ovoid or lacriform, and measured 3.9 to 6.7 × 2.3 to 3.5 (average 5.0 × 2.9) μm. Fragments (approximately 2 mm) were taken from the margin of the internal diseased tissues, cultured on potato dextrose agar (PDA), and incubated at temperatures between 23 and 26°C under alternating light and darkness. Colonies of the fungus initially appeared ash colored and then turned to dark greenish gray. After 14 days of growth, pycnidia and conidia similar to those described on fruit were produced. The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS4/ITS6 and sequenced. BLAST analysis (1) of the 502-bp segment showed a 100% similarity with the sequence of Phacidiopycnis washingtonensis Xiao & J.D. Rogers (GenBank Accession No. AY608648). The nucleotide sequence has been assigned the GenBank Accession No. GU949537. Pathogenicity tests were performed by inoculating three persimmon fruits after surface disinfesting in 1% sodium hypochlorite and wounding. Mycelial disks (10 mm in diameter), obtained from PDA cultures of one strain were placed on wounds. Three control fruits were inoculated with plain PDA. Fruits were incubated at 10 ± 1°C. The first symptoms developed 6 days after the artificial inoculation. After 15 days, the rot was very evident and P. washingtonensis was consistently reisolated. Noninoculated fruit remained healthy. The pathogenicity test was performed twice. Since P. washingtonensis was first identified in the United States on decayed apples (2), ‘Fuji’, ‘Gala’, ‘Golden Delicious’, ‘Granny Smith’, ‘Red Chief’, and ‘Stark Delicious’, apple fruits also were artificially inoculated with a conidial suspension (1 × 106 CFU/ml) of the pathogen obtained from PDA cultures. For each cultivar, three surface-disinfested fruit were wounded and inoculated, while three others served as mock-inoculated (sterile water) controls. Fruits were stored at temperatures ranging from 10 to 15°C. First symptoms appeared after 7 days on all the inoculated apples. After 14 days, rot was evident on all fruit inoculated with the fungus, and P. washingtonensis was consistently reisolated. Controls remained symptomless. To our knowledge, this is the first report of the presence of P. washingtonensis on persimmon in Italy, as well as worldwide. The occurrence of postharvest fruit rot on apple caused by P. washingtonensis was recently described in the United States (3). In Italy, the economic importance of the disease on persimmon fruit is currently limited, although the pathogen could represent a risk for apple. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) Y. K. Kim and C. L. Xiao. Plant Dis. 90:1376, 2006. (3) C. L. Xiao et al. Mycologia 97:473, 2005.

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First Report of Sclerotium rolfsii on Catharanthus roseus

Plant Disease ◽

10.1094/pdis.2000.84.2.200d ◽

2000 ◽

Vol 84 (2) ◽

pp. 200-200

Author(s):

G. E. Holcomb

Keyword(s):

Catharanthus Roseus ◽

Fungal Pathogen ◽

Baton Rouge ◽

Sclerotium Rolfsii ◽

The United States ◽

Madagascar Periwinkle ◽

Basal Stem Rot ◽

First Report ◽

Pathogenicity Tests ◽

Stem Necrosis

Wilt, blight, and stem necrosis were observed on Catharanthus roseus (L.) G. Don ‘Mediterranean Deep Rose’ (MDR) plants (Madagascar or rose periwinkle) in August 1999 at Burden Research Plantation in Baton Rouge, LA. MDR was the only prostrate-form cultivar and the only cultivar of 11 that was diseased. Twelve of twenty-four plants of cv. MDR were killed in the trial planting. White mycelia and small (1 mm diameter) light brown sclerotia were present at the base of infected plants. The suspect fungus was isolated consistently on acidified water agar and maintained on acidified potato dextrose agar (APDA). Pathogenicity tests were done by pipetting 1 ml of blended inoculum (contents of one 7-day-old plate culture grown on APDA in 100 ml of deionized water) at the base of nine 15-cm-tall Madagascar periwinkle plants. Inoculated and noninoculated plants were held in a dew chamber for 3 days at 28°C and placed in a greenhouse where temperatures ranged between 25 and 31°C. All inoculated plants showed wilt, blight, and basal stem rot after 3 days and were dead after 10 days. Noninoculated plants remained symptomless. The fungal pathogen was identified as Sclerotium rolfsii Sacc. and was reisolated from inoculated plants. The fungus was previously reported on Lochnera rosea (L.) Rchb. (=C. roseus) from Taiwan (1). This is the first report of the occurrence of S. rolfsii on Madagascar periwinkle in the United States. Reference: (1) K. Goto. Trans. Nat. Hist. Soc. Formosa 23:37, 1933.

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Occurrence of Blight Caused by Sclerotium rolfsii on Lolium perenne in Argentina

Plant Disease ◽

10.1094/pdis-91-7-0910a ◽

2007 ◽

Vol 91 (7) ◽

pp. 910-910

Author(s):

L. Goldring ◽

M. Lacasa ◽

E. R. Wright ◽

B. A. Pérez ◽

M. C. Rivera

Keyword(s):

United States ◽

Lolium Perenne ◽

Perennial Ryegrass ◽

Tap Water ◽

Sclerotium Rolfsii ◽

Soil Surface ◽

Pathogenic Fungi ◽

The United States ◽

Buenos Aires Province ◽

Pathogenicity Test

A perennial ryegrass (Lolium perenne L.) lawn located at Castelar (Buenos Aires Province) showed disease symptoms during the summer of 2003. Chlorotic patches as much as 15 cm in diameter appeared on the lawn. Later, dead plants with white mycelia developing on the crown and surrounding soil occurred at the periphery of the rings. Plants showed leaf chlorosis and crown and root rot. No sclerotia developed on plant organs. Diseased plants were collected, washed with running tap water for 4 h, and disinfested in 5% NaOCl for 2 min. Pieces, 3 to 5 mm long from symptomatic leaves, crowns, and roots, were incubated on 2% potato dextrose agar (PDA) at 22 to 25°C with a 12-h light/dark cycle. Mycelia growing on the soil surface was transferred to PDA and incubated under the same conditions. After 3 to 4 days, white, conspicuous mycelia that produced sclerotia grew from diseased tissue pieces and soil mycelial samples. Sclerotia were nearly spherical, 1 to 2 mm in diameter, white but turning brown with age, and produced in large numbers over the entire colony surface. Primary hyphae showed clamp connections at the septa. A pathogenicity test was performed with 20 1-month-old plants of L. perenne grown in a 1:1 (v/v) mixture of sand and soil contained in 24- × 17- × 4-cm plastic trays. Seven-day-old fungal cultures grown on PDA were cut into 1- cm2 pieces and placed among the plants on the substrate. Each tray was inoculated with seven inoculum pieces. Five trays of plants were inoculated with the fungus, and plants in five trays that served as controls had only sterile pieces of PDA placed on the substrate. All plants were maintained at 25°C and watered frequently. First symptoms, consisting of chlorosis, were observed 4 days after inoculation. Of the plants, 34, 59, 60, 65, and 70% developed symptoms 6, 9, 14, 17, and 21 days after inoculation, respectively. Control plants remained healthy. The fungus was reisolated from diseased plants and identified as Sclerotium rolfsii Sacc. (teleomorph Athelia rolfsii (Curzi) C.C. Tu & Kimbr.) on the basis of morphological and cultural characteristics (3,4). The disease has been observed causing stalk rot on perennial ryegrass in the United States (1) and Australia (2). To our knowledge, this is the first report of S. rolfsii causing disease on L. perenne in Argentina. 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) D. F. Farr et al. Fungal Databases. Systematic Botany and Mycology Laboratory. Online publication. ARS, USDA, 2007. (3) J. E. M. Mordue. No. 410 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, UK, 1974. (4) Z. K. Punja and A. Damiani. Mycologia 88:694, 1996.

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St. John's Wort versus Counterfeit St. John's Wort: An HPTLC Study

Journal of AOAC International ◽

10.5740/jaoacint.16-0170 ◽

2016 ◽

Vol 99 (5) ◽

pp. 1204-1212 ◽

Cited By ~ 9

Author(s):

Débora A Frommenwiler ◽

Eike Reich ◽

Sidney Sudberg ◽

Maged H M Sharaf ◽

Anton Bzhelyansky ◽

...

Keyword(s):

Hypericum Perforatum ◽

The United States ◽

Reversed Phase ◽

Synthetic Dyes ◽

St John’S Wort ◽

St John's Wort ◽

Detection Mode ◽

Hypericum Perforatum L ◽

States Pharmacopeia ◽

Hptlc Method

Abstract Hypericum perforatum L. is the most commonly used herb for treating depression. Due to the popularity of this botanical, there is a potential for economically driven adulteration of St. John's wort (SJW) products. The goal of this study was to investigate SJW ingredients suspected to be adulterated based on simple preliminary HPTLC tests. Commercial samples were analyzed by HPTLC following the United States Pharmacopeia (USP) monograph methodology, with additional visualization under white light. A number of these samples presented odd methanolic solution colors and unconventional HPTLC fingerprints, suggesting the presence of other species and/or extraneous polar additives. To achieve identification and separation of the polar additives, a new reversed-phase HPTLC method was developed. The adulterants were identified as synthetic dyes in the amounts of 0.51 to 1.36% by weight. Identities of the dyes were confirmed by scanning densitometry and HPTLC-MS. A modified USP method with additional detection mode permitted the identification of eight SJW samples adulterated with dyes and six others with flavonoid fingerprints different from those specified by USP from a total of 37 samples of dry extracts, finished products, and bulk raw herb. A decision flowchart is proposed to guide the detection of adulteration of SJW in a systematic fashion.

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First Report of Southern Blight Incited by Sclerotium rolfsii on Potato (Solanum tuberosum) in Northern Italy

Plant Disease ◽

10.1094/pd-90-1114c ◽

2006 ◽

Vol 90 (8) ◽

pp. 1114-1114 ◽

Cited By ~ 5

Author(s):

A. Garibaldi ◽

G. Gilardi ◽

M. L. Gullino

Keyword(s):

Solanum Tuberosum ◽

Solanum Tuberosum L ◽

Sclerotium Rolfsii ◽

Soil Surface ◽

The United States ◽

Northern Italy ◽

Strong Increase ◽

Southern Blight ◽

White Mycelium ◽

The Moment

During the summer of 2005, plants of potato (Solanum tuberosum L.) showing severe basal rot symptoms were observed in a commercial field near Alessandria (northern Italy). The first symptoms were detected during early July in correspondence with a strong increase of air temperature (as much as 38°C, with an average monthly increase of 10°C) and relative humidity. Infected plants showed dry collar rots and extensive necrosis of cortical tissues. Leaves of infected plants were chlorotic. As the disease progressed, tubers rotted and plants wilted. Infected plants appeared in patches, encompassing 10 to 15% of the cultivated area. In the presence of abundant moisture, a white mycelium occurred on infected tissues. On their surface, infected tubers showed a fan-like mycelial growth. Later, white or light-to-dark brown sclerotia (2 to 4 mm in diameter) developed from mycelium. Clamp connections were present. The diseased tissue was disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 mg/liter of streptomycin sulfate. Sclerotium rolfsii was consistently isolated from infected plants. Pathogenicity of one isolate obtained from infected plants was confirmed by inoculating healthy S. tuberosum plants (cv. Hermes) grown in 2:l volume pots (1 plant per pot, seven replicates). Inoculum that consisted of 1 g/pot of wheat kernels infested with mycelium and sclerotia was placed on the soil surface. Seven noninoculated plants served as controls. The inoculation trial was repeated once. Plants were kept at temperatures ranging between 25 and 32°C and watered as needed. Inoculated plants developed symptoms of leaf yellowing within 10 days, soon followed by the appearance of white mycelium and sclerotia and then eventually wilted. Control plants remained symptomless. Sclerotium rolfsii was reisolated from inoculated plants.Possible attacks of Sclerotium rolfsii on S. tuberosum were described as rarely occurring in southern Italy (3). The disease, detected at the moment in very few farms and on cvs. Hermes and Monalisa, was particularly severe on the last variety, causing 5 to 15% yield losses because of premature plant death and rotting of tubers. This disease has been reported in several countries such as India (1), Israel (2), and the United States of America (4). References: (1) N. S. Bisht. Indian Phytopathol. 35:148, 1982. (2) Y. Elad et al. Soil Biol. Biochem. 16:381, 1984. (3) R. Gigante. Ital. Agric. 87:263, 1946. (4) G. F. Weber. Phytopathology, 33:615, 1943.

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