First Report of Soft Rot Caused by Sclerotinia sclerotiorum on Borage in North Dakota

Borage (Borago officinalis) is an oilseed crop that is being evaluated as an alternative crop in North Dakota. During September 2004, borage plants in a field in Cass County, North Dakota were dying from a watery soft rot. The main stems and lateral branches were affected, and affected plants were usually completely lodged and prostrate. Dead plants had bleached and shredded stems with black sclerotia (9.1 ± 3.0 × 2.6 ± 0.5 mm) inside the pith and on the epidermis. At the time of observation, borage plants were flowering and forming pods and seed. Approximately 60% of the plants were visually affected by the watery soft rot. Sclerotia were collected from diseased plants, soaked in a 0.5% NaOCL solution for 30 s, air dried, and placed in petri dishes containing potato dextrose agar (PDA). A fungus grew from the plated sclerotia that subsequently produced white mycelium and black sclerotia (4.8 ± 1.2 × 2.5 ± 1.0 mm), which is characteristic of Sclerotinia sclerotiorum (Lib.) de Bary (3). To confirm pathogenicity, borage plants were inoculated in the greenhouse with a S. sclerotiorum isolate from field-infected borage. Thirteen borage plants were grown from seed in the greenhouse under natural sunlight at a temperature range of 24 ± 3°C. When plants were at the four-leaf stage (approximately 16 cm high), the second leaf was excised from each plant with the petiole remaining on the plant. The leafless petioles were inoculated using a method previously described (2). Petioles of 10 plants were inoculated with PDA containing mycelium of the S. sclerotiorum borage isolate, while petioles of five plants were inoculated with PDA to serve as a control. Three days after inoculation, plants inoculated with the S. sclerotiorum borage isolate were beginning to wilt and 5 days after inoculation, these plants were completely wilted and prostrate, similar to observations made on field-infected plants. Sclerotia collected from the diseased, inoculated plants were placed on PDA, and S. sclerotiorum was successfully recovered. Control plants inoculated with PDA did not show any disease symptoms. Other plant genera in the Boraginaceae are known hosts of S. sclerotiorum (1); however, to our knowledge, this is the first report of borage as a host. References: (1) G. J. Boland and R. Hall, Can. J. Plant Pathol. 16:93, 1994. (2) L. E. del Río et al. (Abstr.) Phytopathology 90(suppl.):S176, 2000. (3) D. L. Tourneau, Phytopathology 69:887, 1979.

Download Full-text

First Report of White Mold Caused by Sclerotinia sclerotiorum on Echium (Echium vulgare)

Plant Disease ◽

10.1094/pd-89-0684c ◽

2005 ◽

Vol 89 (6) ◽

pp. 684-684 ◽

Cited By ~ 2

Author(s):

L. E. del Río ◽

C. A. Bradley ◽

B. L. Johnson

Keyword(s):

North Dakota ◽

Sclerotinia Sclerotiorum ◽

Oilseed Crop ◽

Razor Blade ◽

New Host ◽

First Report ◽

Agar Plug ◽

Advanced Stages ◽

Stem Lesions ◽

Del Rio

Echium, also known as common viper's bugloss, is a member of the botanical family Boraginaceae. Echium is being evaluated for its potential use as an oilseed crop in North Dakota. In 2003, 40% of echium plants in a field in Cass County were observed showing classical symptoms of infection by Sclerotinia sclerotiorum. Plants in advanced stages of infection were dead. Stems of dead plants peeled off easily when touched and numerous cylindrical, black sclerotia that were 2 to 3 mm in diameter and 4 to 7 mm long were found in the pith. Younger stem lesions were watery soft, many of them with a white cottony growth on them. Sclerotia and infected stem tissues collected from the field were surface disinfested in a 0.5% NaOCl solution for 30 s, rinsed with sterile distilled water, and air dried before plating on potato dextrose agar (PDA). Samples were incubated at room temperature for 1 week. White mycelium and black sclerotia, characteristic of S. sclerotiorum (Lib.) de Bary, were produced in all dishes. Koch's postulates were fulfilled using the petiole inoculation technique (2). Briefly, 4-mm agar plugs containing hyphal tips of a 2-day-old S. sclerotiorum colony growing on PDA were excised and loaded in the wide opening of 100-μl pipette tips. The second true leaf of 15 3-week-old echium seedlings, growing in plastic pots containing Ready-Mix soil, was cut off with a razor blade leaving an approximately 25-mm long petiole attached to the stem. The leafless petioles of 10 seedlings were capped with a loaded pipette, agar plug first, until the petiole tip broke the inner surface of the plug and the petiole came in contact with the mycelium. The other five seedlings were inoculated with agar plugs without mycelium and used as control plants. Three days after inoculation, all seedlings inoculated with S. sclerotiorum wilted and expressed symptoms similar to those observed in the field. None of the control plants showed symptoms of infection. Black sclerotia were retrieved from infected stems 2 weeks after inoculation, and the pathogen was successfully reisolated onto PDA. Several important North Dakota crops are susceptible to S. sclerotiorum. The identification of echium as a new host for S. sclerotiorum should be considered in the event that this crop is promoted as an alternative for North Dakota agriculture. To our knowledge, this is the first report on the susceptibility of echium to S. sclerotiorum. Other members of the Boraginaceae have been identified as hosts for this pathogen (1). References: (1) G. J. Boland and R. Hall. Can. J. Plant Pathol. 16:93, 1994. (2) L. E. del Río et al. (Abstr.) Phytopathology 91 (suppl.):S176, 2001.

Download Full-text

First Report of Sclerotinia sclerotiorum on Niger (Guizotia abyssinica)

Plant Disease ◽

10.1094/pdis.2003.87.5.602c ◽

2003 ◽

Vol 87 (5) ◽

pp. 602-602 ◽

Cited By ~ 1

Author(s):

C. A. Bradley ◽

L. E. del Río ◽

B. L. Johnson

Keyword(s):

North Dakota ◽

Sclerotinia Sclerotiorum ◽

Severe Disease ◽

Disease Outbreaks ◽

Basal Area ◽

Test Method ◽

First Report ◽

Dry Edible Bean ◽

White Mycelium ◽

Del Rio

Niger is a new crop being grown in North Dakota and Minnesota for the commercial birdseed market. In 2002, approximately 60 and 150 ha of niger were grown in North Dakota and Minnesota, respectively. In September 2002, niger plants in a field located near Prosper, ND showed the following symptoms and signs: bleached, shredded, and broken stems at the basal area, and presence of white mycelium and black sclerotia (2.2 ± 0.8 mm diameter) inside the pith cavity. Approximately 40% of plants in that field showed signs or symptoms of infection. Sclerotia were collected from the pith cavity, soaked in a 0.53% NaOCL solution for 30 s, air dried, and placed in petri dishes containing potato dextrose agar (PDA). A fungal colony grew out from the plated sclerotia that subsequently produced aerial white mycelium and black sclerotia characteristic of Sclerotinia sclerotiorum (Lib.) de Bary. To confirm pathogenicity, 2 groups of 10 30-day-old niger seedlings each were inoculated using the straw test method (2) or petiole inoculation test method (1) with mycelium from a S. sclerotiorum isolate obtained from an infected niger plant; 20 seedlings served as a noninoculated control. At the time of inoculation, seedlings were healthy and approximately 14 cm high. Three days after inoculation using either method, tissue at the inoculated area turned gray. The gray lesions progressed across the majority of the seedling tissue and 1 week after inoculation, all inoculated plants were wilted and dead. S. sclerotiorum was reisolated from infected tissue that was placed on PDA. To our knowledge, this is the first report of S. sclerotiorum causing a stem rot disease of niger or any species in the Guizotia genus. Several of the major crops grown in North Dakota and Minnesota, such as canola, dry edible bean, soybean, and sunflower are susceptible to S. sclerotiorum. Growing niger in rotation with these or other susceptible crops could increase S. sclerotiorum inoculum levels and lead to severe disease outbreaks if conditions are favorable. References: (1) L. E. del Río et al. (Abstr.) Phytopathology 90(Suppl.):S176, 2000. (2) R. Petzoldt and M. H. Dickson, Annu. Rep. Bean Improv. Coop. 39:142, 1996.

Download Full-text

First Report of Sclerotinia Stem Rot and Watery Soft Rot Caused by Sclerotinia sclerotiorum on Sand Rocket (Diplotaxis tenuifolia) in Italy

Plant Disease ◽

10.1094/pd-89-1241c ◽

2005 ◽

Vol 89 (11) ◽

pp. 1241-1241 ◽

Cited By ~ 4

Author(s):

A. Garibaldi ◽

A. Minuto ◽

M. L. Gullino

Keyword(s):

Relative Humidity ◽

Sclerotinia Sclerotiorum ◽

Severe Disease ◽

Soil Surface ◽

Soft Rot ◽

Sclerotinia Stem Rot ◽

First Report ◽

Initial Symptoms ◽

Stem Necrosis ◽

White Mycelium

Several species of Diplotaxis (D. tenuifolia, D. erucoides, and D. muralis), known as wild or sand rocket, are widely cultivated in Italy. Rocket is used in Mediterranean cuisine as salad, a component of packaged salad products, and as a garnish for food. In winter 2003, a severe disease was observed on D. tenuifolia grown in unheated glasshouses on commercial farms near Albenga in northern Italy. Initial symptoms included stem necrosis at the soil level and darkening of leaves. As stem necrosis progressed, infected plants wilted and died. Wilt, characterized by the presence of soft and watery tissues, occurred within a few days on young plants. The disease was extremely severe in the presence of high relative humidity and mild temperature (15°C). Necrotic tissues became covered with white mycelium that produced dark sclerotia. Diseased stem tissue was disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 ppm streptomycin sulfate. Sclerotinia sclerotiorum (1) was consistently recovered from infected stem pieces. Sclerotia observed on infected plants measured 1.23 to 3.00 × 1.40 to 5.38 mm (average 2.10 × 2.85 mm). Sclerotia produced on PDA measured 1.00 to 4.28 × 1.00 to 6.01 mm (average 2.38 × 3.23 mm). Pathogenicity of three isolates obtained from infected plants was confirmed by inoculating 30-day-old plants of D. tenuifolia grown in 18-cm-diameter pots in a glasshouse. Inoculum, 2 g per pot of wheat kernels infested with mycelium and sclerotia of each isolate, was placed on the soil surface around the base of each plant. Three replicates of five pots each were used per isolate. Noninoculated plants served as controls. The inoculation trial was repeated once. All plants were kept at temperatures ranging between 10 and 26°C (average 15°C) with an average relative humidity of 80% and were watered as needed. Inoculated plants developed symptoms of leaf yellowing within 12 days, soon followed by the appearance of white mycelium and sclerotia, and eventually wilted. Control plants remained symptomless. S. sclerotiorum was reisolated from inoculated plants. To our knowledge, this is the first report of infection of D. tenuifolia by S. sclerotiorum in Italy as well as worldwide. The disease currently has been observed in the Liguria Region but not yet in other areas where sand rocket is cultivated. The economic importance of this disease for the crop can be considered medium at the moment, but is expected to increase in the future. Reference: (1) N. F. Buchwald. Den. Kgl. Veterin.er-og Landbohojskoles Aarsskrift, 75, 1949.

Download Full-text

First Report of White Mold Caused by Sclerotinia sclerotiorum on Common Sage (Salvia officinalis) in Italy

Plant Disease ◽

10.1094/pdis.2004.88.9.1044b ◽

2004 ◽

Vol 88 (9) ◽

pp. 1044-1044

Author(s):

A. Garibaldi ◽

A. Minuto ◽

M. L. Gullino

Keyword(s):

Sclerotinia Sclerotiorum ◽

Plant Density ◽

Soil Surface ◽

Salvia Officinalis ◽

White Mold ◽

Rooted Cuttings ◽

First Report ◽

Streptomycin Sulfate ◽

High Plant Density ◽

White Mycelium

Salvia officinalis L. is cultivated as an aromatic ornamental plant in Italy. In the spring of 2003, rooted cuttings grown in containers in commercial farms near Albenga (northern Italy) had soft and watery stem tissue covered with whitish mycelium at the soil level. Leaves and stems showed necrotic areas of irregular shape and size. As necrosis progressed, infected plants wilted and died. Wilt occurred within a few days on young plants. Because of high plant density, the pathogen spread rapidly within and across containers to infect many rooted cuttings. Sclerotinia sclerotiorum (Lib.) de Bary (2) was consistently recovered from infected stem pieces of Salvia officinalis that were disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 ppm of streptomycin sulfate. Sclerotia produced on PDA were ellipsoid and measured 1.4 to 4.2 × 1.1 to 2.1 (average 2.1 × 1.5) mm. Pathogenicity of three isolates obtained from infected plants was confirmed by inoculating 30-day-old plants grown in pots (14-cm diameter). Inoculum of each isolate was 14-day-old cultures of mycelium and sclerotia grown on sterile wheat kernels (300 g) and deionized water (320 ml) in a 1-liter flask at 20 to 25°C. Inoculum (10 g) of each isolate was placed on the soil surface around the base of 10 plants. Ten noninoculated plants served as controls. The inoculation trial was repeated once. All plants were kept in a screenhouse at temperatures ranging between 8 and 31°C and watered as needed. Inoculated plants developed symptoms of leaf yellowing, followed by the appearance of white mycelium within 7 days, and eventually wilted within 12 to 15 days. Control plants remained symptomless. White mycelium and sclerotia developed on infected tissues, and S. sclerotiorum was reisolated from inoculated plants on PDA amended with 100 ppm of streptomycin sulfate. To our knowledge, this is the first report of white mold of Salvia officinalis caused by S. sclerotiorum in Italy. The disease has been observed in Canada (1) as well as Tasmania and New Zealand. References: (1) G. J. Bolland and R. Hall. Can. J. Plant Pathol. 16:93, 1994. (2) N. F. Buchwald. Den. Kgl. Veterin.er-og Landbohojskoles Aarsskrift, 1949.

Download Full-text

First Report of White Mold Caused by Sclerotinia sclerotiorum on Thymus × citriodorus in Italy

Plant Disease ◽

10.1094/pdis.2004.88.9.1044a ◽

2004 ◽

Vol 88 (9) ◽

pp. 1044-1044

Author(s):

A. Garibaldi ◽

A. Minuto ◽

M. L. Gullino

Keyword(s):

Sclerotinia Sclerotiorum ◽

Soil Surface ◽

White Mold ◽

First Report ◽

Potted Plants ◽

Inoculation Trial ◽

Initial Symptoms ◽

Commercial Farms ◽

Stem Necrosis ◽

White Mycelium

Thymus × citriodorus is well known for the citrus aroma released by its leaves and is grown as a potted plant in northern Italy. This species is widely used in gardens and landscapes and for culinary purposes. In the Liguria Region alone, 1.5 million plants are grown. In the winter of 2002, extensive chlorosis was observed on potted plants of Thymus × citriodorus cv. Silver Queen grown outdoors on commercial farms near Albenga. Initial symptoms included stem necrosis at the soil level and darkening of leaves. As stem necrosis progressed, infected plants wilted and died. Wilt, characterized by the presence of soft and watery tissues, occurred within a few days on young plants. Necrotic tissues became covered with whitish mycelium that produced dark sclerotia. Sclerotinia sclerotiorum (Lib.) de Bary (1) was consistently recovered from infected stem pieces of Thymus × citriodorus. The diseased stem tissue was disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 ppm of streptomycin sulfate. Sclerotia produced on PDA were ellipsoid and measured 5.2 to 4.4 × 2.1 to 1.5 mm (average 3.5 × 3.0 mm). Pathogenicity of three isolates obtained from infected plants was confirmed by inoculating 30-day-old plants grown in 14-cm-diameter pots in a screenhouse. Inoculum that consisted of wheat kernels infested with mycelium and sclerotia of each isolate was placed on the soil surface around the base of each of 10 plants. Noninoculated plants served as controls. The inoculation trial was repeated once. All plants were kept at temperatures ranging between 5 and 26°C and watered as needed. Inoculated plants developed symptoms of leaf yellowing within 13 days, soon followed by the appearance of white mycelium, and eventually wilted. Control plants remained symptomless. White mycelium and sclerotia developed on infected tissues and S. sclerotiorum was reisolated from inoculated plants. To our knowledge, this is the first report of white mold of Thymus × citriodorus caused by S. sclerotiorum. The economic importance of this disease for the crop can be considered low. Reference: (1) N. F. Buchwald. Den. Kgl. Veterin.er-og Landbohojskoles Aarsskrift, 1949.

Download Full-text

First Report of Sclerotinia sclerotiorum on Gazania sp. Hybrid in Italy

Plant Disease ◽

10.1094/pdis.2001.85.11.1207d ◽

2001 ◽

Vol 85 (11) ◽

pp. 1207-1207

Author(s):

A. Garibaldi ◽

A. Minuto ◽

G. Gilardi ◽

M. L. Gullino

Keyword(s):

Sclerotinia Sclerotiorum ◽

Soil Surface ◽

Soft Rot ◽

The United States ◽

Crown Rot ◽

First Report ◽

Initial Symptoms ◽

Leaf Yellowing ◽

Stem Necrosis ◽

Wheat Kernels

Gazania sp. hybrid is produced in pots in the Albenga Region of northern Italy for export to central and northern Europe. During fall 2000 to spring 2001, sudden wilt was observed in commercial plantings of this ornamental. Initial symptoms included stem necrosis at the soil level and yellowing and tan discoloration of leaves. As stem necrosis progressed, infected plants wilted and died. Wilt followed by soft rot occurred within a few days on young plants after the first leaf symptoms. Necrotic tissues became covered with white mycelia that produced dark, spherical (2 to 6 mm diameter) sclerotia. Sclerotinia sclerotiorum was consistently recovered from infected stem pieces of Gazania disinfested for 1 min in 1% NaOCl, plated on potato dextrose agar amended with streptomycin sulfate at 100 mg/liter. Pathogenicity of three fungal isolates was confirmed by inoculating 45- to 60-day-old plants grown in containers (14 cm diameter). Inoculum that consisted of wheat kernels infested with mycelium and sclerotia of each isolate was placed on the soil surface around the base of each plant. Noninoculated plants served as controls. All plants were maintained outdoors where temperatures ranged between 8 and 15°C. Inoculated plants developed symptoms of leaf yellowing, followed by wilt, within 7 to 10 days, while control plants remained symptomless. White mycelia and sclerotia developed on infected tissues, and S. sclerotiorum was reisolated from inoculated plants. To our knowledge, this is the first report of wilt of Gazania sp. hybrid caused by S. sclerotiorum in Italy. A crown rot of Gazania caused by S. sclerotiorum has been reported from California in the United States(1). Reference: (1) V. M. Muir and A. H. McCain. Calif. Plant Pathol. 16:1, 1973.

Download Full-text

First Report of White Mold Caused by Sclerotinia sclerotiorum on Faba Beans in North Dakota

Plant Disease ◽

10.1094/pdis-12-17-1954-pdn ◽

2018 ◽

Vol 102 (8) ◽

pp. 1669-1669 ◽

Cited By ~ 1

Author(s):

V. Chapara ◽

K. Chittem ◽

L. E. del R. Mendoza

Keyword(s):

North Dakota ◽

Sclerotinia Sclerotiorum ◽

White Mold ◽

First Report ◽

Faba Beans

Download Full-text

First Report of Soybean mosaic virus on Soybean in North Dakota

Plant Disease ◽

10.1094/pdis-93-7-0760c ◽

2009 ◽

Vol 93 (7) ◽

pp. 760-760 ◽

Cited By ~ 1

Author(s):

B. D. Nelson ◽

L. L. Domier

Keyword(s):

North Dakota ◽

Mosaic Virus ◽

Soybean Mosaic Virus ◽

Oilseed Crop ◽

Rt Pcr ◽

High Concentration ◽

Grid Pattern ◽

First Report ◽

History Of ◽

Das Elisa

Soybean, Glycine max L, is grown on 1,420,000 ha in North Dakota and is the most important oilseed crop in the state. Viruses in soybean have not previously been reported from North Dakota (2). In July and August of 2007, 64 soybean fields in Cass, Richland, and Sargent counties in southeastern North Dakota were surveyed for Soybean mosaic virus (SMV). These counties have a high concentration of soybean hectares, a long history of soybean production, and soybean aphid infestations that were observed in 2004 and 2006. Fields were sampled with a grid pattern across the area with at least 8 km (5 miles) between fields. A transect of approximately 60 m through each field was made and 20 leaves were collected at random. Sap was extracted in phosphate buffer and stored at –80°C until tested first using double antibody sandwich (DAS)-ELISA with positive controls and reagents and protocol from Agdia Inc. (Elkhart, IN). Using DAS-ELISA, SMV was detected in 19 of the 64 soybean fields sampled. To confirm the presence of SMV, 12 samples that were positive for SMV by DAS-ELISA also were tested by reverse transcription (RT)-PCR. RNA was extracted from sap by a Qiagen RNeasy Plant Mini Kit (Germantown, MD), reverse transcribed, and amplified with SuperScrip III Platinum SYBR Green One-Step qRT-PCR Kit (Invitrogen Inc., Carlsbad, CA) and SMV-specific primers (5′-TTCAGCACAATGGGTGAGGATG-3′ and 5′-AATTCTGTGTGGCTTGATGTTGC-3′) (1). Eight of the twelve ELISA-positive samples were positive for SMV by RT-PCR, confirming the presence of SMV in the samples. To our knowledge, this is the first report of SMV infecting soybean in North Dakota. References: (1) L. L. Domier et al. (Abstr.). Phytopathology 98(suppl.):S47, 2008. (2) B. D. Nelson and G. Danielson. (Abstr.). Phytopathology 95(suppl.):S164, 2005.

Download Full-text

First Report of White Mold Caused by Sclerotinia sclerotiorum on Hutchinsia alpina in Italy

Plant Disease ◽

10.1094/pdis.2004.88.9.1045a ◽

2004 ◽

Vol 88 (9) ◽

pp. 1045-1045

Author(s):

A. Garibaldi ◽

A. Minuto ◽

M. L. Gullino

Keyword(s):

Sclerotinia Sclerotiorum ◽

Soil Surface ◽

Planting Density ◽

White Mold ◽

First Report ◽

Inoculation Trial ◽

Leaf Yellowing ◽

Commercial Farms ◽

White Mycelium ◽

Wheat Kernels

Hutchinsia alpina (Chamois cress), a plant belonging to the Brassicaceae family, is cultivated as a potted ornamental plant in Italy. In the winter of 2002, leaves and stems of plants grown in pots (14-cm diameter) in commercial farms near Albenga (northern Italy) developed soft and watery tissues covered with whitish mycelium at the soil line. As necrosis progressed, infected plants wilted and died. Dark sclerotia developed on infected tissues. Because of high planting density, the infection spread very rapidly. Sclerotinia sclerotiorum was consistently recovered from infected stem pieces of H. alpina disinfested 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 ppm of streptomycin sulfate. Sclerotia produced on PDA were ellipsoid and measured 1.3 to 9.3 × 1.3 to 4.5 mm (average 3.9 × 2.8 mm) (1). Pathogenicity of three isolates obtained from infected plants grown in a single greenhouse was confirmed by inoculating 90-day-old plants grown in pots (14 cm). Inoculum that consisted of wheat kernels infested with mycelium and sclerotia of each isolate were placed on the soil surface around the base of each of 10 plants. Plants treated with plain wheat kernels served as controls. The inoculation trial was repeated once. All plants were kept at temperatures ranging between 5 and 26°C and watered as needed. Inoculated plants developed symptoms of leaf yellowing, followed by the appearance of white mycelium within 15 days, and eventually wilted while control plants remained symptomless. White mycelium and sclerotia developed on infected tissues, and S. sclerotiorum was reisolated only from inoculated plants. To our knowledge, this is the first report of white mold on Hutchinsia alpina caused by S. sclerotiorum. Reference: (1) N. F. Buchwald. Den. Kgl. Veterin.er-og Landbohojskoles Aarsskrift, 1949.

Download Full-text