scholarly journals First Report of Charcoal Rot of Sugar Beet Caused by Macrophomina phaseolina in Greece

Plant Disease ◽  
2002 ◽  
Vol 86 (9) ◽  
pp. 1051-1051 ◽  
Author(s):  
D. A. Karadimos ◽  
G. S. Karaoglanidis ◽  
K. Klonari
Keyword(s):  
Sugar Beet ◽  
Root Rot ◽  
Pathogenic Fungi ◽  
Macrophomina Phaseolina ◽  
Northern Greece ◽  
Charcoal Rot ◽  
First Report ◽  
Yellow Mustard ◽  
External Part ◽  
Sugar Beet Crop

During the summer of 2000 in the Amyndeon area of northern Greece, sugar beet (Beta vulgaris L.) roots with rot symptoms were observed in many fields. Initially, the plants wilted, and leaves soon turned brown and died. Diseased plants appeared in patches in the field. Brown-black lesions were observed in the external part of the root crown while yellow-mustard colored lesions occurred internally. In advanced stages of decay, masses of sclerotia formed in rotted cavities and roots became mummified. Macrophomina phaseolina (Tassi) Goid. (1) was isolated on potato dextrose agar (PDA) from 30 rotted roots collected in five fields. Cultures produced dark multi-septate mycelium and sclerotia, which were black, smooth, spherical to irregular in shape, and varied in size from 100 μm to 1mm in diameter. Five isolates were evaluated for pathogenicity on surface-sterilized 16-week-old sugar beet roots (cv. Rizor) by placing a 5-mm-diameter PDA plug of actively growing mycelium in wounds made with a sterile knife. Sterile PDA plugs were placed in wounds made in control beet roots. Ten roots were inoculated per isolate. Roots were kept at 25°C in the dark for 10 days. Extensive decay of inoculated roots developed, similar to decay observed in the field, and M. phaseolina was reisolated from rotted tissue. Control roots showed no decay. This pathogen has been previously reported as a root rot pathogen of sugar beet in California, India, and countries of the former USSR. Charcoal rot is of minor economic importance since M. phaseolina attacks mainly weakened plants under conditions of high temperature (2). To our knowledge, this is the first report of charcoal root rot of sugar beet in Greece. References: (1) Anonymous. Macrophomina phaseolina. No. 275 in: Descriptions of Plant Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1970. (2) J. E. Duffus and E. G. Ruppel. Diseases. Page 347 in: The Sugar Beet Crop. Science into Practice. D. A. Cooke and R. K. Scott eds. Chapman and Hall, NY, 1993.

scholarly journals First Report of Charcoal Rot Caused by Macrophomina phaseolina in Sunflower in Turkey

Plant Disease ◽  
2011 ◽  
Vol 95 (2) ◽  
pp. 223-223 ◽  
Author(s):  
A. Mahmoud ◽  
H. Budak
Keyword(s):  
Random Amplified Polymorphic Dna ◽  
Peat Soil ◽  
Pathogenic Fungi ◽  
Macrophomina Phaseolina ◽  
Vascular Bundles ◽  
Internal Transcribed Spacer Region ◽  
Charcoal Rot ◽  
First Report ◽  
Surface Sterilization ◽  
Lower Stem

Charcoal rot symptoms were observed on 2-month-old oilseed sunflower plants (Helianthus annuus L.) in the Eskişehir Province of Turkey in June 2009. The disease was observed in 70% of the fields surveyed and incidence ranged from 10 to 50%. Symptoms were first observed in plants approaching physiological maturity and consisted of silver-gray lesions girdling the stem at the soil line, reduced head diameter compared with noninfected plants, and premature plant death. Pith in the lower stem was completely absent or compressed into horizontal layers. Black, spherical microsclerotia were observed in the pith area of the lower stem, underneath the epidermis, and on the exterior of the taproot. The internal stem had a shredded appearance. Later, the vascular bundles became covered with small, black flecks or microsclerotia of the fungus. Forty plant samples were collected from 10 fields. After surface sterilization with 2% NaOCl, outer tissues sampled from diseased tissues (2 to 3 mm long) of root and stems were removed and transferred to potato dextrose agar containing 250 mg liter–1 of chloramphenicol. Petri plates were incubated for 7 days at 26 ± 2°C in the dark. Ninety-eight percent of the fungal colonies were identified as Macrophomina phaseolina (Tassi) Goidanich based on gray colony color, colony morphology, and the size of the microsclerotia, which ranged from 80 to 90 μm in diameter, from both infected sunflowers and compared with pure cultures (3). All resulting cultures produced abundant microsclerotia. The only other sunflower pathogen known to form microsclerotia is Verticillium dahliae Kleb., whose microsclerotia are irregular in shape and 15 to 50 μm in diameter. Sequence-related amplified polymorphisms technique was used for diversity of M. phaseolina since it has proven to be more informative than amplified fragment length polymorphism, random amplified polymorphic DNA, and simple sequence repeat (2). Results showed a high level of genetic diversity (60%) among the 26 isolates of M. phaseolina. Sequencing of the internal transcribed spacer region (1) showed high homology (>96%) to M. phaseolina (GenBank Accession No. HQ380051). Pathogenicity tests for 20 isolates of M. phaseolina were carried out on three commercially used cultivars, SANAY, TUNCA, and TR-3080. Groups of 10 seedlings were grown separately in an autoclaved peat/soil mixture in 30-cm-diameter plastic pots in a greenhouse at 30 ± 2°C. Soil infestation was performed 1 day before sowing. Two-week-old cultures on barley medium (4) were blended in distilled sterile water and adjusted to 105 sclerotia ml–1. Each pot received 250 ml of inoculant. Each treatment had three replications. Three pots for each cultivar were left uninoculated. Within 3 weeks, five to seven inoculated plants in each pot died. Identical disease symptoms were observed 30 days after inoculation; on the control plants no symptoms were observed. Microsclerotia were produced after 7 weeks at the stem base on 85% of the surviving plants. To our knowledge, this is the first report of M. phaseolina in sunflower in Turkey. References: (1) B. D. Babu et al. J. Plant Dis. Prot. 96:797, 2007. (2) H. Budak et al. Theor. Appl. Genet. 109:280, 2004. (3) P. Holliday and E. Punithalingam. No. 275 in: Description of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1970. (4) M. R. Omar et al. J. Plant Dis. Prot. 114:196, 2007.

scholarly journals First Report of Crown and Root Rot in Strawberry Caused by Macrophomina phaseolina in Israel

Plant Disease ◽  
2005 ◽  
Vol 89 (9) ◽  
pp. 1014-1014 ◽  
Author(s):  
A. Zveibil ◽  
S. Freeman
Keyword(s):  
Root Rot ◽  
Fungal Pathogens ◽  
Macrophomina Phaseolina ◽  
Crown Rot ◽  
Plant Mortality ◽  
Charcoal Rot ◽  
First Report ◽  
Production Stages ◽  
Pure Cultures ◽  
Pathogenicity Assay

A phenomenon of wilting in strawberry (Fragaria × ananassa Duchesne) transplants, cultivated for annual winter production, was observed on several cultivars at 14 farmers' plots in nine growing regions in Israel during September and October 2004. Typical ‘charcoal rot’ symptoms included necrotic root and crown rot accompanied by plant wilting and chlorosis of leaves (1). Pure cultures of Macrophomina phaseolina were isolated from affected roots and crowns of plants (1) when incubated at 25°C in the dark on potato dextrose agar (PDA) (Difco Laboratories, Sparks, MD) medium containing 250 mg/l of chloramphenicol. Dark, oblong sclerotia averaging 40 μm wide by 200 μm long were observed in the infected root tissue and in culture 7 to 10 days after isolation (2). Twenty-two single sclerotium isolates were recovered from five infected cultivars (Yuval, Herut, Tamar, Hadas, and Malach) and three representative isolates were used in two pathogenicity assays. Inoculum of M. phaseolina was produced by blending 3-week-old cultures on PDA plates (9 cm diameter) in 100 ml of sterile distilled water, filtering the suspension through eight layers of gauze, and adjusting the concentration to 105 sclerotia per ml. In the first pathogenicity assay, each of the three isolates was inoculated on five plants (cv. Malach). Plants were produced from nursery runners and potted in a soilless coconut and styrofoam (3:1 vol/vol) medium, 1 liter per pot. Each plant was inoculated by pouring 50 ml of sterile water containing 105 sclerotia per ml per pot. Plants were incubated at 30°C with 12-h day/night conditions and watered with 100 ml every 3 to 7 days. Five noninoculated control plants were included. Necrosis at the base of petioles and chlorosis of leaves, followed by initial wilting of leaves, were observed after 2 weeks on inoculated plants. Plant mortality was first recorded approximately 5 weeks after inoculation and 100% mortality was recorded 10 weeks postinoculation. In the second pathogenicity assay, the same three isolates were used to inoculate four plants each of two different cultivars (Malach and Hadas) as described previously. Identical disease symptoms, as described previously, were observed 17 days after inoculation. Initial plant mortality was observed approximately 6 weeks postinoculation. In both pathogenicity assays, M. phaseolina was readily reisolated on amended PDA from all symptomatic and dead plants, which successfully completed Koch's postulates. Noninoculated control plants remained healthy. Although M. phaseolina has been reported in other crops in Israel, to our knowledge, this is the first report of the pathogen on strawberry in our country. This study suggests that the current soil fumigation regimen for control of fungal pathogens such as M. phaseolina, utilizing alternatives to methyl bromide which is currently being phased out in Israel, may not be adequate to maintain healthy strawberry material at all production stages. A similar observation was recently reported in Florida (2). Charcoal rot of strawberry has also been recorded on strawberry in France, India, and Egypt (1). References: (1) J. Maas. Macrophomina leaf blight and dry crown rot and Macro-phomina root rot and charcoal rot. Pages 26 and 59 in: Compendium of Strawberry Diseases. 2nd ed. J. L. Maas, ed. The American Phytopathological Society, St. Paul, MN, 1998. (2) J. Mertely et al. Plant Dis. 89:434, 2005.

scholarly journals First Report of Root Rot Caused by Macrophomina phaseolina on Atractylodes lancea in China

Plant Disease ◽  
2020 ◽  
Vol 104 (11) ◽  
pp. 3081-3081
Author(s):  
Lin Cai ◽  
Yongzhi Zhang ◽  
Hancheng Wang ◽  
Chen Xu ◽  
Xianchao Sun
Keyword(s):  
Root Rot ◽  
Macrophomina Phaseolina ◽  
First Report ◽  
Atractylodes Lancea

scholarly journals First Report of Charcoal Rot in Tomato Caused by Macrophomina phaseolina (Tassi) Goid. From Pakistan

Plant Disease ◽  
2018 ◽  
Vol 102 (7) ◽  
pp. 1459 ◽  
Author(s):  
S. Hyder ◽  
A. S. Gondal ◽  
R. Ahmed ◽  
S. T. Sahi ◽  
A. Rehman ◽  
...  
Keyword(s):  
Macrophomina Phaseolina ◽  
Charcoal Rot ◽  
First Report

scholarly journals First report of charcoal rot caused by Macrophomina phaseolina on kiwifruit in Turkey

2019 ◽  
Vol 102 (2) ◽  
pp. 535-535
Author(s):  
Muharrem Türkkan ◽  
Halil İbrahim Benli ◽  
Özkan Yılmaz ◽  
Göksel Özer ◽  
Mehmet Yaman ◽  
...  
Keyword(s):  
Macrophomina Phaseolina ◽  
Charcoal Rot ◽  
First Report

scholarly journals Occurrence of Charcoal Rot Caused by Macrophomina phaseolina on Canola in Argentina

Plant Disease ◽  
2006 ◽  
Vol 90 (4) ◽  
pp. 524-524 ◽  
Author(s):  
S. A. Gaetán ◽  
L. Fernandez ◽  
M. Madia
Keyword(s):  
United States ◽  
Buenos Aires ◽  
Vascular Tissue ◽  
Disease Incidence ◽  
Pathogenic Fungi ◽  
Macrophomina Phaseolina ◽  
The United States ◽  
Buenos Aires Province ◽  
Charcoal Rot ◽  
Experimental Plots

Canola (Brassica napus) is an important oleaginous crop in Argentina. Approximately 16,000 ha are grown commercially in the southern region of Buenos Aires Province. In 2003, typical symptoms and signs of charcoal rot were observed on canola plants in experimental plots located at the School of Agricultural Sciences, University of Buenos Aires in Buenos Aires. Average disease incidence across three 5- to 6-month-old plants (cvs. Monty, Rivette, and Trooper) was 12% (range = 7 to 17%). Affected plants appeared in patches following the rows at pod-filling stage. Symptoms included wilted foliage, premature senescence, and death of plants. Black, spherical microsclerotia 78 to 95 μm in diameter were present in vascular tissue of basal stems and taproots. The affected plants were stunted and had unfilled pods. In advanced phases of the disease, areas of silver gray-to-black discoloration were observed in the stem cortex; many plants were killed during late-grain fill, and plants could be pulled easily from the ground because basal stems were shredded. Four samples consisting of five symptomatic plants per sample were randomly collected from experimental plots. Pieces (1-cm long) taken from taproots and basal stems of diseased plants were surface sterilized with 1% NaOCl for 2 min and then placed on potato dextrose agar (PDA). Plates were incubated in the dark at 26°C for 4 days and then exposed to 12-h NUV light/12-h dark for 6 days. Five resulting isolates were identified as Macrophomina phaseolina (Tassi) Goidanich (1) based on the gray color of the colony and the presence of microsclerotia 71 to 94 μm in diameter. Two colonies developed globose pycnidia with one-celled, hyaline, and elliptic conidia. Pathogenicity tests were conducted using four inoculated and three non-inoculated control plants potted in a sterilized soil mix (soil/sand, 3:1) in a greenhouse at 25°C and 75% relative humidity with no supplemental light. Crown inoculations were carried out by placing a disk taken from an actively growing culture of M. phaseolina into wounds made with a sterile scalpel. Control plants received disks of sterile PDA. Inoculated and control plants were covered with polyethylene bags for 48 h after inoculation. Three isolates caused disease on 7-week-old canola plants (cvs. Master, Mistral, Rivette, and Trooper). Characteristic symptoms similar to the original observations developed for all three isolates within 21 days after inoculation on 80% of inoculated plants. The pathogen was successfully reisolated from diseased stem tissue in all instances. Symptoms included leaf necrosis, stunting, decay and collapse of seedlings, and plant death. Control plants remained asymptomatic. The experiment was repeated once with similar results. To our knowledge, this is the first report of the occurrence of M. phaseolina causing charcoal rot on canola in Argentina. This pathogen has been previously reported in the United States (2,3). The results demonstrate the potential importance of this pathogen in Argentina, since two commercial cultivars (Master and Mistral) were apparently susceptible to M. phaseolina. More studies are needed to determine the presence of charcoal rot in canola-growing areas of Argentina. References: (1) Anonymous. Macrophomina phaseolina. No. 275 in: Descriptions of Plant Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1970. (2) R. E. Baird et al. Plant Dis. 78:316, 1994. (3) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989.

scholarly journals First Report of Phytophthora Root Rot of Sugar Beet, Caused by Phytophthora cryptogea, in Greece

Plant Disease ◽  
2000 ◽  
Vol 84 (5) ◽  
pp. 593-593 ◽  
Author(s):  
G. S. Karaoglanidis ◽  
D. A. Karadimos ◽  
K. Klonari
Keyword(s):  
Sugar Beet ◽  
Root Rot ◽  
Soil Extract ◽  
American Phytopathological Society ◽  
Phytophthora Root Rot ◽  
Phytophthora Cryptogea ◽  
First Report ◽  
Solid Media ◽  
Necrotic Spots ◽  
Extract Medium

A severe rot of sugar beet roots was observed in the Amyndeon area of Greece during summer 1998. Infected plants initially showed a temporary wilt, which became permanent, and finally died. Slightly diseased roots showed necrotic spots toward the base, whereas more heavily diseased roots showed a more extensive wet rot that extended upward. Feeder roots also were infected and reduced in number because of decay. Rotted tissue was brown with a distinguishing black margin. In most of the isolations, carried out on potato dextrose agar (PDA), the pathogen obtained was identified as Phytophthora cryptogea Pethybr. & Lafferty Mycelium consisted of fairly uniform, fine hyphae that showed a slightly floral growth pattern. In autoclaved soil-extract medium, chains or clusters of hyphal swellings (average 12 µm diameter) formed. Sporangia were not produced on solid media but were abundant in soil-extract medium. Sporangia were oval to obpyriform in shape, nonpapillate with rounded bases, and varied in size (39 to 80 × 24 to 40 µm). Oospores were plerotic, thick-walled, and averaged 25 µm in diameter. The isolated pathogen, cultured on PDA, could not grow at all at 36°C. The closely related species P. drechsleri Tucker has been reported to cause similar root rot symptoms on sugar beet (3). However, P. drechsleri grows well at 36°C, while P. cryptogea cannot grow at this temperature; this is the major distinguishing feature that separates the two species (1). To test the pathogenicity of the organism, surface-sterilized sugar beet roots (cv. Rizor) were inoculated with 5-mm-diameter PDA plugs containing actively growing mycelium. Sterile PDA plugs were used to inoculate control sugar beet roots. Inoculated roots were kept at 27°C in the dark for 10 days. Extensive decay of inoculated roots developed, similar to decay observed in the field, whereas control roots showed no decay. P. cryptogea was reisolated from rotted tissues. This pathogen has been recognized previously as a cause of root rot of sugar beet in Japan (1) and Wyoming (2). This is the first report of Phytophthora root rot of sugar beet in Greece. References: (1) D. C. Erwin and O. K. Ribeiro. 1996. Phytophthora Diseases Worldwide. The American Phytopathological Society, St. Paul, MN. (2) P. C. Vincelli et. al. Plant Dis. 74:614, 1990. (3) E. D. Whitnew and J. E. Duffus, eds. 1986. Compendium of Beet Diseases and Insects. The American Phytopathological Society, St. Paul, MN.

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