• Mycobiology
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• v.31 no.1
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• pp.57-59
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• 2003

A leaf spot of cotton rose(Hibiscus mutabilis) occurred severely in the flower beds of cotton rose around Uiryeong-gun, Gyeongnam Province in Korea. The causal fungus was identified as Corynespora cassiicola on the basis of cultural and morphological characteristics of the fungus. The fungus grew well on potato dextrose agar and the colony color was gray to brown. Conidia were solitary or catenate, obclavate to cylindrical in shape, and pale olivaceous brown or brown in color. They had 420 pseudosepta, and measured $35.2{\sim}173.6{\times}8.8{\sim}19.9{\mu}m$. Conidia germinated as a bipolar type. Conidiophores were pale to mid brown in color, and measured $74.2{\sim}275.6{\times}3.8{\sim}10.8{\mu}m$. Optimal temperature for mycelial growth was $30^{\circ}C$. The fungal isolate grown on PDA showed strong pathogenicity to cotton rose plant. This is the first report on the corynespora leaf spot of cotton rose(Hibiscus mutabilis) caused by Corynespora cassiicola in Korea.

• The Plant Pathology Journal
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• v.17 no.3
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• pp.180-183
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• 2001

A corynespora leaf spot of pepper, which has not been reported previously in Korea, occurred severely at the major pepper cultivation area of Chinju, Gyeongnam province in 2001. Infection rate ranged from 48.2 to 84.7% in eight fields surveyed. The causal fungus was identified as Corynespora cassicola based on the following cultural and morphological characteristics. The fungi grew well on potato dextrose agar, showing gray to brown color with cultural age. Conidia formed solitary or catenary were obclavate to cylindrical in shape, and pale olivaceous brown or brown in color. They had 420 pseudoseptate and isthmus, and measured 42.7-197.6 x 9.3-$23.5\mu\textrm{m}$. Septate conidiophores were pale to light brown in color, and measured 116.5-836.0 x 4.2-$11.0\mu\textrm{m}$. Conidia germinated as a bi-polar type. Optimal temperature for mycelial growth and conidial germination was $30^{\circ}$ and 25-$30^{\circ}$, respectively. The fungus showed strong pathogenicity to pepper plant, and the symtoms on pepper by the artificial inoculation were similar to those observed in the field. This is the first report on the corynespora leaf spot on pepper (Capsium annuum) caused by Corynespora cassicola in Korea.

• The Plant Pathology Journal
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• v.21 no.2
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• pp.164-166
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• 2005

Corynespora leaf spot occurred severely on balsam pear (Momordica charantia) at Changwon, Gyeongnam province in Korea in November and December 2003. The causal fungus isolated from infected leaves of the plants grew well on potato dextrose agar showing gray to brown color. Solitary or catenary conidia of the fungus were obclavate to cylindrical in shape, and pale olivaceous brown or brown in color. The number of isthmus pseudosepta ranged from 4 to 20 and measured 36~186${\times}$8~19 ${\mu}m$ in size. Conidiophores were pale to light brown in color and measured 94~648${\times}$3~8 ${\mu}m$ in size. Optimal temperature for mycelial growth was $30{\circ}C$. On the basis of mycological characteristics and pathogenicity, the fungus was identified as Corynespora cassiicola (Berk. & Curt.) Wei. This is the first report on the corynespora leaf spot of M. charantia caused by C. cassiicola in Korea.

• Research in Plant Disease
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• v.10 no.2
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• pp.121-125
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• 2004

An epidemic of target leaf spot of cucumber (Cucumis sativus) occurred in commercial greenhouses in Korea in 2000/2001. The early symptoms on the leaves were small brown spots with yellow halos. These lesions became irregular enlarging in diameter and eventually defoliation resulted. The causal agent was a fungus with morphological characteristics matching Corynespora cassiicola. The sequence of the ITS region of C. cassiicola CM2000-1 was identical to that of an authentic strain of Corynespora cassiicola. Optimal germination of spores and mycelial growth on plate was at 3$0^{\circ}C$. A long dew period on the leaf surface and high temperatures were the main contributing factors for disease development and the greenhouse epidemic. Artificial inoculation of the Korean isolate of C. cassiicola revealed resistance in some Korean cucumber cultivars.

• The Korean Journal of Mycology
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• v.19 no.1
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• pp.74-78
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• 1991

A species of Corynespora was isolated from red-brown spots developed on leaves of soybean. The fungus was identified as Corynespora cassiicola and proved to be pathogenic to soybean plants. Growth of this fungus in vitro was optimal at $27^{\circ}C$, and poor at lower than 19 and higher than $35^{\circ}C$. Sporulation was abundant on the potato dextrose malt agar and moderate on V-8 juice agar and potato dextrose agar, The relative susceptibility of several soybean cultivars to Corynespora cassiicola was evaluated in the greenhouse. Cultivar Hwangkum of soybeans appered to be resistant to C cassiicola and other cultivars were susceptible or moderately resistant.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2005.04a
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• pp.45.1-45
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• 2005

• Research in Plant Disease
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• v.19 no.1
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• pp.55-59
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• 2013

The purpose of this experiment was to investigate the development of new spot disease on the leaf and stem of rosemary (Rosmarinus officinalis) in commercial greenhouses at Jeonju and Namwon in Korea. Incidence of target spot on rosemary was higher at the end of the rainy season with high humidity. Those symptoms were black ring spots (3-5 mm in diameter) and withering on green leaves and stems. Conidiophores and conidia were formed on the infected tissue in moist chamber and conidia were shown as the cylindrical and oval types in chain, ranged from 55 to $275{\mu}m$ in length, and 7 to $14{\mu}m$ in width. Conidia with eight to ten pseudosepta were formed on the conidiapore. The optimum growth temperature of isolates was $30^{\circ}C$ on the PDA medium under the dark condition. In the pathogenesis test, the target spot and withering symptoms were appeared on the leaves and stems 3 days after inoculation showing similar symptoms compared to those of in nature. The same fungus was re-isolated from infected lesion, indicating that Corynespora cassiicola caused leaf target spot and twig blight on rosemary. The rDNA ITS nucleotide sequences of the pure cultured isolate from the diseased area on rosemary showed 100% similarity to the sequences of C. cassiicola available in the GenBank database (JQ595296, JQ595297, FJ852715 and AY238606). Therefore, we report that the target spot of leaves and stems in rosemary was caused by C. cassiicola.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.25-27
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• 2003

Since 1993, a total of 50 problematic plant diseases unrecorded in Korea were surveyed in Gyeongnam province. Totally 34 new host plants to corresponding pathogens investigated in this study were 5 fruit trees, 9 vegetables, 12 ornamental plants, 3 industrial crops, and 5 medicinal plants. Among the newly recorded fruit tree diseases, fruit rot of pomegranate caused by Coniella granati and Rhizopus soft rot of peach caused by Rhizopus nigricans damaged severely showing 65.5% and 82.4% infection rate. Among the vegetable diseases, corynespora leaf spot of pepper caused by Corynespora cassiicola and the crown gall of pepper caused by Agrobacterium tumefaciens, powdery mildew of tomato caused by Oidiopsis taurica were the most severe revealing 47.6%, 84.7%, and 54.5% infection rate in heavily infected fields, respectively. In ornamental plants, collar rot of lily caused by Sclerotium rolfsii, gray mold of primula caused by Botrytis cinerea, soot leaf blight of dendrobium caused by Pseudocercospora dendrobium, sclerotinia rot of obedient plant caused by Sclerotinia sclerotiorum showed 32.7 to 64.8% disease incidence. On three industrial plants such as sword bean, broad bean, and cowpea, eight diseases were firstly found in this study. Among the diseases occurring on broad bean, rust caused by Uromyces viciae-fabae and red spot caused by Botrytis fabae were the major limiting factor for the cultivation of the plant showing over 64% infection rate in fields. In medicinal plants, anthracnose of safflower caused by Collectotrichum acutatum was considered the most severe disease on the plant and followed by collar rot caused by Sclerotium rolfsii.(중략)

• The Plant Pathology Journal
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• v.17 no.6
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• pp.378.2-378
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• 2001

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.90.1-90
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• 2003

Colonization of Pseudomonas chlororaphis O6, a nonpathogenic rhizobacterium, on the roots induced systemic resistance in cucumber plants against tai-get leaf spot, a foliar disease caused by Corynespora cassiicola. A cDNA library was constructed using mRNA extracted from the cucumber leaves 12 h after inoculation with C. cassiicola, which roots had been previously treated with O6. To identify the genes involved in the O6-mediated induced systemic resistance (ISR), we employed a subtractive hybridization method using mRNAs extracted from C cassiicola-inoculated cucumber leaves with and without previous O6 treatment on the plant roots. Differential screening of the cDNA library led to the isolation of 5 distinct genesencoding a GTP-binding protein, a putative senescence-associated protein, a galactinol synthase, a hypersensitive-induced reaction protein, and a putative aquaporin. Expressions of these genes are not induced by O6 colonization alone. Before challenge inoculation, no increase in the gene transcriptions could be detected in previously O6-treated and untreated plants but, upon subsequent inoculation with the pathogenic fungus, transcription levels in O6-treated plants rose significantly faster and stronger than in untreated plants. Therefore, the O6-mediated ISR may be associated with an enhanced capacity for the rapid and effective activation of cellular defense responses which becomes apparent only after challenge inoculation on the distal, untreated plant parts, as suggested by Conrath et al. (2002). This work was supported by a grant R11-2001-092-02006-0 from the Korea Science and Engineering Foundation through the Agricultural Plant Stress Research Center at Chonnam National University.