• Research in Plant Disease
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• v.9 no.1
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• pp.47-51
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• 2003

Sclerotinia rot of C. japonica caused by Sclerotinia sclerotiorum was observed throught the growing season in the vinylhouse at the Namyangiu, Yangju and Yangpyung areas. The disease was commonly occurred at late autumn after transplanting and continuously increased until spring in next year, The disease was especially severe at the Yangpyung area among three areas. Three isolates of S. sclerotiorum obtained from C. japonica in different geographic areas were evaluated for ability of sclerotia formation and viability under different temperature. Temperature for mycelial growth ranged from 5 to 3$0^{\circ}C$, with optimum temperature at 15~3$0^{\circ}C$. Sclerotia were fewer formed at low temperature, but their size was larger than that at high temperature. Small size of sclerotia was more viable than those of large size at high temperature. Based on the differences in viability of sclerotia, the relative ranks of sclerotia were in order ~2 mm > 3~4 mm > 5 mm~.

• Mycobiology
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• v.29 no.3
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• pp.154-159
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• 2001

Natural sclerotium formation in two species of Curvularia was observed. The sclerotia were spherical to elongated. The scanning electron microscopical observations of sclerotia revealed that the sclerotia were of two distinct layers of cells, outer loosely woven hyphae and inner contact layer of cells. Different lights, viz. red, blue, green, fluorescent or addition of culture filtrate of Sclerotium rolfsii in the medium did not affect sclerotium formation.

• Korean journal of applied entomology
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• v.15 no.3 s.28
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• pp.153-159
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• 1976

Present paper was attempted to investigate the effects of the light on the sclerotium formation of some isolates of Sclerotinia sclerotiorum(Lib.) do Bary from lettuce, cucumber and rape. The investigations were performed in the both aspects inducing sclerotial primordia from the mycelial colony and developing such primordia. The cultures were grown on potato-dextrose agar and were treated with day-light fluorescent lamps. In the continuous light illumination for 21 days, numbers of sclerotial primordia and matured sclerotia were increased with increasing the light intensity up to about 500 Lux, but on the contrary the dry-weight of matured sclerotia was decreased. In the 800 Lux illumination, induction of the primordia was extremely depressed, and then matured sclerotia were almost not produced. Short-time illumination for 48 hours, although the light intensity was as high as 5000 Lux, increased the numbers of sclerotial primordia and matured sclerotia. Dry-weight of matured sclerotia, however, was slightly increased only at low intensity of 160 Lux. On the other hand, the light shock which u·as alternatively on-of light every one minute for 48 hours increased the number and dry-weight of sclerotia produced, but the former was more effective at 500 Lux shock and the later more effective at 160 Lux shock.

• Mycobiology
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• v.33 no.1
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• pp.1-6
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• 2005

Morphological characteristics of hyphal interaction between Grifola umbellata (Pers. Ex Fr.) Pilat and its companion fungus which related to sclerotia formation from hyphae were investigated by external observations, light microscopy and transmission electron microscopy (TEM). External observations showed that a dense antagonism line was formed by both G. umbellata and companion fungus after their hyphae contacted each other in dual culture. Many hyphal strands emerged on the colony of G. umbellata and differentiated to sclerotia from where hyphal strands crossed. Light microscope observations revealed the process of antagonism line formation. Mature antagonism with structural differentiation, was composed of three main layers: the rind, the rind underlayer and the hypha layer. TEM observations showed that after colonies hyphal contact, a series of reactions always occurred in both G. umbellata and companion fungus. Cells in the center of antagonism line were dead. Cells of G. umbellata adjacent to the antagonism line were usually large and hollow, with unilateral thickened wall, whereas those of companion fungus were empty, with thin or thick wall. Both hyphal interaction at the antagonism line may be one of the main reasons for sclerotia of G. umbellata differentiation from hypha.

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.296-300
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• 1998

When medicinal mushroom, Poria cocos, is cultured , inoculation method of spawn is cross slice inoculation of which the both sides of pine tree were peeled and spawn of P.cocos was inoculated. However, this method required lots of inoculation amount. This study was carried out to improve the culturing method of P. cocos. A good growth of P.cocos was observed in MCM(mushroom complete medium), showing proper mycelia growth and density. In inoculation amount, conventional method(cross slice inoculation) requires 20 bottles of spawn. In contrast, short log method required 8 bottles of spawn and drilling inoculation method 2~3 bottles, which could save by 60% and 85-90% respectively. In the selectrion of tree species, pine and larch had better condition for spawn culture and sclerotia formation condition.In terms of yield , pine was 33.7kg/3.3$m^2$. In the yield of pine, conventional method was 23.4kg/3.3$m^2$, drilling inoculation 29.4kg/3.3$m^2$, short log inoculation 31.7kg/3.3$m^2$, therefore drilling inoculation could increase by 25% and short log inoculation 35%, In addition, management cost was also saved.

• The Plant Pathology Journal
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• v.23 no.3
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• pp.212-214
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• 2007

In 2005 and 2007, a basal stem rot of Disporum smilacinum caused by Sclerotium rolfsii occurred sporadically in a herb farm at Hamyang, Korea. The symptom initiated with water-soaking lesion and progressed into stem rot and wilt of a whole plant. Severely infected plants were blighted and died eventually. White mycelial mats appeared on the lesion at early stage and a number of sclerotia were formed on the stem near the soil line. The sclerotia were globoid in shape, 1-3 mm in size and white to brown in color. The optimum temperature for the growth and sclerotia formation was 30 on PDA and the hyphal width was measured $3-8{\mu}m$. The typical clamp connections were observed in the hyphae of the fungus grown on PDA. On the basis of symptom, mycological characteristics and pathogenicity to the host plant, this fungus was identified as Sclerotium rolfsii Saccardo. This is the first report on the stem rot of D. smilacinum caused by S. rolfsii in Korea.

• Mycobiology
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• v.39 no.3
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• pp.230-232
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• 2011

In this study, we characterized sporadically occurring sclerotium rot caused by Sclerotium rolfsii in Chinese chive (Allium tuberosum Roth.) in farm fields in Sacheon, Korea. The initial symptom of the disease was water-soaked, which progressed to rotting, wilting, blighting, and eventually death. Further, mycelial mats spread over the lesions near the soil line, and sclerotia formed on the scaly stem and leaves. The sclerotia were globoid, 1~3 mm, and white to brown. The optimum temperature for growth and sclerotia formation on potato dextrose agar (PDA) was $30^{\circ}C$. The diameter of the hypae ranged from 4 to 8 ${\mu}m$. Clamp connection was observed on PDA medium after 5 days of incubation. Based on the mycological characteristics, internal transcribed spacer sequence analysis, and pathogenicity test, the causal agent was identified as Sclerotium rolfsii Saccardo. This is the first report of sclerotium rot in Chinese chive caused by S. rolfsii in Korea.

• Mycobiology
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• v.38 no.2
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• pp.156-158
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• 2010

Stem rot disease was found in garlic (Allium sativum L.) cultivated from 2008 to 2010 in the vegetable gardens of some farmers in Geumsan-myon, Jinju City, Gyeongnam province in Korea. The initial symptoms of the disease were typical water-soaked spots, which progressed to rotting, wilting, blighting, and eventually death. White mycelial mats had spread over the lesions near the soil line, and sclerotia had formed over the mycelial mats on the stem. The sclerotia were globoid in shape, 1~3 mm in size, and tan to brown in color. The optimum temperature for growth and sclerotia formation on potato dextrose agar (PDA) medium was $30^{\circ}C$. The diameter of the hyphae ranged from approximately 4 to $8\;{\mu}m$. Typical clamp connection structures were observed in the hyphae of the fungus, which was grown on PDA medium for 4 days. On the basis of the mycological characteristics and pathogenicity of the fungus on the host plants, the causal agent was identified as Sclerotium rolfsii Saccardo. This is the first report of stem rot disease in garlic caused by S. rolfsii in Korea.

• Mycobiology
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• v.37 no.2
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• pp.158-159
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• 2009

In 2007 to 2008, a fruit rot of Melon (Cucumis melo L.) caused by Sclerotium rolfsii occurred sporadically in a farmer's vinyl house in Jinju City. The symptoms started with watersoaking lesion and progressed into the rotting of the surface of fruit. White mycelial mats appeared on the lesion at the surface of the fruit and a number of sclerotia formed on the fruit near the soil line. The sclerotia were globoid in shape, 1${\sim}$3 mm in size, and white to brown in color. The hyphal width was measured 3 to 8 ${\mn}$. The optimum temperature for mycelial growth and sclerotia formation was 30 on PDA. Typical clamp connections were observed in hyphae of grown for 4 days on PDA. On the basis of symptoms, mycological characteristics and pathogenicity to the host plant, this fungus was identified as Sclerotium rolfsii Saccardo. This is the first report of the fruit rot of Melon caused by S. rolfsii in Korea.

• The Korean Journal of Mycology
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• v.26 no.3 s.86
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• pp.396-398
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• 1998

This study was carried out to obtain the basic data for artificial production of Polyporus umbellatus. Among logs consisted of 16 tree species, the log of Stylax japonica inoculated with Polyporus umbellatus not only produced compact sclerotia of $3{\sim}5\;mm$ in their diameters but resulted in the good mycelial density. Also, the sclerotia were observed on 6 different kinds of logs inoculated with Polyporus umbellatus.