• The Plant Pathology Journal
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• 제22권3호
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• pp.211-214
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• 2006

In 2004 and 2005, Phytophthora rot on Luffa cylindrica which had not been reported in Korea occurred in the experimental field at Gyeongsangnam-do Agricultural Research and Extension Services. The disease initiated on leaves and fruits of the plant with small watersoaked dark brown spots and progressed rapidly. The causal pathogen isolated from diseased tissues was identified as a Phytophthora sp. because of aseptate mycelia and zoospores released directly from sporangia. The fungus grew well on PDA and 10% V-8 juice agar showing an arachnoid or rosaceous colony pattern. Sporangia formed abundantly in water and were conspicuously papillate, noncaducous, ovoid to globose, and sized $26\sim62\times19\sim38{\mu}m$. The fungus was heterothallic as producing sexual reproduction structures only when mated with only A2 standard mating type strain. Oogonia and oospores were spherical, smooth walled, and measured as $20\sim28{\mu}m\;and\;16\sim24{\mu}m$, respectively. Oospores were aplerotic and antheridia were amphigynous, unicellula and spherical. Chlamydospores were globose and $20\sim38{\mu}m$ in diameter. Optimum temperature for growth was around $28\sim30^{\circ}C$. The fungus caused similar symptoms on artificially inoculated plant and could be re-isolated thereby proving Koch's postulation. Based on the mycological criteria investigated in this study, the causal fungus of Luffa sylindrica rot was identified as Phytophthora nicotianae. This is the first report of Phytophthora rot of Luffa cylindrica caused by P. nicotianae in Korea.

• Journal of the Korean Wood Science and Technology
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• 제21권1호
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• pp.39-50
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• 1993

The purpose of this study was to describe the micromorphological changes in Korean red pine (Pinus densiflora S. et Z.) wood decayed by a major brown-rot fungus, Lentinus lepideus, using scanning electron microscope and transmission electron microscope. At the end of the 12-week exposure to the fungus in soil block procedure(ASTM 1971), test blocks sustained 5.02% weight loss. The formation of bore hole by hyphae and penetration of hyphae through bordered pit were not observed. Instead, fungal hyphae appeared to penetrate axially tracheid luminar from the the ray cells via cross field pits. Hyphae were mainly found in lignin rich cell corner regions of tracheids, and also extensive degradation of tracheid wall occurred in this region. Extensive degradation of $S_2$ layer occurred without noticeable alteration of the $S_3$ layer, but warty layer and compound middle lamella remained relatively intact. Localized erosion, the characteristic of white rot, was observed in some cell wall and wall components including lignin were found to be decomposed.

• The Plant Pathology Journal
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• 제23권3호
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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.

• The Plant Pathology Journal
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• 제19권2호
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• pp.79-84
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• 2003

Sclerotinia rot occurred severely on some vegetable crops grown in Namyangju, Yangpyung, and Yangiu areas in Korea in 2001-2002. The crops infected with Scterotinia sp. were Adenophora remotiflora, Armoracia lapathfolia, Angelica acutiloba, Angelica archangelica, Anthriscus sylvestris, Aster tataricus, Beta vulgaris var. cicla, Brassica campestris var. marinosa, Brassica juncea var. laciniata, Chicholium intybus, Lactuca indica var. dracoglossa, Lactuca sativa var. oak-leaf, Petroselinum crispum, and Phyteuma japonicum. The fungus associated with the disease was identified as Sclerotinia sclerotiorum, based on the morphological characteristics of the pathogen. The symptoms were water-soaked spots that enlarged later and became a watery soft rot. Infected parts became yellow and then turned brown, followed by death of the whole plant. White mycelia developed on the upper petioles and leaves and on the soil where these plant parts lay. Then black sclerotia in variable size and shape formed from the mycelial mass. Pathogenicity of the fungus was proven by artificially inoculating each crop. This is the first report of Sclerotinia rot on the listed vegetable crops in Korea.

• 식물병연구
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• 제16권3호
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• pp.323-325
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• 2010

2009년 9월 경상남도농업기술원 해바라기 재배포장에서 흰비단병이 발생되었다. 병징은 줄기 부분이 수침상으로 물러지고 부패되면서 병반부와 토양 표면에 흰색의 곰팡이가 솜털모양으로 생기고 갈색의 작은 둥근 균핵을 많이 형성하였다. 균핵의 크기는 1~3 mm이며 균사의 폭은 $4{\sim}8\;{\mu}m$이었다. 균사생육과 균핵형성의 적정온도는 $30^{\circ}C$이었다. 균사 특유의 clamp connection이 관찰되었다. 해바라기에 발생한 병징과 병원균의 균학적 특징 및 병원성을 검정한 결과, 이 병을 Sclerotium rolfsii에 의한 해바라기 흰비단병으로 명명하고자 제안한다.

• 한국균학회지
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• 제36권2호
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• pp.203-205
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• 2008

2006년에서 2008년까지 진주에서 재배중인 페튜니아에서 병이 발생하였다. 병징은 줄기와 잎이 수침상으로 물러지고 썩으면서 갈색으로 변하며 시들어 말라 죽었다. 줄기, 지제부 및 토양 표면에 솜털모양의 흰색 균사체가 생기고 $1{\sim}3\;mm$ 크기의 둥근 갈색 균핵을 많이 형성하였다. PDA배지 상에서 병원균의 균사 폭은 $4{\sim}8\;{\mu}m$이며 clamp connection이 형성되었고 균사생육과 균핵형성 적온은 $30^{\circ}C$이었다. 페튜니아에서 발생한 병징과 병원균의 균학적 특징 및 병원성을 기초로 본 병을 Sclerotium rolfsii Saccardo에 의한 페튜니아 흰비단병으로 명명하고자 제안한다.

• Mycobiology
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• 제38권2호
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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.

• 식물병연구
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• 제17권2호
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• pp.225-227
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• 2011

2009년 9월에 전북 완주군 상관면 조경포장에 재배중인 구절초의 줄기와 지제부위가 수침상으로 무르고 썩으면서 암갈색으로 시들어 말라 죽었다. 병반부와 지제부위의 토양 표면에 흰색의 균사가 자라고 갈색의 구형 또는 부정형의 균핵이 형성되었다. 균사의 생육적온은 $25{\sim}30^{\circ}C$이었으며, 균사의 폭은 4-9 ${\mu}m$이었고, 균핵의 크기는 0.8-3.5(평균 1.8) mm이었다. 균사특유의 clamp connection이 관찰되었다. 분리한 균은 구절초에 대한 실험결과 병원성이 인정되었다. 구절초에 발생한 병징과 분리균의 균학적 특징 및 병원성을 검정한 결과, 이 병을 Sclerotium rolfsii에 의한 구절초 흰비단병으로 명명하고자 한다.

• Journal of the Korean Wood Science and Technology
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• 제24권1호
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• pp.48-53
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• 1996

Brown rot fungus, Tyromyces palustris, has been reported to cause the loss of strength accelerated by oxalate, a non-enzymatic low molecular weight acid, with minute weight loss of decaying wood in early stage. The production of oxalate in relation to wood decaying and the presence of oxaloacetase. an oxalate producing enzyme, were identified during the process. Tyromyces palustris produced the largest amount of oxalate among brown rot fungi. In order to find out the cleavage of pulp fiber, we submerged pulp fiber in oxalate solution and the results showed that the number of short pulp fiber was highly increased, compared with control solution. The pH of decaying wood was decreased to 1.77 which was close to that of saturated oxalate solution, pH 1.2, Thus, the oxalate was thought to be accumulated in the decaying wood, The oxaloacetase which accelerates production of oxalate was derived from fungus, and the production of oxalate by the enzyme was determined by using on UV/Vis spectrophotometer. Therefore, the oxalate was found to be produced by oxaloacetase during decay. The oxalate may cause the acid-hydrolysis of cellulose and hemicellulose. The oxalate was thought to reduce the degree of polymerization and increase the enzyme activity, which resulted in rapid loss of strength in early stage-an identical feature of brown rot fungus.

• 한국식물병리학회지
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• 제10권3호
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• pp.175-180
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• 1994

The fungal pathogen Monosporascus annonballus was first isolated in Korea from the rotted roots of bottle gourd stocks of collapsed watermelon plants in fields near Chochiwon, Choongnam province in July, 1993. Perithecia of M. cannonballus were dark brown to black, globose, 220~570 ${\mu}{\textrm}{m}$ in diam. and had many asci. Asci are hyaline, clavate to pyriform, and 50~120$\times$35~570 ${\mu}{\textrm}{m}$ in size. Ascospores were aseptate, dark brown to black, globose, 25~45$\times$30~50 ${\mu}{\textrm}{m}$ in diam, and borne singly in each ascus. The fungus grew in the temperature range of 4 to 34$^{\circ}C$, best at 3$0^{\circ}C$. The optimum pH for growth was 6.8. Mycelial growth rate of M. cannonballus was 25.5mm/day on PDA at 26$^{\circ}C$. Perithecia began to form after 20-day-growth on PDA and produced mature asci after 30 days or later. In the greenhouse inoculation tests, the fungus developed water-soaked lesions on roots of bottle gourd seedlings and was then reisolated from the lesions. Severed damages on watermelon plants by M. cannonballus are greatly concerned in Korea, since no stocks used for watermelon cultivation have reported to be resistant to the fungus.