• Journal of Ginseng Research
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• v.20 no.1
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• pp.88-95
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• 1996

The effects of media, incubation time, temperature and pH on production of conidia and chlamydospore of Cylindrocarpon destructans (Zinssm.) Scholen causing root rot of Panax ginseng were studied. Microconidia of the pathogen were abundantly produced on V-8 juice agar as a solid substrate with 5.73(log conidia/mm2) and in V-8 broth as a liquid substrate with 6.65 (log conidia/ml) among media tested. No difference was observed on the length of microconidia produced from the media with a range of 9.50∼11.38 $\mu\textrm{m}$. However, tryptic soy agar produced the broadest microconidia (average 5.00 $\mu\textrm{m}$) among the media tested. All the media produced chlamydospores In a range of 1.06∼4.37 (log chlamydospores/mm2) without a significant difference in number, while V-8 juice agar produced the bigger one (18.39 $\mu\textrm{m}$ in diameter) as compared to the tested media. The fungus began to sporulate conidia after three days of incubation and reached maximum at the 8th day. It seemed to be in a stationary phase until 30 days of incubation but was decreased thereafter. Chlamydospore was produced at 4th day after incubation. Maximum production was observed at 8th day and the number seemed to be maintained during the observation period. Both conidia and chlamydospore of the pathogen were able to be spoluated at 10∼25$^{\circ}C$. However, optimum temperatures of conidia and chlamydospore formation were 15∼25$^{\circ}C$ and 10∼20$^{\circ}C$, respectively. C. destrmtans produced conida with an wide range of pH from 3.3 to 8.0 and chlamydospore from 2.8 to 8.0. Number of conidia was increased with an increase of pH up to 4.0. There was no significant difference in the number between 4.0 to 8.0. It seemed to have two optimum pH ranges, 3.3∼4.0 and 7.1∼8.0 for the chlamydospore formation.

• Journal of Ginseng Research
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• v.22 no.4
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• pp.304-309
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• 1998

Incubation condition affecting the chlamydospore formation and isolation from mycelia and conidia of Cylindrocarpon destructanse (isolate ACY-9701), isolated from the root rot lesion of the American ginseng (Panax quinquefolium) was investigated. Chlamydospores were formed from mycilia but not from conidia on the Czapek-Dox agar without carbon or nitrogen source after 20 days incubation at 2$0^{\circ}C$. In the medium added with nitrogen and carbon sources, immatured chlamy-dospore-like cells were formed from microconidia and mycelia as well. Immatured chlamydospore-like cells were formed from mycelia as well as microconidia In corn, kidney bean, and pea root extracts after 20 days incubation at 20"C, while typical chlamydospores were formed from both of them in the root extract of Panax quinquefolium. The 3.6 log chlamydospore/mm" was converted from microconidia in the medium, which was equal to 2.5% conidia formed. Under the light condition (251.1 pmol/m" sec, 12 hrs dark and light cycle), 4.2 log/mm" of chlamydospores were converted from interracially or terminal cells of macroconidia, which was 4.0% of macroconidia produced on Potato dextrose agar (PDA). When mycelia and microconidia were stored at -7$0^{\circ}C$ for 32 days and incubated on PDA after thawing at room temperature to isolate chlamydospores from them, microconidia and mycelia were still alive. Meanwhile, microconidial lysis was found after heating them at 32$^{\circ}C$ for 7 days, but the chlamydospores converted from macroconidia were not lysed up to 13 days at 32"C. to 13 days at 32"C.ot;C.

• Korean Journal Plant Pathology
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• v.13 no.1
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• pp.30-36
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• 1997

The effects of carbon and nitrogen sources on the mycelial growth and sporulation of microconidia and chlamydospores of five isolates of Cylindrocarpon destructans (Zinssm.) Scholten causing root rot of Panax ginseng were studied. For the carbon sources, fructose, glucose, maltose, and sucrose in Czapek-Dox broth showed good mycelial growth of 178∼201 mg in dry weight compared with 64 mg of the control. The best carbon sources tested for conidial formation were sucrose and maltose with 2.75 and 3.03 log conidia/ml, respectively. For the nitrogen sources, aspartic acid, NaNO3, KNO3, arginine, threonine, and leucine increased mycelial growth of the fungi to 208∼231 mg in dry weight without significant difference (p=0.05) among them. Meanwhile the growth with cystine was poor (26.3 mg dry weight), and no conidium and chlamydospore were formed. Maximum microconidial formation was observed in the media with NaNO3 and KNO3 as 3.37 and 3.35 log conidia/ml, and for the chlamydospore formation the (NH4)2SO4-containing medium and the nitrogen-absent medium were the best as 3.40 and 3.57 log chlamydospores/ml, respectively. No conidium was found in the medium without nitrogen sources, in which chlamydospore formation increased 6 times more than in the nitrogen-amended medium. However, deletion of carbon source in the medium did not affect on the formation of conidia and chlamydospores of C. destructans.

• Mycobiology
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• v.44 no.1
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• pp.63-65
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• 2016

Cylindrocarpon destructans causes root rot disease in ginseng and can survive for a long time, producing chlamydospores. We optimized conditions to induce chlamydospore production from the conidia of C. destructans, isolated from Korean ginseng. This will provide the basis for testing the efficacy of control agents targeting these chlamydospores.

• Mycobiology
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• v.46 no.4
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• pp.396-406
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• 2018

A newly isolated white rot fungal strain KU-RNW027 was identified as Trametes polyzona, based on an analysis of its morphological characteristics and phylogenetic data. Aeration and fungal morphology were important factors which drove strain KU-RNW027 to secrete two different ligninolytic enzymes as manganese peroxidase (MnP) and laccase. Highest activities of MnP and laccase were obtained in a continuous shaking culture at 8 and 47 times higher, respectively, than under static conditions. Strain KU-RNW027 existed as pellets and free form mycelial clumps in submerged cultivation with the pellet form producing more enzymes. Fungal biomass increased with increasing amounts of pellet inoculum while pellet diameter decreased. Strain KU-RNW027 formed terminal chlamydospore-like structures in cultures inoculated with 0.05 g/L as optimal pellet inoculum which resulted in highest enzyme production. Enzyme production efficiency of T. polyzona KU-RNW027 depended on fungal pellet morphology as size, porosity, and formation of chlamydospore-like structures.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.163-163
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• 2005

• Korean Journal Plant Pathology
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• v.12 no.4
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• pp.422-427
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• 1996

인삼뿌리썩음병균(Cylindrocarpon destructans)후막 포자의 형성은 CD(Czapek`s dox broth)와 SNY(Spezieller Nahrtoffarmer yeast extract broth)배지에서 진탕배양(2$0^{\circ}C$, 120 rpm)하면 양호하였다. 특히 CD배지에서 2$0^{\circ}C$로 30일간 진탕배양하면 5.99 log 후막포자/ml로 형성되었다. 후막포자의 발아율은 12.9~23.3%로 CD배지와 SNY배지에서 좋았으며 발아적온은 5~1$0^{\circ}C$였고, 최적 pH는 6이었다. 그러나 2$0^{\circ}C$이상에서는 전혀 발아하지 않았으며 pH 7.0이상에서는 발아율이 급속히 저하되었다. 인삼추출물 3%, GA 10 ppm, IAA 10 ppm, NOVOZYM\ulcorner234 20 ppm을 처리 할 경우 대조구에 비해 발아율이 증가하였다. 특히 NOVOZYM\ulcorner234 20 ppm 처리구는 발아율이 무처리에 비해 2배 증가하였다. CD배지(pH5)에 NOVOZYM\ulcorner234 20 ppm과 GA 10 ppm을 조합처리하고 5$^{\circ}C$로 정치배양 할 때 후막포자의 발아율은 49.4%로 가장 높았다.

• Journal of Ginseng Research
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• v.27 no.4
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• pp.195-201
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• 2003

Chlamydospore formation from mycelia and conidia of Cylindrocarpon destructans isolated from the root rot lesion of the Panax ginseng was investigated by scanning electron and light microscopy. Typical chlamydospores were formed only from hyphae but not from conidia on culture media. However, immature chlamydopspore-like cells were formed from microconidia after 12 days of incubation at 20$^{\circ}C$ on Czapek Dox broth (CDB) adjusted to pH 4.0. Chlamydospores were yellowish or reddish brown in color, and produced singly or in chain with the hyphal intercalary or terminal position on potato-dextrose agar, V-8 juice agar and CDB with no addition of nitrogen sources after 16∼20 days of incubation at 20$^{\circ}C$. They were 11.3 to 11.9 $\mu\textrm{m}$ in diameter, having many lumps-like warts on their surface with the length of 1.5 to 1.8 $\mu\textrm{m}$.

• Journal of Ginseng Research
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• v.23 no.3 s.55
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• pp.123-129
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• 1999

Under the light condition of 25,000 Lux (12 hrs dark and light cycle) with scrapping treatment of aerial mycelia of Cylindrocarpon destructans on potato dextrose agar (PDA), V-8 juice agar, and ginseng extract agar, production of the macroconidia was increased to $3.7\~8.1$ fold over them produced in the dark. They were also produced $7.7\~18.0$ times more in the liquid cultures under the light condition than under the dark as well. PDA and V-8 juice agar among the tested were the best for the macroconidium production. On PDA, 1,585 $macroconidia/mm^2$ were produced under the light of 25,000 Lux with scrapping treatment of aerial mycelia of C. destructans, which is 3.2 and 1.4 times more than those produced under 3,000 and 10,000 Lux, respectively. Meanwhile, $20\~99$ macroconidia/$mm^2$ were produced by the non-scrapping under the light condition between 3,000 Lux and 25,000 Lux. The macroconidia were, however, lysed at $6\~7$ days after being incubated under the above range of the light. They were consisted of $1\~3$ cells in a macroconidium while $69.4\~100\%$ of them were the two-celled and the number did not seem to be affected by either the scrapping or the light. Production of chlamydospore converted from mycelia of C. destructans seemed to be promoted by the light and the scrapping as well. The 1,285 chlamydospres/$mm^2$ were produced with the light (25,000 Lux), which is 2.8 and 1.2 times more than those with 3,000 and 10,000 Lux, respectively. Scrapping the aerial mycelia of the cultures increased the chlamydospore formation to 1.9, 2.5 and 1.4 times more than the non-scrapping under the light intensity of 3,000 Lux, 10,000 Lux, and 25,000 Lux, respectively. On PDA, 1 to 8 chlamydospore(s) per catena were formed by all treatments tested and $34.2\~58.9\%$ of them was a single chlamydospore, However, the numbers was affected by neither the light ($3,000\~25,000$ Lux) nor the scrapping the aerial mycelia.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.132.3-133
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• 2003

Leaf blight of kudzu ( Pueraria lobata ) was found in Jeonbuk province in 2002. The main symptoms appeared as leaf blight and showed yellowing and wilting. The causal pathogen of the leaf blight was isolated from symptomed kudzu leaf and produced white to cream, usually floccose mycelium. It readily formed reddish orange mycelium on PDA. It produced typical microconidia and macroconidia. The microconidia were the reniform. The macroconidia were wide, slightly curved, usually 3 to 4 septate and size was 45 ∼ 85 ${\times}$ 5 ∼ l0$\mu\textrm{m}$. The pathogen produced chlamydospore singly on short hyphal branches within 2 to 3 weeks, which was hyaline, globose, and smooth walled. The pathogen was, therefore, identified as Fusarium solani based on cultural and morphological characters. This is the first report on the leaf blight of kudzu caused by Fusarium solani in Korea.