• Analytical Science and Technology
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• v.14 no.2
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• pp.191-195
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• 2001

Cucurbitacin D and F, the protostane type triterpenoid of S. sorbifolia, were isolated with chromatograpic method and used as the standard substances for quantitative analysis. The compounds were identified with $^1H$-NMR, FAB-MS and UV spectrophotometer. They were separated on YMC-Pack ODS-AQ(303)[$250{\times}4.6mm$ I.D., $S-5{\mu}m$, 120A] column by HPLC. Cucurbitacin F was detected at 10.73mg/kg in cortex of S. sorbifolia, but cucurbitacin D was not. The compounds were shown to exihibit significant cytotoxicity($ED_{50}$<$0.1{\mu}g/mL$) against several tumor cell lines and acute toxicity(cucurbitacin D: 4.7mg/kg/day, cucurbitacin F: 2.5mg/kg/day) against BDF-1 mouse.

• Research in Plant Disease
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• v.9 no.3
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• pp.149-152
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• 2003

Black leaf spot disease occurred on Dendrobium phalaenopsis grown in farmer's fields located in Bonggangmyon, Gwangyang-eup, Jeonnam, Korea. Black small spots occurred on leaves at initial stage of infection and the infected leaves turned yellow from the tip. The yellow leaves were falled, resulting in stem blighting or eventual death of the entire plant. White mycelial colony of the causal fungus grown on potato dextrose agarturned dark violet later and optimum temperature for the mycelial growth was $25^{\circ}C$. The causal fungus isolated from the black leaf spot on D. phalaenopsis was identified as Fusarium moniliforme based on the mycological characteristics and pathogenicity. The fungus also caused same symptoms on leaves of Phalaenopsis sp. and Cymbidium sp. as well sa D. phalaenopsis by wound inoculation. This is the first report on black leaf spot of D. phalaenopsis caused by F.moniliforme in Korea.

• Research in Plant Disease
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• v.9 no.3
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• pp.145-148
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• 2003

In April of 2002, the gray mold disease occurred severely on kalanchoe (Kalanch oe blossfeldiana) grown in a nursery in Daesan-myon, Changwon City, Korea. The lesions were started with water-soaked spot and the leaves discolored from the tip and became gray or dark and gradully expanded to whole leaf. The conidia and mycelia of pathogen appearedd on flower, flower stalk and stem. Conidia were gray, 1-celled, mostly ellipsoid or ovoid in shape and were 8~17 ${\times}$5~12${\mu}m$ in size. Conidiophores were 13~34${\mu}m$ in size. The sclerotia were formed abundantly on potato-dextrose agar. The optimum temperature for sclerotial formation was $20^{\circ}C$. Pathogenicity of the causal organism was proved on Kalanchoe blossfeldiana according to Koch,s postulate. The causal organism was identified as Botrytis cinerea based on mycological characteristics. This is the first report on gray mold of Kalanchoe(Kalanchoe blossfeldiana) caused by Botrytis cinerea in Korea.

• Korean Journal Plant Pathology
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• v.13 no.3
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• pp.139-144
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• 1997

A destructive collar rot of apple caused by a species of Phytophthora has widely occurred in Kyungbuk and less extended in Chungbuk, Chungnam and Chunbuk provinces of Korea. Significantly higher incidence of the disease was observed on cv. Fuji when M26 or M9 was used as dwarfing stocks. Incidence of the disease at several orchards in Uisung, Kunwi, Yesan and Muju ranged from 45 to 80%. Twenty-five isolates of the causal fungus were collected and all isolates were identified as P. cactorum on the basis of their cultural and morphological characters. The fungus produced markedly papillate and broadly ovoid deciduous sporangia both on agar and in water, and a short pedicel was attached to each sporangium. Oospores were readily formed on clarified V8 agar by single isolates and all the antheridia were paragynous. The fungus neither grew nor produced oospores under 5 and over 33$^{\circ}C$. The destructive collar rot of apple caused by P. cactorum has not been reported in Korea previously.

• Korean Journal Plant Pathology
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• v.1 no.1
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• pp.67-71
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• 1985

A severe infection on pepper fruits by a black mold fungus was observed in the fields, Suweon. Conidia of Alternaria sp. were isolated from the infected fruits. Based on the morphological characters and size of the conidia, the fungus was identified as Alrernaria alternata (Fries) Keissler. The single spore isolates of A. alternata were weakly or not pathogenic on non-wounded pepper fruits, but highly virulent on fruits wounded with sandpaper or heated-glass rod. The infection on the wounded fruits were more severe on red fruits than on immature green ones. No visible infection was found on leaves and stems when 60-day-old plants of pepper were inoculated with the fungus. In July of 1984, the field losses of pepper fruits caused by black mold were $2.0\~22.5\%$ in Suweon.

• Korean journal of applied entomology
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• v.22 no.3 s.56
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• pp.198-202
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• 1983

A mosaic disease of gladiolus has been commonly observed with an infection rate of $43.3\%$ in the field. Bean Yellow Mosaic Virus(BYMV) produced veinal spreading lesions on Cheonopodium amaranticolor, veinal necrosis and severe leaf distortion on Phaseolus vulgaris 'Scotia' and mosaic on Vi cia faba. Cucumber Mosaic Virus(CMV) produced local lesions on C. amaranticolor, mosaic symptoms on Nicotiana glutinosa and Cucumis sativus. BYMV and CMV were transmitted by the green peach aphid. Purified BYMV and CMV had a typical maximum absorption at 260nm. In agar gel diffusion test, BYMV and CMV gave positive reaction with their homologous antiserum. The size of BYMV was 750nm in length, and CMV was 30nm in diameter.

• Research in Plant Disease
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• v.10 no.4
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• pp.337-340
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• 2004

In April of 2003, the gray mold disease caused by Botrytis cinerea was occured in zinnia seedlings grown in greenhouse at Gyeongsangnam-do Agricultural Research and Extension Services, and farmer's nursery. The symptoms of infected plants were started with water-soaking lesions in flower bud, leaves and stems. The lesions gradually expanded and infected plants became withered and discolored to gray or dark from the tip. The conidia and mycelia of the pathogen were appeared on flowers, leaves and stem. The conidia were gray, 1-celled, mostly ellipsoid or ovoid in shape and were 5${\sim}$16 ${\times}$ 4${\sim}$8 ${\mu}m$ in size. Conidiophores were 12${\sim}$28 ${\mu}m$ in size. The pathogenic fungi formed sclerotia abundantly on potato dextrose agar. The optimum temperature for sclerotial formation was $20^{\circ}C$. Pathogenicity of the causal organism was proved according to Koch's postulate. The causal organism was identified as Botrytis cinerea Persoon: Fries based on mycological characteristics. This is the first report on gray mold of Zinnia elegans caused by Botrytis cinerea in Korea.

• Research in Plant Disease
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• v.17 no.3
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• pp.402-404
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• 2011

The Sclerotium blight was found on Phalaenopsis spp. at Dong-du-cheon city, and Hwa-seong city, Gyenggido, Korea in September 2009. The symptom included yellowing on lower leaves and wilt of a whole plant. Severely infected plants were blighted and died eventually. White mycelial mats appeared on the surface of basal stem and bulbs and the sclerotia were formed on stems, roots, and sphagnum moss. The sclerotia were spherical, 1-3 mm and white to brown. The optimum temperature for the growth and sclerotia formation was $25-30^{\circ}C$ on PDA. On the pathogenicity test, the first symptom appeared 5 days after inoculation and developed to severe stem rot and blight. On the basis of mycological characteristics and pathogenicity, the causal fungus was identified as Sclerotium rolfsii. This is the first report on the sclerotium blight on Phalaenopsis spp. caused by Sclerotium rolfsii in Korea.

• Research in Plant Disease
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• v.16 no.3
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• pp.320-322
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• 2010

The Sclerotium blight was found on Neofinetia falcata at Yong-in city, Gyenggi-do, Korea. The symptom occurred low leaves yellowish and wilt of a whole plant. Severely infected plants were blighted and dies eventually. White mycelial mats appeared on the surface of basal stem and bulbs and the sclerotia were formed on stems, roots, and sphagnum moss. The sclerotia were spherical in shape, 1~3 mm in size and white to brown in color. The optimum temperature for the growth and sclerotia formation was $25{\sim}30^{\circ}C$ on PDA. On the pathogenicity test, the first symptom was appeared 5 days after inoculation and development to severe stem rot and blight. The causal fungus was identified as Sclerotium rolfsii and we suggested to call that the new Sclerotium blight on Neofinetia falcata caused by Sclerotium rolfsii in Korea.

• The Korean Journal of Mycology
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• v.29 no.1
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• pp.75-78
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• 2001

The powdery mildew of Statice (Limonium shinuatum) extensively occurred in the experimental farm of Changwon Floricultural Experiment Station, Kyongsangnam-do Agricultural Research and Extension Services in 2000. Both sides of the leaves, petioles and stems were covered with the white fungal spores and mycelia, and then the leaves, petioles and stems became dark-colored, eventually died. The conidia and conidiophores formed on the lesion were observed. Conidia were cylindric to ellipsoid, $25.3{\sim}49.4{\times}12.3{\sim}7.2{\mu}m$ in size and borne singly on conidiophore. Fibrosin bodies were not observed. Conidiophores were stright with 2-4 cylindric cells, and $65.7{\sim}124.8{\mu}m$ in size. Appressorium was lobed type. Cleistothecia were not formed. This is the first report on powdery mildew of Statice (Limonium shinuatum) caused by Oidium sp. in Korea.