• Mycobiology
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• v.29 no.2
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• pp.104-106
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• 2001

Alternaria cassiae Jurair & Khan was recorded on seeds of sickle senna(Cassia tora L.). Seed infection ranged from $25{\sim}45%$ in two samples. Developing roots and shoots turn brown and died in case of severe infection. Detailed descriptions were given on the habit characters of the fungus and on the morphology of conidiophores and condia. This is the first report of A. cassiae on seeds of Cassia.

• The Korean Journal of Mycology
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• v.12 no.2
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• pp.75-77
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• 1984

An undescribed Cercospora leaf spot of pepper grown in a greenhouse was observed at Jinju area in 1983. The symptom of this disease showed frog eyes spot on lower leaves of pepper. Leaves and petiole of pepper plant inoculated with spore suspension of this pathogen app­eared leaf spot after 2 weeks and exhibited cicular, brown frog eyes spot. This fungus was grown slowly on PDA and produce condia on infected leaves. The occurrence of this disease was responsi­ble for factors with high temperature and humidity conditions in the ill-ventilated greenhouse. This causal fungus was identified as Cercospora capsici Heald et. Wolf from the shape and length of the conidiophores, the length of the condia, and pathogenic behaviors.

• Korean Journal Plant Pathology
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• v.13 no.4
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• pp.255-256
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• 1997

The mass sporulating method for conidia of Mycosphaerella nawac the causal organism of the spotted leaf casting of persimmon was investigated in this experiment. The conidia of M. nawae were sporulated on artificial media after prolonged period of incubation. The maximum amount of conidia of $39.0{\times}10^4/ml$ was harvested from 90-day old culture on PDA at $25^{\circ}C.$

• Journal of Sericultural and Entomological Science
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• v.42 no.2
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• pp.99-103
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• 2000

This study was carried out to investigate incubating characteristics, LTSEM observation, nature of a disease of infected silkworms(bombyx mori), LD$\_$50/, optimum infective condition for mass production and infection percentage(%) on conservation periods. On the V8 media, the colony was 0.5∼2.0cm/8 days in diameter and white or slighty colored with a white fluffy to powdery appearance. The conidia was subglobos in shape, zig-zag appearance, 1-celled, hyaline and 3.2$\times$2.4 ㎛ in size on the average. The conidiophore was irregular grouped, hyaline, rounded or flask-shaped. The LD$\_$50/ values of the 2nd and 4th silkworms were each other 6.6142(Log) in natural temperature and humidity (25$\^{C}$, 65%). On optimum infective condition for mass production, all of preservation time(hr.) postinoculation in 1.0$\times$10$\^$8/ conidia/㎖ was over 97% and only 20 hr in 1.0$\times$10$\^$7/ condia/㎖ was over 90%.

• Research in Plant Disease
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• v.15 no.1
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• pp.23-29
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• 2009

Cooking oil and yolk mixture (COY), a environmentally acceptable plant protection agent, and COY+$CaCO_3$+neem oil mixture were studied to control the powdery mildew occurring on eggplant, paprika, cherry tomato and maturity tomato in glass houses and vinyl houses during 2005 to 2007. The morphological changes of the pathogenic fungi on the leaf surface before and after treatment of COY were observed. COY made of rape seed oil and COY+$CaCO_3$+neem oil mixture were sprayed three times with 5 days interval to foliar parts of eggplant, paprika and tomato and the disease development were examined 5 days after final spray. In eggplant, the control efficacy of COY to powdery mildew was 94.6%. In paprika, the control efficacy of COY to powdery mildew was 91.6% and that of COY+$CaCO_3$+neem oil mixture was 96.2% that revealed little higher than COY itself. In tomatoes(cherry or maturity tomato), the control efficacy of COY were about 91 %, however, when COY mixture were sprayed to tomato leaves and stems the powdery mildew was controlled completely. Typical and healthy mycelia, conidiophores and condia were observed through scanning electron microscope in COY unsprayed leaf surface, on the other hand destroyed and winkled mycelia and conidiophores were observed in COY treated leaves regardless host plants nor taxonomic differences of fungi.

• Korean Journal of Microbiology
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• v.31 no.1
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• pp.1-8
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• 1993

lntergeneric hybrids formed between Aspergillus niger and Penicillium verruculosum were obtained by nuclear transfer technique. Nuclei isolated from wild type and auxotrophic mutants of donor strains were transferred into the protoplasts of different auxotrophic mutants as recipient strains. Several auxotrophic mutants were isolated from conidiospores of the two strains mutagenized with ultraviolet and N-methyl-N'-nitrosoguanidine. Optimal conditions for formation of intergeneric hybrids were investigated. Frequencies of intergeneric hybrid formation by nuclear transfer were $7{\times}10^{5}~1{\times}10^{5}$. From observations of genetic stability. DNA content. nuclear stain and conidial size. it was suggested that their karyotypes are aneuploid. In addition. the hybrids possess the 1.1~2.3-fold higher cellulase activities than those of parental strains. It was also revealed that some hybrids had different isozyme patterns compared to those of parental strains by CMCase and $\beta$-glucosidase activity assays.

• Research in Plant Disease
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• v.14 no.1
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• pp.68-70
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• 2008

Brown leaf spots on leaves of kiwifruit(Actinidia deliciosa) were observed at farmers' orchards in Suncheon and Goheung, Jeonnam Province, Korea in June, 2006. They developed to form dark brown ring spots and severely infected leaves resulted in defoliation during the growing season of kiwifruit. Alternaria sp. was isolated from the diseased leaves repeatedly and was identified as Alternaria alternata on the basis of its mycological characteristics on potato dextrose agar and its pathogenicity was confirmed by wound inoculation on healthy leaves of kiwifruit. A. alternata formed gray to dark sooty gray colony and produced numerous conidia on potato dextrose agar. The conidia, commonly in long chains of 5 or more produced on conidiophores, have $3{\sim}5$ transverse and $1{\sim}2$ longitudinal septa and mostly ovoid or obclavate in shape and were pale brown golden brown in color. The condia were $16.5{\sim}42.1{\times}6.7{\sim}19.5\;{\mu}m$ in size and conidiophores were $8.6{\sim}112.7\;{\mu}m$ in length. This is the first report on the brown ring spot on leaves of kiwifruit caused by A. alternata in Korea.

• Journal of Korean Society of Forest Science
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• v.6 no.1
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• pp.19-23
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• 1967

The fungus which belongs to Alternaria has been isolated from "damping-off" infected seedlings of pitch pine (Pinus rigida Mill.) in the nursery (seed bed) of Chung Puk College, Cheong-Ju. The author has carried out this study regarding to (1) the effects of H-ion concentration on the growth of fungus, (2) the effects of temperature and humidity on the conidia germination, (3) the effects of temperature and humidity on the conidia formation. The summary of obtained in this experiments is as follows: 1. The suitable H-ion concentration for growth of isolated fungus is in the range of PH 4.0-9.5, the most suitable of it is PH 6.5-8.0. 2. The germination of the conidia is suppressed at below $0^{\circ}C$ or at $40^{\circ}C$ and above, the range of optimum temperature for the germination is $5^{\circ}C-35^{\circ}C$, the percentage of germination is highest at $20^{\circ}C$. And under relative humidities of 10% or below, the germination is suppressed, favorable relative humidities $85%{\cdots}100%$. 3. The formation of the conidia is suppressed at below $10^{\circ}C$ or at $34^{\circ}C$ and above, the favorable condition of the condia formation is as follows; Temperature; $22^{\circ}C-28^{\circ}C$ Relative humidity:85%-100%.