• Journal of Korean Society of Forest Science
• /
• v.79 no.3
• /
• pp.322-329
• /
• 1990

A group of Pinus densiflora trees attacked by Rhizina root rot were observed at Kangnung. Diseased roots are characterized by rot patches, radial rot traces or formation of adhesive soil masses. The damage has proceeded about 6m per annum, and the pathogen in the infected soil was detected by trap logs. Ascospores of Rhizina undulata was germinated by heat shock at $37^{\circ}C$ for 24 hours or at $40^{\circ}C$ for 17 hours. The mycerial growth was optimum on PDA medium at $25-30^{\circ}C$and pH 5.6-6.3. Coniferous trees were more susceptible than non-coniferous trees in inoculation test in vitro.

• Korean Journal of Agricultural Science
• /
• v.12 no.2
• /
• pp.242-252
• /
• 1985

In order to get information on the ecology of rice false smut, germination ability and pathogenicity of sclerotia and chlamydospores of the pathogen, environmental conditions affecting the disease outbreak and varietal resistance have been investigated. 1. The degree of outbreak of rice false smut was higher in the upland rice in comparison with the paddy field rice in respect to the number of affected grains per ear, the size and weight of smut balls formed on affected grains as well as the ratio of sclerotial formation produced on smut balls. 2. Germination percentage and days required for germination of overwintered sclerotia placed on the soil surface in July were 81% and 19 days, respectively, while those of overwintered sclerotia treated in May were 60-70% and 41 days. Sclerotia placed on the soil surface or under 1 cm depth of the soil surface and incubated at $25-30^{\circ}C$ were germinated well, whereas those placed under 3 cm or 5 cm depth of the soil surface were not germinated at all. Germinability and stroma productivity of sclerotia were reduced when the sclerotia were cutted into small pieces. 3. The average number of stroma formed on a sclerotium was six and that of perithecia formed in a stroma was about 50 to 140. 4. Percentage of germination of chlamydospores on the yellow balls was very high and was decreased as the color of the balls being darken with maturation. 5. Panicle of rice plants were successfully infected by injection inoculation with suspention of ascospores and chlamydospores of the pathogen to the sheaths at the booting stages, while seeding infection by spraying with suspensions of chlamydospores was unsuccessful. 6. More number of infected grains was distributed on basal parts of an affected ear than that of infected ones distributed upper parts of the ear, when the affected ear was divided into five parts from its basal portion to the apical of the ear. 7. The occurrence of the disease was more severe in the late maturing varieties of rice in comparison with the early maturing varieties. 8. When the level of nitrogen applied was increased, the incidence of disease increased, and the infection percentage of the disease was increased as the transplanting date was delayed. 9. The weight of panicles and 1000 kernels and the ratio of ripenness were reduced, and the contamination degree of grains with chlamydospores were increased as the number of smut balls per panicle were increased.

• The Korean Journal of Mycology
• /
• v.11 no.2
• /
• pp.99-101
• /
• 1983

Black root rot caused by Cylindrocladium crotalariae is one of the most serious soilborne disease in soybean. Plant height reduction of Hwangkeum Kong was 38% by the rotting of the whole main root and 9% by rotting of the half of the main root as compared with partial discoloration in the main root. Pod number per plant and seed weight were significantly reduced by the increase of the disease severity. Important yield components such as number of pods per plant and seed weight were negatively correlated with the soybean black root rot severity.

• Korean Journal of Veterinary Research
• /
• v.17 no.2
• /
• pp.79-81
• /
• 1977

In this study, the serological survey on bovine babesiosis was conducted using indirect fluorescent antibody technique. A total of 472 serum samples were taken and tested with the following results. 1. 63.3% or 299 out of 472 serum samples were positive against bovine babesiosis. 2. The positive rate in Seoul, Jeon-buk and Jeju areas were 63.8, 30.6 and 91.4 per cent, respectively. 3. In spring, the rate of positive reaction was 37.5 to 54.0 per cent, in summer it was 69.1 to 81.8 per cent and in autumn 65.3 to 68.5 per cent.

• The Korean Journal of Mycology
• /
• v.11 no.1
• /
• pp.27-32
• /
• 1983

Five species of the genus Pythium were identified from 91 isolates which were collected from rice seedlings in machine transplanting nursery boxes and paddy fields in Korea. They included P. graminicola complex, P. monospermum complex, P. rostratum complex, and P. ultimum complex. The most frequently found species of the genus Pythium was P. graminicola complex followed by P. monospermum complex. Rice seed germinability was greatly decreased by being infested with P. graminicola complex at nursery box. P. graminicola complex was the most virulent in terms of prohibiting germinations and stunting plants in nursery boxes.

• The Korean Journal of Mycology
• /
• v.11 no.1
• /
• pp.33-34
• /
• 1983

흰가루병(病)에 감염(感染)된 괭이밥(Oxalis corniculata L.)을 1982년(年) 6월(月) 수원(水原)에서 다수(多數) 채집(採集)하였다. 병원균(病原菌)의 형태적(形態的) 특징(特徵)을 검경(檢鏡)한 결과(結果), 한국산(韓國産) 미기록(未記錄) 흰가루병균(病菌)인 Oidium oxalidis McAlp.로 동정(同定)되었다. 이병식물(罹病植物)은 10월말경(月末頃) 거의 고사(枯死)하였으며, 이 병원균(病原菌)의 완전세대(完全世代)는 관찰(觀察)되지 않았다.

• The Korean Journal of Mycology
• /
• v.8 no.1
• /
• pp.53-57
• /
• 1980

An undescribed black root rot of soybean, caused by Cylindrocladium crotalariae, was observed in Suweon area. The diseased plants showed yellowing at the top and dry rot at the root. Lesions of roots and stems in the soil were red to brown and main roots were cracked. Although not observed the disease in the field, leaves of inoculated test plants in the greenhouse exhibited circular, brown lesion surrounded by chloratic halos. The fungus was recovered in culture from the infected stem and root, and the perithecia of Calonectria crotalariae were demonstrated to be present as well as the cylindrocladium state. The fungus was pathogenic to the root, stem, petioles and leaves of soybean. The probable source of primary inoculum was microsclerotia formed in infected soybean root and stem from the previous season's soybean debris. Black root rot by this fungus was considered to be one of detrimental factors to the maximum yield of soybean. From the morphological and physiological characteristics and pathogenic behaviors, this fungus was identified as Cylindrocladium(Calonectria) crotalariae.

• Korean Journal of Veterinary Research
• /
• v.20 no.1
• /
• pp.33-38
• /
• 1980

1. In adult ICR-SLC mice, significant increase in the occurrence of the Tyzzer's disease was noted when the reticuloendothelial system was blockaded with the carbon particles. The most suitable bloakading time was 2 hours before inoculating Tyzzer's organisms, the route was intraperitoneal and the dose was 3mg/body. 2. Survival rate of the experimental group ICR-SLC suckling mice receiving BCG ($3{\times}10^8$) 6 days prior to intraperitoneal inoculation of Tyzzer's organisms was 80 percent, but the control group was 17%. 3. In comparing the survival rate of the nude/nude mice with the nude/+ mice, the former congenitally thymus deficient mice are 11 percent, but the latter are 67 percent.

• Korean Journal of Veterinary Research
• /
• v.23 no.2
• /
• pp.183-186
• /
• 1983

The clinical and histopathological observation of leucocytozoonosis was carried out during July, 1982 at a poultry compound in Gyeongbuk province and the results were summarized as follows: 1. Leucocytozoonosis was observed in 36,900 of 59,900 chickens (61.6%) and the mortality rate was 18.3% (6,760 of 36,900 chickens infected). 2. Clinical findings were anorexia, dyspnea, paleness of comb, greenish diarrhea and reduction of egg production. 3. Gross lesions were yellowish white spots scattered on parenchymal organs and swelling of liver and spleen. In addition, petechiation and ecchymosis of small intestine, egg yolk and subcutaneous tissues were observed. 4. Histological findings were infiltration of mononuclear cells in liver, heart and lung, appearance of megaloschizonts in heart, liver, proventriculus and pancreas, proliferation of foreign body giant cells in heart, and hyperemia and swelling of all parenchymal organs.

• Korean Journal of Veterinary Research
• /
• v.16 no.2
• /
• pp.173-177
• /
• 1976

The authors encountered a case of Babesiasis in Korean native cative cattle at Gyeongbug prefecture. After the clinicohematological observation the patient was treated a single dose of ganaseg and the following results were obtained. 1. Initial symptoms observed were high fever, anorexia, depression and cessation of rumination and these were followed by marked hemoglobinuria and mild degree of icterus. 2. The erythrocyte count decreased to $3.6{\times}10^6/mm^3$ and the infected erythrocyte rates were 9.7 percent with Babesia sp. and 0.2 percent with Theileria sp. 3. Marked increase in band neutrophil was observed. 4. The morphology of the protozoa in erythrocytes was different from that of so-called large-type Piroplasma: various forms including paired pear-shaped, single round, oval and pear-orspindle-shaped were detected, of which the former two forms were dominant. 5. A single dose of ganaseg administered intramuscularly was highly effective for the treatment of Babesiasis.