• 한국균학회지
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• 제10권4호
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• pp.177-180
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• 1982

Gaeumannomyces graminis var. tritici was first isolated from rice in 1981. Sheath rot of rice seedling in box culture for machine transplanting was produced by artificial inoculation of the causal organism. Especially sheath rot was developed from crown to leaf sheath above water level. Perithecia were usually formed in dead leaf sheaths and in PDA culture. They were black, globose, and immersed with obliquely erumpent neck. Asci were unitunicate with an apical ring and contained 8 spores. Ascospores were hyline, slender, $80{\sim}140\;um$ in length. Each spore showed $3{\sim}4\;septa.$ Based on morphological and cultura characteristics, the isolate from seeds was identified as Gaeumannomyces graminis (Sacc.) Arx & Olivier tritici J. Walker.

• 식물병과 농업
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• 제1권2호
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• pp.18-21
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• 1995

Mycosphaerella nawae, the causal organism, of spotted leaf casing disease of persimmon, was isolated from infected leaves showing typical symptom. The cultural characteristics of the fungus were compared on artificial media. Among 24 different combinations of culture media and supplements, oatmeal agar+persimmon leaf extract (PLE) and PAD+ PLE+streptomycin showed the highest rate of isolating as 57.1%. The best medium for mycelial growth of the fungus was PDA+persimmon leaf powder (PLP). The colony diameter was reached 47mm for 30 days at 2$0^{\circ}C$. PDA+PLE also supported good mcyelial growth showing 46mm of diameter in same condition. The optimum growth temperature of this fungus in PDA was recognized fairly low. The mycelial growth was higher at 2$0^{\circ}C$ than 15$^{\circ}C$. The variation of pH between pH 4 to pH 8 did not affect to the mycelial growth of the pathogen.

• 한국가축번식학회지
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• 제21권4호
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• pp.325-333
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• 1997

Recent evidence indicates that growth factors modulate response of mammary epithelial cells to environmental stress. The objective of this study was to examine the cellular and biochemical responses of mammary tissue to environmental stress caused by artificial mastitis. For experimental a, pp.oach, toxins of most mastitis causing organisms(Staph. aureus or Strep. agalactiae) and heat stress(42$^{\circ}C$) were artificially exposed to mammary tissue. Effects of these environmental stresses on cell growth, cell death and heat shock protein synthesis were examined. Lactating mammary tissure were cultured under basal medium(DMEM) su, pp.emented with insulin(10$\mu\textrm{g}$/ml) and aldosterone(1$\mu\textrm{g}$/ml). All treatment groups in heat stress at 42$^{\circ}C$ incubation significantly decreased DNA synthesis rates in comparison with those at 39$^{\circ}C$(P<0.05), however, these decreased DNAa synthesis rates were recovered by addition of adenosine(10$\mu$M) and IGFI(10ng/ml). Similar results were obtained when tissue growth rates were measured by DNA content/tissue. Strep. agalactiae toxin did not significantly decreased DNA content/tissue in comparison with no treatment of bacterial toxin with or without heat stress, however, tended to decrease DNA contents/tissue without heat stress. In the fluorography analysis, heat stress(42$^{\circ}C$ incubation) slightly increased 35S-methoionine labelled 70kd protein synthesis. These results indicate that environmental stress caused by artificial mastitis slightly decreased mammary growth or mammary size, however, these results could be recovered by addition of adenosine and IGF-I.

• 한국패류학회지
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• 제19권1호
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• pp.33-40
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• 2003

To obtain the basic information on culture conditions for the larvae of Saxidomus purpuratus, experiments were conducted on the population from southern coast for (1) the success in fertilization and development from artificial fertilization among different months of a year, (2) the viability of sperms after exposure to seawater, (3) and the effects of temperature, salinity, and food organism on the survival and growth of larvae. Gametes obtained from dissection showed high rate of fertilization at all months. But the rate of development was higher only May-July. Developmental success seemed to be related with the quality of eggs at the time of fertilization. Developmental times for 2-cell, 4-cell, 8-cell, blastula, trochophore larva, and veliger larva at 20$^{\circ}C$ were 1.5, 2, 4, 18, 24, and 32 hr, respectively. Sperms could survive for more than 8 hr, however, actively swimming sperms could be found within 1 hr after exposure to seawater. It is recommended that sperms should be used for fertilization as soon as possible when they are exposed to seawater. At temperature of 35$^{\circ}C$, all the larvae died during 48 hr. Larval survival decreased when salinity was either lower than 20 psu or higher than 40 psu, and was 0% when salinity was 10 psu. Optimal range of temperature and salinity for rearing larvae of S. purpuratus were 20-25$^{\circ}C$ and 20-40 psu, respectively. Larvae grew from 111.5 to 235.3 ${\mu}$m during 21 days. Larvae fed mixed diets grew faster than unialgal diets. The fastest growth was observed when larvae were fed on the mixture of Isochrysis galbana and Nannochloris oculata.

• 한국패류학회지
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• 제27권1호
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• pp.77-86
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• 2011

The unwanted artificial oil-spill has severely contaminated the coastal environment in the world. Level of contamination has so far been monitered by various indicator species including mussel, oysters, flounder, and cockle. In this study, we decided to use the oyster as a model organism to observe the morphological changes being exposed to the artificial oil-spill in the coastal areas in Taean, Korea. The oysters were collected from four local sites (Sindu-ri, Uiwang-ri, Jonghyeon-dong, Ansan and Uihang-ri) exposed to various levels of pollution after an oil spill in Taean. Microscopic analysis of the hepatopancreatic microstructure in the digestive gland from the collected oysters show that the swelling, whorl, and destruction phenomenon of the nuclear membrane, a well-known microstructure induced by heavy metal exposure, was observed. Nuclear body (Nb), another typical characteristic of contamination or infection were also observed in some samples. Necrosis was observed in tissue samples collected from the area with a high degree of oil pollution. In addition, parasite-like particles (virus, perkinsus) were observed in most samples. Taken together, these results suggest that oil contamination in the oyster habitats influences the cytopathological changes in Crassostrea gigas.

• 수산해양교육연구
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• 제12권1호
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• pp.11-21
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• 2000

연구해역의 인공어초의 시설상태는 전반적으로 양호한 편이나 부분적으로 하단 부분이 약간 매몰되었고, 조류에 의해 약간 해저가 패여 있었다. 극히 일부를 제외하고는 대부분 어초로서의 기능을 유지하고 있다고 판단되었다. 1. 조사해역에서 20종의 어류가 어획되었고, 잠수조사 관찰종은 10종이었다. 2. 부착생물로서는 수산식물 5종과 수산동물 5종이 관찰되었다. 3. 단위 노력당 어획량은 시설구와 비교구를 비교하면 통발 2.12 : 1.41, 연승 10.23 : 5.43. 삼중자망 4.93 : 2.86를 보였다. 4. 어구별 종조성은 시설구와 비교구를 비교하면 통발 94 : 58, 연승 85 : 37, 삼중자망 118 : 62를 보였다. 따라서 전반적으로 인공어초 시설구에서 비교구 보다 약 2 배의 어획효과가 높았다.

• 한국응용곤충학회지
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• 제4권
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• pp.25-28
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• 1965

본 병은 그 병징이 종래에 알려진 일반 묘썩음병과는 달리 검은빛 균사가 수중의 종자표면을 뒤덮어 자라면서 종자표면을 흑변시킬 뿐만 아니라, 종자의 주위토양까지도 흑변시켰으며, 발아한 종자는 최고 3cm 이상은 자라지도 못하고 흑변하여 부패하였다. 병원균은 자연상태에서나 인공배양기상에서나 포자를 형성하지 않았으며, 균사는 현미경하에서 암색을 띄었고 뚜렷한 격막을 갖고 있었다. 따라서 종래의 벼모썩음병 병원균의 대부분이 Phycomysetes에 속했으나 본병원균은 불완전균을 닮아 있었으며, 앞으로 그 구명을 위한 계속적인 연구가 필요했다. 본병의 발병환경은 모든 면에서 종래의 벼 모썩음병과 거의 동일했으며, 특히 종자가 발아할 때의 환경조건이 절대적인 영향을 미쳤다. 본병균은 종자를 통해서 전염되는 경우는 없었으며, 오직 감염된 토양에 의해서만 전염된다는 것을 알 수 있었다.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2002년도 추계국제학술대회
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• pp.156-156
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• 2002

The goal of this study is to develop a biomarker used in monitoring abnormal behaviors of Japanese medaka (Oryzias latipes) as a model organism caused by hazardous chemicals that are toxic and persistent in the ecosystem. A widely used insecticide, diazinon (O, O-diethyl O- (2-isopropyl-4-methyl-6-pyrimidinyl) phosphorothioate), is highly neurotoxic to fish, and it is also well known that it causes vertebral malformation and behavioral changes of fish at relatively low concentrations. The fish behaviors were observed on a real time basis using an image processing and automatic data acquisition system. The genes potentially involved in the abnormal behaviors were cloned using suppression subtractive hybridization (SSH) technique. The untreated individuals showed common behavioral characteristics. When the test fish was affected by diazinon at a concentration of 0.1 and 1 ppm, some specific patterns were observed in its behavioral activity and locomotive tracks. The typical patterns were enhanced surfacing activity, opercular movement, erratic movement, tremors and convulsions as reported previously. The number of genes up-regulated tty diazinon treatment were 97 which includes 27 of unknown genes. The number of down-regulated genes were 99 including 60 of unknown genes. These gene expression patterns will be analyzed by the artificial neural networks such as self organization map (SOM) and multilayer perceptron (MLP), revealing the role of genes responsible for the behaviors. These results may provide molecular biological and neurobehavioral bases of a biomonitoring system for diazinon using a model organism such as fish.

• 식물병연구
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• 제12권2호
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• pp.125-128
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• 2006

2005년부터 2006년까지 진주시 초장동 농가육묘장에서 대목으로 사용한 박 (품종 : FR 커플)과 접수로 사용한 수박 (품종 : 삼복꿀수박) 에서 P. cubensis에 의한 노균병이 발생하였다. 병징은 갈색 또는 암갈색의 작은 반점이 생기고 진전됨에 따라 다각형의 병반이 형성되고 심할 경우 시들어 말라죽는다. 포자낭은 난형 또는 타원형으로 크기는 $20{\sim}32{\times}14{\sim}18{\mu}m$이었다. 포자낭경은 직립하여 나뭇가지 모양으로 끝부분에 포자낭을 많이 형성하며 크기는 $140{\sim}380{\times}4{\sim}8{\mu}m$이었다. 수박에서 병원성을 검정하였다. 대목으로 사용한 박과 접수로 사용한 수박에서 발생한 병원균의 균학적 특징을 조사한 결과, Pseudoperonospora cubensis에 의한 노균병으로 동정되었다.

• 한국패류학회지
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• 제22권2호
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• pp.175-182
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• 2006

본 연구는 2004년 3월 10일 남해 강진 만에서 채취한 피조개 어미 1,200 마리를 확보하여 수온조절에 의한 인위적인 성성숙을 유도하였으며, 성숙 유도된 어미로부터 잔존율, 비만도, 생식소 조직검사, 적산수온 및 성숙소요일수를 조사하였다. 성 성숙유도된 어미의 잔존율은 $20^{\circ}C$가 94.8％로 가장 높았고, $23^{\circ}C$가 90.3％, 대조구(자연수온구)가 84.8％이었고, $26^{\circ}C$가 18.1％로 온도가 높을수록 잔존율이 낮은 경향이 있었다. 42일 째 생식소 조직의 암컷의 완숙기 출현율은 $23^{\circ}C$ 실험 구에서 67%로 가장 높았고, $20^{\circ}C$ 실험구에서 56%, $26^{\circ}C$에서 22%였으며, 자연수온 실험구에서는 성숙이 매우 늦어 완숙기에 이르지 못하였다. 수컷의 경우, $23^{\circ}C$ 실험구에서 완숙기 출현율이 100%로 가장 높았고, $20^{\circ}C$ 실험구에서 87%, $26^{\circ}C$에서 73%였으며, 자연수온 실험구에서는 50% 순으로 나타났다. 성숙소요일수는 $23^{\circ}C$와 $20^{\circ}C$에서 각각 42일 및 49일, 대조구인 자연수온 $(9.5-14.8^{\circ}C)$에서는 79일이였으며, 성 성숙 유도율은 $20^{\circ}C$와 $23^{\circ}C$에서 각각 55.5% 및 60.5%로 타 실험구와는 유의한 차이를 나타내었다 (p < 0.05). 따라서 $20^{\circ}C$ 실험구 (적산수온: $1,295^{\circ}C$) 가 피조개 어미를 인위적으로 성 성숙을 유도하는데 가장 좋은 것으로 판단된다.