• Research in Plant Disease
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• v.9 no.1
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• pp.32-35
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• 2003

Pink rot of potato (Solanum tuberosum L.) occurred at Pyeongchang in Gangwon and at Bosung in Junnam province since 1999. The disease incidence in the surveyed areas was about 5% of harvested potatoes in 2002. Affected tubers showed a dull brown appearance and the lenticels and eyes on tubers turned dark brown. The cut surface of the diseased tuber colored faint pink and the entire surface of the diseased tuber becomes deep salmon pink within 30 min. The pathogen isolated from the diseased tubers was identified as Phytophthora erythroseptica based on morphological and cultural characteristics. Mycelial mat was fairly fluffy, rosette or stellate patterns and rounded or angular hyphal swellings were farmed in water, Temperature for mycelial growth was ranged from 5 to 3$0^{\circ}C$ and optimal temperature was $25^{\circ}C$. Non-papillate sporangia were persistent on stalk and ellipsoid, ovoid, obpyriform or distorted in shape, often with a constriction distal in the middle. Size of sporangia was 41.3~69.6$\times$26.8~47.4 (av, 55.5$\times$37.1) ${\mu}{\textrm}{m}$. Sexuality of Phytophthora erythroseptica was homothallic. Oogonia were 30~46 ${\mu}{\textrm}{m}$ in diameter and oospores were 28~35 ${\mu}{\textrm}{m}$ in diameter, Elongated or cyclindrical antheridia were all amphigynous. This is the first report on potato pink rot caused by Phytophthora erythroseptica in Korea.

• Korean journal of applied entomology
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• v.44 no.4 s.141
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• pp.299-306
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• 2005

Soybean seed injury was analyzed in the experiments that soybean pods were allowed to be sucked by adults of the bean bug, R. clavatus, and were picked with a specimen pin. While attack by the bean bug at podding stage of soybean caused the increase of empty pods and completely-undeveloped seeds, attack at full seed stage caused the increase of seeds wi distinct injury mark on seed-coat. The ratio of deformed seed was lower than those of injury-marked seed and undeveloped seed when attacked during all stages. In at full bloom stage hardly produced injury-marked seeds and deformed seeds. When the injured seeds were dyed with acid-fuchsine solution, stylet sheaths of R. clavatus formed on seed-coat were observed in 83% of undeveloped seeds formed under attack during podding stage and in 91% of injury-marked seeds formed during full seed stage. In pods injured with a specimen pin at full seed and full maturity stages, no healthy seeds could be obtained from the pods. And the more picked at full seed stage, the more deformed seeds were produced and the higher weight reduction of injury-marked seed occurred. However, pin-injury at full maturity stage didn't give rise to weight reduction of seeds.

• Development and Reproduction
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• v.2 no.1
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• pp.101-109
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• 1998

Spermatogenesis and reproductive cycle of the razor clam, solen grandis, were investigated monthly by histological and cytological observations. Samples were collected from natural intertidal population at Oshik-do, Kunsan, Korea, for one year, beginning from January to December, 1993. solen grandis is dioecious. Morphological structures of the spermatozoon of this species ar esimilar to those of other bivalve spermatozoa having a primitive type; i.e., a small head, a cap-shaped acrosome and a short mid-piece with four mitochondria surrounding axial filament. The head of spermatozoon is approximately 2 \mu m in length and sperm tail is about 20 \mu m long. The axoneme of tail flagellum consists of nine pairs of peripheral microtubules at the periphery and a pair of central microtubules at the center. Four spherical mitochondria form the paranucleus. Spawning occures once a year between early June and July, and the main spawning was observed in July when seawater temperature reaches above 20 \circ C. The reproductive cycle of male razor clam can be divieded into fivesuccessive stages; early active (December to january), late active (January to march), mature (March to early August), partially spawned (June to July), and spent/inactive stage (August to December).

• Investigative Magnetic Resonance Imaging
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• v.15 no.2
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• pp.146-153
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• 2011

Purpose : To describe normal anatomy and compare the differences of external genital organs and urethra on MR imaging in pre- and postmenopausal women. Materials and Methods : A total of 19 pre- and 18 postmenopausal healthy women underwent pelvis MR imaging at 1.5 T. Two radiologists retrospectively scored and compared the image quality of female external genitalia and urethra on axial T2-weighted images (T2WI) and axial fat-suppressed contrast-enhanced T1-weighted images (FSCE-T1WI) by using Wilcoxon signed ranks test. The radiologists compared the wall thickness or size of external genital organs and urethra on FSCE-T1WI between two groups by using Student t test. Results : Image quality was better with FSCE-T1WI than with T2WI in all subjects (p < 0.05). The vestibular bulb, clitoris and labium minor were more clearly visualized on FSCE-T1WI in premenopausal subjects rather than in postmenopausal subjects (p < 0.05). The urethra had a target-like appearance with three layers in premenopausal and postmenopausal subjects. Postmenopausal subjects were observed to have significantly smaller vaginal wall thickness, urethral wall thickness and vestibular bulb width than premenopausal subjects (p < 0.05). Conclusion : The anatomy and morphologic changes of female external genital organs and urethra were well discernible on FSCE-T1WI.

• Journal of the korean veterinary medical association
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• v.34 no.8
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• pp.547-550
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• 1998

수의사들은 수캐와 고양이를 구입하기전 수캐의 번식력에 대한 검사를 요청 받을 때가 가끔 있다. 미국의 경우 Kennel club 지침에서는 7개월 보다 어린 개 또는 12세 이상된 개를 종견으로 등록할때는 번식력에 대한 소견서 혹은 증명서를 제출하여야만 한다고 되어있다. 번식력 검사에는 수캐의 완전한 병력을 수집해야하며 병력으로 과거 상처, 질병, 예방접종, 투약상태, 고환이 음낭으로 하강한 상태, 년령, 음낭부종 또는 외상의 발생상태 등이 포함되어야한다. 또한 애완동물의 가계에 대한 번식력에 대해서도 찾아보도록 노력해야 한다. 환축을 검사하기전 병력을 축주에 문의하는 것도 하나의 좋은 방법이다. 건강한 수컷이 암캐와 교미를 하지 못할 경우에는 번식관리의 검사에 세심한 주의를 기우려야 한다. 또한 산자의 최종출생일, 산자수, 교미회수, 번식시킨 암컷의 수, 교미형태, 수컷의 성욕 및 승가행위 등에 과한 것들을 조사해야 할 것이다. 이러한 병력으로 수컷은 항상 불임성을 최초에 불임성을 보였는지 또는 저임성을 보였는지를 알수있게 된다. 새끼를 낳아보지 못한 개와 고양이는 선천적으로 불임이 되고 이러한 수컷도 예후는 불량하다. 개와 고양이가 과거에 새끼를 임신한 경험이 없다면 생식기의 전염성 또는 염증과 관련이 있을 수도 있다. 축주는 개 인공수정을 하기 위하여 정액을 채취할 때 물, 소독약 및 윤활제 등으로 인하여 정자의 사멸을 의식하지 못하고 있기 때문에 채취방법을 상세하게 설명하여 주어야 한다. 또한 암컷의 번식문제에 대해서도 상세하게 검사하여야 하며 개와 고양이가 불임되는 가장 흔한 이유는 번식관리에 문제점이 있으며, 이와 같은 경우에는 암컷을 검사하기 전에 수컷을 검사하는 것이 중요하다. 수컷의 검사는 사진으로도 용이하므로 비용도 절감되나 암컷은 생식기관을 검사하여야 되기 때문에 많은 경비가 든다. 그러나 번식력의 유일한 증거는 태아를 생산하는 것이며 많은 다른 검사 방법으로 평가 할 수도 있으나 번식력을 증명할 수는 없다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.6
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• pp.509-519
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• 1987

Annual reproductive cycle of the Damselfish, Chromis notatus collected monthly at the four coastal areas around Chejudo, Korea are studied on the bases of histological observations of gonadal tissue and various quantitative variables including gonadosomatic index (GSI), fatness, egg diameter composition and the first maturity. The ovary consisted of a pair of saccular structure with many ovarian sacs. Oogonia proliferated along the germinal epithelium of the ovarian sac. Young oocytes with basophilic cytoplasm showed several nucleoli along the nuclear membrane. When the oocytes reached about $450{\mu}m$ in diameter, nucleus migrate toward the animal pole, nuclear membrane disappeared and most of cytoplasm were filled with yolk materials and oil drops. After ovulation, residual follicle and growing oocytes remaining in the ovarian sacs degenerated. But early young oocytes without follicle layer were not degenerated, and growing continuously till the next year. The testis consisted of a pair of lobular structures in the right and left were united in the posterior seminal vesicle. Cortex of testis was composed of many sperm ducts connected with lobuli. GSI began to increase from March, starting season of longer day length and higher water temperature, and reached the maximum value between June and August. It began to decrease from September with the lowest value appearing between October and February without any evident variation. The annual reproductive cycle could be devided into five successive stage : growing(April to Many), mature(May to August), ripe and spent (June to August) and recovery and resting stage(September to March). The spawning peak occurred from June to August. According to the frequency distribution of egg diameter, Chromis notatus was a polycyclic species to spawn twice or more in a spawning season. Fatness, correlated with gonadal phases, was remarkably decreased by spawning. Percentage of the first maturity . in femate and male fish ranging from 7.0 to 7.9 cm were $50\%$ and from 9.0 to 9.9 cm in total length $100\%$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.185-191
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• 1981

The purpose of this paper is to define and describe a series of growth stages for maize. cv. MTC-l (early) and Suweon No. 19 (late) that are easily identifiable by both professional agronomists and farmers. Plants were grown at a density of 60cm row with plant spacing of 15cm at six different seeding times in 1980. Leaf development indices with ten grades (LDI) were identified and defined in accordance with the development of a leaf blade. Leaf appearance rate (LAR) was ca. 3 days and it was not influenced by the variety or seeding time. The elongation of the first internode above the ground level began in a month after emergence and it corresponded to the 8th or 9th leaf stage. Internodes elongated in regular sequence of node position. The morphological change of silks related closely with the development of kernel. The duration of generative development was not influenced by varieties and seeding time but that of vegetative growth was influenced. A new scheme for the maize which was made by the developed leaves, visible nodes above ground level, morphological change of silks and development of kernel was proposed.

• Development and Reproduction
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• v.8 no.1
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• pp.19-25
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• 2004

Pax6, a member of the highly conserved homeobox gene family, is known to be expressed in spatially and temporally restricted pattern during embryogenesis. To examine the spatial expression pattern of Pax6 in malaria vector mosquito Anopheles stephemi, in different molecular environment, the germ line transformation technique using piggyBac transposon combined with the use of Pax6 specific 3xp3-EGFP marker was utilized. Four transgenic lines with a transformation rate of 6.7% were established. Transgenes were stably expressed in subsequent several generations. The transgenic lines showed 3 different expression pattern with spatial specificity, possibly due to enhancing and/or silencing position effects. In two transgenic lines, noble expression pattern of Pax6 was observed in the region that has not been previously reported in any animal species. The results show that the tranposon piggyBac mediated germ line transformation system can be used as an efficient tool for the generation of diverse spatially restricted reporter gene expression.

• Journal of fish pathology
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• v.26 no.1
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• pp.39-44
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• 2013

Saprolegnia isolate from wild brook lamprey was identified on the basis of its morphological and molecular characteristics. The isolates showed aseptic hyphae and clavate zoosporagium. Zoospores discharge was typically saprolegnoid. Neither oogomia nor antheridia was observed in this study. ITS sequence obtained from the isolate was compared with other Saprolegnia spp. to analyse their phylogenetic relationships. Results showed that the isolate belongs to clade I including Saprolegnia parasitica. Based on the asexual organs, zoospore discharge manner and ITS sequence analysis, the isolate was identified as S. parasitica.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.1-11
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• 2007

Light is an environmental component inevitably regulating photosynthesis and photo-morphogenesis, which are involved in the plant growth and development. Studies were conducted at the International Rice Research Institute, Philippines in 2004 and 2005, with aims to investigate 1) morphological responses of rice plants to low radiation, 2) morphological alteration of shade-grown plants when exposed to high light intensity, and 3) photosynthetic responses of shade-grown rice plants. Reduction in solar radiation by 40% induced increases in the area on a single leaf basis, biomass partitioning to leaves, and chlorophyll meter readings but brought about retardation of tiller development and decrease in above-ground biomass production of rice varieties. When the shade-grown plants from two weeks of transplanting to panicle initiation were exposed to full solar radiation after panicle initiation, they demonstrated less increase in chlorophyll meter readings and more decrease in leaf nitrogen concentrations from panicle initiation to flowering than control plants that were grown under the ambient solar radiation for whole growth period after transplanting. Shade-grown rice plants exhibited lower carbon assimilation rates but higher internal $CO_2$ concentrations on a single leaf basis than control plants, when measurements for shade-grown rice plants were made under the shading treatments. But when the measurements for shade-grown plants were made under the full solar radiation, light-saturated carbon assimilation rates were similar to control plants. Response of photosynthetic rates to varying light intensities was not considerably different between shading treatments and control. Yield reduction was observed in the shading treatments from panicle initiation to flowering and from flowering to physiological maturity, mainly by less spikelets per panicle and poor grain filling, respectively.