• Korean Journal of Ichthyology
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• v.30 no.2
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• pp.84-91
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• 2018

The study about maturity and spawning of Korean Mandarin fish, Siniperca scherzeri collected using the set net and gill net in Soyangho Lake from April to November 2014 was conducted. The number of individuals was 401 (female: 204, male: 197). The total length of females ranged from 113 mm to 365 mm and that of males was from 140 mm to 342 mm. The water temperature in May which is the start of spawning season indicated about $15^{\circ}C$ and gradually increased to July ($26^{\circ}C$). Gonadosomatic index (GSI) of females indicated 2.3%, 4.6% and 3.1%, respectively, in May to July. Males' value showed the similar pattern recording 8.0%, 6.6% and 4.5% in the same time. According to histological observations of gonadal tissue, the most of female in May had the gonadal tissue of maturing and mature stage. And the ovary of June was mostly in the stage of ripe and spawning and a number of individuals in July was recovery stage. In the case of male, a number of males in May showed in the stage of mature. The testis of June showed that mature sperm was releasing. And the testis of July was mostly in recovery stage. The total length at 50% group maturity was estimated 245.16 mm. As shown in the above, the main spawning period of S. scherzeri was May to June.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.4
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• pp.35-37
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• 1979

To investigate the genetic system in resistance to powdery mildew winter wheat cultivar Diplomat which has stable field resistance was crossed with high yielding susceptible winter type Caribo and Hayman's generation mean analysis technique was employed. Mildewing rate on flag-leaf at both heading-flowering and ripe stages were recorded according to lame's quantitative scale. The result indicated that additive gene effect was more important and significant role in the inheritance of resistance while dominant gene effect was minimum, and digenic interations were absent. Narrow sense heritability of resistance at ripe stage was higher than that of heading-flowering stage.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2004.10a
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• pp.103-103
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• 2004

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.4
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• pp.383-391
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• 1995

In order to find out the distribution of neuropeptide Y (NPY) recently known as the gonadotropin (GtH) stimulation neurohormone in the brain tissues of marine teleost, detection and localization of NPY like substance in brain of two rockfish species, Sebastes oblongus and S. schlekeli were done by immunohistochemisty. Distribution of GtH cells in hypophysis were also observed by aldehyde fuchsin (AF)-fast green-orange G stain to compare with gonadal phases of the rockfish species. NPY immunoreactive cells were detected in olfactory bulb, telencephalon and mesencephalon of the brain, and NPY immunoreactive fibers were distributed not only in olfactory bulb, telencephalon and mesencephalon but also in optic nerve, hypothalamus and optic tectum. Regardless of ovarian maturation in two rockfish species, NPY immunoreactive fibers were observed in the neurohypophysis adjacent to the AF negative cells in the rostral pars distalis of hypophysis in both species. Moreover, the fibers were distributed in the rostral and proximal pars distalis near to the GtH cells of the hypophysis in both species possessing the growing or mature oocytes. Slight AF stainable GtH cells were detected in hypophysis of two species before parturition (S. oblongus) and in mature stage (S. schlegeli), but AF stainability of the cells in the proximal pars distalis after parturition was more increased than that of the cells Tn mature stage or before parturition. The size and nucleus diameter of GtH cells in S. oblongus and S. schlegeli before parturition were significantly bigger than those of GtH cells in individuals after parturiton (S. oblongus) or with resting ovary (S. schlegeli) (P<0.01).

• Journal of Embryo Transfer
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• v.9 no.1
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• pp.95-102
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• 1994

본 연구는 종모우의 선발방법으로 난포란을 이용하여 실험실내 정자의 수정능력을 직접 검정하여 평가코자 시도되었다. 즉 본 실험은 후대검정중에 있는 한우 후보종모우 15두의 동결융해정자의 수정능력을 평가하기 위하여 정액을 고장액(HIS)에 처리한 후 DM에서 6시간 그리고 소 난포액이 20% 첨가된 DM에서 4시간 전배양하여 수정능을 획득시켜 정자의 활력과 첨체 반응율을 조사하였고 전배양된 정자의 체내(토끼 난관) 또는 체외수정능력을 조사하기 위하여 FCS 15%, 발정암소혈정(CSS) 10%가 첨가된 mKRB에서 체외성숙된 한우난포란과 수정시켜 수정능력을 평가하였으며 인공수정에 의한 개체별 수태율과도 비교 검토한 바 다음과 같은 결론을 얻었다. 1. 한우 난포란의 체외성숙율은 BSA 첨가구 에서 43.8%, FCS 15% 첨가구에서 67.4%, CSS10% 첨가구에서 69.9%이었다. 2. 토끼 난관에서 체외수정율은 BSA 참가구에서 43.8%, FCS 15% 참가구 41.2% 및 CSS 10% 참가구 35.0% 이었다. 3. 후보종무우 15두의 정액을 HIS-DM으로 처리후 6시간 전배양하였을 때 정자의 활력지수는 9-32%였고 첨체반응율은 19-44% 이었으며 20% 난포액을 첨가하여 4시간 전배양 하였을 때 정자의 활력지수는 9-13% 이었고 첨체반응율은 20-43%로 개체간에 차이가 있었다. 4. 체외수정율은 6.6-85.7%였으며, 발정암소혈청(CSS) 10%가 첨가된 mKRB에서 성숙시킨 난포란이 FCS 15% 첨가된 mKRB에서 성숙시킨 난포란보다 다소 높았으나, 정자수정능획득방법간에는 차이가 없었 다. 5. 체외수정율에 있어서 전배양후 정자활력지수와는 부의 상관이 었으며, 첨체반응율과는 낮은 정의 상 관을 나타냈다. 6. 종모우의 수태율은 체외수정율, 정자활력지수 및 첨체반응율과 낮은 정의 상관관계를 나타냈다. 7. 종모우의 개체간 수태율 우열순위에서는 수정율순위와의 사이에 더욱 낮은 부의 상관관계를 보였다. 8. 이상의 연구결과 비록 후대정검중의 제한된 자료로 인하여 종모우 수태율과 체외수정율간에 유의적 인 상관관계는 없었으나, 연결 한우 수정율 평가에 대한 실험실내의 검정가능성을 찾을 수 있었다.

• Journal of Korean Society of Forest Science
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• v.96 no.6
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• pp.730-736
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• 2007

The heterogeneity of forest environment plays an important role in the structure and dynamics of tree population, the composition of forest community, and the maintenance of species diversity. Based upon the research data of the nine hectare permanent plot in the typical mixed broadleaved-Korean pine forest, this study was conducted to analyze the characteristics of spatial pattern of Acer tegmentosum population for seedlings, saplings, and living and dead trees so as to evaluate the effect of micro-topography on spatial pattern of the species. The results noted that A. tegmentosum preferred to gentle slopes. There was no difference in density of seedlings by the variation of aspect, but the density of saplings, and living and dead trees was high on the western and southeastern slopes. Living trees of A. tegmentosum showed the clumped pattern for all scales within 150 m and highest at the scale of 30 m. Dead stems of the species indicated the clumped pattern within 111 m, highest at the scale of 72 m, and random pattern beyond the scale of 111 m (P < 0.01 ). The similarity of occurrence by developmental stages of A. tegmentosum showed that seedlings vs. saplings, saplings vs. living trees, and living trees vs. dead stems had highly positive correlation to each other, respectively (P < 0.01 ), indicating that the occurrence of previous developmental stages was positively correlated to following stages.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.1
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• pp.132-138
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• 1997

In order to obtain the basic information for seedling production of surf clam, Spisula sachalinensis, annual reproductive cycle was investigated from March 1994 to May 1995. S. sachalinensis was dioecious. The gonads are located between the digestive diverticula and muscle tissue of the foot. The condition factor was reached its maximum (0.19) in June, and then decreased to 0.16 in July. In November, the value was the lowest and then increased slowly. The age and minimum size for sexual maturation were 2 years old and about 50 mm in shell length, respectively. However, less than $10\%$ of sexually undifferentiated individuals were larger than 80 mm in shell length. On the other hand, the size of mature oocytes was ranged to $50\~60{\mu}m$ in diameter and testis-ova was observed in testis of the mature stage. Annual reproductive cycle could be classified into five successive stages : multiplicative (October to January), growing (February to April), mature (April to June), spawning (June and July) and degenerative and resting (August and September) stages.

• Journal of Aquaculture
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• v.17 no.1
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• pp.81-88
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• 2004

Annual gametogenic cycle of Manila clam Ruditapes philippinarum collected from Shi-Heung-Ri beach in Jeju was investigated for the 12 month period from May 2001 to April 2002. Water temperature varied from 10 to 27$^{\circ}C$ and salinity from 27 to 35 psu during the course of study. Most of the clams collected in March were in indifferent or in early developing indicating that clams initiated gametogenesis when water temperature becomes 14 to 15$^{\circ}C$. In early June, most of the clams were in developing, expanding follicles and exhibiting growing oocytes. Fully ripe gonads were observed in clams collected during late June to early August. Spawning clams were observed as early as in early June although the spawning activity reached its maximum in early August. Condition index (CI) was rapidly increased from July to early August and then dropped in late August, indicating that most of clams in Shi-Heung-Ri beach spawn in late summer when water temperature was within a range of 25 to 27$^{\circ}C$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.2
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• pp.151-158
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• 2011

Forty nine accessions of the Sorghum bicolor (L) Moench collected from different agronomical zone of Gangwondo province, Korea were characterized morphologically on field trial. Plant length, stem diameter, tiller number, ear type, ear length, ear width, leaves length, leaves width and leaf color differed significantly in the cultivated accessions. Out of forty nine test accessions, six accessions (12.2%) showed comparatively taller height, measuring more than 300 cm, while, other ten test accessions (20.4%) were measured from 200~300 cm. There were no significant differences in the diameter of stem in the collected test accessions (2~3 cm). Of the total test accession, seven accessions showed leaf length of over 70 cm, and twenty two test accession revealed leaf length between 60-70 cm. Forty nine of the collected test accessions showed narrow and short leaves with white mid vain. These results provided additional information for the breeding programs and conservation of Sorghum bicolor as a bio-energy crop.

• Journal of Aquaculture
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• v.14 no.4
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• pp.213-220
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• 2001

To study the effect of salinity on maturation and spawning, two series of experiments were carried out during November, 1998- July, 1999 and January, 1999- March 2000. In the first series, the control group (C) was reared at 14.3$^{\circ}C$ and 35.1$\textperthousand$ S, but the experimental group was reared at 33.8$\textperthousand$ S. In the second series, they were also exposed to approximately the same temperature but the experimental group was reared at still lowered salinity of 2p.6$\textperthousand$. Survival, food intake and growth of the experimental groups in either series reared at lower salinities were higher than those of their respective control groups. At lower salinity, larger number of females attained spontaneous sexual maturity and successfully spawned. Hatching success of the eggs spawned by the experimental females reared at lower salinities was also higher (54-56$\textperthousand$) than that (~19%) of the control group reared at higher salinity.