• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.3-3
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• 2023

우리나라 딸기는 시설재배 발전과 품종개발로 겨울을 대표하는 과일로 변신하였다. 이는 저온단일에서 꽃이 만들어져 착과되는 생태적(일계성)특성 때문이다. 우리나라의 딸기 정식기는 95%이상이 촉성작형으로 9월 중순 정식한 후 11월 하순부터 이듬해 5월 하순까지 약 6개월간 수확한다. 반대로 여름작형은 고온장일에서 꽃이 만들어져 착과되는 사계성 품종을 이용하는데 우리나라 500m 이상의 산간 고랭지에서 3-4월에 정식한 후 6월부터 11월까지 수확하지만 생산량은 전체의 0.3% 미만이다. 또한 여름딸기는 제과용으로만 사용되고 있어 6월부터 11월 사이에 신선딸기의 단경기가 발생된다. 이러한 문제를 재배적으로 해결하기 위해 일계성 품종을 이용하여 겨울부터 봄까지 포기냉장한 후 여름과 가을에 꺼내어 정식하면 45일 내외에 수확하는 주냉장 억제작형을 시도하였으나 우리나라에선 실용성이 떨어져 사라져간 기술이다. 그러나 네덜란드는 우리나라와 같은 주냉장기술을 활용(Waiting bed system, Table top system)하여 여름과 가을철에도 딸기를 생산하고 있다. 이 작형은 냉장기간이 길고 재배기술도 까다로울 뿐만아니라 1화방만 수확하여 수량성이 낮은 단점이 있다. 한편 미국에서는 일계성 품종이 품질은 좋으나 고온기에 꽃대발생이 어렵고 사계성은 품질이 떨어지는 단점을 극복하기 위해 일장의 길이와 관계없이 꽃대가 형성되는 중일성 딸기 품종을 보급하여 세계적으로 가장 많은 재배면적을 점유하고 있다. 연중생산이 가능한 중일성 품종을 개발하기 위해 먼저 유전자원을 수집하였고 품질이 좋은 일계성 품종을 중일성 품종과 교배하여 채종하였다. 교배종자를 파종하여 묘를 만든 후 정식하여 실생개체를 선발한 결과 고온장일 조건에서 개화되는 사계성(중일성)율은 약 10-20% 범위로 매우 낮았다. 선발된 우량계통은 영양번식을 통해 증식하여 생산력, 특성, 지역적응성 검정과정을 통해 품종을 개발하였다. 이렇게 단교잡에 의한 중일성 품종 선발육종은 선발율이 0.05%으로 매우 낮았다. 이렇게 우리나라 최초의 중일성딸기 '고슬' 품종이 개발되었다. 이 '고슬'은 9월부터 수확이 가능한데 이 때의 딸기 가격이 kg당 20,000원 이상으로 높으며, 수확기간은 '설향'보다 4개월 더 길게 재배가 가능하다. 연중재배를 위해서는 항상 8-25℃의 범위을 유지해야 품질이 높아지므로 재배관리가 중요하다. 흰가루병에는 저항성이 있으나 시들음병과 탄저병에는 약하고 당도와 경도가 높고, 향이 매우 진하다. 식물공장에서 매우 인기가 있는데 안정된 꽃대발생과 대과, 고당도와 함께 수술의 화분량이 많아 수정이 잘되는 특성으로 식물공장 사업이 확장되고 있는 중동나라에서도 로열티 계약(UAE 등)이 예정되어 있다. 1년 연중 개화되고 착과되는 특성으로 가정에서 기르는 반려식물로도 인기가 있다. 또한 아열대 고랭지대는 항상 서늘한 날씨이기 때문에 한번 정식후 1년 연중생산이 가능하여 2023년 베트남과 로열티 계약(1.6억원)을 하였다. 또한 '고슬'은 우리나라 신선딸기 수출 단경기에 생산되어 주년생산 수출체계에도 기여할 것으로 본다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.264-273
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• 2020

'Ilpum', a Korean short-grain mid-late maturing rice cultivar, was developed in 1990, more than 30 years ago. Despite its age, it has been the most widely grown cultivar in the Gyeongbuk province of South Korea for more than 25 years, making it the most important rice cultivar for the people of the Gyeongbuk province. The aim of this study was to analyze the relationship between the rice yield of "Ilpum', the main rice cultivar in the Gyeongbuk province, and climate elements in the Daegu (southern plain area) and the Andong (inland mountainous area) regions in Gyeongbuk, South Korea. The rice yield over the past five years increased by about 13% and 24%, compared to that produced in the late 1990s in Daegu and the early 2000s in the Andong region, respectively. The number of panicles per hill and the grain ripening rate significantly affected rice yield in the 'Ilpum' cultivars in the Daegu region. The faster heading was a factor in the increase in 'Ilpum' rice yield in the Andong region. The air temperature has been rising and sunshine duration has been increasing from the late 1990s to present in both regions. Rice yield was evaluated to understand the effect of climate factors. The rice yields increased owing to the long sunshine duration during the grain-filling stage in both regions. In Andong, increasing the maximum temperature during the vegetative stage increased rice yield. Rising air temperature during the reproductive stage also increased rice yield. In particular, long sunshine hours throughout the whole rice growing period increased the rice yield of this cultivar in the Andong region.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.293-298
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• 2004

Microinjection of DNA is a general method for generating transgenic animals, but the rate of transgenesis in chickens is very low. So it was carried out to investigate the efficiency of liposome-mediated gene transfer in stage one cell of chicken embryo with GFP expression vector. In order to determine efficiency and duration of the introduced foreign gene, it was microinjected DNA with liposome or naked DNA into the germinal disc of stage one cell or stage-X chicken embryo. Analysis of reporter gene expression in day-4 embryos showed that GFP expression was observed only in the liposome-mediate embryo groups and detectable up to day-8 embryos. The results suggest that stable integration of the introduced gene using liposome is a rare event. Nevertheless the liposome-mediated gene transfer may be a useful method to transfer a foreign gene into the stage one cell of chicken embryos.

• Research in Plant Disease
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• v.6 no.1
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• pp.23-26
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• 2000

Effects of infection time of the clubroot pathogen, Plasmodiophora brassicae, on yield loss of Spring-sown Chinese cabbage plants were examined in field experiments. Yield loss of Chinese cabbage plants increased as the infection time becomes early. Plants infected at 20 days after transplanting or earlier were completely killed before harvest, and those infected at 30 days after transplanting were healthy in appearance but their head weights were reduced to 59% with poor commodity value. The plants infected 40 days after transplanting were not affected in yield. Development of root hairs in diseased plants was greatly reduced as the infection progressed, and root length was reduced to 1/2 to 1/3 of that of healthy plants. root galls were first developed 20 days after inoculation and rapidly enlarged to reach the peak in size 20 days from initial development, and decayed thereafter. Development and decay of root galls tended to be faster at later season as air temperature became high, regardless of the infection time. Diseased plants started to wilt approximately 10 days after root gall development. Root galls began to decay 10 days after initial plant wilting, and then were completely rotten within following 10 days. Based on the results, root gall development stages on spring-sown Chinese cabbage plants could be grouped into 20 days of root gall enlargement period, and 10 days of root gall decay period, followed by survival period in soil.

• Korean Journal of Animal Reproduction
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• v.17 no.2
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• pp.113-120
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• 1993

To provide the optimal culture conditions for the developm,ent of in vit개 produced embryos, we have been investigated various culture media as well as co-cultrue systems using porcine cumulus cells or mouse fetal fibroblast cells. Porcine ovaries were brought to the laboratory from local slaughter house within 1 hour after slaughtering and cumulus oocytes complexes were recovered from antral follicles(3~5mm) with 23 gauge needle. To maturate follicular oocytes, cumulus oocytes complexes were washed three times with TCM-199 containing 25mM HEPES and incubated(39$^{\circ}C$, 5% CO2 in air) in various maturation media for 42 hrs. Ejaculated and liquid storaged boar spermatozoa capacitated with different sperm capacitation methods and media were rpepared for fertilizing of matured follicular oocytes in vitro. Fertilization was performed by adding 5~10${\mu}\ell$ fo capacitated spermatozoa containing 1~5$\times$105 sperm/ml to droplets. Eighteen to twenty-eight hours after sperm insemination, fertilized eggs were washed three times with culture media and transferred to the various culture media, to the culture media with a monolayer of somatic cells. The in vitro development rates of 1-cell embryos cultured with three times with culture media and transferred to the various culture media, to the culture media with a monolayer of somatic cells. The in vitro development rates of 1-cell embryos cultured with three different media, m-KRB, BECM and TCM-HEPES were 0~1.0%, showing extremely lower rates. Especially, most of embryos were observed to arrest the development beyond 4-cell stages. The rates of embryos developed to 2-, 4-, 8-, 16-, 32-cell and morula or blastocyst stage in co-culture with porcine cumulus cells and mouse fetal fibroblast cells were 61.1~67.0%, 59.0~58.0%, 42.5~43.1%, 28.4~30.2% and 20.4~21.0%, respectively. These development rates upto morula or blastocyst stages were significantly higher than those of the embryos cultured in the basic culture medium(P<0.01). These findings suggest that co-culture of in vitro fertilized eggs with porcine cumulus cells or mouse fetal fibroblast cells enhance the development of fertilized eggs to morula or blastocyst stage in vitro.

• The Korean Journal of Malacology
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• v.25 no.2
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• pp.145-151
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• 2009

The ultrastructural changes in germ cells during oogenesis of the melania snail, Semisulcospira libertina libertina have been investigated by light and electron microscopy. The ovary is located on the surface of the hepatopancreas in the spiral posterior region. The ovary exhibited greenish color in the gonadal mature season. The ovary was composed of a number of oogenic follicles. Oogenesis was divided into five stages with histological features: (1) oogonia, (2) previtellogenic, (3) initial vitellogenic, (4) active vitellogenic, and (5) mature stages. Oogonia were oval in shape, $4-6\;{\mu}m$ in diameter, and had a large nucleus. Previtellogenic oocytes were about $20\;{\mu}m$ in diameter and the cytoplasm reacted with hematoxylin in H-E satin. Initial vitellogenic stage, oocytes were $60-80\;{\mu}m$ in diameter, and small yolk granules of low electron density are scattered in the cytoplasm. Oocytes in the initial vitellogenic stage were connected with ovarian follicle by egg stalk. Active vitellogenic oocyte were $100-120\;{\mu}m$ in diameter. Electron density, size and quantity of yolk granules that are distributed in the cytoplasm have increased from the previous stage. Result of TEM observations, the oocyte contains well-developed Golgi complex, endoplasmic reticula and tubular mitochondria in the cytoplasm. Cytoplasm of mature oocyte was filled with proteinaceous yolk globules of high electron density. In this stage, the length of microvilli in the egg envelope was approximately $1.1\;{\mu}m$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.193-203
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• 2019

The aim of this study was to analyze the relationship between rice yield and climate elements in Daegu (southern plain area) and Andong (inland mountainous area) regions. Over the past 20 years, rice yield has increased in both regions. The rice yield of middle and mid-late maturing cultivars in the recent 5 years increased by about 10% and 18%, respectively, compared to that produced in the early 2000s in the Daegu region. In the Andong region, the rice yield of mid-late maturing rice cultivars in the recent 5 years was higher by about 7% than that of the early 2000s. The number of panicles per hill and grain ripening rate significantly affected rice yield in mid-late maturing cultivars. In addition, the grain weight and grain ripening rate significantly affected rice production in middle maturing cultivars grown in the Daegu region. With regard to the middle maturing cultivars, the relationship between grain weight and rice yield had a positive significant correlation in both regions. To understand the effect of climate factors on rice yield, the milled rice yield of several rice cultivars produced over the past 20 years (1999-2018) at both locations, Daegu and Andong, were evaluated. The rice yields increased owing to long sunshine duration during the grain filling stage in the Daegu region. In Andong, rising maximum temperature during the vegetative stage increased rice yield of early and mid-late maturing cultivars. Long sunshine hours increased yield of mid-late maturing cultivars in both regions.

• Korean Journal of Animal Reproduction
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• v.16 no.4
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• pp.311-316
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• 1993

Bovine follicular oocytes were matured, fertilized and cultured in vitro. Oocytes with or without cumulus cells were transferred into TC-I99 medium supplemented with 10% FCS 8 h after insemination, and embryos cleaved to 2- to 8-cell stage 56 h after insemination were cultured further for 5 days. The proportions of embryos developed to morular and blastocyst stages were significantly higher (P<0.0l) in those cultured with(31%) than without(15%) cumulus cells. When the embryos were cultured with cumulus cells in the medium with different protein sources, the highest proportion(59%) of embryos developed to morular or blastocyst stage was obtained in medium with BSA(P<0. O01). Higher proportions of embryos were degenerated during culture with FCS(15%) or CS(14%) compared with BSA(3%). The present results indicate the early development of in-vitro fertilized bovine embryos can be maintained efficiently by BSA when they were co-cultured with cumulus cells.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.127-132
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• 2004

We isolated 50 strains from sludge of wastewater treatment aeration tank using selective medium for Thio-bacillus sp. by membrane filtration method. They were identified as Thiobacillus neapolitanus (7), T. tepidarius (4), T. dientrificans (5), T. versutus (23), T. intermedius (2) and T. perometabolis (9). We selected Thiobacillus versutus strain KT51, which had the highest removal efficiency (100％) of hydrogen sulfide and the highest removal efficiency (85％) of dimethyl sulfide for 30 min in screen test. Also Thiobacillus versutus strain KT81 had the highest removal efficiency (26％) of dimethyl disulfide for 30 min in screen test. In applification of lab-scale reactor (closed-biological treatment) using Thiobacillus versutus strain KT51, results were 99.8％ (＜0.02 ppm) removal efficiency of hydrogen sulfide for 15 min.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.88-88
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• 2001

소 난포란을 체외에서 성숙, 수정시킨 후, 2~8 세포기 수정란을 체외배양액인 CR$_1$aa에 일정량의 nitric oxide scavenger, Hb와, inhibitor인 L-nitro - L- arginine methyl ester (L-NAME)를 첨가 배양하여 체외발육에 미치는 영향을 검토하고자 실시하였다. 체외수정 후 체외배양 48시간에 난구세포의 제거 유.무에 따라 CR$_1$aa 배양액에 hemoglobin을 0, 1, 5$\mu\textrm{g}$/$m\ell$를 첨가한 구의 상실배기이상 체외발육성적은 난구세포를 제거한 구에서 23.8%, 33.3% 및 26.8%였으며, 난구세포를 제거하지 않은 구에서는 각각 39.5%, 54.8% 및 48.8%로써 난구세포를 제거하지 않은 구에 Hb를 1$\mu\textrm{g}$/$m\ell$를 첨가한 구가 여타구 보다 통계적으로 높은 결과를 얻었다(P<0.05). 체외수정 후 체외배양 96시간 후 난구세포를 제거 유.무에 따라 Hb를 0, 1, 5$\mu\textrm{g}$/$m\ell$를 첨가하였을 때, 상실배기 이상 체외발육성적은 난구세포를 제거한 구에서 각각 28.6%, 46.2% 및 39.1%였으며, 난구세포를 제거하지 않은 구에서는 각각 33.9%, 67.2% 및 46.0%로써, 난구세포를 제거하지 않은 구에 Hb를 1$\mu\textrm{g}$/$m\ell$첨가구가 여타구에 비해 통계적으로 유의하게 높게 나타났다( P<0.05).CR$_1$aa배양액에 L-NAME를 0, 10, 50 및 100mM을 첨가한 구에서 상실배이상 발육된 체외발육성적은 각각 55.6%, 64.9%, 58.8% 및 66.7%로써 L-NAME 첨가구가 무첨가구에 비해 커다란 차이가 나타나지 않았다(P>0.05). 본 실험의 결과로 볼 때, nitric oxide scavenger인 hemoglobin의 첨가는 체외수정 후 체외배양 96시간에 1$\mu\textrm{g}$/$m\ell$ 첨가하는 것이 체외수정란의 체외 발육율을 향상시켰으며, nitric oxide inhibitor인 L-NAME는 첨가 농도에 관계없이 체외수정란의 체외발육율에 영향을 미치지 않는 것으로 나타났다. 본 실험에서 생산된 배반포기 체외수정란의 세포수에는 커다란 차이가 인정되지 않았다.