• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.77-81
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• 1995

When cultured on MS medium supplemented with 0.5 mg/L NAA alone or 1.0 mg/L 2,4-D and 0.5 mg/L BA, immature zygotic embryos of Stewartia koreana formed embryogenic calli and somatic embryos. In investigate effect of sucrose concentration on somatic embryo development, embryogenic calli were transferred to MS basal medium containing 1.5,3, 6 or 9% sucrose. The greatest frequency of somatic embryos was obtained on medium containing 6% sucrose. However addition of 1.5 or 9% sucrose to medium inhibited somatic embryo germination and development into normal plantlet After 5 weeks of hardening culture on medium containing 6% sucrose, somatic embryos were transferred to half strangth MS medium supplemented with 0.1% charcol, wherein these embryo developed into the normal plantlets.

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.167-171
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• 1994

This study was carried out to investigate the possibility of plant regeneration through somatic embryogenesis in suspension culture of Aralia elata S. Callus was induced from the explants of leaf and petiole cultured in the MS media containing 2,4-D and TDZ. More embryogenic calli were formed from petiole and with combination treatment of 24-D and TDZ. The quarter strength MS medium was effective for increasing number of somatic embryos. Mannitol supplemented to the quarter strength MS medium, reduced somatic embryo formation but inositol increased. Normal plantlets(86%) were regenerated from mature somatic embryos in MS basal medium and 50% of those survied when transplanted to the vermiculite in greenhouse.

• Journal of Plant Biotechnology
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• v.31 no.2
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• pp.121-126
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• 2004

Bleeding heart (Dicentra spectabilis L. Lemaire) is one of the most valuable wild flower in Korea. This work was conducted for the mass production of somatic embryos through suspension culture and more effective plant regeneration system in Dicentra spectabilis. High-frequency embryogenic callus proliferation was achieved in SH liquid medium supplemented with 1 mg/L 2,4-D. Half-strength SH medium was suitable concentration for somatic embryo induction and germination. About 5,000 embryos were produced per 250$m\ell$ flask after 4 weeks of culture. Germination rate of somatic embryos was decreased when GA$_3$ was added in medium. The plantlets showed a 58％ survival rate when transferred to pots after 1 month of culture. The results indicate that micropropagation procedure via somatic embryogenesis can be applied for an efficient mass propagation of Dicentra spectabilis.

• Journal of Plant Biotechnology
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• v.32 no.2
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• pp.129-134
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• 2005

Effective micropropagation system via somatic embryognesis was established for a Phytophthora resistant Aralia elata cultivar. Different kinds of growth regulators were needed to induce embryogenic callus with different explant sources. When leaf explants were used, a combination of 2,4-D, TDZ and L-glutamine was needed, whereas when petiole and root explants needed only 1.0 mg/L 2,4-D. Embryogenic callus induction rate under the optimum culture condition was 75.0%, 67.0% and 83.0% from leaf, petiole and root segment, respectively. Somatic embryo germination and plantlet conversion rate appeared to be influenced greatly by various osmoticums. More than 90% of embryos germinated when treated with sucrose, glucose and maltose. However, the highest conversion rate (72%) was recorded on medium with 2% sucrose only. The converted plantlets grew normally on 1/2MS basal medium, were acclimatized on artificial soil mixture and survived more than 95% in the greenhouse condition. The results suggest that the species can be clonally propagated through in vitro culture system via somatic embryogenesis.

• Journal of Ginseng Research
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• v.23 no.4
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• pp.199-204
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• 1999

Cotyledon explants of Korean ginseng (Panax ginseng C.A. Meyer), a perennial medicinal plant, produced direct somatic embryos at a high frequency on MS medium without growth regulators. Cytokinin highly suppressed the somatic embryogenesis but stimulated direct fomlation of adventitious buds. BAP was more effective than kinetin for the formation of adventitious bud. IBA combination with cytokinin enhanced the frequency of adventitious bud formation. The highest frequency of adventitious bud formation were $40\%$ at 0.05 mg/l IBA and 5 mg/l BAP. Adventitious buds were mainly formed near the distal portion of cotyledon, while somatic embryos were only formed near the proximal portion of cotyledon. Adventitious buds were covered with sheath similar to axillary buds in the zygotic embryos, and then leaf-like epicotyls were developed.

• Nuclear Engineering and Technology
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• v.13 no.3
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• pp.161-167
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• 1981

For determination of mutation frequency induced by chronic irradiation of low dose gamma rays, Tradescarrfia clone 4430 was exposed to Co-60 ${\gamma}$ rays with different exposure rates from 3.6mR/day to 182R/day in or out of the Gamma Field at Kumkok Experiment Farm of KAERI. Somatic mutations based on pink mutant events of the stamen hair cells were clearly observed by the treatment. The pink mutant events were increased proportionally with increasing exposure rates of gamma ray except for relatively high dose rates of 105 R/day and 182 R/day, indicating saturation effect of mutation. The somatic pink mutations could be fairly detectable even in the low dose rate of 3.6mR/day. Therefore, this stamen hair system of Tradescantia clone 4430 seemed to be an reasonable test system for detecting mutability of low level irradiation. These results imply that artificial mutation induction in the fruit and ornamental trees could be expected in the ${\gamma}$-field.

• Korean Journal of Plant Tissue Culture
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• v.25 no.2
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• pp.119-123
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• 1998

In order to investigate the possibility of in vitro mass propagation via somatic embryogenesis from Sicyos angulatus L., effects of plant growth regulators and carbon sources on callus induction and somatic embryogenesis were evaluated. Optimal combinations of plant growth regulator for callus induction from cotyledon and inflorescence explants were 2,4-D 2.0 mg/L + BA 0.1 mg/L and 2,4-D 1.0 mg/L + BA 0.1 mg/L in MS basal medium supplemented with sucrose 30 g/L,, respectively. Somatic embryogenesis was observed from cultured inflorescence explants, but it could not be achieved from leaf or cotyledon explants. The most effective plant growth regulators for somatic embryogenesis from callus was NAA 1.0 mg/L + kinetin 10 mg/L in the half strength of MS basal medium supplemented with 20 g/L sucrose.

• Korean Journal of Plant Tissue Culture
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• v.25 no.4
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• pp.231-236
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• 1998

Carrot cotyledon explants cultured on MS medium with 1 mg/L 2,4-D were transferred to a hormone-free solid medium overlaid with filter paper in order to elucidate the effect of simple physical treatment on the development and germination of somatic embryos. Transfer of the explants cultured for one week on MS basal medium overlaid with 3 sheets of filter paper on to MS basal medium increased somatic embryo production 2-39 times over the one week culture on medium without filter paper overlay. Maturation and germination of somatic embryos was more prominent on medium overlaid with filter paper than on medium without filter paper. The explants cultured for one week on filter paper overlay added with liquid medium showed prominent decrease in somatic embryo formation compared to filter paper overlay only. It is suggested that the filter paper overlay affected the moisture environment of the somatic embryos developing on it.

• Korean Journal of Plant Tissue Culture
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• v.21 no.5
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• pp.303-308
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• 1994

Shoot apical meristem dome explants from cassava plants (Ghanaian local variety) produced somatic embryos at a frequency of 32% when cultured on MS medium supplemented with 2 mg/L 2,4-D. Somatic embryo segments formed secondary embryos at frequencies of up to 93% when cultured on medium containing 1 mg/L 2,4-D for 2 to 3 weeks. Since the somatic embryos were not capable of converting into plantlets, adventitious shoot were induced from the sliced embryo segments by culturing them on medium containing 0.1 to 5 mg/L BA. After 8 weeks of culture, numerous shoots formed on the segments at frequencies up to 100%. The shoots were rooted and successfully transplanted to potting soil.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.56-56
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• 2002

복제기법을 이용한 체세포 복제우의 생산에 있어서 문제점은 복제란의 이식후 수태율이 매우 낮으며 이에 대한 근본적인 원인을 해석하고, 수태율을 증진시킬 수 있는 새로운 방법이 요구되고 있는 실정이다. 따라서 본 연구는 체세포 복제 가축의 수태율이 낮은 근본적인 원인을 규명하기 위한 기초자료를 확보할 목적으로 복제란 이식우의 임신기간 중혈중 progesterone, cortisol, IGF-Ⅰ 및 IGF-Ⅱ의 농도를 분석하여 복제우의 수태율을 높이기 위하여 시험을 실시하였다. (중략)