• Korean Journal of Plant Tissue Culture
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• v.28 no.5
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• pp.273-276
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• 2001

In order to develop effective acclimatization methods for Aralia elata plantlets regenerated from somatic embryos, various acclimatizing conditions were compared regarding both survival rate and growth of the plantlets. The plantlets were transplanted into plastic boxes containing artificial soil in the presence of either several levels of MS liquid media, distilled water, 2% sucrose or 0.1% hyponex solution. They were then cultured by spraying of distilled water twice a week and maintained in the normal tissue culture room. Perlite was proved to be better than vermiculite on survival rate and growth of the plantlets. As the size of perlite (larger than 0.2 cm in diameter) increased, both the survival rate and growth of the plantlets improved. Among the various MS liquid media and different aqueous solutions tested, distilled water appeared to result in the best survival rate and growth. MS media were also effective in increasing survival rate and supporting growth when diluted to 1/4 and/or 1/8. The acclimatized plantlets could be transplanted directly onto the nursery bed and grown normally. The above results suggest that plantlets regenerated from somatic embryos of Aralia elata be effectively acclimatized using a plastic box containing perlite with distilled water treatment.

• Journal of Plant Biotechnology
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• v.40 no.2
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• pp.79-87
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• 2013

The aim of this study was to establish plant regeneration from leaf explants of Sedum tosaense Makino, which is globally rare and endangered species. The leaf explants of S. tosaense were cultured on the MS medium supplemented with different concentration of BA and NAA for callus induction. Callus induction was showed the highest (100%) on MS medium containing $2.0mg{\cdot}L^{-1}$ BA and $1.0mg{\cdot}L^{-1}$ NAA. The highest number of shoots were regenerated when callus were cultured on MS medium containing $2.0mg{\cdot}L^{-1}$ BA and $1.0mg{\cdot}L^{-1}$ NAA for 5 weeks. The axillary bud were cultured on the MS media supplemented with combination of BA and NAA for in vitro propagation. The highest number of adventitious shoot (7.9 per explants) formed at $1.0mg{\cdot}L^{-1}$ NAA and $2.0mg{\cdot}L^{-1}$ BA. For rooting, MS medium supplemented with or without $2.0g{\cdot}L^{-1}$ activated charcoal was tested. The optimal results were observed using MS medium supplemented with $2.0g{\cdot}L^{-1}$ activated charcoal, on which 85.7 (No. of root), 4.6 cm (length of root). 1,200 ppm $CO_2$ and 350 ppm $CO_2$ were supplied for make certain the effects of $CO_2$ on pre-acclimatization by photoautotrophic culture. 1,200 ppm $CO_2$ treatment was established higher than 350 ppm $CO_2$ treatment. Soil acclimatization of in vitro plantlets was the best in mixture soil consisted of peat moss and perlite with 100% survival rate and they showed the maximum growth.

• Journal of Plant Biotechnology
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• v.29 no.2
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• pp.117-121
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• 2002

We have developed an in vitro micropropagation system via shoot formation from axillary buds using nodal segments of Corylopsis coreana. Explants from both juvenile tree (one-year-old greenhouse stock seedlings) and mature tree (ten-years-old tree in nursery) were compared with regard to propagation efficiency. Combined treatment of both BA and zeatin were effective on shoot proliferation since the best result was obtained on MS medium supplemented with 0.5∼3.0 mg/L zeatin and 0.2 mg/L BA. Generally, juvenile explants were better in both shoot proliferation and growth than mature explants. However, as the duration of in vitro culture was proceed to 6 months, explants from mature tree also produced three shoots per explant. Distinctive differences in rooting and adaptability to soil of shoots obtained from mother trees. Whereas shoots originated from juvenile explants rooted as high as 97%, those from adult explants showed 62% rooting. Similar result was also observed in soil acclimatization. The plantlets derived from juvenile plants survived 67%, while only 48% of those from adult trees survived. The results showed a possibility of the micropropagation of Corylopsis coreana through shoot formation from axillary buds. In addition, the advance of the research still remain to enhance the frequency of acclimatization of plantlets from mature trees for practical application.

• Plant Resources
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• v.7 no.1
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• pp.1-6
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• 2004

In vitro proliferation system was achieved by using nodal segment excised from greenhouse grown juvenile stock plants of Alnus japonica. Stem explants were cultured on MS medium supplemented with different plant growth regulators of cytokinin and/or their combinations. The most effective cytokinin source was the combination of zeatin 2.0 mg/L and TDZ 0.05 mg/L producing the average number of shoots (16.8 $\pm$ 3.6). In addition, healthy roots were formed after small clumps of shoots were transferred to half strength of MS medium containing IBA 0.02 mg/L with optimal rooting capacity. Soil acclimatization was successfully conducted in cell tray containing artificially mixed soil with 92 % survival rate.

• Journal of Ginseng Research
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• v.40 no.4
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• pp.409-414
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• 2016

Background: The low survival rate of in vitro regenerated Panax ginseng plantlets after transfer to soil is the main obstacle for their successful micropropagation and molecular breeding. In most cases, young plantlets converted from somatic embryos are transferred to soil. Methods: In vitro thickened taproots, which were produced after prolonged culture of ginseng plantlets, were transferred to soil. Results: Taproot thickening of plantlets occurred near hypocotyl and primary roots. Elevated concentration of sucrose in the medium stimulated the root thickening of plantlets. Senescence of shoots occurred following the prolonged culture of plantlets. Once the leaves of plantlets senesced, the buds on taproots developed a dormant tendency. Gibberellic acid treatment was required for dormancy breaking of the buds. Analysis of endogenous abscisic acid revealed that the content of abscisic acid in taproots with senescent shoots was comparatively higher than that of taproots with green shoots. Thickened taproots were transferred to soil, followed by exposure to gibberellic acid or a cold temperature of $2^{\circ}C$ for 4 mo. Cold treatment of roots at $2^{\circ}C$ for 4 mo resulted in bud sprouting in 84% of roots. Spraying of 100 mg/L gibberellic acid also induced the bud sprouting in 81% roots. Conclusion: Soil transfer of dormant taproots of P. ginseng has advantages since they do not require an acclimatization procedure, humidity control of plants, and photoautotrophic growth, and a high soil survival rate was attained.

• Korean Journal of Medicinal Crop Science
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• v.10 no.3
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• pp.217-221
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• 2002

Callus induction and embryogenesis were studied in three different genotypes of Acanthopanax senticosus, to develop a protocol for somatic embryogenesis and acclimatization. Young leaf, stem, node, petiole, peduncle, flower and root explants were collected from 3-year old trees of A. senticosus accessions (Korea, Russia and Japan). Callus was obtained from all cultured explants but showed the higher rate of callus formation in flower cultured. For the three A. senticosus accessions, callus was well formd on MS media containing 2mg/ l of 2,4-D and 2mg/ l of TDZ, 4mg/ l of 2,4-D and 1mg/ l of TDZ than other treatments. For three A. senticosus accessions, when callus transferred to MS medium with 2,4-D, embryogenic cell formed. For A. senticosus accessions Korea, embryogenic cells were obtained on callus induced from petiole, stem, node and root explants, and induction rate was lower than 3%. 200mg of embryogenic callus was transferred to MS free liquid medium and somatic embryos of heart stage were obtained after 45days of culture. When somatic embryo of germination stage were transferred to solid medium, most of the embryos were regenerated into plantlets on 1/4 MS medium. Normal plants with both shoots and roots were transferred to greenhouse soil and were successfully acclimatized.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.110-118
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• 2016

We compared germination efficiency for somatic embryos (SE) of Liriodendron tulipifera using semi-solid (SS), temporary immersion bioreactors (TIB), and continuous immersion bioreactors (CIB) to produce vigorous plants. The bioreactors were designed to be immersed in liquid media with plantlets with an adjustable immersion time. TIB and CIB improved germination rates up to 80.86% and 95.21%, respectively, however, CIB produced more hyperhydric plantlets than TIB. The height of plantlets in TIB was significantly higher than for those in CIB. Fresh weights of plantlets grown in CIB of were significantly lower than for those grown in TIB. The lowest chlorophyll concentration was found in in vitro plantlets from CIB. We examined abnormally developed leaves, stems, and apical zones of in vitro plantlets that were produced in CIB. Among the three types, SS showed the highest stomatal density and the shortest stomatal length in in vitro plantlets. After acclimatization, plants from CIB exhibited the lowest values in biomass, such as height, root collar diameter, leaf fresh weight, leaf length, leaf width, petiole length, petiole diameter, and leaf area. Photosynthesis and transpiration rates of ex vitro plants were not significantly different among the three culture types, but stomatal conductance was higher in TIB than in the SS and CIB. Therefore, the results suggest that TIB is the preferable bioreactor to improve in vitro plantlet regeneration of L. tulipifera. TIB-originated plants showed higher growth rate than SS and CIB after transferring to soil.

• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.568-572
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• 2010

In order to develop an efficient micropropagation system for a rare tree species, Empetrum nigrum var. japonicum K. Koch, the effect of medium salt, cytokinins and auxin at different concentration were evaluated. Shoot induction from axillary bud was better on WPM medium than on MS medium. Although there was no significant differences observed in shoot induction among the salt strengths of WPM medium, whereas healthy shoots were developed on basal WPM medium. In comparison of the cytokinins affecting shoot proliferation, zeatin was better than BA, whereas BA exhibited more effectiveness on shoot elongation. In vitro root formation was better on WPM medium than on 1/2MS medium and achieved the highest rooting rate when 5.0 mg/L IBA treatment. 93% of rooted plantlets were survived on artificial soil mixture after 4 weeks of acclimatization. Above results suggest that a rare tree species, E. nigrum var. japonicum can be micropropagated via axillary bud cultures.

• Journal of Plant Biotechnology
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• v.30 no.3
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• pp.275-279
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• 2003

Excised cotyledons and embryo axises of zygotic embryos of Rhus vemicifera were cultured on Murashige and Skoog(MS) medium with various concentrations of 2,4-D. About 3-5% of explants produced callus. Embryogenic callus was preferentially induced from basal parts of embryo axis of zygotic embryos seeds when they were cultured without removal of seed coats. Somatic embryos were developed from embryogenic callus in growth regulator-free medium after 2-3 subcultures on medium with 1.0mg/L 2,4-D and these embryos were matured to cotyledonary stage. Plantlets with well-developed shoots and roots from embryos were obtained on $\frac{1}{4}$MS medium with GA$_{3}$. After acclimatization of plantlets on artificial soil, they were exposed to soil pots.

• Proceedings of the Ginseng society Conference
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• 2004.05a
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• pp.17-28
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• 2004

As Korean ginseng is hybrid, an individual variation is very severe, and it takes long times in new breeding because it is required 4 years to pick the seed. But, transformation technique makes the high-functional breeding in short time. The focus of these ginseng studies is to find and secure the useful gene. And it is urgent to accumulate the fundamental data for the molecular breeding and secure the useful genes. Therefore, transformation and soil acclimatization technique are necessary to molecular breeding in use of the introduction of functional genes. In this study, it add to secure of new regulation gene and useful gene as to accumulate the fundamental data for the place where it will contribute to raise the national competitive power. To analyze the useful genes in large scale, we constructed CDNA libraries with various tissues, species, and treated tissue. EST analysis of ginseng perform in large scale and build the EST database of ginseng. We perform the full length sequencing about the selected lots of clones that include the entire open reading frame of the amino acid residues and construct cDNA chip with the parental EST clones. Establishment of the transformation and a soil acclimatization system throuth the re-introduction of the selected ginseng gene that related with the secondary metabolism and anti-stress into the ginseng.