• Horticultural Science & Technology
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• v.16 no.3
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• pp.355-357
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• 1998

Various temperatures and plant growth regulators were assessed to investigate the nature of the dormancy and bud sprouting of stem cutting of Hibiscus syriacus 'Honghwarang'. The bud sprouting was promoted as temperature increased. Under $30^{\circ}C$ condition, stem cuttings began sprouting at 4days after cutting and showed 100% sprouting at 6 days after cutting. With GA or BA treatment, the cuttings started sprouting at 6 days after cuttings under $25^{\circ}C$ condition and reached 65% sprouting, which was not different from the results without hormone treatments. However, ABA dipping under below $25^{\circ}C$ condition resulted in low sprouting, whereas under over $25^{\circ}C$ condition they started sprouting at 6 days after cutting and reached 93% at 12 days after cutting, which indicated that ABA is not effective on inhibition of sprouting under high temperature condition.

• Journal of Plant Biotechnology
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• v.45 no.4
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• pp.382-391
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• 2018

The objective of this study was to determine the most effective medium condition of shoot proliferation and root formation for the efficient in vitro micropropagation of M.26 (Malus pumila Mill). Simple sequence repeat (SSR) markers were used to analyze the genetic diversity of micro-propagated and greenhouse grown M.26. Shoot proliferation was carried out in MS (Murashige and Skoog) containing benzyladenin (BA, $0.5{\sim}5.0mg{\cdot}L^{-1}$) and thidiazuron (TDZ, $0.01{\sim}0.1mg{\cdot}L^{-1}$). The highest number of shoots (10.67 shoots per explant) was induced by adding BA at a concentration $1.0mg{\cdot}L^{-1}$. TDZ treatments caused higher hyperhydricity rate in cultured explants than in BA treatments. There was no significant effect of both BA and auxin on shoot proliferation, and the optimum proliferation medium for M.26 was MS medium containing $1.0mg{\cdot}L^{-1}$ BA. To find a suitable medium composition for shoot rooting, we tested different concentrations indole-3-butyric acid (IBA) and ${\alpha}$-naphthaleneacetic acid ($0.5{\sim}5.0mg{\cdot}L^{-1}$), MS medium (1/4-1), sucrose ($0{\sim}30g{\cdot}L^{-1}$). The shoots showed good rooting on half-strength MS medium containing $1.0mg{\cdot}L^{-1}$ IBA and $15-20g{\cdot}L^{-1}$ sucrose. The rooting rate (100%), number of roots (10.45 ~ 13.60 roots per explant), root length (7.41 ~ 8.33 cm), and shoot length (4.93 ~ 5.38 cm) were good on this medium. Fifteen SSR primers were detected in a total of 30 alleles in 20 micro-propagated plantlets, all SSR profiles from micro-propagated plantlets were monomorphic and similar to greenhouse grown control plantlet M.26 plant. The results indicated that M.26 micro-propagated plantlets were genetically stable.

• Korean Journal of Medicinal Crop Science
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• v.8 no.1
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• pp.14-20
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• 2000

This experiment was conducted to investigate the effects of length of storage period under low temperature, $CO_2$ enrichment and addition of plant growth regulators in Murashige and Skoog medium on the plant regeneration of Korean ginseng (Panax ginseng C. A. Meyer). Seeds were treated for 60 and 80 days respectively under $5^{\circ}C$ environment. 2500ppm of $CO_2$ was enriched by ventilation. Three plant growth regulators added to the medium were Indolbutyric acid, Benzyladenin and Gibberellic acid (GA3). The result indicated that : The capacity of differentiation was higher in the aged cotyledons from the seeds treated for 80 days under low temperature condition than in those treated for 60 days. $CO_2$ enrichment had stimulating effects on the growth and development of shoot primordium significantly but less effects on the formation of adventitious buds. From one zygotic embryo hundreds of plantlets were differentiated. $CO_2$ enrichment had effects on the formation of both indirect somatic embryo and direct somatic embryo. Indirect somatic embryo showed little growth and differentiation, being undifferentiated vascular stele and epicotyl. Direct somatic embryos were formed on the epidermis of backside basal part of cotyledon. Those embryos developed to whole plant having latent bud.

• Korean Journal of Medicinal Crop Science
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• v.7 no.4
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• pp.296-302
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• 1999

This experiment was conducted to study the effect of $CO_2$(0, 2, 500, 5, 000, 10, 000ppm) enrichment by enabling ventilation on micropropagation of multi-shoot and on the saponin contents in vitro in Korean ginseng (Panax ginseng C. A. Meyer). Embryo was cultured in Murashige and Skoog medium added 3mg/ l of Indolbutyric acid, Benzyladenin and Gibberellic acid $(GA_3)$, respectively. $CO_2$, enrichment had little effects on the number of adventitious buds and shoots originated from adventitious buds. The ratio of differentiated shoots to adventitious buds were about 50% in $CO_2$, enrichment treatment. The shoots originated from adventitious bud showed more rapid growth and had larger leaf area than the shoots originated from the leaf primordia did. The number of shoot primordia was the highest in 2, 500ppm of $CO_2$ enrichment treatment. On the contrary, 10,000ppm of $CO_2$, enrichment made smaller the number of shoot primordia and ratio of shoots to shoot primordia. The range of shoots differentiated was from shoot primordia were 15. 4 to 23. 9. The rate of dry weight of cultured shoots showed lowest (7. 5%) in control and highest (8. 59%) in 2, 500ppm of $CO_2$, enrichment. Rate of in vitro flower in control was 7.6% and that in 2500ppm of $CO_2$ was about twice (15.7-16.3%) as much as in control. Flower number per a embryo cultured was about 1.2-1.3. In the multi-shoots with callus enriched by 2, 500ppm of $CO_2$, the contents of crude saponin and ginsenosides in multi-shoots alone were higher than in multi-shoots with callus. The characteristics of ginsenosides in multi-shoots were especially the higher content of ginsenoside Rd, Re, and $Rg_1$.