• Korean Journal of Plant Tissue Culture
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• v.26 no.3
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• pp.143-148
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• 1999

This study was conducted to elucidate the effects of ascorbic acid and dehydroascorbic acid on somatic embryogenesis from the cultured cells of carrot. Ascorbic acid in culture medium merely stimulated the proliferation of non-embryogenic cells but dehydroascorbic acid in medium induced embryogenic cells from non-embryogenic cells accompanying the inhibition of cell proliferation. Ascorbic acid in medium inhibited somatic embryogenesis from embryogenic cells while dehydroascorbic acid in medium enhanced somatic embryogenesis from the cells as well as non-embryogenic cells. This enhancement was limited to globular embryos and the maturation to cotyledonary embryos was inhibited by dehydroascorbic acid treatment. From the above results it is suggested that carrot callus cultures on medium containing dehydroascorbic acid could quickly induce embryogenic cells. In addition after brief culture of embryogenic cells on development medium containing dehydroascorbic there by acid the subculture of the cells to MS basal medium resulted in the high frequency production of somatic embryos.

• Korean Journal of Plant Tissue Culture
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• v.26 no.4
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• pp.289-291
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• 1999

Hypocotyl explants from 7 days old seedlings of one $F_1$ hybrid cultivar and two pure lines of cucumber formed embryogenic calli at frequencies of up to 8% when cultured on Murashige and Skoog medium (MS) supplemented with 1 mg/L 2,4-D for 3 weeks. Embryogenic calli gave rise to somatic embryos. When slices of somatic embryos were cultured on the same medium for 4 weeks, they formed embryogenic calli. Embryogenic cell suspension cultures were established with embryogenic calli in MS liquid medium with 1 mg/L 2,4-D. Embryogenic potential of cell suspension cultures was maintained by subculturing every seven days. When the level of 2,4-D in the medium was lowered to 0.2 mg/L by diluting with liquid MS basal medium, embryogenic cell suspension cultures underwent development into numerous somatic embryos. When plated onto MS basal medium, over 95% of somatic embryos developed into plantlets. Plantlets were transplanted to potting soil and grown to maturity.

• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.245-258
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• 2000

Somatic embryogenesis has become a major tool in the study of plant embryology, as it is possible in culture to manipulate cells of many plant species to produce somatic embryos in a process that is remarkably similar to zygotic embryogenesis. Traditionally, the process has been studied by an examination of the ex vitro factors which influence embryo formation. Later structural, physiological and biochemical approaches have been applied. Host recently, molecular tools are being used. Together, these various approaches are giving valuable information on the process. This article gives an overview of somatic embryogenesis by reviewing information on the morphogenesis, physiology, biochemistry and molecular biology of the process. Topics covered include a brief description of the factors involved in the production of embryogenic cells. Carrot cell suspension is most commonly used, and the development of a high frequency and synchronous system is outlined. At the physiological and biochemical lev-els various topics, including the reactivation of the cell cycle, changes in endogenous growth regulators, amino acid, polyamine, DNA, RNA and protein metabolism, and embryogenic factors in conditioned medium are all discussed. Lastly, recent information on genes and molecular markers of the embryogenic process are outlined. Somatic embryogenesis, the best example of totipotency in plant cells, is not only an important tool in studies in basic biology, but is potentially of equal significance in the micropropagation of economically important plants.

• Korean Journal of Medicinal Crop Science
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• v.15 no.5
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• pp.346-351
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• 2007

An efficient somatic embryogenesis and plant regeneration protocol was developed for Schisandra chinensis Baill, using embryogenic cell suspensions and optimized media conditions. Friable embryogenic callus was induced from cotyledonary leaf and hypocotyl explants of 7 days old seedlings on MS agar medium supplemented with 1.0 to $4.0\;mg\;l^{-1}$ of 2,4-dichlorophenoxyacetic acid (2,4-D). Fast growing and well dispersed embryogenic cell suspensions were developed within two months when embryogenic calli were transferred to MS liquid medium containing $1.0\;mg\;l^{-1}\;2,4-D$. One third strength of MS medium was the best for both overall growth and development of somatic embryos in liquid culture. Over 3400 viable somatic embryos were produced from each 150 ml flask with an initial cell density of 30 mg in 30 ml medium. Germinated somatic embryos developed in liquid medium converted into plantlets after transferred to half-strength MS semi-solid medium. Approximately 90% of the converted plantlets were successfully transplanted to soil and grew into fertile plants.

• Korean Journal of Plant Resources
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• v.24 no.3
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• pp.280-285
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• 2011

In this study, we established a novel somatic embryogenesis and plant regeneration system through cell suspension culture of white dandelion (Taraxacum coreanum NAKAI.). Embryogenic calli could be initiated from leaf and root explants of sterile seedlings on solid Murashige and Skoog (MS) medium supplemented with 1.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) after 3-week cultures. To proliferate embryogenic calli rapidly, cell suspension culture was performed with transferred to liquid MS medium with various combinations of plant growth regulators (PGRs) including 2,4-D, ${\alpha}$-naphthalene acetic acid (NAA), indole-3-acetic acid (IAA), $N^6$-benzylamino purine (BAP), thidiazuron (TDZ), and kinetin. During suspension cultures, embryogenic calli not only greatly proliferated, but shoot organogenesis also simultaneously occurred from the surface of somatic embryos. Among them, TDZ at lower concentration, 0.1 mg/L produced the highest efficiency of somatic embryo formation and shoot organogenesis. Rooting of embryogenic calli with adventitious shoots was done on solid MS medium containing 0.1 mg/L NAA and 0.3% activated carbon. Nearly 80% of embryogenic calli with shoot organogenesis could be rooted normal. Well-rooted plantlets were transferred into pots under a greenhouse condition, and plants derived from this system appeared phenotypically normal.

• Journal of Plant Biotechnology
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• v.29 no.3
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• pp.185-188
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• 2002

Off-white, friable embryogenic calluses were formed on the internal integument of mature seeds of yuzu (Citrus junos) cultured on Murashige and Skoog's basal medium at a frequency of 1.2%. Embryogenic calluses were proliferated when cultured on medium with 1 mg/L 2,4-D. Upon transfer to medium with 0.1 mg/L kinetin, embryogenic calluses produced numerous somatic embryos. Embryogenic suspension cultures were established by placing embryogenic calluses into liquid medium with 1 mg/L 2,4-D. When plated onto medium with 0.5 mg/L ABA, embryogenic cells developed into somatic embryos at a high frequency, and then regenerated into plantlets. Plantlets were successfully transplanted to potting soil and grown in a greenhouse.

• Korean Journal of Medicinal Crop Science
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• v.14 no.4
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• pp.255-260
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• 2006

Culture conditions for high frequency plant regeneration via somatic embryogenesis from embryogenic cell suspension cultures of Hovenia dulcis are described. Germinated somatic embryos were selected for induction of secondary embryogenesis. Friable embryogenic cells were induced directly from somatic embryos when transfer to 1/3 MS solid or liquid medium lacking plant growth regulators. The temperature strongly effected on induction of secondary embryognesis than other conditions in culture. All somatic embryos produced friable embryogenic cell clumps within 10 days when germinated somatic embryos cultured in 1/3 MS medium at $30^{\circ}C$ in suspension culture. No somatic embryos formed from embryogenic cell suspension cultures at $18^{\circ}C$. Numerous somatic embryos were induced and subsequently developed uniformly into germination stage from suspended cell clumps after 4 weeks of culture on $18^{\circ}C$. Plantlets conversion were observed on $18^{\circ}C$ when germinated somatic embryos were transferred to 1/3 MS solid medium without plant growth regulators or supplemented with 0.1-0.5 mg/l benzyladenine.

• Journal of Plant Biotechnology
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• v.31 no.3
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• pp.219-223
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• 2004

Embryogenic calli were induced from petioles of Aralia elata on MS solid medium supplemented with 1.0 mg/L 2,4-D. When embryogenic calli were transferred to MS liquid medium supplemented with 1.0 mg/L 2,4-D, embryogenic cells and embryogenic cell clusters were developed after 2 weeks of culture. Embryogenic cells were filtered through a 250 ${\mu}{\textrm}{m}$ sieve and the passed cells were proliferated and maintained in MS liquid medium supplemented with 1.0 mg/L 2,4-D. Embryogenic cell clusters entrapped on the sieve were transferred to 1/2 MS liquid medium without plant growth regulators, globular-shaped embryos were developed from embryogenic cell clusters after 2 weeks of culture. Numerous early stage somatic embryos could be developed to heart-shaped, torpedo-shaped, cotyledonary embryos and plantlets in 5 L bioreactor. Above results suggest that effective somatic embryo proliferation can be achieved via bioreactor culture systems in Aralia elata.

• Journal of Forest and Environmental Science
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• v.23 no.1
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• pp.5-9
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• 2007

Zygotic embryos just after harvest of seeds were immature globular to heart stage. Maturation of zygotic embryos rapidly proceed when zygotic embryos together with small excised parts of endosperm were cultured on 1/3-strength MS solid medium with 2% sucrose, and the zygotic embryos were germinated within two months. Embryogenic callus was formed from the excised segments of germinating zygotic embryos of Eleutherococcus pedunclus on Murashige and Skoog (MS) medium with $4.5{\mu}M$ 2,4-D. The embryogenic callus formation occurred at a low frequency (less than 7%) from hypocotyl segments. The embryogenic calli were maintained on the same medium as primary medium. High frequency somatic embryogenesis was obtained after the cells were transferred to medium lacking 2,4-D. Cotyledonary embryos were germinated and converted into plantlets on medium with $20{\mu}M$ $GA_3$. Embryogenic callus and somatic embryos were produced spontaneously on the surfaces of roots and/or hypocotyls of plantlets. The frequency of embryogenic callus formation was 85% in roots and 34% in hypocotyls. Therefore maintain of cell lines performed very easily. Plantlets with developed epicotyls at more than 3 cm acclimatized at high frequency (89%). While plantlets with small epicotyls (less than 1 cm) were acclimatized at low rate (32%). The soil survived plantlets produced new sprouts after over wintering in the field.

• Journal of Plant Biotechnology
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• v.6 no.4
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• pp.229-233
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• 2004

Partial desiccation of embryogenic calli cultures or somatic embryos leads to different physiological changes and maturation of somatic embryos, leading to improved plant regeneration. Embryogenic calli was induced from immature inflorescence segments and young leaf rolls of sugarcane (Saccharum officinarum hybrids CoC-671) on Murashige and Skoog's basal medium enriched with different concentrations of 2,4-D ($1-4\;\cal{mg/l}$), L-glutamine ($100\cal{mg/l}$), malt extract ($100\cal{mg/l}$), casein hydrolysate ($1000\;\cal{mg/l}$) and coconut milk ($5\%$) and solidified with $0.2\%$ gel rite. The embryogenic calli were subjected to desiccation for 1-8 h. Desiccation of the calli for 6-7 h resulted in enhancement of plant regeneration frequency ($83-96\%$) as compared to control ($12\%$). Plantlets exhibited vigorous growth to maturity in the greenhouse. Partial desiccation of embryogenic calli offers as a simple method for improving plant regeneration frequency in sugarcane.