• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.482-483
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• 2012

In this paper, the operation of current-fed quasi-Z-source inverter (QZSI) with buck-boost function, improved reliability, and regeneration capability is analyzed. The modified space modulation technique for controlling effectively both shoot-through time and zero voltage time is suggested. The simulation result is carried out in order to verify the performance of proposed technique.

• Horticultural Science & Technology
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• v.19 no.3
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• pp.315-319
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• 2001

The study was carried out to develop a simple and efficient system to regenerate plants from cotyledon and hypocotyl tissues of Chinese cabbage (Brassica campestris L. ssp. pekinensis cv Seoul). Among the various combinations of naphthalene acetic acid (NAA) and 6-benzyladenine (BA) tested, the best shoot induction medium for cotyledon, with 2.67 shoots per explants, contained $2.0mg{\cdot}L^{-1}$ NAA, $1.0mg{\cdot}L^{-1}$ BA and $16.7mg{\cdot}L^{-1}$ $AgNO_3$. The shoot induction medium with $1.0mg{\cdot}L^{-1}$ NAA, $5.0mg{\cdot}L^{-1}$ BA and $16.7mg{\cdot}L^{-1}$ $AgNO_3$, was best for shoot induction from hypocotyl explants, with 1.87 shoots per explants. After shoot induction, regenerated shoots were excised and rooted on rooting medium. Rooted plantlets were then hardened in the high humidity growth chamber and transplanted to pots, and then grown in the greenhouse. Regenerated plants appeared phenotypically normal and there were no changes in chromosome number.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.233-236
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• 2006

This study was conducted to investigate somatic embryogenesis capacity using callus derived from bud meristems in sweetpotato. Shoot apical meristem explants $(height:150{\mu}m;base:\;350{\mu}m)$were cultured on MS medium supplemented with 1 mg/L 2/4-D. Embryogenic callus were observed in five cultivars when their shoot apices were cultured on MS medium supplements with 1 mg/L 2,4-D. After 6 weeks of culture, greater than 80% of the survived explants produced embryogenic calli and the calli gave rise to somatic embryos at frequencies of 72% (Yulmi), 60% (Shinhwangmi), 78% (Geonmi), 70% (KoKei 14), 40% (Sinjami). The regenerated plants developed into whole plantlets after they were transferred onto the fresh hormon-free MS medium of 74% (Yulmi), 82% (Shinhwangmi), 86% (Geonmi), 74% (Kokei 14), 41% (Sinjami) respectively.

• Korean Journal of Plant Resources
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• v.18 no.3
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• pp.382-389
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• 2005

This study was conducted to establish the system of effective in vitro propagation by various explant sources culture of Bippeastrum hybridum Hort, 'Dazzler'. We tested the effects of optimal explant source, plant growth regulators on bulblet formation and plant regeneration. Callus was readily produced on the different tissues excised from floral buds whereas, bulbs and shoots were formed only on pedicel explants as compared with anthers, styles and ovaries. Pedicel is the best optimal explant for in vitro propagation. Two distinct pathways, organogenesis through callus and direct bulblet formation, could be recognized in pedicel culture. Up to the $80-100\%$ of bulblet formation and shoot organogenesis from the pedicel in fifteen days before anthesis were effectively induced by MS medium supplemented with 0.5 mg/L NAA and 1.0 mg/L BA. Plantlet regeneration was successfully achieved from pedicel-derived callus, via shoot bud induction or direct bulblet formation. The bulblets with blooming flower were produced within 2 years.

• Journal of Plant Biotechnology
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• v.30 no.4
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• pp.381-385
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• 2003

An efficient method of plant regeneration from Acanthopanax chiisanensis somatic embryos was developed. Cotyledonary somatic embryos were obtained in liquid Murashige and Skoog (MS) medium from embryogenic cell suspension cultures. They were desiccated for 0 to 72 hr and then cultured on MS medium containing NAA, BA, GA$_3$, (0-0.5mg/L). The highest multiple shoots formation (100％) was obtained from 72 hr desiccated somatic embryos on ifs medium with 0.5mg/L NAA＋0.5mg/L BA or 0.5 mg/L NAA＋0.5mg/L BA＋0.5mg/L GA$_3$ after 6 weeks culture. Plant conversion from multiple shoots was not high. The highest plant conversion from multiple shoots was obtained on 1/3MS medium with 1.0mg/L GA$_3$. Converted plantlets were transferred to ex vitro condition and the highest survival rate (70％) of the plantlets was obtained on plastic pots containing vermiculite and sand. These results indicate that micropropagation procedure can be applied for an efficient mass propagation of Acanthopanax chiisanensis.

• Journal of Plant Biotechnology
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• v.29 no.3
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• pp.189-192
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• 2002

An efficient plant regeneration system of major cultivars of sweetpotato (Ipomoea batatas (L.) Lam.) in Korea via somatic embryogenesis was established. Embryogenic calli were formed from shoot apical meristems of sweetpotato cultivars when cultured on LS medium supplemented with 1 mg/L auxin (2,4-D, picloram, dicamba). Among three kinds of auxin, 1 mg/L 2,4-D showed the highest embryogenic calli induction rate. After 4 weeks of cultures on LS medium supplemented with 1 mg/L 2,4-D, embryogenic calli induction rates of Sinhwangmi, Zami, Yulmi, and White Star were 86%, 78%, 76%, and 80%, respectively. Upon transfer onto LS basal medium, most of somatic embryos developed into plantlets. Regenerated plantlets were transplanted to potting soil and grown to mature plants in a greenhouse.

• Korean Journal of Plant Tissue Culture
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• v.24 no.1
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• pp.37-41
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• 1997

The in vitro regeneration and genetic transformation systems in hot pepper(Capsicum annuum L.) have not been routinely available, which has been a major limiting factor in the application of new genetic manipulations. An efficient procedure to regenerate whole pepper plants and to generate transgenic plants expressing a foreign gene was established. A relatively high frequency of plant regeneration was observed when hypocotyl and cotyledon explants were cultured on MS medium supplemented with NAA 0.1 mg/L plus zeatin 2.0 mg/L or IBA 10.0 mg/L plus BAP 1.0 mg/L. Addition of AgNO$_3$5 $\mu$M to these media improved the regeneration frequency up to 8%. For plant transformation, hypocotyl and cotyledon explants of hot pepper were precultured on shoot induction media without kanamycin added for 2 days, and then cocultured with Agrobacterium tumefaciens pDY183 for 2 days. Putative transformants were obtained from selection media containing 100 mg/L kanamycin sulfate and 500 mg/L carbenicillin. Putatively selected transformants were confirmed by amplification of selectable marker genes (ADA and NPT II) by polymerase chain reacion. Successful transcripts of ADA gene were detected by Northern blot analysis. Enzyme activity of ADA was also examined by spectrophotometric analysis, and expression of ADA gene in hot pepper suggests the potential application of ADA gene as a selectable marker in plants.

• Journal of Plant Biotechnology
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• v.32 no.1
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• pp.51-55
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• 2005

Chinese leymus (Leymus chinensis Trin.) is a perennial grass that is widely distributed at high pH sodic and arid soil in the northeastern Asia. An efficient regeneration system was established through somatic embryogenesis of mature seeds to understand its high adaptability to harsh environmental conditions on the basis of molecular biology. The calli were efficiently induced (about $70\%$) from mature seeds on MS medium supplemented with $1.5\;\cal{mg/L}$ 2,4-D. Somatic embryos were formed from the surface of embryogenic callus on MS medium supplemented with $2.0\;\cal{mg/L}\;kinetin\;and\;0.5\;\cal{mg/L}$ NAA after 3 weeks of culture. Roots were induced from the shoot when transferred to MS medium without plant growth regulator for 1 week. Plant regeneration rate was $36\%$ and regenerated plantlets were grown to normal mature plants in pot. An efficient plant regeneration system in this study will be useful for molecular breeding of L. chinensis.

• Journal of Korean Society of Forest Science
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• v.77 no.2
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• pp.199-207
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• 1988

Three clones of Populus alba ${\times}$ P. grandidentata have been tested for susceptibility to Agrobacterium tumefaciens strains A281 and A348. We determined the optimum concentration of kanamycin sulfate for effective selection of leaf disc-derived, transgenic tissues transformed using Agrobacterium binary vector pGA472 containing a neomycin phosphotransferase gene (NPT-II) which confers kanamycin resistance. Of the wild type Ti plasmids contained by the two Agrobacterium strains, pTiBo542 of strain A281 appears to be best suited to serve as a helper plasmid for binary vector systems. A relatively low concentration (10mg/l) of kanamycin sulfate inhibited adventitious shoot initiation from leaf discs on regeneration medium. Transformed kanamycin-resistant calli were obtained by culturing Agrobacterium inoculated leaf discs on selective regeneration medium. The transformed kanamycin-resistant calli continued to grow on regeneration media supplemented with kanamycin sulfate to levels of 50 and 200mg/l. The growth of non-co-cultivated control calli was severely inhibited on regeneration medium containing 50mg/l kanamycin sulfate.

• Journal of Plant Biotechnology
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• v.46 no.1
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• pp.32-36
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• 2019

Calla lilies (Zantedeschia spp.) are monocotyledonous ornamental plants which belongs to the Araceae family. After the release of elite calla cultivar, an efficient propagation system is needed for commercial use. Despite the use of conventional propagation methods such as splitting of tubers and rhizomes of calla, rapid and efficient propagation system should be developed. In order to achieve this goal, stem segments contained apical meristems derived from calla lily cultivar (cv. Gag-si) were cultured on Murashige and Skoog (MS) medium supplemented with various concentrations of cytokinin and auxin. This was aimed at inducing embryogenic calluses, shoots and multiple shoots. As a result, about 25% of induction rates of yellow embryogenic calluses were observed with MS medium containing both $0.5mg{\cdot}L^{-1}\;NAA$ and $1.5mg{\cdot}L^{-1}\;BA$ as growth regulators. In the experiments involving the regeneration from embryogenic calluses through shoot formation, MS medium supplemented with $0.5mg{\cdot}L^{-1}\;IAA$ and $2.0mg{\cdot}L^{-1}\;BA$ showed the highest rates at approximately 85 ~ 90% with regard to the formation of shoots in calla. Moreover, multiple shoots needed for rapid propagation were generated when explants were cultured on MS medium supplemented with $0.5mg{\cdot}L^{-1}\;IAA$ and $2.0mg{\cdot}L^{-1}\;BA$ with 40% of formation rate. In this study, the combination of auxin and cytokinin showed positive effects on both the induction of embryogenic calluses, the formation of shoots as well as multiple shoots in calla. The regeneration system described here can contribute to the development of breeding programs of calla in the future.