• Korean Journal of Plant Resources
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• v.28 no.3
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• pp.363-369
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• 2015

Sweet potato has low regeneration capacity, which is a serious obstacle for the fruitful production of transgenic plants. Simple and rapid regeneration method from storage root explants of purple sweet potato (Ipomoea batatas L.) was investigated. The embryogenic callus was observed from 4 cultivars and its highest rate was induced at 1 μM 2,4-D after 5 weeks of culture. Result revealed that a low concentration of 2,4-D and low light intensity was important factors for embryogenic callus formation. After subculture on medium with 5 μM ABA for 4 days, subsequently, occurred the regeneration of shoots within 4 weeks when these embryogenic callus was transferred onto the MS hormone free medium. Regenerated shoots were developed into platelets, and grown normal plants in the greenhouse. We developed a simple and quickly protocol to regenerate plantlets in storage root explants of purple sweet potato. This regeneration system will facilitate tissue culture and gene transfer research of purple sweet potato.

• Journal of Forest and Environmental Science
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• v.30 no.4
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• pp.405-411
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• 2014

Wild Korean ginseng has been recognized as highly precious medicine since ancient times. Nowadays, the population of wild ginseng in the forest of Korean peninsula is very rare due to indiscreet harvest. In this work, we investigated the plant regeneration via somatic embryogenesis from embryogenic callus of old wild ginseng (more than 50 years-old) and compared the features of plants regenerated from 5-years old and 50 years-old ginseng. Induction of embryogenic callus from adventitious roots of 50 year-old wild ginseng required 83 weeks of culture, but only 10 weeks were sufficient for 5 year-old ginseng. Height and width of plants derived from the old wild ginseng was smaller and slender compared to the plantlets derived from 5 year-old ginseng. Total chlorophyll contents was 2-6 time lower in plantlets regenerated from 50 year-old wild ginseng than those from 5 year-old ginseng, but anthocyanin content was higher in 50 year-old ginseng. Our results revealed that plants regenerated from old wild ginseng have different morphological and physiological characters probably due to age-dependent phenomenon.

• Plant Biotechnology Reports
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• v.3 no.3
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• pp.251-257
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• 2009

Embryogenic callus was obtained from bulb segments of Iris pseudacorus on Murashige and Skoog (MS) medium with 2,4-dichlorophenoxyacetic acid (2,4-D) alone or in combination with kinetin. When early globular somatic embryos were subcultured onto MS medium with $4.52{\mu}M$ 2,4-D, high frequency of somatic embryogenesis was obtained. Deprivation of 2,4-D was required for maturation. Mature somatic embryos had an elongated scutellum with a notch on the base of scutellum. Separation of embryos from embryo clusters was necessary to enhance the frequency of germination. Germination was stimulated by separation of embryos from embryo clusters and transfer onto fresh half-strength MS medium with 3% sucrose. After acclimation in artificial soil in greenhouse for 2 months, 96.4% of plantlets survived.

• Plant Resources
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• v.2 no.1
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• pp.1-9
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• 1999

The callus from the hypocotyl region of immature embryo of Citrus junos Sieb. was efficiently induced in the $\frac{1}{2}$ MS medium containing 45uM BA after 8 weeks culture. The callus was developed into the two callus type, embryogenic callus and nonembryogenic callus, which can be distinguished by visual examination depending on color and appearence. In vitro regeneration of callus established efficiently in the hormone-free MS medium from the embryogenic callus. In order to investigate the physiological changes depending on the developmental stage of embryo, the embryo was formed in the MS medium. The embryogenic and nonembryogenic callus, and the various stages of the somatic embryo were examimed the changes of esterase activity, and their isozyme patterns as well. The protein content and esterase activities was gradually increased on the developmental stages of embryo. Total protein pattern were different by the SDS-PAGE and were appeared strong band of 23 KD in the torpedo stage. The pattern of the esterase isozyme was exhibited a difference between embryogenic callus and nonembryogenic callus. It was appered pI 6.0, 8.0, 8.2 in the embryogenic callus. Also the new band of pI 4.75 was appeared in the cotyledon. These results suggest that the changes of esterase activities and isozyme patterns are importent factor in the differentiation and development of citrus.

• Journal of Plant Biotechnology
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• v.5 no.3
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• pp.169-172
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• 2003

Somatic embryogenesis was initiated from in vitro grown leaf explants of rose following an induction period of four weeks on MS basal medium supplemented with auxin and several subcultures on MS medium with cytokinin. '4th of July' showed the highest regeneration frequencies on 1 mg/L NAA followed by culture on medium with 4 mg/L zeatin. The embryogenic callus was propagated on MS medium with NAA, zeatin and $GA_3$. Germination of somatic embryos was achieved on MS medium with 1 mg/L BA. Somatic embryo derived plantlets were hardened and successfully transferred to the greenhouse.

• Korean Journal of Plant Tissue Culture
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• v.22 no.6
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• pp.323-327
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• 1995

This experiment was carried out to observe the origin and developmental pattern of somatic embryos of Oenanthe javanica ($B^{L}.$) DC. The experiment included observation of embryogenic cells and their development stages by light microscope, transmission electron microscope and scanning electron microscope. The embryogenic cells, which were smaller than non-embryogenic cells in size with expanded nucleus and dense cytoplasm. When stained with hematoxylin, the embryogenic cells were readily distinguished from the non-embryogenic cells of which cell walls were stained with safranin. It was observed at somatic embryos developed from single cells on the epidermis of developing embryos or in the surface or inside of embryogenic clumps by segmentation pattern. Observation with a transmission electron microscope revealed that the embryogenic cells had dense cytoplasm expanded nucleus, small vacuoles, large amyloplasts containing starch grains, and abundant organelles including lipid bodies. Under a scanning electron microscope, embryogenic callus was shown to consist of very smaller cells than non-embryogenic cells in an orderly arrangement and covered with a net-like structure, while the non-embryogenic callus consisted of large cells, irregular in size and arrangement, and covered with a gelatin-like material.

• Korean Journal of Plant Tissue Culture
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• v.27 no.3
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• pp.233-238
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• 2000

To obtain a basic information of the development of Genus Viola, morphological and histological observation of in vitro calli and cells in Viola culture cells were investigated. There were two callus types obtained by long term subculture of wild viola (Viola partrinii DC. ) petiole callus. One was friable callus - soft and pale green in color and small cells in size, and the other was compact callus - compact and deep bluish green in color, large cells in size. In scanning electron microscopic observation, friable callus was composed of voculated cell around small. cell clump, while compact callus was composed of cells filled with protoplasm Somatic embryogenesis was observed from suspension culture of the compact callus.

• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.879-886
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• 2004

Effects of culture mediwn supplements and osmotic stress treatment on embryogenic callus induction and somatic embryogenesis were investigated in order to optimize tissue culture conditions of alfalfa(Medicago sativa L.). SH mediwn containing 5mgIL 2,4-D and 0.2mgIL kinetin was optimal for embryogenic callus induction from cotyledon tissue of alfalfa. Somatic embryos were formed when the embryogenic callus was cultured on SH mediwn supplemented with ImgIL 2,4-D and 2mgIL BA. Supplementation of 5mM L-proline and IgIL casein hydrolysate into the regeneration mediwn further increased plant regeneration frequency. Osmotic stress treatment of callus appeared to improve the frequency of somatic embryo formation, but the frequency of somatic embryo formation differed by the osmotic stress treatment using different osmotic stressors. The highest plant regeneration frequency of 30.7% was observed when embryogenic callus was treated with 0.7M sucrose for 18h. Efficient regeneration system established in this study will be useful for molecular breeding of alfalfa through genetic transformation.

• Plant Resources
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• v.8 no.2
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• pp.81-86
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• 2005

An efficient plant regeneration system of Gentiana scabra through somatic embryogenesis was established. Leaves and roots of seedlings of Gentiana scabra excised after germination were cultured on MS basal medium with 2,4-D, NAA or BA. Embryogenic callus was obtained on MS medium with 0.5 mg/L 2,4-D alone or 0.1 mg/L 2,4-D combimation with 1.0 mg/L BA after 45 days of culture. These embryogenic calli gave rise to somatic embryos, which subsequently developed into plantlets on MS medium without PGRs. Also, shoots were effectively differentiated from embryogenic callus when root segments were cultured on MS medium supplement with 0.1 mg/L 2,4-D and 1.0 mg/L BA. Shoots were effectively rooted on MS medium without PGRs. In vitro flowers were formed from plantlets cultured on MS medium with $5\%$ sucrose after 60 days of culture.

• Journal of Plant Biology
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• v.37 no.3
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• pp.381-385
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• 1994

The highest degree of callus formation was obtained from the shoot tips of Dianthus superbus when cultured on the MS medium supplemented with 2.0 mg/L NAA and 0.5 mg/L BAP. Embryogenic calluses were obtained from the seperated friable calluses on MS medium containing 2.0 mg/L 2,4-D after 7-8 wk of culture. For plant regeneration, embryogenic calluses were selected and cultured on te proliferation medium. After 3 wk, somatic embryos appeared on MSK medium (0.5 mg/L NAA, 2.0 mg/L kinetin) and N6 medium (2.0 mg/L kinetin, 0.1 mg/LNAA, 0.1 mg/L 2,4-D and 2.0 g/L casein hydrolysate). When these somatic embryos were kept under continuous illumination, shoots were successfully regenerated on the both media. The shoots were rooted on MS medium supplemented with 2.0 mg/L NAA.