• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.1
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• pp.1-6
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• 2009

In order to optimize tissue culture conditions for genetic transformation of zoysiagrass (Zoysia japonica Stued.), the effect of plant growth regulators and culture medium supplements on embryogenic callus induction from mature seeds of a cultivar 'Zenith' were investigated. The optimal concentration and treatment period of NaOCl is 30% (v/v) for 60 minutes. Cultivation of mature seed on the callus Induction medium containing 3 mg/L 2,4-D and 3 mg/L dicamba showed 17.5% of embryogenic callus formation frequency. Supplementation of 1 g/L casein hydrolysate and 500 mg/L L-proline improved frequency of embryogenic callus induction. Audition of the medium with 5 mg/L $AgNO_3$ and 20 mg/L cysteine enhanced frequencies of embryogenic callus induction. Efficient callus induction system established in this study will be useful for molecular breeding of Boysiagrass through genetic transformation.

• 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.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.1067-1074
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• 2005

In order to optimize tissue culture conditions of Kentucky bluegrass(Poa pratensis L.), effects of culture medium supplements, media and cultivars on embryogenic callus induction and regeneration of plants were investigated. MS medium containing 3mg/L 2,4-D and 0.1mg/L BA was optimal for embryogenic callus induction from mature seeds. The highest plant regeneration frequency(57.7%) was observed when the embryogenic calli were cultured on N6 medium supplemented with 1mg/L 2,4-D and 3mg/L BA. Among several basic media, MS and N6 medium were optimal for callus induction and plant regeneration, respectively. Genotype was an important factor in plant regenerability. ‘Newport’ showed to have higher regeneration frequency of 53.4%. Regenerated plants were grown normally when shoots transplanted to the soil. A short tissue culture period and high-frequency regeneration system would be beneficial for molecular breeding of Kentucky bluegrass through genetic transformation.

• Journal of Plant Biotechnology
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• v.35 no.1
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• pp.81-86
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• 2008

This study describes conditions for plant regeneration from protoplasts-derived from embryogenic callus of satsuma mandarin. Plants were generated via somatic embryogenesis. Protoplasts isolated directly from nucellar callus induced from immature ovule of satsuma mandarin cv. Okitsu (Citrus unshiu Marc.) were cultured in 0.6M $BH_3$ medium. Cell division and plating efficiency were affected by protoplast culture method. The liquid over solid method was the most effective for formation of microcalli. Most of microcalli grew rapidly and transferred onto embryoid formation medium. Optimum embryoid formation medium was MT medium containing 1.5 g/L malt extract, 0.146 M sucrose and the medium for plantlet regeneration was MS medium containing 0.09M sucrose, 1.0 mg/L $GA_3$. No differences were noticed in growth habits and leaf characters such as shape, thickness, and colour between protoplast-derived plants and nucellar seedlings. This plant regeneration system from protoplasts-derived from embryogenic callus provides an alternative way for producing new scion and rootstock cultivar from citrus species which can not be crossed.

• Korean Journal of Plant Tissue Culture
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• v.27 no.2
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• pp.149-154
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• 2000

Embryogenic suspension cultures were initiated using embryogenic callus from immature inflorescence explants (Aralia cordata Thunb.) cultured on solid MS medium containing 1 mg/L 2,4-D for 8 weeks and then the embryogenic callus was proliferated in liquid MS medium containing 1 mg/L 2,4-D. After sieving the suspensions (pore size 270$\mu$m), embryogenic cells were cultured in liquid MS medium with cytokinins (kinetin, BA, zeatin) for two weeks. When the embryogenic cells were transferred to liquid MS basal medium, primary somatic embryos were developed after 5 weeks of culture. Secondary embryos were developed directly from the primary torpedo and cotyledonary embryos cultured in solid MS basal medium. Frequency of secondary embryogenesis was higher on medium containing 2 mg/L kinetin than the other cytokinins. Plant regeneration was highly recorded by placing secondary cotyledonary embryos induced from primary cotyledonary embryos in MS medium containing 2 mg/L kinetin or 2 mg/L zeatin (25.4% and 28.6%, respectively). The plant regeneration from secordary embryos was prohibited by tertiary embryogenesis.

• 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.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.1
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• pp.52-60
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• 2004

The optimized in vitro culture system was investigated for improvement of regeneration efficiencies by observing the responses of scutella-derived callus of Korean rice (Oryza sativa L.). Large variations of callus induction (43.9-93.9%) and shoot regeneration (0-88.7%) were observed among the rice cultivars depending on medium. However, shoot regeneration was significantly improved by selected utilization of basal medium, growth regulators, and carbon sources. N6 basal medium was more efficient for embryogenic callus induction than MS or LS basal medium, while MS was superior to N6 for shoot regeneration. The calli of highly regenerative cultivars grew faster and showed higher rates of green tissue formation (GT) and shoot regeneration (SR) and lower rate of callus browning (CB) than those of recalcitrant cultivars. Although a higher level of kinetin stimulated the GT and SR in highly regenerative cultivars, $10\textrm{mgL}^{-1}$ kinetin generally suppressed the GT and SR, while CB was accelerated compared to $2\textrm{mgL}^{-1}$ kinetin. Additional benefits of sorbitol combined with maltose (or sucrose) under $5\textrm{mgL}^{-1}$ kinetin were certainly confirmed on regeneration efficiencies compared to sucrose alone as carbon source and osmotic regulator. This combination showed high rate of GT and SR with multiple shoots while low rate of CB. With MSRK5SM-Pr medium ($5\textrm{mgL}^{-1}$ kinetin, 3% sorbitol, 2% maltose, $500\textrm{mgL}^{-1}$ proline), the regeneration efficiencies of total 17 out of 24 cultivars were practically improved 160% on average compared to MSRK2S ($2\textrm{mgL}^{-1}$ kinetin, 3% sucrose) control medium. Especially, the medium was most effective to the cultivars showing a medium level of regenerability such as Daesanbyeo and Dongjinbyeo and Suwon477, enhancing efficiencies more than 300-600% compared to MSRK2S medium.

• Journal of Plant Biotechnology
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• v.32 no.2
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• pp.123-128
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• 2005

A series of experiments were performed to establish regeneration system through friable embryogenic callus (FFC) of Lilium longiflorum 'Nellie White'. Only hard and regular callus was induced from bulb scales on medium containing 2.0 mg/L dicamba and $30{\sim}90$ g/L sucrose. The induced hard callus was subcultured on medium with 2.0 mg/L dicamba and 30 g/L sucrose, and used as a material for induction of FEC. In order to induce FEC, induced hard and regular callus was chopped into $1{\sim}2\;mm$ segments, and re-cultured on medium with 2.0 mg/L dicamba and 90 g/L sucrose. FEC was induced from chopped hard calli by the subcultures of two months interval. The induction rate of FEC was enhanced when hard callus was subcultured on same medium. FEC was proliferated more than 5 times on medium with $1.0{\sim}2.0\;mg/L$ dicamba and 90 g/L sucrose. Bulblet differentiation from FEC was very favorable on MS medium supplemented with 0.1 mg/L BA, 1.0 mg/L NAA and 30 g/L maltose, but many differentiated bulblets were changed to vitrificated ones. The differentiation of normal bulblets was most effective on medium containing $0.5{\sim}1.0\%$ activated charcoal and 30 g/L sucrose.

• Journal of Plant Biotechnology
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• v.41 no.2
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• pp.89-93
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• 2014

Long-term subcultured rose embryogenic calluses, which had been maintained for more than 5 to 6 years since the first embryogenesis from calluses induced from in vitro roots of rose, were identified as potential material for the development of transgenic plants. The first embryogenic calluses from 'Sweet Yellow' and two breeding lines (KR056002 and KR056006) were obtained in 2007 and 2009, respectively. Subsequently, we found that plants regenerated from long-term embryogenic calluses (LEC). Whereas the LEC from 'Sweet Yellow' takes 3 to 4 months to regenerate plants, those of the two breeding lines take 4 to 5 months. This period of time is the same as that taken for plants to regenerate from the first embryogenic callus. New embryogenesis was observed from atypical bodies (ABs) that appeared during the process of long-term subculture. We found that it is possible to use the AB as a material for new embryogenesis.