• Journal of Plant Biotechnology
• /
• v.34 no.1
• /
• pp.25-29
• /
• 2007

Plant regeneration system from zygotic embryos (2n=24) of Lilium lancifolium Thunb. via bulblet formation was estabished. Zygotic embryos of Lilium lancifolium formed bulblets and somatic embryos simultaneously when they cultured on MS medium supplemented with low concentration of 2,4-D. The highest frequency of bulblet and somatic embryo formation from zygotic embryos of Lilium lancifolium was 66.7% and 56.7%, respectively. The frequency of bulblet and somatic embryo formation was decreased when they cultured on MS medium over than 1 mg/L of 2,4-D. To regenerate whole plants, somatic embryos formed on zygotic embryos were transferred to MS basal medium. However somatic embryos did not fully converted into plantlets. Further incubation in the light, elongated somatic embryos formed numerous bulblets at the base of somatic embryos. Upon transfer to MS basal medium, bulblets were successfully converted into plantlets after further 4 weeks of culture in the light. After acclimatization, plantets from bulblets were transferred to soil and grown to normal plants in growth chamber (approximately $30\;{\mu}mol\;m^{-2}s^{-1}$, 16/8h photo period, $25^{\circ}C$) The chromosome analysis revealed that plants regenerated from zygotic embryos showed 2n=24. These results indicate that chromosome stability of source tissue is maintained during plant regeneration via bulblet formation.

• Journal of Plant Biotechnology
• /
• v.6 no.1
• /
• pp.55-61
• /
• 2004

Callus induction and somatic embryogenesis are fundamental to cotton tissue culture biotechnology. An efficient protocol for callus induction, somatic embryogenesis and their maturation have been developed to regenerate plantlets from cotton (Gossypium hirsutum L.) variety coker 312. Embryogenic callus was initiated from hypo-cotyl region that was used as an explant at seedling stage when it was about 7-8 days old. Callus induction was achieved through culturing hypocotyls (5-7mm) on $MS_{1a} medium supplemented with 2,4-D (0.1 mg/L) and KT (0.5 mg/L) for six weeks. A friable, colorless, bulky and well proliferating callus becomes greenish with the addition of NAA (2.0 mg/L), ZT (0.1 mg/L) and removal of 2,4-D (M $S_{1b}$) cultured for two weeks then again transferred to $MS_{1a}. 2,4-dichlorophenoxyacetic acid (2,4-D) promoted the proliferation of embryogenic callus, but had a negative effect on the differentiation and germination of somatic embryos. ZT (0.1mg/L) and activated charcoal (2g/L), both hormones play an important role in differentiation and germination of somatic embryos in hypocotyls derived embryogenic callus but in case of cotton, such a capability have been observed on MS medium with 1.92 g/L $KNO_3$, but it is considered to attain somewhat more improvement. High embryogenesis frequency was achieved through nutrient deficient stress treatment. The frequency of globular embryogenesis (two-three folds) was achieved when well proliferating callus was (from $MS_{1a}$ media) cultured on MS (1/5 strength) medium for four weeks. Here the development of anthocyanins is the best indicator for somatic embryogenesis. However, when embryoid callus was cultured on MS (full strength) medium, the globular embryos were developed into normal plantlets immediately. In this procedure 27.49% cotyledenary embryos were developed. Of that 70% cotyledenary embryos were developed not only into normal plantlets but rooted simultaneously, when cultured on MS (with 0.05 mgg/L giberrelic acid) medium. So complete plants could be regenerated through somatic embryogenesis from hypocotyl explants within 6 months.s.

• Korean Journal of Plant Tissue Culture
• /
• v.21 no.5
• /
• pp.299-302
• /
• 1994

Immature zygotic embryos (up to 4mm in length) were cultured on MS medium supplemented with 0.5 to 8mg/L 2,4-D. Up to 87% of them formed somatic embryos on the plumule without producing an intervening callus. The site of somatic embryo formation was confirmed by culturing plumule explants, which consisted of shoot apical meristem domes with 1 or 2 leaf primordia excised from 2-week-old seedlings. When the concentration of 2,4-D was increased over 4 mg/L, the plumule explants produced nonembryogenic calli only, whereas the distal end of the cotyledons directly formed numerous somatic embryos at frequencies of up to 60%. Upon transfer onto MS basal medium,2 out of 15 somatic embryos converted into plantlets. The plantlets were potted to a soil mixture and grown to maturity in a phytotron.

• Reproductive and Developmental Biology
• /
• v.32 no.4
• /
• pp.249-253
• /
• 2008

Interspecies somatic cell nuclear transfer (iSCNT) is a valuable tool for studying the interactions between an oocyte and somatic nucleus. The object of this study was to investigate the developmental competence of in vitro-matured porcine oocytes after transfer of the somatic cell nuclei of 2 different species (goat and rabbit). Porcine cumulus oocytes were obtained from the follicles of ovaries and matured in TCM-199. The reconstructed embryos were electrically fused with 2 DC pulses of 1.1kV/cm for $30{\mu}s$ 0.3M mannitol medium. The activated cloned embryos were cultured in porcine zygote medium-3 (PZM-3), mSOF or RDH medium for 7 days. The blastocyst formation rate of the embryos reconstructed from goat or rabbit fetal fibroblasts was significantly lower than that of the embryos reconstructed from porcine fetal fibroblast cells. However, a significantly higher number of embryos reconstructed from goat or rabbit fetal fibroblasts cultured in mSOF or RDH, respectively, developed to the morular stage than those cultured in PZM-3. These results suggest that goat and bovine fetal fibroblasts were less efficacious than porcine-porcine cloned embryos and that culture condition could be an important factor in iSCNT. The lower developmental potential of goat-porcine and porcine-bovine cloned embryos may be due to incompatibility between the porcine oocyte cytoplasm and goat and bovine somatic nuclei.

• Korean Journal of Medicinal Crop Science
• /
• v.14 no.4
• /
• pp.255-260
• /
• 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
• /
• v.6 no.2
• /
• pp.87-90
• /
• 2004

An efficient plant regeneration system in alfalfa (Medicago sativa L.) through somatic embryogenesis was established. Embryogenic callus was obtained by culture of hypocotyl segments on MS medium with 0.02mg $L^{-1}$ IAA and 1.0mg $L^{-1}$ zeatin after 45 days of culture. Embryogenic calli were converted to the somatic embryos when transferred to either MS medium without plant growth regulators (PGRs) or MS medium containing various cytokinin (BA, kinetin and zeatin). Most of the somatic embryos were developed into plantlets on MS medium supplemented with 0.1 mg $L^{-1}$ kinetin. Also, secondary embryos appeared on the surface of primary embryo but they showed abnormal growth. Regenerated plantlets were transplanted to pots containing vermiculite and perlite for further analysis.

• Journal of Plant Biotechnology
• /
• v.29 no.4
• /
• pp.253-257
• /
• 2002

To establish the optimum condition for plant regeneration from somatic embryos of Acanthopanax sessiliflorus Rupr. et Maxim, a medicinal plant, somatic embryos were induced from zygotic embryo-derived embryogenic callus in hormoen-free MS medium. To induce plantlet conversion, cotyledonary somatic embryos were cultured on MS solid medium with GA$_3$at various concentrations (0~10 mg/L) for three weeks. Plantlets were transferred to 1/3 MS solid medium with 0.5% charcoal for 7 weeks. Stem length was increased proportionally to the concentration and treatment period of GA$_3$. Also, the highest leaf width (8.9 mm) and leaf number (2.84) of plantlet were obtained when plantlets were converted on 5,10 mg/L GA$_3$pretreatments, respectively. The highest plant conversion frequency (66.7%) was obtained when the somatic embryos were cultured on medium containing 5 mg/L GA$_3$ for 3 weeks and then were transferred to 1/3 MS medium with 0.5% charcoal. The highest survival rate of soil transfer was 90% when plantlets were regenerated on medium with 5 mg/L GA$_3$ for 3 weeks and then transferred to plastic pots containing vermiculite and sand mixture for 4 weeks.

• Journal of Korean Society of Forest Science
• /
• v.87 no.1
• /
• pp.57-61
• /
• 1998

Somatic embryo induction, plant regeneration, and field establishment were investigated from tissue cultured winter buds of a 10-year-old tree Aralia elata. Embryogenic calli were obtained from cultures of winter buds on MS medium supplemented with 2,4-D. A number of somatic embryos were regenerated from the calli on an embryo induction medium supplemented with 2,4-D and BA. Although abnormal somatic embryos were frequently observed, most of the embryos formed were morphologically normal. All somatic embryos at the later stage of maturity germinated successfully, but only 14% of them could be developed into plantlets on MS basal medium. The plants regenerated from the somatic embryos survived well in the field (survival rates : more than 95%) and have grown normally for three years after transplanting.

• KSBB Journal
• /
• v.11 no.1
• /
• pp.107-114
• /
• 1996

The enhancing effect of excreted cell factors on the production of somatic embryos from suspension cultures of Daucus carota was studied as a function of factors including molecular size, harvesting time, injection period, and concentration of the extracellular compounds. The production of late-stage embryos was increased up to 1, 500 embryos/ml compared with control cultures when high molecular size and extracellular factors, extracted from newly established embryo culture at early stationary phase, were added at the starting time. The stimulating effect on the production of somatic embryos can be attributed to the presence of high molecular size(> 10 kDa) compounds.

• Korean Journal of Plant Tissue Culture
• /
• v.21 no.1
• /
• pp.7-14
• /
• 1994

Immature zygotic embryos of five Korean soybean cultivars cultured on Murashige and Skoog's (MS) medium supplemented with various concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D) produced somatic embryos without forming an intervening callus. The highest frequency (up to 90%) of somatic embryo formation was obtained when zygotic embryos were cultlued on medium containing 1 to 2 mga 2, 0-D in four cultivars. However the frequency was highly variable to the cultivars. Transversely sliced primary somatic embryo halves were also capable of forming secondary embryos at frequencies of up to 70% when cultured on medium containing 0.1 to 1 mg/L 2,4-D. Somatic embryos formed on zygotic embryos cultured on medium containing 0.1 to 0.2 mg/L 2,4-D had two cotyledons more frequently than one horn-type cotyledon and those on medium containing 0.5 to 4mg/L 2,4-LD had a horm-type cotyledon at a prominently higher freequency. However somatic embryos on medium containing 10mg/L or higher concentrations of 2,4-D were usually shunted at the globular stage even after transfer to medium containing lower concentrations of 2,4-D or other growth regulators. non somatic embryos with one or two cotyledons or a hem-type cotyledon were transferred to medium containing $GA_3$, those with two cotyledons converted to plantlets at a higher frequency (25%) than the others.