• Proceedings of the Plant Resources Society of Korea Conference
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• 2000.10b
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• pp.16-17
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• 2000

Aralia elata is found in mountain areas all over Korean peninsula. Aralia elata is the scientific name for Japanese angelica tree. The tree belongs to the family Araliaceae, commonly known as ginseng family. Bud sprouts from apical shoot tip of the plants are rich in flavor and thus mainly used for both folk medicine and vegetable. The stalks with apical buds are gathered in the early spring and planted in sandy soil or water in the greenhouse. The sprouting buds are then collected and sold as fresh vegetable. Although the plants have been used for food, they have been cultivated in a very small scale. In spring, local farmers just go around mountain areas to search the trees and gather the stalks as much as they get and sell them to the market. No conservation efforts have been made to stop the exploitation or to save the dwindling population. We tried to provide local farmers with the plants that may be used as an alternative to stalks from wild populations. This will hel! p conserve the wild populations. However, it is hard to propagate them either by conventional cuttings or by seed germination in a short period of time. Mass propagation using tissue culture systems have shown a great promise with several woody plants. Recently we developed a mass propagation technique via somatic embryogenesis system using mature and/ or juvenile explants for Aralia elata. Several factors affecting somatic embryogenesis system including SE(somatic embryo) induction, embryogenic callus proliferation, SE germination, plant regeneration and transplanting to field will be presented. And some problems arising for the somatic embryogenesis system will be also discussed.lso discussed.

• Korean Journal of Plant Resources
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• v.27 no.3
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• pp.242-248
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• 2014

This study was conducted to establish an efficient transformation system by using somatic embryogenesis in an important Korean native conifer, Korean fir (Abies koreana). Embryogenic masses were induced from mature zygotic embryos of the Korean fir on Schenk and Hildebrandt medium, which was supplemented with thidiazuron. For genetic transformation, the embryogenic masses were co-cultivated with a disarmed Agrobacterium tumefaciens strain C58/pMP90 containing the plasmid vector pBIV10 or LBA4404 containing the plasmid vector MP90. Both vectors contain the kanamycin resistance and beta-glucuronidase (GUS) reporter genes. A total of 48 lines of embryogenic masses were selected on mLV medium containing $50{\mu}g/mL$ of kanamycin after 4 weeks of culture, following 3 days of co-cultivation with A. tumefaciens strain C58/pMP90 carrying pBIV10 (none of the lines was cultivated with strain LBA4404 carrying MP90). Quantitative real-time PCR was performed, and high levels of GUS transcripts were observed in the 48 putative transgenic lines; however, the control (non-transgenic line) showed negative results. Results of histochemical staining showed that the expression of the GUS reporter gene was observed in somatic embryos that developed from the embryogenic masses of all 48 lines. Stably transformed cultures were successfully produced by co-cultivation with A. tumefaciens strain C58/pMP90 carrying pBIV10 in Korean fir. Here, we have reported an Agrobacterium-mediated gene transfer protocol via somatic embryogenesis that may be helpful in developing breeding and conservation strategies for the Korean fir.

• Korean Journal of Plant Tissue Culture
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• v.25 no.2
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• pp.125-129
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• 1998

Cucumber (Cucumis sativus L.) plants were regenerated through organogenesis and somatic embryogenesis in cotyledon and hypocotyl cultures. The shoots were efficiently formed on the basal region of cotyledons cultured on MS medium containing 1.0㎎/L zeatin and 0.1㎎/L IAA in all cultivars used. Embryogenic calli were formed on hypocotyl segments cultured on MS medium containing 1.0㎎/L 2,4-D in cv. group 'Nakhab' and maintained by consecutive subculture on the same medium every 2-3 weeks without loss of embryogenic ability. Upon transfer to MS basal medium, high frequency somatic embryogenesis was achieved easily from embryogenic callus. Regenerated plantlets through organogenesis and somatic embryogenesis were transplanted to pots and gradually acclimatized to greenhouse condition where they subsequently produced fruits.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.343-356
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• 2010

Plant micropropagation techniques include bud cultures using apical or axillary buds, organogenesis through callus culture or adventitious bud induction, and somatic embryogenesis. In Korea Forest Research Institute (KFRI), the first tissue culture trial in woody plant was initiated from the bud culture of hybrid poplars (Populus alba x P. glandulosa) in 1978. Since then several mass propagation techniques have developed from conifer and hardwood species, resulting in allowing practical application to Poplars, Birches and some oak species. In addition, useful micropropagation and genetic resources conservation techniques were established in some rare and endangered tree species including Abeliophyllum distichum. Among various in vitro propagation techniques, somatic embryogenesis is known to be the most efficient plant regeneration system. Since the first somatic embryo induction was reported in Tilia amurensis by KFRI in 1986, various protocols for direct or indirect somatic embryogenesis systems have developed in conifer and hardwood species including Larix leptolepis, Pinus rigida x P. taeda F1, Kalopanax septemlobus and Liliodendron tulipifera, etc. However, most of these technologies have been developed using juvenile tissues, i.e. immature zygotic embryos or mature embryos. Therefore it has been difficult to directly application to tree breeding program due to their unproven genetic background. Recently remarkable progresses and new approaches have been achieved in mature tree somatic embryogenesis. In this article we reviewed several micropropagation techniques, which have been mainly developed by KFRI and recent international progresses.

• Plant Biotechnology Reports
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• v.2 no.1
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• pp.87-92
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• 2008

An improved protocol for high frequency plant regeneration via somatic embryogenesis from zygotic embryo-derived cell suspension cultures of watershield (Brasenia schreberi) was developed. Zygotic embryos formed pale-yellow globular structures and white friable callus at a frequency of 80% when cultured on halfstrength MS medium supplemented with $0.3mg\;l^{-1}$ 2,4-D. However, the frequency of formation of pale-yellow globular structures and white friable callus decreased slightly with increasing concentrations of 2,4-D up to $3mg\;l^{-1}$, where the frequency reached ~50% of the control. Cell suspension cultures from zygotic embryoderived white friable callus were established using half-strength MS medium supplemented with $0.3mg\;l^{-1}$ 2,4-D. Upon plating of cell aggregates on half-strength MS basal medium, approximately 8.3% gave rise to somatic embryos and developed into plantlets. However, the frequency of plantlet development from cell aggregates was sharply increased (by up to 55%) when activated charcoal and zeatin were applied. Regenerated plantlets were successfully transplanted to potting soil and grown to normal plants in a growth chamber. The distinctive feature of this study is the establishment of a high frequency plant regeneration system via somatic embryogenesis from zygotic embryo-derived cell suspension cultures of water-shield, which has not been previously reported. The protocol for plant regeneration of watershield through somatic embryogenesis could be useful for the mass propagation and transformation of selected elite lines.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.2
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• pp.131-135
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• 2000

The vitellin of the fireflies, Luciola unmunsana and L. lateralis was characterized. The vitellin of L. unmunfon is composed of two subunits, designated Vnl (195 kDa) and Vn2 (185 kDa) in SDS-polyacryamide gel electrophoresis. These two subunits of vitellin of L. unmunsana gradually decreased during embryogenesis. As expected, these protein bands were presented in female adult hemolymph and egg extracts, but not in male. The vitellin of L. lateralis is also composed of two subunits, designated Vnl (195 kDa) and Vn2 (180 kDa) in SDS-PAGEi and these two protein bands gradually decreased during embryogenesis. Western blot analysis using each of polyclonal antiserum against vitellins of L. unmunsana and L. lateralis showed that two antisera strongly crossereacted with vitellin subunits of L. unmunsana and L. lateralis, suggesting that vitellins of L. unmunsana and L. lateralis have similarity with each other.

• Plant Biotechnology Reports
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• v.5 no.2
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• pp.177-186
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• 2011

This study describes for the first time in Pinus genus a plant regeneration system via a combined pathway of somatic embryogenesis and organogenesis from immature seeds of radiata pine. Somatic embryos were obtained from embryogenic line 2162 of Pinus radiata D. Don on EDM basal medium containing $60{\mu}M$ ABA and 6% sucrose. The explants used for organogenesis experiments were either freshly collected somatic embryos or somatic embryos germinated for 1 week. Germination medium was half-strength LP medium, supplemented with 0.2% activated charcoal. Different induction periods and BA concentrations were assayed for shoot induction. After induction treatments, explants were elongated on the same medium used for germination stage. Rooting medium was quarter-strength LP medium supplemented with three different auxin treatments: $1.5mg\;L^{-1}$ 1-naphthalene acetic acid (NAA), $1.5mg\;L^{-1}$ indole-3-butyric acid (IBA) and $1mg\;L^{-1}$ IBA with $0.5mg\;L^{-1}$ NAA (MIX). The effect of the photon flux ($120mmol\;m^{-2}\;s^{-1}$ and darkness) in the first week of the explants in the rooting media was also tested. This methodology could offer an alternative to overcome some problems associated with somatic embryogenesis such as the seasonality of embryogenic tissue (ET) initiation or a low embryo production from the ET, a particularly important issue in the case of genetically transformed ETs.

• Journal of Crop Science and Biotechnology
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• v.11 no.2
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• pp.107-110
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• 2008

A high-efficiency, reproducible somatic embryogenesis system for strawberry cultivar Chandler was developed. Thirty-one somatic embryos per explant(max no.) were recorded in leaf discs which were cultured on medium containing MS salts+$B_5$ vitamins+2% glucose+4.0 mg $1^{-1}$TDZ(Thidiazuron) and incubated at $10{\pm}1^{\circ}C$ under darkness for one week followed by three weeks under 16-h photoperiod. The scanning electron microscopic(SEM) ontogeny revealed the normal development of somatic embryos from globular to heart-shaped and dissection microscopy from torpedo-shaped to cotyledonary-stage embryos. The maximum germination percentage of 48% could be obtained on MS medium containing kinetin(1.0 mg $1^{-1}$) and the maximum survival percentage(79%) of plantlets after four weeks was found to be in the mixture of vermiculite, peatmoss, and soilrite(1:1:1).

• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.299-307
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• 2000

A large amount of information is currently available for somatic embryogenesis of plants. However, one common problem related to somatic embryos is that the conversion rate can be low for some species. Apical meristems are responsible for post-embryonic growth of the embryo. The low percentage observed is most likely a result of poor apical meristem development or defects in the meristem organization during somatic embryogenesis. In flowering plants, apical meristems are well developed by the late heart stage of zygotic embryo development. In conifers, such as white spruce, apical meristems are formed at the pre-cotyledon stage. Thus, apical meristem development occurs very early, prior to the maturation stage of embryo development. Once formed, meristems are stably determined. In the somatic embryo, as exemplified by white spruce, since embryo development is not synchronous, tissue differentiation including apical meristem formation occurs throughout the“maturation”stage. Different apical meristem organizations can be found among different individuals within a population. In contrast to their zygotic counterparts, the apical meristems appear not to be stably determined as their organization, as the shoot apical meristem especially, can be easily modified or disrupted. Precocious germination seldom results in functional plantlets. All these observations suggest that the conditions for somatic embryo maturation have not been optimized or are not suitable for meristem formation and development. The following strategies could improve meristem development and hence conversion: 1. Simulate in ouuio conditions to promote meristem development prior to the“maturation”treatment.2. Prevent deterioration of apical meristem organization during somatic embryo maturation.3. Promote further meristem development during embryo germination.

• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.319-322
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• 1998

Culture conditions for high frequency embryogenesis and plant regeneration in anther cultures of various F$_1$ hybrid and homozygous lines of pepper (Capsicum annuum L.) are described. Anthers pigmented less than halfway from the distal end were dissected from the flower bud in which petals elongated 2 mm higher than the receptacle. They were placed on Dumas medium supplemented with 0.1 mg/L 2,4-D and 0.1 mg/L kinetin. After four weeks of culture, embryos began to appear on anthers. After eight weeks of culture, frequencies of embryo formation reached up to 58.3%. Upon transfer to MS basal medium, greater than 95% of embryos developed into plantlets.