• Korean Journal of Plant Tissue Culture
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• v.25 no.2
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• pp.115-118
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• 1998

This experiments were carried out to determine the optimum concentrations of plant growth regulators for the direct embryogenesis from the cotyledon culture of Paeonia lactiflora Pall. Zygotic embryos rescued from true seeds were developed abnormally in the medium containing ABA. But somatic embryogenesis from cotyledons of abnormal seedlings was induced more effectively. Also the somatic embryogenesis from cotyledons was promoted in the medium containing ABA. The frequency of embryogenesis was maximum(59.9%) from the cotyledons cultured on MS medium containing 0.5 mg/L ABA on which the frequency of somatic embryos with two cotyledons was 22.6%.

• Korean Journal of Plant Tissue Culture
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• v.27 no.3
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• pp.227-232
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• 2000

This study was carried out to elucidate the effect of cadmium on somatic embryogenesis and plant regeneration from cultured cells of Daucus carota L. Embryogenic calli were induced from cotyledon explants of carrot seedlings cultured on MS solid medium supplemente with 1 mg/L 2,4-D Embryogenic cells proliferated on medium supplemented with 1 mg/L 2,4-D were also cultured in liquid MS medium containing various concentrations (50, 100, 200, 500, 1000 $\mu$M) of cadmium for one week and then transferred to MS basal medium. Somatic embryogenesis occurred in suspension culture treated with 50 $\mu$M and 100 $\mu$M cadmium or untreated with cadmium. When cadmium was treated in suspension culture, production of two and four cotyledonary somatic embryos was reduced, but that of three cotyledonary somatic embryo was increased. Two cotyledonary embryos showed higher regeneration frequency than abnormal somatic embryo with one, three and four cotyledon. Regardless of cotyledonary variation, germination frequency of somatic embryos treated with cadmium was decreased in compared with that of embryos in basal medium.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.11a
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• pp.174-175
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• 2001

미나리 묘를 대량으로 생산하는데 있어서 체세포배를 이용하는 방법이 매우 유리하다. 체세포배는 계절에 영향을 받지 않고 좁은 공간에서 한꺼번에 많은 량의 묘를 생산할 수 있다. 또한 생물반응기 등을 이용하여 대량 생산할 수 있으면 실생묘를 대체할 수 있을 것으로 생각된다. 배양기 내의 공기 환경의 영향은 삼각플라스크를 이용한 소규모 배양에서는 문제가 되지 않았지만 배양기가 커짐에 따라 공기 환경의 변화도 커져 체세포배의 발생과 발아에 영향을 미친다. 체세포배를 배양하는 기간은 배발생과 발아로 나누어, 세포에서 배가 발생하는 처음 2주 동안에는 밀폐 환경, 즉 환기가 거의 되지 않는 환경이 유리하지만 이후의 발아 동안에는 산소를 많이 요구한다. 삼각플라스크를 이용한 소규모 배양에서는 aluminum foil을 플라스크의 뚜껑으로 하여, 배지를 교체할 때를 제외하고는 배발생과 발아가 진행되는 전 배양 기간 동안 이를 유지한다. 배가 발생하는 초기 2주의 경우는 이 밀폐 환경이 발아를 촉진시킨다. 그러나 배가 발아하여 정상 식물체로 발달하는데는 유리하지 않다. 체세포배는 발아할 때 산소를 많이 필요로 하며 에틸렌이 많이 축적되면 발아율이 낮아지며, 적절한 공기 환경이 주어지면 체세포배 발아가 동조화되어 균일한 묘를 얻을 수 있고 수확시기도 예측할 수 있다. 본 실험에서는 배가 발아하는 기간 동안 플라스크 내의 공기 환경을 다르게 하기 위해 플라스크를 막는 뚜껑의 소재를 달리하여 배양한 후 발아율을 측정하였다. 또한 가장 효율적인 환기량을 구명하기 위하여 인위적으로 플라스크에 공기를 넣어 강제 환기시키는 실험을 수행하였다. 미나리 cell은 처음 8일까지는 생장을 하지 않다가 이후 급속히 생장을 시작하여 35일 정도까지는 생장을 하다가 다시 생장이 둔화되었다. 밀폐시킨 삼각플라스크에서 자라는 Cell은 상태도 좋지 않고 전반적인 증식량도 적었다. Cell은 환기정도에 민감한 것으로 판단되며 삼각플라스크에서 약 35일 정도의 생장 주기를 가지는 것으로 사료된다. 배양 3주까지는 플라스틱 뚜껑으로 밀폐시킨 bottle에서 가장 많은 체세포배를 얻었다. Air filter를 달아 2일 마다 신선한 공기를 넣어 주었을 때는 배의 발달이 많이 늦어져 배양 3주째에 다른 처리보다 배의 수가 훨씬 적었다. 체세포배가 발달하는 동안에는 산소를 많이 요구하지 않으나 성숙하는 동안에는 산소를 많이 요구하는 것으로 생각된다.

• Korean Journal of Plant Resources
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• v.11 no.1
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• pp.9-14
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• 1998

Two types of somatic embryos were directly induced from the immature zygotic embryos of the wild prunus yedoensis in Mt. Halla after 16 weeks of culture on MS medium supplemented with 0.1mg/L $GA_3$ and 0.1mg/L BAPor 0.5mg/L $GA_3$ and 0.1mg/L BAP. One was normal single embryo with a single basal part. Normal somatic embryos germinated successfully on 1/2 MS medium. However, abnormal nulticotyledonary somatic embryos, formed shoots only on hormone free MS medium and about 80% of shoots rooted on MS medium with 0.5mg/L IBA. The mximum frequency (62.5%) of normal somatic embryos was directly obtained from the zygotic embryo 30 days after full blooming but it was decreased with further maturation.

• Korean Journal of Plant Tissue Culture
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• v.22 no.4
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• pp.207-211
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• 1995

Immature zygotic embryos from immature seeds of Wasabia japonica (cv Dalma) were isolated and cultured on modified MS medium supplemented with 2,4-D, IAA, and BA. Immature zygotic embryos were classified into torpedo shape and cotyledon stage. The highest rates of callus formation were obtained of 1.0mg/L IAA(torpedo stage, 90.0%)and 1.0mg/L 2,4D plus 0.1mg/L BA(cotyledany stage,84.3%). Somatic embryos after 60 days of culture. These numerous somatic embryo could be seperated and subcultured on the same media for further propagation. After 90 days of culture, most somatic embryos were developed well organized embryos which were able to produce into whole plants.

• Journal of Plant Biology
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• v.39 no.1
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• pp.71-77
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• 1996

Embryogenic callus was selected from callus induced from hypocotyl segment cultures of Daucus carota seedlings on MS basal medium supplemented with 1.0 mg/L 2,4-D. Cell clumps prepared from the embryogenic callus were transferred to MS medium without 2,4-D for somatic embryo development. Cotyledonary abnormalities were frequently observed on somatic embryos developed after the incubation of cell clumps in MS basal medium with 1.0 mg/L 2,4-D for one week and then subculture in the same medium but without 2.4-D for two weeks. The percentage of abnormalities was as follows: 5% one cotyledon, 21% three cotyledons, 6% four cotyledons, 5% five cotyledons, 0.2% six cotyledons and 1% trumpet-like cotyledons. On the other hand, the normal somatic embryo with two cotyledons appeared at 63%. The germination rate of somatic embryos was higher in two cotyledon somatic embryos than in multicotyledonary embryos. Trumpet-like somatic embryos did not germinate normally showing limited elongation and enlargement of roots and cotyledons without shoot development. From anatomical examination circular procambium in the root of somatic embryo began to branch around the middle regions of the hypocotyl which extended into the cotyledons through the cotyledonary nodes and the number of branched procambial strands in hypocotyl was equal to the number of cotyledons. Monocotyledonous somatic embryo always had larger cotyledon than that of somatic embryos with multicotyledons and had horseshoe-like cotyledons where the procambium was of the same structure.ucture.

• Korean Journal of Plant Tissue Culture
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• v.22 no.5
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• pp.291-298
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• 1995

This study describes plant regeneration from leaf explant of Bupleurum falcatum through somatic embryogenesis, and the effect of 2,4-dichlorophenoxyacetic acid on somatic embryo abnormalities. The relationship between the cotyledon number of somatic embryo and its germinability is also described. Embryogenic calli were selected from calli formed on explants cultured on MS solid basal medium supplemented with 1 mg/L 2,4-D. Cotyledonary abnormalities were observed in somatic embryos which were developed from calli cultured on MS medium with 1 mg/L 2,4-D for 6-week and then subcultured on 2,4-D free MS medium for 3 weeks. The frequency of abnormalities was as follows: 7% of somatic embryos had one cotyledon, 65% of them had two cotyledons, 25% three cotyledons, 5% four cotyledons, 2% five cotyledons, and 3% trumpet-like cotyledons. The two cotyledon somatic embryos were germinated at a frequency of 80%. However the germination frequency of one cotyledon embryo and multicotyledonary embryo was lower than that of the two cotyledon somatic embryo. All of trumper-like somatic embryos did not germinate. Histological observations of multicotyledon embryo showed circular procambium in the root but pocambial strands in the cotyledonary node or upper hypocotyl. The number of the strands was equal to the cotyledon number.

• Journal of Plant Biotechnology
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• v.39 no.2
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• pp.93-98
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• 2012

This study was conducted to evaluate effects of somatic embryos (SEs) induction with different kinds and concentrations of osmoticum, with gelrite and SEs germination with different abscisic acid (ABA) and embryogenic tissue lines (ETLs) in Japanese red pine (Pinus densiflora). In comparison of somatic embryos induction with different kinds and concentrations of osmoticum, the highest record (45/90 mg FW) was obtained from the treatment of 0.1 M maltose+3.75% PEG 4000. In addition, the higher one was also recorded from 0.2 M maltose (41 SEs), it turned out this treatment was also effective in induction of SEs with previous one. In effects of various gelrite concentrations for SEs production, no SEs were occurred in the treatment of 0.4 or 0.6% gelrite, however, the highest no. of SEs shown in 1.0% gellrite (41 SEs), and some comparable results were also marked with 0.8 (37.3 SEs) or 1.2% (39.7 SEs) gelrite. Therefore, SEs can be produced from above 0.8% concentration of gelrite. Finally, in comparison of SEs germination with different concentrations of ABA, ETLs, and AC, the best germination rates (45%) were obtained from the SEs derived from both concentrations of 150 and $200{\mu}M$ ABA in 06-6 ETL and when cultured on germination supplemented with 0.2% AC. When SEs were cultured on germination medium without AC, best germination rate (28.9%) came from the SEs which cultured on $250{\mu}M$ ABA in 06-6 ETL.

• Korean Journal of Medicinal Crop Science
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• v.6 no.4
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• pp.294-298
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• 1998

The factors affecting direct somatic embryogenesis from different parts of explant in liquid culture of Scrophularia buergeriana were investigated. Direct somatic embryogenesis was dependent on the explant tissues and stem was the most efficient explant. Rapid shoot development occurred on stem after 3-week culture but roots were not developed yet. Plantlets were not formed through somatic embryogenesis after 3-week culture of petiole. Though direct somatic embryo was not observed from leaf segment culture for 3 weeks, normal plantlets were developed after 8-week culture. BA played the main role for somatic embryogenesis in liquid culture and adding of either IAA or NAA caused rather adverse effects. Culture of stem segments in MS liquid medium with BA at 0.5 mg/ l or 0.1 mg/ l was proved to be the most efficient method for producing plantlets through direct somatic embryos.

• Journal of Plant Biotechnology
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• v.33 no.4
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• pp.297-302
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• 2006

In general, the proliferation of orchids via somatic embryos has been used for mass production of somatic clones because of high propagation efficiency. In spite of high propagation rate, this method often brings somaclonal variation, especially polyploid frequency. Therefor we here concentrated to investigate the relationship between endopolyploidization patterns of explants and the occurrence of tetraploid variant in clonally proliferated Doritaenopsis via somatic embryo regeneration system. In the fully developed somatic embryo, upper part contained 2C to 16C while middle and lower parts showed 2C to 32C DNA content. Two-week-old embryo contained 2C to 16C, whereas those regenerated after 4 to 10-week-old contained 2C to 64C nuclei. Results showed that endoreduplication was variable depending upon tissue types, ages, and parts in one species. lower part of somatic embryo having high endoreduplication degree increased the regeneration of tetraploid variants by about 3-fold comparing to upper part of somatic embryo culture. polyploid frequency occurrence might be closely related to the high levels of endoreduplication of somatic embryos used as explant. It suggested that the upper part of somatic embryo having comparatively low endoreduplication degree is suitable for the stable in vitro propagation system.