• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.150-155
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• 2008

This experiment was carried out to investigate the effect of proton ion and gamma-ray irradiation on microspore culture of the flower buds of $M_2$ generation in winter type of Brassica napus L. ssp. oleifera. The seeds of three rape varieties, 'Halla', 'Naehan' and 'Tammi' were pretreated with proton ion and gamma-ray 400 Gy and 600 Gy, respectively. When microspore culture techniques were used, embryogenesis was increased in some varieties by proton ion and gamma-ray irradiation treated flower buds of $M_2$ generation than control. In genotypes 'Naehan' showed the highest embryo production frequency, but 'Tammi' showed lowest embryo production frequency. Some of the embryoids developed directly into plantlets, whereas others developed abnormally multilobe. Plants were regenerated and successfully acclimatized in pots.

• 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.

• Korean Journal of Animal Reproduction
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• v.19 no.3
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• pp.227-234
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• 1995

This study was carried out to investigate the effects according to the time course of glucose exposure on the development of one-cell embryos beyond morula in CR$_laa$ medium. One-cell zygotes from B6CBA F$_1$ mice were recovered at 24 ~ 25h after hCG and cumulus cells were removed with 0.1% hyaluronidase. The embryos were pooled and subsequently divided into each groups and cultured in CR$_laa$ at 37$^{\circ}C$ in 5% CO$_2$ in aIr. The embryos were either, placed in CR$_laa$ containing various concentration (5.5, 16.5, 27.5 and 38.5 mM) of glucose for 1 min. and subsequently returned to the fresh culture medium (without glucose), or were transferred to the same media containing glucose at 72 h post hCG. The results obtained in these experiments were summarized as follows: 1. The development rates of zygotes, recovered from the oviducts in M2 and cultured in CR$_laa$ with 3mg/Im FAF-BSA, to expanded blastocysts (25.7%) and hatching bIastocysts (17.6%) were significantly higher than those of zygotes recovered in TL Hepes (0% and 0%, respectively). 2. The development rates of one-cell embryos exposed to 27.5 mM glucose at 72 h post hCG for 1 min, were 68.8% (CR$_1$+BSA) a and 77.1% (CR$_1$+FBS) of expanded blastocyst stage, but there were no significant differences between the embryos exposed for 1 min. or transferred at 72 h. 3. Regardless of glucose concentration (5.5, 16.5, 27.5 & 38.5mM), 45.7~61.5% of embryos developed to the blastocyst stage. There were no significant differences between any of the treatments on the devel-opment of one-cell embryos. Therefore, the detrimental effect of highly concentration was not appeared.

• Animal Systematics, Evolution and Diversity
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• v.17 no.1
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• pp.35-47
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• 2001

The postembryonic development of the Korean crayfish, Cambaroides similis (Koelbel, 1892), was described in detail and compared with those of other known species of Astacidae and American Cambaridae, and phylogenetic relationship of the genus Cambaroides was discussed. Ovigerous females of the Korean crayfishes appear in May. Durations of juvenile stages 1 and 2 are two and four weeks at 15.0 $\pm$ 0.5$^{\circ}C$, respectively. From juvenile stage 3, it leaves from its mother. It is considered that C. similis is very closely related more to the Astacidae than to the Cambaridae in the characteristics of the maxillule of juvenile stage 1 and the antenna, maxilla, pleopod, and telson of juvenile stage 2.

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.115-120
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• 1995

A method for cryopreservation of suspension cultured embryogenic cells derived from immature zygotic embryos of rice (Korean cultivars, Donggin-byeo and Taebaeg-byeo) was developed. The highest cell regrowth after storage in liquid nitrogen was obtained when Donggin-byeo cells were cryoprotected with a mixture of 2 M DMSO and 0.4 M sucrose and Taebaeg-byeo cells with a mixture of 0.64 M DMSO and 0.4 M sucrose at frequencies of 88% and 90%, respectively, Pretreatment in a high osmotic medium was not necessary. Upon transfer to $N_{6}$ medium suplemented with lmg/L NAA and 5 mg/L kinetin, the regenerated calli gave rise to numerous somatic embryos which subsequently underwent development into plantlets. Among approximately 100 plantlets, 25% of them were albinos.s.

• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.335-339
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• 1998

The factors affecting the isolation and culture of the protoplast of embryogenic callus, derived from immature ovule in Citrus junos, were examined. An incubation time in enzyme solution of 16 hrs was preferable for protoplast isolation. Efficient protoplast yields were obtained from the treatment of equal concentration of 0.7 M $\textrm{BH}_{3}$ to the enzyme solution containing 1.0% cellulase, 1.0% macerozyme and 0.2% pectolyase. Protoplast cultured in MT medium with 0.1 mg/L 2,4-D showed vigorous division and some of them formed callus. Induced callus was subcultured on solid MT medium but the callus showed very slow growth. The above results show the possibility to culture from protoplast fusion in Citrus genera.

• 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 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.

• Korean Journal of Plant Resources
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• v.21 no.1
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• pp.60-65
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• 2008

Kalopanax pictus was cultured in vitro to find out optimal condition for embryogenic cells proliferation in liquid media rapidly. Embryogenic cells were induced from leaves and petiols of Kalopanax pictus. Optimum culture medium appeared to be a 1/2MS medium supplemented with 2.0mg/L 2,4-D and 0.1mg/L BA. To find out optimal conditions, embryogenic cells were cultured some condition as different concentrations of 2,4-D, medium and sucrose. There was cultured on 1/2MS liquid medium containing different concentration of 2,4-D. When embryogenic cells were cultured on 1/2MS liquid medium supplemented with 1.0mg/L 2,4-D, cell propagation rate was higher than other concentration of 2,4-D. When embryogenic cells were cultured on different media that MS, Gambols B5, N6, White, SH medium, observed the highest multiplication rate among Gambols B5 and White medium. To find out of effect of sucrose to embryogenic cells propagation, we tested cells under different concentrations. Optimal concentration of sucrose appeared to be a basal medium added 3% sucrose. Above results suggest that optimal conditions for proliferation of embryogenic cells were established Gambols B5 and White medium added 1.0mg/L 2,4-D and 3% sucrose. There is every possibility achieving embryogenic cells proliferation via bioreactor culture system in Kalopanax pictus.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.4
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• pp.317-323
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• 2012

For the establishment of an efficient embryogenesis from microspore culture in Brassica napus L. domestic cultivar 'Tammiyuchae', four different factors affecting microspore embryogenesis and plantlet regeneration were investigated. The highest embryogenesis rate was achieved when microspores at late uninucleate to early binucleate stage were isolated from flower buds with a length of 3.0~3.5 mm. On average, 388 embryos generated from 1 ml of microspores media. The highest number of embryos was obtained when microspores were subjected to $32.5^{\circ}C$ for 2 days. Embryogenesis of 'Tammiyuchae' was increased with increasing microspore culture density up to about $5{\times}10^4ea/mL$. Gradually higher culture density repressed embryogenesis of microspores. Regeneration rate of shoots from microspore-derived embryos was observed in MS solid medium supplemented with $0.5mg{\cdot}L^{-1}$ NAA and $1.0mg{\cdot}L^{-1}$ BA, and grew well in MS solid medium without plant growth regulators.