• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.2
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• pp.123-128
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• 1986

The characteristics such as characters of seed, fruit and endosperm, development of embryo, dehisced and germination rate of seeds which harvested at 10 days intervals from 20 days to 60 days after pollination were determined to clarify the optimum time for seed production of ginseng. The sizes of length, width and thickness of fruits, seeds and endosperms investigated on 20 days after pollination were not largely different from those that harvested after 60 days. But the weights of fruits and seeds were increased along with the delay of harvesting time. The seeds which harvested from 30 to 60 days showed comparatively high dehisced and germinated rates, especially 40 days in dehisced rates and 50 days in germinated rates. The embryos were rapidly grown in early stage. Lengths of the embryo on 20 days after pollination were approximately grown to 30 ${\mu}{\textrm}{m}$. And after 30 days pollinated, embryos were not only more rapidly grown to 213 ${\mu}{\textrm}{m}$ but also cotyledon premodia were developed in this time and completely formed after 40 days.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.2
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• pp.143-149
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• 1986

Anatomical changes in the forming and germinating processes of tobacco seeds were investigated to obtain basic information on the ecological characteristics of tobacco seeds. Seed development studied through the longitudinal section of the fertilized ovule clarified that the cell division of the zygote was initiated after 7 days of flowering. After 12 days of flowering, perfect seed constituents such as cotyledon, epicotyle and radicle were formed and those were expressed to recognizable level of germinability. After 15 days of flowering germination rate reached higher than 30% and 17 and 21 days after flowering a perfect seed which have 70% or higher germinability were produced. Seed size was ranged between 0.3-0.6 mm and varietal differences were noted in the given seed size range. Under the light treatment, the morphological changes were observed by elongation of radicle after 2 days of imbibition and apparent germination after 3 days of imbibition. But no responses of the seeds imbibed 6 days under the dark condition were observed.

• Applied Biological Chemistry
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• v.31 no.2
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• pp.205-210
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• 1988

The changes in peroxidase and catalase activities, and isoperoxidase patterns in different parts of mung bean seedling caused by the treatment with plant growth substances, $GA_3$ and ABA, were examined. As germination proceeded, the activity of peroxidase in all part except hypocotyl was increased, while that of catalase decreased. The separate application of $GA_3$ and ABA increased the activity of peroxidase which was more influenced by $GA_3$ than by ABA only in cotyledon, while that of catalase was more affected by ABA than by $GA_3$. Electrophoretic study revealed that the number of isoperoxidase was increased continuously in all parts during development. A greater influence was exerted on the intensity of isozyme than the number of isozyme by the hormonal treatment.

• Korean Journal Plant Pathology
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• v.3 no.1
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• pp.8-12
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• 1987

Fusarium oxysporum, F. moniliforme, F. solani, F. equiseti, F. semitectum, and F. sporotrichioides were detected from seeds, roots and cultivated soil of Phaseolous vidissimus collected from Kyung-gi Provincial Rural Development Administration. The rate of seedling desease incidence was $60\%$ by testing of seed germination using a large petri-dish. According to the blotter method, F. moniliforme showed $7\%$ infection at seed-coat and $2\%$ at cotyledon and embryo. Their pathogenicities of F. moniliforme, F. semitectum, F. equiseti, and F. sporotrichioides isolated from seeds were recognized on seedlings by water-agar test tube methods. F. oxysporum and F. solani isolated from infected-roots had their pathogenicity by water-agar test tube method but were weakly pathogenic by soil treatment method. Their pathogenicities of F. oxysporum. F. solani and F. uiseti isolated from cultivated-soil were recognized by water-agar test tube method. These F. oxysporum and equiseti isolates had their pathogenicities but F. solani was weakly pathogenic by soil treatment method.

• Journal of Plant Biotechnology
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• v.29 no.1
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• pp.51-57
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• 2002

For the plant regeneration of soybean (Glycine me L. Merr.), the shoot formation rate, optimal medium and tissue conditions were examined using Korean soybean cultivars. Among the parts of seedling, a node that includes one cotyledon showed the highest shoot formation rate among other tissues. Half-strength B5 medium was more efficient than full strength medium. Formation rates of pair shoots (1 to 2 shooting) were higher in the when benzyl adenine was supplemented. The formation rates of multiple shoots, that is, 4 to 5 in shooting, were high when thidiazuron was supplemented. Multiple shoot was de novo formed in cutting side of cotyledonary node. The effective concentration of thidiazuron for shoot induction treatment was 2 mg/L. Among the 27 cultivars, multiple shoot formation rates were high in the 11 cultivars including 'Heugcheongkong, and pair shoot formation rates were high in the 16 cultivars including 'Malikong'.

• Korean Journal of Plant Tissue Culture
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• v.25 no.4
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• pp.231-236
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• 1998

Carrot cotyledon explants cultured on MS medium with 1 mg/L 2,4-D were transferred to a hormone-free solid medium overlaid with filter paper in order to elucidate the effect of simple physical treatment on the development and germination of somatic embryos. Transfer of the explants cultured for one week on MS basal medium overlaid with 3 sheets of filter paper on to MS basal medium increased somatic embryo production 2-39 times over the one week culture on medium without filter paper overlay. Maturation and germination of somatic embryos was more prominent on medium overlaid with filter paper than on medium without filter paper. The explants cultured for one week on filter paper overlay added with liquid medium showed prominent decrease in somatic embryo formation compared to filter paper overlay only. It is suggested that the filter paper overlay affected the moisture environment of the somatic embryos developing on it.

• Korean Journal of Plant Tissue Culture
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• v.25 no.4
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• pp.267-271
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• 1998

Cotyledon explants of lettuce were cocultured with Agrobacterium tumefaciens LBA4404::pBKS-GR1 harboring glutathione reductase(GR) gene in MS medium supplemented with 0.1 mg/L NAA and 1.0 mg/L 2ip for 48 hr. These explants were transferred to MS medium supplemented with 0.1 mg/L NAA and 1.0 mg/L 2ip, 50 mg/L kanamycin, and 500 mg/L carbenicillin. After 4 weeks of subculture, kanamycin-resistant shoots were obtained on selection medium. Leaves of putative transformants survived on selection medium containing 100 mg/L kanamycin. Incoporation of the GR gene into lettuce was confirmed by PCR analysis of genomic DNA. Southern blot analysis showed that ECL-labeled GR gene was hybridized to the expected amplified genomic DNA fragment of about 1.8 kb from transgenic lettuce. The presence of mRNA in transgenic lettuce was confirmed by RT-PCR with total RNA of transgenic lettuce. In progeny test of transformants, R$_1$ seeds were resistant to kanamycin (200mg/L) on MS medium.

• Korean Journal of Plant Tissue Culture
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• v.21 no.5
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• pp.287-291
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• 1994

In order to elucidate the effect of abscisic acid (ABA) on the abnormality of somatic embryos, somatic embryos were induced from embryogenic cell clumps derived from cotyledon segment of Aralia cordata. When embryogenic cell clumps were pretreated medium containing 0.2 mg/L ABA for 3 weeks before transferring to MS basal medium, the frequency of embryos with normal cotyledons enhanced 68% as compared with control. However when clumps pretreated in medium containing 0.2 mg/L ABA were transferred to medium containing 0.1 mg/L ABA, the Sequency decreased to about 29%. In the case of globular embryos cultures in medium containing various concentrations of ABA (0.01 to 1.0mg/L), the frequency of dicotyledonary embryo formation decreased propotionally to ABA concentration. Also, when somatic embryos at various stages were cultured in medium containing ABA, those with polycotyledons appeared at higher frequency.

• Korean Journal of Plant Tissue Culture
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• v.28 no.4
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• pp.197-200
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• 2001

Agrobacterium tumefaciens MP90 harboring PAT (phosphinothricin acetyltransferase) and NPTII-GUS gene were used for the genetic transformation of lettuce (Lactuca Sativa L.). Shoot regeneration from cotyledon explants were obtained from the MS medium supplemented with 0.1 mg.L$^{-1}$ NAA, 1.0 mg.L$^{-1}$ 2ip, 50 mg.L$^{-1}$ kanamycin and 500 mg.L$^{-1}$ carbenicillin after cocultivation with A. tumefaciens for 2 days. Kanamycin resistance test of transgenic plants indicated that the NPTII gene was integrated into the lettuce genome and was stably expressed. PCR and northern blot analysis indicated that bialaphos resistance gene (PAT) was stably integrated into the lettuce genome. The transgenic plant sprayed with Basta (1500x) remained healthy with continuous growth, while the control group exhibited fatality.

• Journal of Plant Biotechnology
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• v.29 no.1
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• pp.31-36
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• 2002

The patterns of adventitious root formation from cotyledons for each cultivar of soybeans were compared. The results of adventitious root formation in cultivars are classified as two groups; the first group showed the direct adventitious root formation, and the second group resulted in the callus and adventitious root formation. The cultivars that have much callus formation had less the adventitious root formation. The adventitious root formation in the cotyledonary explants was occured only at the inoculation of adaxial side. When adaxial and abaxial side was inoculated simultaneously, the adventitious roots were formed at the adaxial side. Thus, it suggests that there must be direction to some extent. Starch in the cotyledonary explants were more abundant at the 4 days after induction than at the early stage of the adventitious root formation, but the starch was not observed after 7 days, that the growth stage of adventitious roots.