• Plant Resources
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• v.4 no.1
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• pp.53-58
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• 2001

The effect of carbenicillin on the dedifferentiation and the regeneration efficiency of plant tissues of horseradish(Armoracia rusticana) was evaluated, Inhibition effect for callus initiation was observed when leaf blade, root and petiole segments were grown on MS medium containing 500 mg/L to 2000 mg/L carbenicillin and 0.5 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D). The regeneration of horseradish shoots from leaf blade, root and petiole explants were decreased as the addition of carbenicillin increased from 1000 mg/L to 2000 mg/L in MS medium containing 0.5 mg/L of 6-benzylaminopurine (BAP) or kinetin. Especially, 500 mg/L carbenicillin treatment significantly inhibited shoot induction when leaf blade explants were grown on hormone-free MS medium. It was suggested that the toxic effects of combinations of carbenicillin and 2,4-D may be due to high auxin activity levels.

• Korean Journal of Plant Tissue Culture
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• v.26 no.4
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• pp.245-250
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• 1999

Plantlets derived from leaf blade-segment culture of a variegated tobacco (Nicotiana tabacum L. cv. BY-4) that was induced by a heavy-ion ($^{14}N$) beam irradiation to proembryos, were characterized. When explants from both white and green sections of leaves of the variegated plant were cultured on MS medium containing 0.1 mg/L NAA and 1.0 mg/L BAP, the white sections yielded only white shoots, whereas the green sections generated approximately 47.2% green, 37.4% white and 15.4% variegated shoots. In the F1 generation of a green tobacco derived from the leaf blade-segment culture, the segregation ratio of green to white was 1,651:54. Furthermore, reciprocal crosses showed that all of the progenies was green, indicating that the variegation is not maternally inherited. When the signal intensity of photosynthesis genes was determined by DNA gel blot analysis using the variegated leaves derived from green sections of variegated leaves, there were more of the rbcL, psbA, 16S rDNA and 23S rDNA chloroplast genes in the white sections than the chloroplast genes in wild type and green sections of the variegated plants.

• Journal of the Korean Institute of Landscape Architecture
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• v.31 no.6
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• pp.73-76
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• 2004

This study was conducted to investigate the growth responses of Polystichum lepidocaulon as influenced by 4 different shadings(Control, 50%, 70%, 90%). Under 50 or 70% shading, plant height, stipe length, blade length, blade width, and number of spores increased compared with the other shadings, except the number of frond and shoots. The plants grown under control was shown as smaller with more yellowish green leaf color, and under 90% shading the growth was slightly inferior to those under the 50 or 70% shading. Fresh weight and segment area of frond was better in increased shade levels, but they decreased in under 90% shading. Dry weight and segment thickness decreased as shading increased. Chlorophyll contents increased in proportion to lowered light intensity. Thus, 50 or 70% shading of Polystichum lepidocaulon seemed to maintain the highest growth.

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.207-214
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• 2003

This study was carried out to establish a novel bioassay system for screening of compounds affecting aromatic amino acid or anthocyanin biosynthesis through investigating a degree of sucrose-induced anthocyanin formation such as size of plant material, buffer conditions, light intensity and irradiated duration, incubation temp., etc were determined and standard procedure (suitable experimental condition) was set up as follows. The second leaf blade of white corn seeding induced by fluridone treatment were segmented into a size of 5${\times}$5 min. The segments were floated on the solution of 1% sucrose in 1.0mM MES buffer (pH6.0∼6.5) and incubated at 26$^{\circ}C$ for 2days under the continuous light condition(70∼100$\mu$mol m$^{-2}$ s$^{-1}$ ). Anthocyanin in the purpled tissues was extracted with methanol containing 1% HCl and the optical density of the clear supematants was determined at 528mm. Influences of some chemicals were tested using this system. Glyphosate, 5-enolpyruvylshikimate 3-phosphate synthase inhibitor, showed most sensitive response with I$_{50}$ value at 3.3$\mu$M. Dicyclohexylcarbodiimide(DCCD) and parachloromercuribenzenesulfonic acid(PCMBS) had a relatively strong ingibition with I50 value at 7.1$\mu$M and 10.2$\mu$M, respectively. These results show that sucrose-induced anthocyanin formation in white com leaf segment provide a very simple and rapid system for searching new compounds affecting aromatic amino acid or anteocyanin biosynthesis by screening at less than 10$\mu$M.

• Journal of Plant Biotechnology
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• v.1 no.2
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• pp.101-107
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• 1999

The leaf blade-segments of albino tobacco (Nicotiana tabacum L.) were cultured on MS media containing different concentrations of BAP (0, 0.4, 2.2, 4.4, 22.2 ${\mu}{\textrm}{m}$) with or without NAA (0, 0.5, 2.7 ${\mu}{\textrm}{m}$). Multiple shoots were induced on the media containing 0.4 to 2.2 ${\mu}{\textrm}{m}$ BAP. The best condition for multiple shoot induction with root formation was MS media containing 4.4 ${\mu}{\textrm}{m}$ BAP and 0.5 ${\mu}{\textrm}{m}$ NAA. The regenerated albino plants showed a significant reduction in accumulation of chlorophylls and carotenoids. The drastic reduction of the pigments content was associated with the distinct alterations in gene expression in the albino plants. firstly, the expression of plastid genes, such as rbcL, psbA, 165 rDNA and 235 rDNA, was reduced at the level of transcripts in the regenerated albino plants. Secondly, the alteration of structure of the plastid genes was not detected in the albino plants. However, the copy number of the plastid genes whose transcription level was reduced greatly was increased approximately two-fold, although the transcriptions of nuclear gene (255 rDNA) showed the wild-type level.

• Korean Journal of Plant Taxonomy
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• v.35 no.4
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• pp.287-294
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• 2005

Three unrecorded fern species from the flora of Korea, Nephrolepis cordifolia, Athyrium epirhachis, and Asplenium castaneo-viride, are reported here. Nephrolepis cordifolia, recognized as introduced species and cultivation in Korea until now, is found in the wild at the entrance of small cave in Jeju island. Athyrium epirhachis is found under the Quercus acuta forest at about 400 - 500 m alt. in Jeju island. This species is similar to A. otophorum but different from the latter by having once pinnately divided leaf blade and the decurrent base of ultimate segment. Asplenium castaneo-viride is hybrid between A. ruprechtii and A. incisum and is distinguished from parental species by presence of proliferation, shape of leaf blade, pattern of venation, and leaf texture.