• Journal of Plant Biotechnology
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• v.32 no.1
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• pp.15-21
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• 2005

The expression patterns of cyclin genes, which play a crucial role on cell cycle control, were analyzed with rice calli and leaf blades from seedlings. When callus was transferred from media containing the combinations of 2,4-D and kinetin under the dark conditions to medium supplemented with cytokinin-only on 7 days after the cultures, the expression levels of A-, B- and C-type cyclins from callus were increased significantly. Despite the fact that cyclin genes were well expressed on leaf blades rather than other organs in rice seedlings, rice leaf blades grown on the medium containing various combinations and concentrations of cytokinin for 24 hours had no major effect on the expression patterns of cyclins except zeatin. The relation between cytokinin regulation and the expression of cyclins of rice is discussed.

• Journal of Plant Biology
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• v.39 no.4
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• pp.231-235
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• 1996

The calli obtained from the bulbs of A. victorialis var. platyphyllum on MS based medium containing 2 mg/L 2, 4-D and 1mg/L BA. Plants from calli were regenerated on MS basal media supplemented with combinations of NAA and four kinds of cytokinin, BA, zeatin, kinetin and 2iP, and with only each cytokinin. The good response of shoot regeneration was observed in the media with combinations of NAA and BA or zeatin, and with only BA or zeatin. Shoot regenerating response in the medium with combinations of NAA and BA or zeatin, and with only BA or zeatin. Shoot regerating response in the medium with combinations of NAA and BA or zeatin was about two times higher than that in the mediuim with only BA or zeatin. From the karyotypic analysis of the regenerated plants, abnormal diploids, aneuploids and mixoploid with structural aberrations were investigated. The somaclonal variants (AV 16-04, AV 13-03) were shown the considerable differences from normal diploid regenerant (AV 18-03) in the external morphology.

• Journal of Plant Biotechnology
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• v.29 no.2
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• pp.123-127
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• 2002

Effect of cytokinins (BA, TDZ, zeatin, 2iP, and kinetin) applied either singly or in combination on in vitro growth of two grape cultivars ('Cabernet Sauvignon' and 'Campbell Early') was investigated as a serial work for mass production of grapevine nursery stocks. In single treatment, shoot growth of two cultivars was most favorable in control. Shoot proliferation was satisfactory with 10 $\mu$M BA regardless of cultivars and cytokinin combinations, followed by TDZ. Other treatments resulted in very poor or no branching. Total explants ready for subculture produced by 10 $\mu$M BA outnumbered those by other treatments. TDZ was also effective. TDZ significantly increased the fresh weight and callus formation while shoot growth was unsatisfactory. Shoot growth response of two cultivars in combined treatments was also most favorable in control as was in single treatments. When TDZ was combined with zeatin, 2iP, and kinetin which failed to induce branching, proliferous branching was induced though the shoot number was behind that of single treatments of BA and TDZ. TDZ was very effective for total number of explants and fresh weight, showing 10-fold increase.

• Plant Resources
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• v.7 no.1
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• pp.1-6
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• 2004

In vitro proliferation system was achieved by using nodal segment excised from greenhouse grown juvenile stock plants of Alnus japonica. Stem explants were cultured on MS medium supplemented with different plant growth regulators of cytokinin and/or their combinations. The most effective cytokinin source was the combination of zeatin 2.0 mg/L and TDZ 0.05 mg/L producing the average number of shoots (16.8 $\pm$ 3.6). In addition, healthy roots were formed after small clumps of shoots were transferred to half strength of MS medium containing IBA 0.02 mg/L with optimal rooting capacity. Soil acclimatization was successfully conducted in cell tray containing artificially mixed soil with 92 % survival rate.

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.179-184
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• 2003

In order to establish micropropagation system Anthurium andreanum 'Atlanta', dwarf type, shoots of A. andreanum were cultured on medium supplemented with cytokinin. Callus was formed from the base of shoots. high frequency callus induction was obtained on medium with 10.0mg/L BA or 10.0mg/L TDZ(thidiazuron) at more than 71.8%. The shoots were cultured on media with various combinations and concentrations of TDZ, BA and 2.4-D to enhance callus induction. Callus was induced at more than 72.6% and grew vigorously on media containing 10.0mg/L BA and 0.0∼0.5mg/L 2.4-D, or 1.0mg/L TDZ. Stimulation effects of cytokinin by 2.4-D did not occur in combined treatments of cytokinin and 2.4-D. Callus was cut into sections(7${\times}$10mm), and then cultured on media with BA alone or BA and 2.4-D to regenerate shoots and to stimulate the callus growth. Shoot regeneration and callus growth were effective on media with 10.0mg/L BA alone, or 10.0mg/L BA and 0.1mg/L 2.4-D. In combined treatments of BA and 2.4-D, stmulation effects of cytocinin by 2.4-D also did not occur. Callus growth was decreased, accordiong to increasing the concentration of 2.4-D. In cimbined treatments of TDZ and 2.4-D in shoot regeneration and callus proliferation, stimulated effects of cytokinin by 2.4-D did not occur entirely. Media with 0.5∼1.0mg/L TDZ ingibited the regeneration and rooting of shoots, and callus growth from callus sections. Addition of 2.4-D on medium with TDZ ingibited the regeneration and rooting of shoots, and callus growth. Rooted plantdts were acclimatized in greenhouse. The plantlets were survived more than 98% in soil of vermiculite alone or mixed perlite 1 and vermiculite 1.

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.479-484
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• 2000

This study was conducted to examine the effects of explant sources and plant growth regulators on mass propagation of Cyclamen persicum. Tuber, cotyledon, and petiole tissues were cultured on MS medium supplemented with different concentrations and combinations of auxins and cytokinins. Shoots were not induced from calli on cotyledon and petiole explants cultured on MS medium containing various concentrations of 2,4-D or NAA. However, multiple shoots were formed directly from tuber explants cultured on the medium containing 0.5 and 1.0 mg/L 2,4-D or NAA. In MS medium with cytokinin alone, TDZ was more effective in shoot formation than BA or kinetin in all explants. The combinations of NAA and BA was found to be most effective in shoot formation from tuber, cotyledon and petiole explants. Especially, shoots were formed from all the tuber explants on the medium containing 0.5 mg/L of NAA and BA. Hormonal effects on root formation were examined by subculturing single shoots on MS medium containing NAA or IBA. The medium with 0.5 mg/L IBA was most effective in root induction and subsequent plantlet regeneration.

• Korean Journal of Agricultural Science
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• v.13 no.2
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• pp.168-175
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• 1986

Leaf segments of tomato (Lycopersicum escullentum Mill) were cultured on the MS medium supplemented with the concentration of 0, 0.2, 0.5, 2.0 or $5.0mg/{\ell}$ NAA, 2,4-D and/or BA. The treatments were able to induced callus, however the best combinations for the induction of callus were $2.0mg/{\ell}$ BA and 2.0 or $0.5mg/{\ell}$ NAA. Shoot formation was stimulated at the treatment of 2.0 or $5.0mg/{\ell}$ BA, and root formation was stimulated on the medium of 0.2, 0.5, 2.0 or $5.0mg/{\ell}$ NAA plus 0, 0.2 or $0.5mg/{\ell}$ BA.

• 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.

• Journal of Plant Biotechnology
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• v.31 no.1
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• pp.37-41
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• 2004

In vitro culture system was established to induce multiple shoots of Thymus quinquecostatus Celak. by investigating the effects of cytokinins. Stem explants were cultures on MS medium supplemented with either five drfferent plant growth regulators or their combinations under light or dark condition. The most effective cytokininsource was the combination of BA 1.0mg/L and TDZ 0.1mg/L for producing shoots (6.05$\pm$1.51), zeatin 2.0mg/L and TEZ 0.1mg/L for elongating shoots (3.27$\pm$0.66cm) under the light condition. In addition the most effective cytokinin was 2-ip 2.0mg/L for producing shoots(5.20$\pm$1.81), zeatin 2.0mg/L for elongating shoots(5.64$\pm$1.24cm)under the dark condition. Overall, the average percent for in vitro shooting was greater than 89.58％.

• Korean Journal of Plant Tissue Culture
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• v.26 no.1
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• pp.1-6
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• 1999

In order to obtain plantlet derived by anthers, the anthers of Lilium asiatic hybrid 'Gran Paradiso' were cultured on Murashige and Skoog's medium supplemented with various combinations of auxin and cytokinin. The most suitable pollen stage of anther culture for the callus induction was 3 days before anthesis at the early to late binucleate stage. Organogenic calli were induced on MS medium supplemented with 5.0 mg/L 2,4-D alone and the combination of 1.0 mg/L 2,4-D and 1.0 mg/L kinetin, however, the combination of NAA and BA was more effective than that of 2,4-D and kinetin on plant regeneration through organogenesis. Shoots were formed from the induced callus on the medium with 0.5 mg/L NAA and 1.0 mg/L BA after 180 days of culture. Multiple shoots with 3-4 leaves, roots, and bulblets were formed on the medium with the combination of 2.0 mg/L NAA and 2.0 mg/L BA after 250 days of culture. The chromosome from root tip of the regenerated plantlet showed the diploid (2n=2x=24). Diploid plants were transferred to the pots and all plants were flowered in two years.