• Korean Journal of Plant Tissue Culture
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• v.24 no.2
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• pp.83-86
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• 1997

To produce and supply the healthy potato, basic seed potatoes were produced by stem cutting, microtuberization and hydroponic culture. The total number of tubers and the total tuber weight per $\textrm{m}^2$ of potato were more in hydroponic culture as each products were 1, 152 and 4, 492g than in the stem cutting (75 and 4, 136g) or microtuberization (1, 080 and 1, 080g) using petridishes. The total yield per 10a in the field was propagated highly stem cutting > propagated microtubers > hydroponics > microtubers. The number of tubers per 10a produced by hydroponics (33, 064) was higher than any other methods. This indicated the hydroponic culture can be used in the multiplication of basic seed potatoes.

• Journal of Plant Biology
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• v.36 no.1
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• pp.51-57
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• 1993

The microtuber was efficiently formed on SH medium containing 9% sucrose from the in vitro propagated shoot of potato (Solanum tuberosum cv. Sumi). In order to investigate gene expression depending on the development stage of microtuber, we examined the changes of peroxidase and esterase activities, and their isozyme patterns as well. Peroxidase and esterase activities were the highest at the 7 day-culture of the microtuber and subsequently decreased on the stage of microtuberization, whereas esterase activity increased at the stage of 60 day-culture. However, their activities in the ordinary tuber were higher than those of 60 day-cultured microtuber. In addition, in the peroxidase isozyme pattern two new bands of pI 7.05 and pI 4.65 were appeared at the 15- day and 60 day-cultures, respectively, as shown by isoelectric focusing. Various bands in the sterase isozyme pattern were shown at the 7 day-culture, and the band patterns were a large difference, comparing those of shoot and tuber. New bands in the esterase isozyme pattern also appeared at the 15 day- (pI4.52) and 60 day-cultures (pI 4.48). These results suggest that the changes of peroxidase and esterase activities and isozyme patterns are an important factor in the differentiation and development of potato.

• Korean Journal of Medicinal Crop Science
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• v.7 no.3
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• pp.155-161
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• 1999

This study was carried out to develop the propagation system using in vitro induced- microtubers of yams (Dioscorea alata L.). Effects of kinds of media, mineral composition, sucrose concentration (0, 2, 4, 6, 8, 10%), photoperiod (0, 8, 12, 16, 24h), and growth regulators (NAA, IAA, ZR, JA-Me, ABA) on the development of microtubers, roots, and shoots in nodal stem segment cultures of D. alata L. were evaluated. Microtuberization in nodal stem segment occurred on all the media supplemented with growth regulator and sucrose. Among basic media, 1/2MS medium was the best in microtuber induction. NAA was shown to be the most effective among the growth regulators. Optimal NAA concentration was 1mg/l. The microtuberization was the highest at the concentration of 6% sucrose. When the nodal stem segment were cultured under darkness, the tuberization was increased markedly compared to those cultured under light condition. It was also noticeable that the culture in medium with NAA produced only microtubers and roots, but no shoots, in nodal segments. In this study, the optimal medium composition for microtuberization in nodal stem segment was found to be 1/2MS medium supplemented with 1mg/l NAA and 6% sucrose under dark condition at $25^{\circ}C$.

• Journal of Plant Biotechnology
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• v.45 no.2
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• pp.125-130
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• 2018

In this experiment, we investigated the effects of various carbon sources and concentrations on the microtuber induction and acclimatization of the yam (Dioscorea cayenensis). First, the effects of the in vitro carbon sources and concentrations on the microtuber induction were examined. The highest efficiency of the microtuber induction was obtained in the 7% sucrose treatment, whereas the glucose treatment shows no effect on the microtuber formation. Secondly, the effects of the survival rate and the microtuber formation rate after the acclimatization were examined. The diameter (6.1 mm) and fresh weight (0.5g) of the tuberous root are the highest in the pretreatment of the 7% sucrose. Although the survival rate of the pretreatment of the low concentration sucrose (3% sucrose) is 100 %, the growth and development were inhibited. These results suggest the 7% sucrose treatment is appropriate for the yam microtuber formation and acclimatization. In addition, this protocol could be used for the propagation of virus- or disease-free clones and the multiplication of elite yam cultivars.

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.252-256
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• 1998

A Study was conducted to investigate comparison of in vitro tuberization between normal and transgenic potato plantlets harboring adenosine deaminase gene in potato cultivar of Desiree. In time course study of in vitro tuberization, the rate of tuberization in four lines were increased till 6 weeks. but maintained stil after 7 weeks. Microtuber initiation of transgenic lines, 43 and 39 were faster than other lines, but no difference was observed after 5 weeks compared with normal plantlets. In all transgenic lines, the majoirty of microtubers produced were small(less than 100 mg) and medium(100-200mg) size rather than large size(more than 200 mg). Among 4 lines , line 9 produced the highest number of microtubers per each culture vessel. The results of this experiment suggest that there is no significant difference in microtuber production efficiency between normal and transgenic potatoes.

• Journal of Plant Biotechnology
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• v.35 no.1
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• pp.63-68
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• 2008

Single-node stem pieces ca. 1 cm in length containing a axillary bud were obtained from in vitro plants of potato (Solanum tuberosum L.). The influences by a position of the node and the existence of a leaf at the node were observed in the single-node culture on the 8% sucrose MS medium. The effect of CCC was also investigated for the microtuberization. The apical part node was excellent in the tuberization not to mention shoot length, fresh weight, diameter, the number of node on the in vitro culture of a single-node than the lower part. The differences in the diameter of a tuber formed in the part of the axillary bud on all treatments including the cultivation of the apical part node were not recognized. However, the fresh weight of the tuber showed high value in the tuber formed at the axillary bud of shoot apex part. At 20 days after cultivation, tuberization was promoted in the new stolen that developed from the bud of node with a leaf under SD condition of 8 hours at $20^{\circ}C$. The tuberization from axillary bud of the single-node without leaf was inhibited at high temperature of $28^{\circ}C$ regardless of daylength. Whereas, tuberization at $20^{\circ}C$ and $28^{\circ}C$ was similar without the difference under SD condition but the tuber formation ratio were low. CCC 500 mg/L promoted tuberization and the effect was also showed even under LD condition at $28^{\circ}C$. The inhibiton of tuberization under LD and high temperature condition could be solved by treatment with CCC.

• Journal of Forest and Environmental Science
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• v.24 no.2
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• pp.79-88
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• 2008

Twenty-eight of 44 Indian Ceropegia species are endemic and their survival is threatened. As a step towards conservation, we implied in vitro methods for the sustainable propagule production in C. hirsuta, C. lawii, C. maccannii, C. oculata and C. sahyadrica. Effects of explant, growth regulators, sucrose and photoperiod were studied. High frequency microtuber production was achieved with the seedling-apical buds, grown on MS medium containing 4-6 mg $1^{-1}$ BAP, 3-8% (w/v) sucrose, under continuous illumination. Each microtuber, when subcultured proliferated to form a cluster of secondary microtubers. Every primary and secondary microtuber bore at least one shoot-bud and a root primordium. Each tuber (formed with any of the significantly effective treatments) weighed more than 500 mg, enough to plant directly in non-sterilized soils. Microtubers could be produced and proliferated round the year. Proliferation could be solely attributed to in vitro procedures as these plants bear solitary tubers in vivo. Microtubers could be sprouted in vitro to prepare ready to pot plantlets. As, this novel method succeeded for all five species, though they belong to different eco-physiological backgrounds, we recommend its implementation in the conservation programs for a broader range of Ceropegia species, supported by other integrated strategies.

• Journal of Plant Biotechnology
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• v.40 no.3
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• pp.147-155
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• 2013

In this experiment, we report for the first time mass propagation by in vitro mircrotuberization of Codonopsis lanceolata. We first examined the effect of cytokinins on multiple shoot induction. 2.0 $mg{\cdot}L^{-1}$ of kinetin not only gave the highest rate of shoot induction (19.1%) but also the elongation of shoot (17.1 mm). Secondly, we investigated the effect of sugars on in vitro microtuberization from nodal segments. The diameter of tuberous roots was enlarged in the half-strength MS medium supplemented with 145.9 mM sucrose. Histological analysis revealed that the number of parenchymatous cell containing starch grains increased in the tuberous roots. In addition, unlike in non-tuberous root, vascular bundles were scattered inner cortex layer. Thirdly, in order to preserve and stimulate the germination, microtubers were stored at $4^{\circ}C$ refrigerator during 9 months and then transplanted to the artificial soils (vermiculrite : peatmoss = 1:1 v/v), resulting that the rates of survival and germination were 75% and 70%, respectively. These results indicated that mass propagation of C. lanceolata was achieved by in vitro microtuber formation, suggesting that this protocol might be applied for not only the propagation of elite clones but also conservation of C. lanceolata germplasm.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.331-338
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• 2007

One-node stem pieces ca. 1 cm in length containing a axillary bud and a fully expanded leaf were obtained from it in vitro plants of potato (Solanum tuberosum L.). Leaves were removed and the nodes were cultured on the MS medium to investigate the effects of temperature, day length, sucrose, and CCC in microtuber formation and development. The fresh weight of microtubers after 80 days increased significantly at 8% sucrose and $20^{\circ}C$ compared with $28^{\circ}C$. The tuberization and development were reduced at $28^{\circ}C$ except short-day treatment of 8 hours at 8% sucrose. The fresh weight and diameter were increased on the culture medium added CCC 500 mg/L. The potato tuberization was promoted under short daylength, and it showed great effect by treatment with the CCC. Though the tuberization was promoted at low temperature of $20^{\circ}C$ in a histologic change of an axillary bud part cell of a potato, the cells were able to observe the swelling growth. Swelling growth of tissue was stimulated in the darkness and was more remarkable by addition of CCC. In particular, in the visual ratio of cell division for each position in the tissue, the cortex part showed larger ratio of cell expansion than that of the pith part. The effect of CCC was identified at 8% sucrose in the darkness. The effect of CCC was not showed in sucrose 3% under long daylength of 16 hours. As a result, the fact of a substance with AGPase important for starch composition was certified by the result with the inclose of AGPase activity on high concentration of sucrose, CCC, and dark treatment by which tuber formation and development are promoted.