• Journal of Plant Biotechnology
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• v.35 no.3
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• pp.223-228
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• 2008

This study was conducted to investigate an optimal condition for shoot proliferation and regenerate shoots from in vitro leaflet and embryogenic calli from in vitro roots in rose. The effect of BAP on shoot proliferation was somewhat different depending upon genotypes or gelling agents. Leaflets with petiole cut from donor shoots which had been cultured in MS medium supplemented with 0.1 $mg{\cdot}L^{-1}$ NAA for six weeks was effective for regeneration of adventitious buds(ABs) as well as shoot elongation of Rosa hybrida cv. Sweet Pink. Culturing seven leaflet explants per petri plate($100mm{\times}15mm$) was effective for regeneration of ABs. Embryogenesis was shown in the calli induced from roots of Rosa hybrida cv. Sweet Pink cultured in the SH medium supplemented with 11 $mg{\cdot}L^{-1}$ 2, 4-D for four weeks. Color of calli induced from roots was yellow although their color was a little different as type of basal medium.

• Korean Journal of Plant Tissue Culture
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• v.21 no.4
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• pp.227-231
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• 1994

The experiments were conducted to obtain culture conditions on optimal cultural conditions for propagation of a topical orchid, Haemaria discolor, through shoot tip cultrue in vitro. Survival percentage of shoot tip explant, in initial culture media was higher in H$_3$P$_4$ medium than in Murashige and Skoog's medium. Explants, cultured in H$_3$P$_4$ medium containing 1.0 mg/L kinetin, showed more shoot elongation when compared with those on other media. When the distal part of stem (pseudobulb) was longitudinally sectioned into half and cultured in H3P4 medium containing 0.1 mg/L 2ip, 0.1, or 1.0 mg/L kinetin, shoots from axillary bud were much more elongated under light condition.

• International Journal of Industrial Entomology and Biomaterials
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• v.22 no.1
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• pp.11-15
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• 2011

Impact of pruning date, shoot age and weather parameters on the severity and development of grey leaf spot (Pseudocercospora mori) of mulberry was studied. The disease severity (%) increased with increase in shoot age irrespective of pruning date. Maximum disease severity was observed in plants pruned during second week of October and minimum in plants pruned during last week of December. Significant (P<0.05) influence of date of pruning, shoot age and their interaction was observed on the severity of the disease. Apparent infection rate (r) was significantly higher during plant growth period from day-48 to day-55. Average apparent rate was higher in plants pruned during first week of September and least in plants pruned during third and fourth week of December. Multiple regression analysis revealed contribution of various combinations of weather parameters on the disease severity. A linear prediction model [$Y=66.05+(-1.39)x_1+(-0.219)x_4$] with significant $R^2$ was developed for prediction of the disease under natural epiphytotic condition.

• Korean Journal of Plant Resources
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• v.16 no.1
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• pp.34-39
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• 2003

Corm apical meristem cultures of thirteen glasshouse freesia cultivars were tested to investigate the possibility of micropropagation using MS basal medium supplemented with 2,4-D, NAA(0.1, 0.5, 1.0mg/L, respectively) and BA (0.5∼2.0mg/L). The majority of the tested cultivars could be induced callus and shoot buds in all culture condition. The combinations of NAA and BA appeared superior to that of 2,4-D and BA depending on cultivars for callus induction and shoot formation. Among the cultivars, 'Golden Yellow' showed the highest regeneration capacity on MS media with 0.5mg/L NAA and 1.0 mg/L BA. The highest percentage of regeneration and the greatest number of shoot from calli were obtained through successive subculture on MS medium supplimented with 0.5mg/L BA. In that condition, more than 60 ％ shoot regeneration and average of 25.1 shoots per explant was achieved. Transformed shoots on half-strength MS medium without plant growth regulators rooted easily.

• Korean Journal of Plant Tissue Culture
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• v.27 no.1
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• pp.19-23
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• 2000

The experiment was carried out to investigate the influence of light condition and polarity of explant on adventitious shoot formation from cotyledon of apple in vitro The treatment of light culture after 10days dark treatment showed effective result than other treatments on the rate of adventitious shoot formation on light intensity treatments and also the treatment of blue light treatment after 4days dark treatment showed more effective result than other treatments in light quality treatments. The polarity of explant influence on adventitious shoot formation. Adventitious multiple shoot formation occured at the proximal end of an excised cotyledon. In other words. shoot organogenesis occured at the proximal cut surfaces of both proximal and distal explants rather than at the distal cut surface of proximal explants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.1
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• pp.52-60
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• 2004

The optimized in vitro culture system was investigated for improvement of regeneration efficiencies by observing the responses of scutella-derived callus of Korean rice (Oryza sativa L.). Large variations of callus induction (43.9-93.9%) and shoot regeneration (0-88.7%) were observed among the rice cultivars depending on medium. However, shoot regeneration was significantly improved by selected utilization of basal medium, growth regulators, and carbon sources. N6 basal medium was more efficient for embryogenic callus induction than MS or LS basal medium, while MS was superior to N6 for shoot regeneration. The calli of highly regenerative cultivars grew faster and showed higher rates of green tissue formation (GT) and shoot regeneration (SR) and lower rate of callus browning (CB) than those of recalcitrant cultivars. Although a higher level of kinetin stimulated the GT and SR in highly regenerative cultivars, $10\textrm{mgL}^{-1}$ kinetin generally suppressed the GT and SR, while CB was accelerated compared to $2\textrm{mgL}^{-1}$ kinetin. Additional benefits of sorbitol combined with maltose (or sucrose) under $5\textrm{mgL}^{-1}$ kinetin were certainly confirmed on regeneration efficiencies compared to sucrose alone as carbon source and osmotic regulator. This combination showed high rate of GT and SR with multiple shoots while low rate of CB. With MSRK5SM-Pr medium ($5\textrm{mgL}^{-1}$ kinetin, 3% sorbitol, 2% maltose, $500\textrm{mgL}^{-1}$ proline), the regeneration efficiencies of total 17 out of 24 cultivars were practically improved 160% on average compared to MSRK2S ($2\textrm{mgL}^{-1}$ kinetin, 3% sucrose) control medium. Especially, the medium was most effective to the cultivars showing a medium level of regenerability such as Daesanbyeo and Dongjinbyeo and Suwon477, enhancing efficiencies more than 300-600% compared to MSRK2S medium.

• Proceedings of the Botanical Society of Korea Conference
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• 1999.07a
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• pp.85-89
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• 1999

Somatic embryogendesis is one of good examples of the basic research for plant embryo development as well as an important technique for plant biotechnology. This paper describes the direct somatic embryogenesis from zygotic embryos of Panax ginseng is reversely related to normal axis growth of zygotic embryos by the experiment of various chemical treatments. Under the normal growth condition, the apical tips of embryo axis produced an agar-diffusible substance, which suppressed somatic embryo development from cotyledons. Although the cells of zygotic embryos were released from the restraint of embryo axis, various factors were still involved for somatic embryo development. Electron microscopic observation revealed that the ultrastructure of cells of cotyledon epidermis markedly changed before initiation of embryonic cell division, probably indicating reprogramming events into the cells embryogenically determined state. Polar accumulation of endogenous auxin or cell-cell isolation by plasmolysis pre-treatment is the strong inducer for the somatic embryo development. The cells for the process of somatic embryogenesis might be determined by the physiological conditions fo explants and medium compositions. Direct somatic embryos from cotyledons fo ginseng were originated eithrer from single or multiple cells. The different cellular origin of somatic embryos was originated either from single or multiple cell. The different cellular origin of somatic embryos was depended on various developmental stages of cotyledons. Immature meristematic cotyledons produced multiple cell-derived somatic embryos, which developed into multiple embryos. While fully mature cotyledons produced single cell-derived single embryos with independent state. Plasmolysis pretreatment of cotyledons strongly enhanced single cell-derived somatic embryogenesis. Single embryos were converted into normal plantlets with shoot and roots, while multiple embryos were converted into only multiple shoots. GA3 or a chilling treatment was prerequisite for germination and plant conversion. Low concentration of ammonium ion in medium was necessary for balanced growth of root and shoot of plantlets. Therefore, using above procedures, successful plant regeneration of ginseng was accomplished through direct single embryogenesis, which makes it possible to produce genetically transformed ginseng efficently.

• Korean Journal of Plant Resources
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• v.18 no.3
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• pp.456-461
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• 2005

This study was carried out to induce plant regeneration via shoot formation from sucker explants of Rubus fruticosus L. To induce adventitious shoots, sucker explants were sterilized in $1.2\%$ NaOCl solution, and cultured on the MS solid medium supplemented with kinetin (0.5, 1.0, 3.0 mg/L) and BA (0.5, 1.0, 3.0 mg/L), respectively. As above, to induce adventitious shoots, sucker explants were cultured on the MS solid medium supplemented with IBA (0, 0.1, 1.0 mg/L) and BA (0, 0.1, 1.0, 2.0 mg/L). After 4 weeks of culture, the highest frquency $(100\%)$ of shoot formation from sucker explants was obtained from the medium with 1.0 mg/L BA. The highest shoot number per explant from in vitro shoot explants was 5.3. After 10 weeks of culture, the number of shoot per explant was increased. The highest frequency $(85\%)$ of root formation was obtained at 0.5 mg/L glycine medium, when the explant with shoot were cultured on the MS medium containing glycine at various concentrations from 0 to 2.0 mg/L. The survival rate of the plantlets after transfer to plastic pots containing sand, soil, and vermiculite (1:1:1, vol.) was $95\%$. The results indicate that micropropagation procedure can be applied for an efficient mass propagation of Rubus fruticosus.

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.325-329
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• 2017

A micropropagation method via callus for Ranunculus kazusensis Makino, an endangered species, was established. When stem segments were cultured on MS media supplemented with 1.0 mg/L IAA, NAA, IBA and 2,4-D, the highest frequency of callus induction was achieved on MS medium supplemented with 1.0 mg/L NAA. Multiple shoot per explant was obtained, the MS medium containing 1.0 mg/L BA and 0.5 mg/L NAA. Additionally, effect of activated charcoal (AC) and sucrose on shoot growth in in vitro culture were examined. The most suitable conditions for shoot growth after 4 weeks of culture were the MS medium with AC and sucrose. This in vitro propagation protocol will be valuable for conservation and mass propagation of this endangered plant.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.131-132
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• 2003

Leaf discs and apical meristems were cultured in Murashige and Skoog (MS) medium supplemented with cytokinin and auxin at different concentrations. Callus production was observed in all tested media after six days of incubation. Callus produced in the presence of high concentration of NAA (2.0mg/1) was fragile in texture and yellow in colour. Highest callus formation was observed from leaf discs in the medium supplemented with 1.0mg/1 NAA and 0.5 mg/l BAP in dark at $25{\pm}1{\circ}C$. Percentage of callus formation was 95% and mean callus fresh weight was 654.88 43.53 mg. Shoots were induced from the callus after 4 weeks in 1/2MS medium supplemented with BAP and kinetin both at 0.5mg/1. When elongated shoots were separated and transferred into multiplication medium (MS+0.5mg/1 BAP+0.5mg/1 kinetin) multiplication rate was 6.4 after 6 weeks. Higher concentrations of BAP caused callus production at the base. Direct shoot induction was observed from apical meristems in MS medium in the presence of 0.175 mg/1 IAA + 2.25mg/1 BAP and 0.175 mg/1 IAA + 3.0 mg/1 BAP in 16 hour day at $25{\pm}1{\circ}C$. Explants (apical meristems) elongated to form a single shoot forming a callus at the base. Adventitious buds were sprouted out from the base. Percentage explants which producing shoots was 28.57 and 65.5 respectively. Multiple shoot induction was also observed in the same media. Highest multiple shoot production was observed in the presence of 0.175 mg/l IAA and 3.0mg/l BAP, Mean number of shoots per explant was 5.36 and the mean shoot length was $16.66{\pm}4.15$mm. Shoots (20 30m length) were tested for root induction. Excised shoots were transferred into rooting media, which contains different concentrations of NAA and IAA. Best rooting performance was observed in 1/2MS medium supplemented with 0.1mg/1 NAA after 10 days of incubation in 16 hr photoperiod at $25{\pm}1{\circ}C$. Mean number of roots per shoot was 6 and the mean root length was 252mm. Rooted plantlets were transferred into sterile coir dust:sand (1:4) mixture and maintained in a humid chamber for two weeks, They were gradually exposed to the natural environment. After three weeks they were transferred to pots containing coir dust:sand (1:2) mixture for further development where the 90% survival was observed.