• Korean Journal of Medicinal Crop Science
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• v.14 no.1
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• pp.23-26
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• 2006

One of micropropagation methods was investigated by using a multiple-shoots protocol. Multiple shoot formation was obtained from excised axillary buds of Hypericum erectum on half-strength or basal MS medium supplemented with TDZ or BA. The optimal combination of shoot multiplication for the production of more shoots with a suitable size was MS medium supplemented with $0.005\;mg{\cdot}L^{-1}$ TDZ (6.5 adventitious shoots per node). In vitro rooting was carried on half-strength MS medium with $1\;mg{\cdot}L^{-1}\;GA_3\;and\;0.5\;mg{\cdot}L^{-1}$ IBA treatment. In addition, the rooted cuttings were showed a better root growth in the greenhouse and survived in more than 90%. The results show that the species can be micropropagated effectively by the application of axillary bud culture systems.

• Korean Journal of Plant Tissue Culture
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• v.22 no.4
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• pp.189-194
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• 1995

Calli were successfully induced from immature embryos of Citrus junos SIEB. cultured on 1/2 MS medium supplemented with 40.4 BA. Plant were regenerated from immature embryo derived callus on MS medium with 5 $\mu$M BA. The calli were morphologically characterized by two types: one was whitish and the other was yellowish. After 16 weeks of culture, shoots and root were formed on calli. Plantlets were transplanted to soil and successfully grown to a whole plant Also, the arrangement of the cells showed many differences according to developmental stages of callus and organogenesis. The small cells were compact in callus cultured for 6 weeks and the extended cells which divided actively appeared in it after 8 weeks of culture. The globular protrusion of compacted cells occurred in callus after 10 weeks of culture, and the neighboring cells were liquefied. Oil sac surrounded by the liquefied cell was observed in the leaf and was formed by rupture of liquefied cells.

• Korean Journal of Plant Tissue Culture
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• v.25 no.2
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• pp.125-129
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• 1998

Cucumber (Cucumis sativus L.) plants were regenerated through organogenesis and somatic embryogenesis in cotyledon and hypocotyl cultures. The shoots were efficiently formed on the basal region of cotyledons cultured on MS medium containing 1.0㎎/L zeatin and 0.1㎎/L IAA in all cultivars used. Embryogenic calli were formed on hypocotyl segments cultured on MS medium containing 1.0㎎/L 2,4-D in cv. group 'Nakhab' and maintained by consecutive subculture on the same medium every 2-3 weeks without loss of embryogenic ability. Upon transfer to MS basal medium, high frequency somatic embryogenesis was achieved easily from embryogenic callus. Regenerated plantlets through organogenesis and somatic embryogenesis were transplanted to pots and gradually acclimatized to greenhouse condition where they subsequently produced fruits.

• Journal of Plant Biotechnology
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• v.50
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• pp.176-182
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• 2023

Plant regeneration protocols for adventitious shoot organogenesis from apple (Malus domestica 'Fuji') leaf explants were developed in the present study. The effects of dark incubation periods in the early stages of culture, pre-treatment methods, the number of explants per culture container, the type of culture containers, and the orientation of the explants on culture media were evaluated to determine the optimal shoot regeneration conditions for 'Fuji' apple leaf explants. Light incubation of explants produced minimal response. However, dark incubation of explants for 4 weeks during the initial culture period enhanced shoot regeneration frequency. Comparing the number of explants per container, a higher percentage of shoot regeneration was obtained with nine explants per container compared with four explants per container. Pre-treatment, before culture, by dipping explants in a liquid regeneration medium containing 40 g/L of sorbitol for 2 hours produced the highest shoot formation rate, and the time of shoot formation was accelerated. The percentage of shoot regeneration and number of shoots per regenerating explant reached a maximum of 87.5% and 4.7, respectively. The regenerated shoots were elongated and rooted on a rooting medium of 1/4 MS with 0.2 mg/L IBA. The plantlets were successfully acclimatized, and the regenerated plants produced normal phenotypes.

• Tuberculosis and Respiratory Diseases
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• v.55 no.1
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• pp.59-68
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• 2003

Background : In intubated patients, cultures of endotracheal aspirates (EA) are apt to contamination throughout the endotracheal tube. Therefore, the identification of etiologic agents via conventional EA cultures is not always reliable. In order to differentiate a pulmonary infection from a non-infectious disease, and to identify the true etiologic agent of acute pulmonary infection, blinded protected specimen brushing (PSB) was used, and its efficacy evaluated. Methods : In 51 intubated patients, with suspected pneumonia, blind PSB were performed, and the results compared with blood and EA cultures. A protected specimen brush was introduced through the endotracheal tube, and settled at the affected large bronchus. A specimen brush was introduced to the expected region using the blind method. The tip of the brush was introduced with an aseptic technique after vigorously mixed for 1 minute in $1cm^3$ of Ringer's lactate solution. The specimens were submitted for quantitative culture within 15 minutes, with a culture being regarded as positive if the colony forming units were above $10^3/ml$. Results : Of the 51 patients, 15 (29.4%) had community-acquired pneumonia (CAP), 27 (52.9%) hospital-acquired pneumonia (HAP) and 9 (17.6%) non-infectious diseases. The sensitivity and specificity of the quantitative PSB culture for the diagnosis of pneumonia were 52.4 and 88.9%, respectively. The sensitivity and specificity of EA were 78.6 and 77.8%, respectively. The blind PSB was superior to the EA for the identification of true etiologic agents. Of 53 episodes of 27 HAP patients, MRSA (Methicillin-resistant staphylococcus aureus) (41.5%) was the most common causative agent followed by Pseudomonas aeruginosa (15.1%), Klebsiella sp. (7.5%) and Acinetobacter sp. (7.5%). Conclusions : As a simple, non-invasive diagnostic modality, the blind PSB is a useful method for the differentiation of a pulmonary infection from non-infectious diseases and to identify the etiologic agents in intubated patients. A blind PSB can be performed without bronchoscopy, so is safer, more convenient and cost-effectiveness for patients where bronchoscopy can not be performed.

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.161-166
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• 1994

Since garlics (Allium sativum L.) are propagated through cloves, infection by virus or other pathogens may become severe problem if not using high quality seed bulbs every year resulting in the reduction of yield and bulb quality, In order to solve this problem, the establishment of virus-free bulb production and its supply system have been required because no chemicals were found to eliminate viruses from seed bulbs. This experiment was conducted to develop an effective production technique of high quality seed bulbs using shoot-tip culture. Over 90% of shoot-tips explanted on January L 1990 were survived at constant temperature of either 20, 24 or 28$^{\circ}C$, wheres 88% at alternate temperature (28/20$^{\circ}C$). The growth of shoot and root was most vigorous at constant 24$^{\circ}C$, and least at alternate temperature (28/20$^{\circ}C$) condition. When shoot-tips were explanted June 21 to August 1,1991, survival and growth of shoot-tips was most vigorous on MS medium supplymented with 0.1 mg/L NAA and 2 mg/L kinetin and least 1 mg/L Gh$_3$. The shoot-tips taken from the seed bulbs stored at 4$^{\circ}C$ for 15 to 60 days were placed on MS medium, shoot growth and in vitro bulblet formation increased slightly as affected by the increase of told treatment period at 4$^{\circ}C$.

• Korean Journal of Plant Tissue Culture
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• v.21 no.4
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• pp.239-246
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• 1994

The genotypic (2n, 3n, 4n) response of watermelon in vitro shoot tip culture was evaluated. Different genotypes had similar response in terms of shoot formation and growth. Shoot formation was better at lower concentration of 0.3 mg/L BA and higher concentration of 5-10.0 mg/L 2iP and kinetin, but growth of newly formed shoot was inhibited. With further subculture, kinetin did not promote shoot formation Better shoot formation was observed at 0.3-0.5 mg/L BA. Combination of 0.3 mg/L BA and 0.3-0.5 mg/L BA was effective in shoot multiplication, growth and induction of more internodes. Varrying levels of light intensity and agar concentration did not affect the performance of tetraploid plants. Higher light intensity and agar concentrations decreased the number of shoot formed in triploid plane. Growth in both genotype, however was inhibited. Higher light intensity was found to promote leaf senescence in all genotypes. All growth inhibitors decreased the number of shoots formed and slowed plant growth there by prolonging duration of cultures. Growth inhibitors were to observed to decrease incidence of hyperhydricity in culture. No difference in shoot formation was observed in each of the concentrations used in Ancymidol, TIBA, CCC and PP333. Shoot formation and growth was more inhibited in ABA treatments. Leaf expansion and growth was poor in all treatments.

• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.205-212
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• 1987

To examine the morphogenetic response, stem segments of 8 Populus spp. and 3 different explants of P. nigra var. italica were cultured on MS (Murashige and Skoog 1962) and WPM (Woody Plant Medium) medium containing various phytohormones. The results obtained were as follows: 1. Shoot regeneration and development from stem segment of 8 Populus spp. showed a quite difference according to the section and the species. All of the species of Leuce and Tacamahaca section did not form adventitious buds, while most of explants showed axillary or dormant bud elongation after 4 weeks. But P. nigra var. italica of Aigeiros section showed a successful adventitious bud formation (mean 5.4 buds per explant). 2. Leaf, petiole, and internode segment of P. nigra var. italica showed a quite differences according to media and ex plants upon the morphogenetic response. Adventitious bud formation from leaf was more abundant and readily initiated on the abaxial side than on the adaxial side. Mean number of 103 adventitious buds per explant was obtained from abaxial side of leaf segment cultured on WPM medium containing $0.2mg/{\ell}$ BAP for 5 weeks. 3. 2,4-D (2,4-dichlorophenoxy acetic acid) supplemented to media appeared to be negative upon the adventitious bud formation of P. nigra var. italica, while it promoted callus formation from all explants. Especially, NAA (${\alpha}$-naphtalene acetic acid) or NAA combination with BAP (6-benzylaminopurine) promoted root regeneration from the all explant of P. nigra var. italica in this study.

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.137-143
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• 1994

In an attempt to optimize the in vitro-regeneration conditions necessary for the genetic manipulation of tomato species, we examined several hybrid lines and wild species (peruvianum, pimpinellifolium, glandulosum) of Lycopersicon for. their, different regeneration ability. The basal medium used for callus growth and organogenesis was MSB (MS + B5) supplemented with three combinations of TDZ (Thidiazuron) 0.5mg/L+NAA 0.5mg/L, BA 2.0mg/L+NAA0.05 mg/L, and zeatin 3.0 mg/L + IAA 0.02 mg/L. In the genotype of Lycopenicon grandulosum, combination of TDZ and NAA was more effective in inducing shoot and root differentiation than those of BA and NAA or zeatin and IAA. When all genotypes tested were considered, however combination of zeatin and IAA was shown to be the best in shoot regeneration. Result indicate that callus and organogenesis of Lycopenicon species are dependent upon the hormone types and plant genotypes, but MSB medium with zeatin 3.0 mg/L + IAA 0.02 mg/L maybe appropriate for genotype-independent plant regeneration system of Lycopercicon species. We also tried TDZ as a cytokinin source in tomato tissue culture and found it highly significant in tomato regeneration system.

• Journal of Chest Surgery
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• v.37 no.6
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• pp.474-481
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• 2004

Background: Tracheal transplantation is necessary in patients with extensive tracheal stenosis, congenital lesions and other oncologic conditions but bears. many critical problems compared to other organ transplantations. The purpose of this study was to develop intestine-cartilage composite grafts for potential application in tracheal reconstruction by free intestinal graft. Material and Method: Hyaline cartilage was harvested from trachea of 2 weeks old New Zealand White Rabbits. Chondrocytes were isolated and cultured for 8 weeks. Cultured chondrocytes were seeded in the PLGA scaffolds and mixed in pluronic gel Chondrocyte bearing scaffolds and gel mixture were embedded in submucosal area of stomach and colon of 3 kg weighted New Zealand White Rabbits under general anesthesia. 10 weeks after implantation, bowels were harvested for evaluation. Result: We identified implantation site by gross examination and palpation. Developed cartilage made a good frame for shape memory. Microscopic examinations included special stain s howed absorption of scaffold and cartilage formation even though it was not fully matured. Conclusion: Intestine-cartilage composite graft could be applicable in the future as tracheal substitute and should be further investigated.