• Korean Journal of Plant Tissue Culture
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• v.28 no.2
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• pp.61-67
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• 2001

Using mature seed-derived callus, optimal conditions for efficient callus growth and plant regeneration, and regeneration efficiency by callus type were investigated in zoysiagrass (Zoysia japonica steud.). Callus induction was highest when the seeds were cultured on MS medium containing 2 mg/L 2,4-D, 0.2 mg/L BAP, 4 mg/L thiamine-HCl and 100 mg/L $\alpha$-ketoglutaric acid. Callus growth was highest when callus were cultured on MS medium containing 0.5 mg/L 2,4-D, 0.05 mg/L BAP, 4 mg/L thiamine-HCl and 100 mg/L $\alpha$-ketoglutaric acid. Plant regeneration was highest when callus was transferred on MS medium containing 3% maltose and 1 mg/L BAP, or 1 mg/L thidiazuron (TDZ). The combinations and concentrations of 2,4-D and BAP were shown to be critical factors for both the frequency and the type of callus. And four morphologically distinct types of callus were induced from the 2,4-D and BAP treatment. Type I,II and III calli produced shoots upon subculture, while the watery callus, type IV produced roots without shoots. Of four types of callus, type I exhibited the maximum frequency (82%) of shoot regeneration and the minimum frequency (4%) of albinism.

• Journal of Plant Biotechnology
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• v.41 no.4
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• pp.216-222
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• 2014

This study was carried out to develop an efficient transformation protocol via particle bombardment with PLBs (protocorm-like bodies) in Phalaenopsis. To achieve this aim, osmoticum treatment and an increasing shooting chances in particle bombardment process were applied for this study. In addition, pCAMBIA3301: ORE7 vector which contains a herbicide-resistance bar gene as a selectable marker and ORE7 gene as a gene of interests were employed. With regard to the increasing chances of shooting in particle bombardment, double shooting was the best results with 1.5 ~ 2.5 times higher than those of a single or triple shooting treatment in the productioon of PPT (D-L-phosphinothricin)-resistant PLBs. However, regeneration rate of shoots in double shooting was not high as a single shooting. Further, double shooting showed 35 ~ 40% higher than that of a single shooting in the frequency of browning. Regarding effects of different osmotic treatments, combination of 0.2 M sorbitol with 0.2 M mannitol showed the best results in transformation efficiency, regeneration of transformants and reduction of browning. Putative transgenic Phalaenopsis plants were analyzed by PCR analysis and confirmed the presence of bar and ORE 7 gene. Also, real-time PCR was conducted by using 21 transgenic plants and showed only 4 plants had one copy of transgene; whereas, the other 17 plants had more than 2 copies of transgene. Transgenic phalaenopsis plants produced in this study were transferred to pots and flowered normally without morphological variations in flower and leaf.

• Journal of Life Science
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• v.23 no.2
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• pp.267-272
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• 2013

This study was conducted to eliminate viruses from citrus-infected plants using micrografting and thermotherapy. Six citrus cultivars including a 'Setoka' hybrid were used as plant sources. The TAS-ELISA technique demonstrated that several plants were CTV positive. However, no CTV symptoms were detected in plants obtained from shoots and treated at a high temperature of $40^{\circ}C$ during the day and night and micrografted for two weeks with old trifoliate orange rootstock in vitro. Indexing of CTV, SDV, and CTLV for RT-PCR analysis of the eleven citrus seedlings, including 'Setoka', 'Samdajosang', 'Pungkwang', 'Shiranuhi', and 'Ehimekashi dai28go' was virus free following the micrografting and thermal therapy.

• Korean Journal of Organic Agriculture
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• v.25 no.1
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• pp.125-134
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• 2017

This study was carried out to examine the effects of soil sulfur mixture on the control apple valsa canker in apple orchard for two years. In organic apple orchard, The recovery percentages of apple valsa canker were compared among control (no treatment), lime sulfur, and soil sulfur in organic orchards. In conventional apple orchards, those of recovery percentages were compared among control, neoasozin, lime sulfur, and soil sulfur. Compared with control, soil sulfur treatments significantly improved the recovery percentages of apple valsa canker infected trees in organic orchard. However, there were no differences between lime sulfur and soil sulfur treatment in organic apple orchard, except BongHyun orchard experiment in 2013. Compared with control fruit qualities, fruit skin red color and fruit firmness were improved in lime sulfur and soil sulfur treatment, respectively. In conventional orchard, apple trees treated with lime sulfur, soil sulfur or neoasozin improved recovery percentages, compared with those of control trees. Soil sulfur treatments recovered 87.5~97.5% of infected 'Fuji'/MM106 apple trees in organic and conventional apple orchards. The trees applied with neoasozin showed significant lower shoot growth than those of soil sulfur treatment in conventional orchard. Soli sulfur treatment improved fruit red color, but did not affected fruit weight, fruit firmness, soluble solids concentrations, and titratable acidity.

• Horticultural Science & Technology
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• v.31 no.1
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• pp.95-102
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• 2013

Binary trans-activation (pOp/LhG4) system is one of the regulatory systems of transgene expression. The target gene expression is achieved by crossing the reporter plants with an activator in this system. In this study, we used the features of this system in Chinese cabbage as a way to protect genetic resources and new varieties. To establish pOp/LhG4 system in Chinese cabbage, we designed an activator (35SLhG41300), and reporter constructs (pOpGUSBart) and co-transformed using Agrobacterium. The transgenic plants were selected by antibiotics and the functional activity of pOp/LhG4 system was confirmed by GUS expression. To induce the tissue-specific function, we constructed pOp/LhG4 system (795LhGBart) using female tissue specific promoter (ProAt1g26795) of Arabidopsis. Co-transformed transgenic plants clearly showed tissue specific expression in Arabidopsis. The results suggest the possibility of the system's application of $F_1$ generation can be restricted by expressing the target gene to protect a new variety and genetic resource in Chinese cabbages.

• Journal of Life Science
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• v.12 no.1
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• pp.96-105
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• 2002

To investigate expression of the artificial gene encoding a repeated tripeptide lysyl-glutamyl-tryptophan in tobacco plant, the plant binary vector, pART404 has been constructed, which contains the duplicated CaMV 35S promoter, an artificial gene coding for repetitive polymer (Lys-Glu-Trp)$_{64}$, and nopaline synthase (nos) terminator. The recombinant expression vector was introduced in Nicotiana tabacum (var. Xanthi) via Agrobacterium tumefaciens-mediated trans-formation. The transgenic calli selected by kanamycin containing medium were then regenerated to whole plants. Southern blot analysis indicated that five transgenic plants (No. 1, 7, 9, 43, 45) showed the hybridizing signals at 1.1 kb of the expected size on EcoRI digestion and each of the transgenic plants contained 1 or 3 copies of the artificial gene inserted into its genome. By northern blot analysis, the size of the hybridized total RNA was estimated to be approximately 1.2 kb and the RNA appeared generally to have the integrity. Western blot indicated that the protein was detected at the position of 33 kDa and the expression level of the polypeptide in the transgenic plant (No. 45) was measured to approximately 0.1% of the total protein.

• Journal of Korean Society of Forest Science
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• v.76 no.4
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• pp.357-360
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• 1987

1. The hair cells on adaxial surface turned out to be penetration way of Gleosporium Thea sinensis in tea plant. 2. The most parts of Gleosporium Thea sinensis generated in tea plant were young leaves with first-fifth leaves from tip of shoot. 3. The proper temperature for spore germination on leaf is $25-27^{\circ}C$, soaked by water for 12 hours. 4. For prevention of Gleosporium Thea sinensis the drug-spay in tea plant would be the most effective when sprayed at this temperature range, and the control of Gleosporium Thea sinensis would be possible through selection of tea plant with few hairs. 5. The treatment of bordeaux mixture to prevent growth of conidiospore was 48.3% more effective than in control plot which were not sprayed. 6. The effect of sprayed bordeaux mixture decreased to about 28.5% after one week of spray.

• Journal of Korean Society of Forest Science
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• v.78 no.2
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• pp.189-197
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• 1989

This study was carried out to produce the grafts of Juglans sinensis by juvenile grafting method which epicotyl of newly germinated seeds were used as stocks and juvenile fresh shoots were used as scion. The results obtained were as follows ; 1. When plastic tube installed covering up seed with soil up to 6cm height for diameter increment of epicotyl, the epicotyl can be grown up to thickness of 10mm. 2. When the soft fruit branches and the soft water sprout with the terminal bud 8cm to 12cm long were used as scions, the survival rates showed 90 Percent. 3. The optimum date for making juvenile grafts was around the 20th of May, and the survival rates of grafted seedlings showed 86 percent in average. 4. The grafted seedlings showed first sprouting the 15th of June, that is 25 days after making graft, and the sprouting rate was 72 percent. 5. The height-growth of grafted seedlings finished at the end of July, and diameter growth lasted into the end of October. 6. There was positive correlation between the height of grafted seedlings and the diameter at root collar. 7. In general, it takes two years to make plantable graft seedlings from hardwood scion and stock, but the juvenile graft seedlings can be easily obtained in a year and so it seems to be economic.

• FLOWER RESEARCH JOURNAL
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• v.16 no.3
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• pp.211-217
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• 2008

To build up data for mutation breeding of lily, sensitivity to irradiation of bulb, seed and pollen was investigated. The bulbs of seven cultivars including 'New Wave' were very sensitive to gamma rays. Non-irradiated bulbs produced plants with bloom as normal. However, irradiated bulbs showed retarded growth and did not flower. Bulbs of 'New Wave' and 'Tiny Dino' irradiated with 125Gy gamma rays survived, but their growth rate dropped considerably. Part or whole leaves of the other cultivars except 'New Wave' and 'Tiny Dino' withered. Moisture content of individual scale was 72~78% depending on cultivar. Bulblet formation from untreated scales was 100%. Among all irradiated scales only 'Siberia' scales showed 8.5% bulblet formation when irradiated with 50Gy gamma rays. Pollen germination as affected by gamma ray irradiation had no consistent tendency. When dosage of $F_1$ 'Augusta' seeds reached 300Gy, their survival ratio was drastically decreased. Bulblet formation in vitro was observed only in non-irradiated seeds. Lethal dose ($LD_{50}$) of seed was less than 100Gy. Height and width of $F_1$ 'Augusta' bulblets in vitro irradiated with gamma rays decreased as dosage increased regardless of the culture method. The percentage shoot formation was 100% in non-irradiated bulblets and 15~60% in irradiated ones.

• FLOWER RESEARCH JOURNAL
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• v.18 no.1
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• pp.29-32
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• 2010

This study was conducted to determine the effects of cutting position, media, and auxin on rooting of Artemisia keiskeana cuttings. In the cutting positions, the cutting of middle and basal positions had a better growth in the both upper and lower part than the cutting of the top position. Especially, the cutting of the middle position showed the highest rooting rate, at 68.3%. In the media, peatmoss showed the latest date on the rooting initiation. Also, the growth, survival rate and rooting rate of the upper part and lower part were low. However, the cutting in vermiculate showed the fastest date on the rooting initiation, and had a significant effect on the growth of the upper part and lower part, showing the highest rooting rate and survival rate in all tested media. When cuttings were treated by auxin, the rooting rate and growth of cuttings were higher than the control. The control showed the lowest rooting rate, at 41%, while, the auxin treatment showed the highest, rate over 80%. Whereas when treated by NAA, the lower part of cuttings had a better growth than these treated by IBA. Also, the higher the concentration of auxin was, the higher the rooting rate and growth rate of Artemisia keiskeana cuttings were.