• Membrane Journal
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• v.24 no.2
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• pp.158-166
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• 2014

In this research, microporous and bicontinuous poly vinylidene fluoride(PVDF) hollow fiber membranes were prepared via hybrid process of the thermally induced phase separation (TIPS) and stretching method. The mechanism of the membrane preparation is based on liquid-liquid phase separation. The final membranes have characteristic structures which have both bicontinuous and fibrillar morphology by applying the stretching method. They showed quite different structure when compared with the spherulitic or nodular structure from S/L TIPS and bicontinuous structure from L/L TIPS. At first, PVDF hollow fiber precursors were prepared via TIPS method using various kind of diluent mixtures. We used gamma-butyrolacton, dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP) as diluents. We could make hollow fiber membranes which had porous outer surface or dense outer surface by controling the parameters such as cooling conditions, PVDF concentration and the ratio of diluent mixtures. Finally, these hollow fiber were stretched at room temperature and diluents were extracted by ethanol. Effects of the stretching ratio on the membrane morphology were investigated using scanning electron microscope (SEM), and its effects on water flux, porosity, pore size, roughness and tensile strength were examined.

• Journal of Plant Biotechnology
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• v.2 no.3
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• pp.151-155
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• 2000

Shoot proliferation was obtained from shoot tips and nodal explants of Vitex negundo L. on MS medium supplemented with either BAP or KIN (0.1-2.0 mg/L) alone or in combination with NAA (0.1 mg/L). The concentrations of cytokinins combined with NAA produced multiple shoots from shoot tips and nodal explants. The highest mean percentage (84.3$\pm$8.0) of shoot multiplication's were observed on nodal explants in the presence of BAP (1.5 mg/L) and NAA (0.1 mg/L) followed by shoot tips (65.0$\pm$5.0). The regenerated shootlets were rooted on MS basal medium IAA, IBA, NAA (0.1-1.5 mg/L). The maximum number of roots (51.0$\pm$2.6) was achieved on the medium containing IBA (1.0 mg/L) followed by other auxins (NAA, IAA). The regenerated plants were successfully transferred to a mixture of vermiculate and soil. About 95% of the plantlets survived when transferred to the field.

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.101-104
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• 1995

The experiment was conducted to identify the optimal in vitro propagation condition for P. lactiflora Pall. Through apical shoot tip and axillary shoot tip culture of winter bud. When apical shoot tip and axillary shoot tips excised from winter bud were cultured on MS medium supplemented with various concentrations of plant growth regulators, all the apical shoot tips elongated regardless of the composition of the medium but axillary shoot tips responded differently. Shoot of 'Uisong' local cultivate was well elongated in the medium containing 0.01mg/L NAA. Frequency of shoot formation and subsequent shoot growth in axillary shoot tip culture were promoted in the medium containing 0.01 mg/L NAA and 5.0mg/L zeatin. 30% of the elongated shoots were vigorously rooted on the medium containing 0.1mg/L NAA with vermiculite as a support medium.

• Korean Journal of Plant Resources
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• v.32 no.6
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• pp.689-697
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• 2019

This study describes an efficient and widely applicable droplet-vitrification following cryopreservation for shoot tips of strawberry (Fragaria × ananassa Duch.) cvs. 'Wonkyo3114' and 'Gurumi40'. The shoot tips were precultured in Murashige and Skoog (MS) liquid medium supplemented with sucrose (0.3-0.5M). Precultured explants were osmoprotected with loading solution (LS, C4) containing 20% glycerol and 20% sucrose for 40 min and exposed to dehydration solution (B5) containing 40% glycerol and 40% sucrose for 40 min at 25℃, Subsequently, the explants were transferred onto droplets containing 2.5 μL PVS3 on sterilized aluminum foils (4 cm × 0.5 cm) prior to direct immersion in liquid nitrogen (LN) for 1 h. The highest regrowth rate (%) in both the cultivars was obtained when the shoot tips were precultured with MS + 0.3M sucrose for 40 h at 25℃. The cryopreserved shoots tips exhibited 55% regrowth rate by culturing in NH₄NO₃-free MS medium supplemented with 3% sucrose, 1.0 g/L casein, 1.0 mg/L GA₃, and 0.5 mg/L BA for 5 weeks and in MS medium supplemented with 0.5 mg/L GA₃ for 8 weeks. This result shows that droplet-vitrification could be employed as a promising method for cryostorage of strawberry germplasm.

• Journal of Plant Biotechnology
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• v.31 no.1
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• pp.61-65
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• 2004

In order to micropropagate uniform plantlets of Alocasia cadieri Chantrier in vitro, the shoot tips were cultured on media containing various concentrations of BA and thidiazuron (TDZ). Multiple shoot formation from shoot tips was very effective on medium containing 0.1mg/L TDZ. The formed shoots from shoot tips were separated into a shoot, and cultured on media with BA, TDZ, and NM combination for proliferation. The shoots were multiplied very vigorously on medium with 0.5mg/L TDZ and 0.5mg/L NAA. The rooting and growth of multiplied shoots were more effective on medium with 2.0g/L activated charcoal, rather than those with IBA and NAA. Rooted plantlets show high survival in soil mixed with perlite 1: vermiculite 1 or vermiculite alone.

• Korean Journal of Plant Resources
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• v.33 no.6
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• pp.675-681
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• 2020

This study describes an efficient and stable droplet vitrification following cryopreservation of strawberry shoot tip (Fragaria × ananassa Duch.) accessions 'Massey' and 'MDUS3816'. The shoot tips were precultured in Murashige and Skoog (MS) liquid medium supplemented with sucrose (0.3-0.7M). Precultured explants were osmoprotected with loading solution (LS, C4) containing 17.5% glycerol and 17.5% sucrose for 40 min and exposed to dehydration solution (B1) containing 50% glycerol and 50% sucrose for 40 min at 25oC. Subsequently, the explants were transferred onto droplets containing 2.5 µL PVS3 on sterilized aluminum foils (4 cm× 0.5 cm) prior to direct immersion in liquid nitrogen (LN) for 1 h. The highest regrowth rate (%) in both the cultivars was obtained when the shoot tips were precultured with 0.3M sucrose for 30 h + 0.5M sucrose for 16 h at 25oC. The cryopreserved shoots tips exhibited 57.8 % recovery rate by culturing in NH₄NO₃-free MS medium supplemented with 3% sucrose, 1.0 g/L casein, 1.0mg/L GA₃, and 0.5 mg/L BA for 5 weeks and in MS medium supplemented with 0.5 mg/L GA₃ for 8 weeks. Variation was not observed in both of ploidy analysis and morphological investigation on plantlets of two accessions cryopreserved under variable preculture conditions.

• Korean Journal of Plant Resources
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• v.29 no.6
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• pp.635-641
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• 2016

Sweet potato (Ipomoea batatas L.) shoot tips grown in vitro were successfully cryopreserved by encapsulation-vitrification. Encapsulated explants are very easily manipulated, due to the relatively large size of the alginate beads, and a large number of samples can be treated simultaneously. In this study, the effects of sucrose preculture, cryoprotectant preculture, and post-warm recovery media on regrowth, following liquid nitrogen (LN) exposure, were investigated to establish an efficient encapsulation-vitrification protocol for sweet potato. Shoot tips of plants grown in vitro were precultured in 0.3 M sucrose for 2 d before encapsulation. Encapsulated shoot tips were pre-incubated in liquid MS (Murashige and Skoog) medium containing 0.5 M sucrose for 16 h, before preculturing in sucrose-enriched medium (0.7 M sucrose) for 8 h. Shoot tips were osmoprotected with 35% plant vitrification solution 3 (PVS3) for 3 h, before being dehydrated with PVS3 for 2 h at $25^{\circ}C$. The encapsulated and dehydrated shoot tips were transferred to 2 mL cryotubes, suspended in 0.5 mL PVS3, and plunged directly into liquid N. High levels of shoot formation were obtained for the cv. Yeulmi (65.7%) and Yeonwhangmi (80.3%). The regrowth rates of cryopreserved samples in Yeulmi (78.9%) and Yeonwhangmi (91.3%), following culture on ammonium-free MS medium for 5 d, were much higher than those cultured on standard MS medium (65.7% and 80.3%, respectively). This encapsulation-vitrification is a promising method for the long-term preservation of sweet potato.

• 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.221-225
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• 1994

This experiment was conducted to identify the optimal in vitro propagation condition of Cnidii rhizoma (Cnidium officinale Makino). It was effective to reduce contamination and improve regeneration of shoot when shoot tips taken in July were cultured in 1/2 strength Murashige and Skoog medium supplemented with 500 mg/L carbenicillin disodium 1.0 mg/L BA and 1.0mg/L $GA_3$followed by surface sterilization of explant source in solution of 1% sodium hypochlorite for 20 minutes. When shoot tips were 쳐cultured in 1/2 strength MS medium with 0.5 mg/L BA and 60 g/L sucrose, shoot elogation and subsequent multiplication of the formed shoot were favorable than in other media. Regenerants were well rooted in 1/2 strength MS medium containing 3.0 mg/L NAA.

• Korean Journal of Plant Resources
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• v.28 no.6
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• pp.690-696
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• 2015

We micropropagated pear (Pyrus species) using shoot tips and nodal explants from three pear genotypes. The ability to establish shoot tip cultures, proliferate shoots, induce rooting, and acclimatize the resulting plantlets are all elements of in vitro micropropagation. Shoots were induced from shoot tips on Murashige and Skoog medium (MS) with five different plant growth regulator combinations. The highest shoot formation rates were achieved for the three genotypes using MS supplemented with 1.0 mg/L N⁶-benzyladenine (BA) and 0.1 mg/L gibberellic acid (GA₃). The maximum shoot number and shoot length for the three cultivars were recorded with 2.0 mg/L BA and 0.2 mg/L indole-3-butyric acid (IBA) in multiplication medium using nodal explants produced from microshoots. Nodal explants with one or two axillary buds cultured for three weeks initiated roots on medium supplemented with various concentrations of 1-naphthaleneacetic acid (NAA) or/and IBA in half-strength MS medium for adventitious rooting. The highest rooting response was with the combination of 0.2 mg/L NAA and 0.2 mg/L IBA. A combination of NAA and IBA resulted in a significant increase in the rooting ratio over NAA or IBA alone. In this medium, the root formation rate according to ranged from 68.9% for the BaeYun No. 3 genotype to 51.8% for the Hwanggeum genotype. We also investigated the influence of the concentration the polyamine phloroglucinol in rooting medium. For all three genotypes, the highest rooting ratio, longest root length, and greatest root number were observed in the treatments with 75-150 mg/L phloroglucinol. Most rooted plants were acclimatized successfully.