• 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.

• Journal of Korean Society of Forest Science
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• v.77 no.4
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• pp.445-452
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• 1988

This study was conducted to establish practical micropropagation of jujube cultivars ('Geumsumg', 'Bokjo') by axillary bud culture. The results are summerized as follows : 1. Addition of activated charcoal to half-strength Murashige and Skoog(MS) medium supplemented with 0.5mg/l benzylaminopurine(BAP) enhanced shoot and root growth. At 500mg/l activated charcoal level 'Geumsung' showed best result, and shoot length and the number of multiple shoot were 6.4cm and 10.0, respectively. At 1,000mg/l activated charcoal level 'Bokjo showed best result, and shoot length and the number of multiple shoot were 7.5cm and 12.4, respectively. 2. As indole-3-butyric acid(IBA) concentration increased, rooting and callus growth of microshoot were enhanced. The optimum IBA concentration for shoot elongation and multiplication was 1.0mg/l. 3. Growth responses of shoot-tip and axillary bud segments between two jujube cultivars were different. 'Geumsung' showed that axillary bud explants were about twice better than shoot-tip explants for shoot multiplication, but 'Bokjo' showed that shoot-tip explants mere better than axillary bud explants for shoot elongation and multiplication. 4. In acclimatization processes of plantlets produced in vitro, the survival of plantlets with only root primordia in soil medium was better than that of plantlets with several routs resulting in 97.8%. 5. In cutting of in vitro-derived microshoot, paclobutrazol was more effective than IBA, naphth-aleneacetic acid(NAA) and $Rooton^{(R)}$ in rooting and root growth.

• Plant Biotechnology Reports
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• v.3 no.4
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• pp.333-340
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• 2009

Developmental anomalies in the plumule meristem of peanut (Arachis hypogaea L.) somatic embryos resulted in poor shoot differentiation and reduced plant recovery. Existing meristems with caulogenic potential have never been tested for embryogenesis in peanut. The present experiment was designed to test the mature zygotic embryo axis derived plumule with three meristems for somatic embryogenesis. Embryogenic masses and embryos developed from the caulogenic meristems in the axils. Exposure of 2 weeks in primary medium with $90.5{\mu}M$ 2,4-D suppressed the shoot tip differentiation temporarily which then regained the ability to form the shoot on withdrawal of 2,4-D. Exposure of 4 weeks in primary medium with $90.5{\mu}M$ 2,4-D suppressed the shoot tip differentiation irreversibly. No shoot formation was noted from the tips in any of the cultures which were in secondary medium with $13.6{\mu}M$ 2,4-D. Development of somatic embryos directly from axillary meristems was confirmed histologically. Conversion frequency of these embryos was 11%. Thus, in this report, we describe a method to obtain somatic embryos from the determined organogenic buds of the axillary meristem, by culturing the nodal explant vertically on embryo induction medium. It also displays the possibility of obtaining both embryogenic and organogenic potential in two parts of the same explant simultaneously. The possibility of extending this approach for genetic transformation in in vivo system through direct DNA delivery or Agrobacterium injection in meristems can also be explored. Using Agrobacterium rhizogenes, we have demonstrated the possibility of gene transfer in the axillary meristems of seed-derived plumule explant.

• Journal of Korean Society of Forest Science
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• v.95 no.5
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• pp.585-590
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• 2006

In vitro-grown axillary shot-tip meristems of Lycium chinense Mill. from cold-acclimated plant were successfully cryopreserved using a vitrification technique. After loading for 15 minutes with a mixture of 2.0 M glycerol and 0.4 M sucrose ($20^{\circ}C$), small segments (1-2 mm, 3-4 mm, and 5-6 mm) were cut from axilary buds and exposed to the cryoprotectant solution containing 30% glycerol, 15% ethylen glycol,15% dimethyl sulfoxide (DMSO), and 0.4 M sucrose at $0^{\circ}C$ for 30-120 minutes prior to direct plunge into liquid nitrogen (LN). After rapid thawing ($40^{\circ}C$), the segments were washed with MS medium containing 1.2 M sucrose for 0-35 minutes, and then transferred onto recovery-growth medium. The highest survival rate (about 90%) was obtained with cold-hardening treatment, and cryopreserved explants were successfully recovered to plantlets. No abnormal morphological changes were observed with the recovered plants after cryopreservation.

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.353-357
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• 1998

This study was conducted to determine the effect of growth regulators, genotype, and cutting position on the rooting and root growth from cutting of Chrysanthemum zawadskii H.. Rooting rate of Keungugeolcho in the treatement of IBA 500 and 1000 ppm was the better than those of other treatments of IAA, NAA and Rooton. Rooting rate differed depending on the genotype. Hangryobonggugeolcho was better than Keungucheolcho in rooting rate. The treatment of rooton remarkably induced many roots from the cuttings of eight accessions of Chrysanthemum zawadskii H.. Also, rooting rate and number of root differed depending on cutting position. When cuttings including shoot tip were cultured on tray containing bed soil, rooting rate and number of root induced from cuttings with shoot tip was higher than when cuttings without shoot tip and with lateral axillary bud were cultured.

• Journal of Plant Biotechnology
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• v.5 no.2
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• pp.101-105
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• 2003

To eradicate several viruses such as PVX, PVY, and PLRV which often cause considerable damages to the growth and yields of potatoes, several stems including shoot tips were excised from the potato plants grown for 50 days and electric shock was treated. Shoot tips excised from electric-shocked stems were transferred into the medium supplemented with antiviral compound, ribavirin to examine the combinatorial effect. When treated only with 20 mg/L ribavirin, PVX concentration in the regenerated plant-lets was slowly decreased as repeating sub-culture and finally, it took 32 weeks to reach completely PVX-free stock. With an electric shock treatment (10 mA electric current), all the replicates became free from PVY. However, PLRV was not completely eradicated from 94P70-4 and 93P29-3 lines even by treating with 10 mA electric shock. In this case, both electric shock and antiviral compound treatments in axillary buds from the stem segment were successful in eradicating viral contamination.

• Korean Journal of Plant Resources
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• v.19 no.3
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• pp.385-391
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• 2006

In vitro-grown axillary buds of Melia aredarach were successfully cryopreserved by vitrification. On the MS medium supplemented with BA 1 mg/L, multiple shoots were developed within $4{\sim}5$ weeks. Plantlets of Melia azedarach were cold-hardened at $10^{\circ}C$ for a 16-hr photo-period for 6 weeks. Excised axillary shoot-tips from hardened plantlets were precultured on a solidified Murashige & Skoog agar medium (MS) supplemented with 0.7 M sucrose for 1 day at $25^{\circ}C$. Axillary shoot-tip meristems wert dehydrated using a highly concentrated vitrification solution (PVS2) for 60 min at $0^{\circ}C$ prior to a direct plunge into liquid nitrogen (LN). The PVS2 vitrification solution consisted of 30% glycerol (w/v), 15% ethylene glycol (w/v), 15% DMSO (w/v) in MS medium containing 0.4M sucrose. After short-term warming in a water bath at $40^{\circ}C$, the meristems were transferred into 2 ml of MS medium containing 1.2M sucrose for 15 min and then planted on solidified MS culture medium. Successfully vitrified and warmed meristems resumed growth within 2 weeks and directly developed shoots without intermediary callus formation. The survival rate of cold-hardened plantlets for 3 and 4 weeks was 90%. We did not find any difference in PCR-band patterns between control and cryopreserved plants. This method appears to be a promising technique for cryopreserving axillary shoot-tips from in vitro-grown plantlets of Medicinal plants.

• 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.

• Journal of Plant Biotechnology
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• v.6 no.2
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• pp.77-85
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• 2004

Development of efficient plant regeneration and genetic transformation protocols (using the Particle Inflow micro-projectile Gun and the shoot-tips as target tissue) of Sorghum bicolor (L.) Moench in terms of expression of the reporter gene, $\beta$-glucuronidase(uidA) is reported here. Two Indian cultivars of sorghum were used in the study, viz. M-35-1 and CSV-15. Plant regeneration was achieved from one-week-old seedling shoot-tip explants via multiple-shoot-clumps and also somatic embryos. The multiple-shoot-clumps were produced on MS medium containing BA (0.5, 1.0 or 2.0 mg/$L^{-1}$), with biweekly subculture. Somatic embryos were directly produced on the enlarged dome shaped expansive structures that developed from shoot-tip explants (without any callus formation) when cultured on MS medium supplemented both with BA (0.5, 1.0 or 2.0 mg/$L^{-1}$) and 2,4-D (0.5 mg/$L^{-1}$). Whereas each multiple-shoot-clump was capable of regenerating more than 80 shoots via an intensive differentiation of both axillary and adventitious shoot buds, the somatic embryos were capable of 90% germination, plant conversion and regeneration. The regenerated shoots could be efficiently rooted on MS medium containing 1.0mg/$L^{-1}$ IBA and successfully transplanted to the glasshouse and grown to maturity with a survival rate of 92%. The plant regeneration efficiency of both the genotypes were similar. After the micro-projectile bombardment, expression of uidA gene was determined by scoring blue transformed cell sectors in the bombarded tissue by an in situ enzyme assay. The optimal conditions comprising a helium pressure of 2200 K Pa, the target distance of 11 cm with helium inlet fully opened and the use of osmoticum have been defined to aid our future strategies of genetic engineering in sorghum with genes for tolerance to biotic and abiotic stresses.

• 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.