• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.157-160
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• 1994

Culture conditions for high Sequency somatic embryogenesis and plant regeneration in tissue cultures of sweet potato of two Korean cultivars 'Puyojaerae' and 'Yulmi' are described. Shoot apical meristem explants (height 150 $\mu\textrm{m}$; base: 350 $\mu\textrm{m}$) were cultured on MS medium supplemented with 1 mg/L 2,4-D. After 6 weeks of culture, greater than 80% of the survived explants produced embryogenic calli. When transferred onto MS medium with 0.1 mg/L each of 2,4-D and kinetin, the calli gave rise to somatic embryos at frequencies of 71% ('Puyojaerae') and 63% ('Yulmi'), respectively: When somatic embryos at various developmental stages measured in length were transversely cut into two halves and cultured on MS medium with 1 mg/L 2,L-D, the upper halves produced secondary embryos more frequently than the lower ones, and halves of somatic embryos less than 1 mm in length had a higher competence for secondary embryo formation than longer ones of either cultivar. However 'Puyojaerae' somatic embryo halves showed a higher frequency of secondary embryo formation than 'Yulmi' ones on the whole. Upon transfer onto MS basal medium, most of the primary and secondary somatic embryos underwent development into plantlets. The plantlets were transplanted to potting soil and grown to maturity in a phytotron. The overall results suggest that the shoot apical meristem culture system for somatic embryo formation in sweet potato previously established by us (SABRAOJ 21: 93-101) may be applicable regardless of it genotypes.

• Journal of Plant Biotechnology
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• v.40 no.1
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• pp.55-58
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• 2013

Immature embryos of Glycine max L. was cultured on Murashige and Skoog's (MS) medium supplemented with 1 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D). After 6 to 8 weeks of culture, immature embryos produced somatic embryos. Of somatic embryos, two cotyledonary embryo (14%), one cotyledonary embryo (37%), fused cotyledonary embryo (43%), and stunted globular embryos (6%) were observed. The procambial strand of cotyledons originated from circular procambial tissues of lower hypocotyl. The circular procambial tissues were independently divided into one or two procambial strand at the edge of cotyledonary-node, and then connected to each cotyledon to form somatic embryos with one or two cotyledons. When cotyledon was a fused type, the circular procambial strand in lower hypocotyl was continuously connected to the cotyledon. Also, somatic embryos with two cotyledons developed a functional shoot apex with the tunica-corpus structure. In contrast, somatic embryos with one or fused cotyledon formed an abnormal shoot apex without the tunica-corpus structure or with non-dome shape in the inter-cotyledonary area. These results indicated that the variation of cotyledon in somatic embryos is closely related to procambial differentiation and shoot apical meristem development.

• Journal of Plant Biotechnology
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• v.29 no.1
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• pp.37-40
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• 2002

Sweet potato is a crop vegetatively propagated by vine cuttings, an ineffective method for maintaining pathogene-free stock plants. As an alternative method, single-node cultures of virus-free plantlets derived from apical meristem in sweet potato (cv. Yulmi) was examined. Effective pH range, sugar concentration and nodal order were investigated to establish an in vitro mass propagation system with high quality virus-free stock plantlets to farmhouse. Although the plantlets grew at wide range of pH, the most effective pH of the medium was 4.8 in single-node cultures. High sugar concentration of 60∼80 g/L resulted in increased growth response in shoot length, root length, number of node, leaf area and fresh and dry weight of shoot and root, whereas reducing sugar contents below 6% was showed reduced growth response. The first node including meristem tip was the best for the rapid growth of plantlets and the other nodes also showed a very similar growth response. Uniform plantlet can be obtained massively at the same time by culture of single node except for the first node including meristem tip. In conclusion, the most effective pH range and sugar concentration of medium for the growth of plantlets via single-node cultures was 4.8, 60∼80 g/L respectively. The first node was the best for the rapid propagation of plantlets in nodal order.

• 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.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2003.10a
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• pp.161-161
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• 2003

• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.99.1-99.1
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• 2007

See Full Text

• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.36.1-36.1
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• 2007

See Full Text

• Korean Journal of Plant Resources
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• v.17 no.1
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• pp.1-6
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• 2004

Apical meristems tissue were cultured on LS medium with different zeatin and NAA concentrations to compare their potential to regenerate shoots, roots and bulblet formation. Shoot regeneration from apical meristem was effective on LS medium added with zeatin 0.1, 0.5, 1.0 mg/L alone treatment or zeatin 0.5 mg/L and NAA 1.0 mg/L combination treatment. A high frequency of root regeneration was obtained on LS medium supplemented with zeatin 0.5 mg/ and NAA 1.0 combination treatment. Linsmaier and Skoog(LS) medium with NAA 3.0 mg/L and zeatin 1.0 mg/L combination treatment gave the best results for normal bulblet formation#KW=Allium wakegi ; plant regeneration ; bulblet formation

• Korean Journal of Plant Tissue Culture
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• v.21 no.4
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• pp.193-200
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• 1994

The effects of sucrose concentration and nitrogen source on shoot growth and in vitro formation of garlic (Allium sativum L. cv Seosan) bulblet were investigated in order to systematize propagation of high quality garlic through a shoot apical meristem culture. Shoot differentiation was not affected by sucrose concentration and nitrogen source, but plantlets which contain medium of NH$_4$- N or NH$_4$ + NO$_3$ were vigorous and healthy in .appearance. Shoot growth was vigorous in changeing of nitrogen source. The best quality of in vitro bulblets was obtained in culture on the medium containing 8% sucrose and NH$_4$ - N, and the formation of bulblet was more effective when plantlets were subjected to cold treatment before use. NH$_4$-N was a major factor for shoot growth and bulblet development, but NO$_3$-N was not and suppressed $K^{+}$absorption. The level of ethylene production was not affected by different nitrogen sources, however this production was enhanced in medium containing a higher concentration of sucrose.e.

• Korean Journal of Plant Taxonomy
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• v.38 no.1
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• pp.51-61
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• 2008

Leaves are indeterminate organs and possess a lot of genes which is involved in establishing leaf polarities. These polarities are regulated relatively early during leaf development and defined relative to the factors intrinsic to the primordia and interactions with the shoot apical meristem (SAM). Recently, several genes that control the polarity of lateral organs have been identified. Our genetic study of deformed root and leaf1 (drl1) mutant, which produces narrow, filament‐like leaves and defective meristems, revealed that DRL1 is involved in the regulation of SAM activity and leaf polarity. The DRL1 gene was found to encode a novel protein showing homology to Elongator‐associate protein (EAP) of yeast KTI12. The amino acid sequence of DRL1 is universally conserved in prokaryotes and eukaryotes. DRL1 and the plant DRL1 homologs clearly formed a monophyletic clade, suggesting the evolutionary conservation of DRL1 homologs was maintained in the genomes of all land plants.