Cytokinins induce direc somatic embryogenesis of Dendrobium chiengmai pink and subsequent plant regeneration
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Four auxins (2,4-dichlorophenoxyacetic acid [2,4-D], indole-3-acetic acid [IAA], indole-3-butyric acid [IBA], and naphthaleneacetic acid [NAA]), and five cytokinins (N 6-[2-isopentenyl]-adenine [2iP], N 6-benzyladenine [BA], 6-furfurylaminopurine [kinetin], 1-phenyl-3-(1,2,3-thiadiazol-5-yl)-urea [TDZ], and 6-[4-hydroxy-3-methylbut-2-enylamino]purine [zeatin]) were examined for their effects on direct embryo induction from leaf explants of Dendrobium cv. Chiengmai Pink cultured on 1/2 Murashige and Skoog (MS) medium. Whether in light or darkness, explants easily became necrotic and no embryos were obtained on growth regulator-free or auxin-containing media after 60 d of culture. By contrast, five cytokinins tested induced direct embryo formation from leaf explants, and explants cultured in light had a higher embryogenic response compared with those cultured in darkness. The best condition for direct embryo induction was at 18.16 μM TDZ cultured in light for 60 d, where 33% of explants formed a mean number of 33.6 embryos per explant. During subculture on growth regulator-free 1/2 MS medium, embryos gradually developed into plantlets. Secondary embryogenesis was occasionally found on sheath leaves of embryos. Regenerated plantlets were successfully transplanted and grown in a greenhouse environment.
Key wordscytokinin direct somatic embryogenesis leaf explant
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- Arditti, J.; Ernst, R. Micropropagation of orchids. New York: John Wiley; 1993:311–365.Google Scholar
- Chen, J. T.; Chang, W. C. Direct somatic embryogenesis and plant regeneration from leaf explants of Phalaenopsis amabilis var. formosa Shimadzu. Bio. Plant. (in press); 2005.Google Scholar
- Dawns, C. J. Biological techniques in electron microscopy. New York: Barnes and Noble; 1971.Google Scholar
- Manorama, P.; Rao, A. N.; Goh, C. J.; Loh, C. S. Leaf callus development in Aranda and Dendrobium. In: Fifth ASEAN Orchid Congress, Singapore, 1984:102–109.Google Scholar
- Nayak, N. R.; Rath, S. P.; Patnaik, S. In vitro propagation of three epiphytic orchids, Cymbidium aloifolium (L.) Sw., Dendrobium aphyllum (Roxb.) Fisch and Dendrobium moschatum (Buch-Ham) Sw. through thidiazuron-induced high frequency shoot proliferation. Sci. Hortic. 71:243–250; 1997.CrossRefGoogle Scholar