troduction. Moreover, the results provided by the study of Cymbidium hybridaDFR have suggested a
transgenic approach to produce orange-colored Cymbidiumflowers, i.e., the introduction of a DHK-cat-
alyzing DFR into a DHK accumulating Cymbidiumand subsequent crossing with elite lines [97]. The de-
velopment of transgenic plants with altered flower color, however, will depend on a more efficient trans-
formation system than those presently available. Orchid cells are recalcitrant to tissue culture
manipulations in that plant regeneration from dedifferentiated cells has yet to be achieved. A report [101]
on particle bombardment of Cymbidiumorchid has attempted to address these drawbacks by adopting a
liquid culture system to stimulate active proliferation of the meristematic tissues before and after particle
bombardment. This system may provide a step toward genetic engineering of orchids with improved char-
acteristics.
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