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

High frequency direct shoot proliferation was induced in the shoot segments of three epiphytic orchids, Cymbidium aloifolium (L.) Sw., Dendrobium aphyllum (Roxb.) Fisch. and Dendrobium moschatum (Buch-Ham) Sw. on Murashige and Skoog's medium (MS) containing N-6-benzyladenine (BA) or thidiazuron (TDZ) with the latter being more effective at 2.2-4.5 mu M. Shoots which developed on a TDZ containing medium elongated following transfer to a medium containing 2.2 mu M BA and 10.8 mu M naphthaleneacetic acid (NAA). Concentrations of TDZ above the optimal level had an inhibitory effect on shoot regeneration. In both Dendrobium species the number of shoot bud formation was greatly influenced by explant orientation, Regenerated shoots were rooted on MS containing 10.8 mu M indole-3-butyric acid (IBA). The plantlets were acclimated and eventually transferred to garden. (C) 1997 Elsevier Science B.V.