Clonal Propagation of Orchids

Methods for clonal propagation of the two major morphological groups of orchids, i.e., sympodials and monopodials, are presented. The first group, sympodials, includes such genera as Cymbidium, Cattleya, Dendrobium , and Oncidium . They are characterized by a multibranching rhizome that can supply an abundance of axillary shoots for use as explants. They were among the first orchids to be successfully propagated, and techniques for their in vitro initiation (i.e., establishment) and subsequent proliferation are well established (1 –8 ). The second group, monopodials, include Phalaenopsis and Vanda , and are characterized by a single, unbranched axis that possesses few available axillary shoots for use as explants. Significantly different in their morphologies, these two groups require different approaches to explant selection and subsequent culturing. The successful large-scale micropropagation of monopodials is, in fact, a relatively recent achievement (9 ) and is the culmination of a wide variety of studies using different media compositions and supplements (10 –20 ).