Clonal propagation of orchids

This chapter will deal with methods of clonal propagation for members of the two major morphological groups of orchids. The first group, sympodials, includes such genera as Cymbidium, Cattleya, Dendrobium, and Oncidium. They are characterized by a multi-branchingrhizome 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 Phaluenopsis and Vanda, and are characterized by a single, unbranched axis of growth that possesses few readily available axillary shoots for use as explants. Significantly different in their morphologies, the 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): the culmination of a wide variety of studies using different media compositions and supplements (10-18).