Orchid micropropagation: the path from laboratory to commercialization and an account of several unappreciated investigators JOSEPH ARDITTI F.L.S. Department of Developmental and Cell Biology, University of California, Irvine, CA92697-2300, U.S.A. AND ABRAHAM D. KRIKORIAN Department of Biochemistry and Cell Biology, and Institute for Cell and Developmental Biology, State University of New York, Stony Brook, NY 11794-5215, U.S.A. Received August 1995, accepted for publication June 1996 A commonly held view is that the ideas and basis for the practice of orchid micropropagation arose de novo in 1960 from the work of Georges Morel in France. In this paper we argue that the crucial developments in micropropagation were made by Gavino Rotor in 1949 in the USA and Hans Thomale in 1957 in Germany, and that Morel’s work needs to be seen in the context of a long line of research achievements in the in vitro culture of a wide range of explanted tissues and organs from plants of many species. A critical, historical, analysis of the events as they relate to clonal orchid multiplication is offered here. Two important technical innovations for orchid micropropagation — the use of activated charcoal to darken nutrient media and the adoption of liquid culture environments for part of the process— are examined in detail. In addition, an unusual US patent claiming invention of ‘a method for rapidly reproducing orchids’, especially cattleyas, is analysed. The origin of the micropropagation process claimed in this patent, said by the nominal inventor to go back as far as 1950, is discussed, but the claim remains unsubstantiated. Finally, consideration is given to the problems of adjudicating unequivocal priority for ‘discovery’ of a process as complicated and as broad as micropropagation. ©1996 The Linnean Society of London ADDITIONAL KEY WORDS: — activated charcoal – ‘mericloning’ – propagation in vitro – stem tip culture – tissue culture. CONTENTS Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 184 Orchid seed germination and the first in vitro culture of orchids . . . . . . . . . 184 Foundations of stem tip culture . . . . . . . . . . . . . . . . . . . . 187 Plant hormones . . . . . . . . . . . . . . . . . . . . . . . 187 Auxins . . . . . . . . . . . . . . . . . . . . . . . . . . 188 Coconut water and cytokinins . . . . . . . . . . . . . . . . . . . 188 Culture of stem tips . . . . . . . . . . . . . . . . . . . . . . . . 189 Botanical Journal of the Linnean Society (1996), 122: 183–241. With 56 figures 183 0024–4074/ 96/ 011183 + 59 $25.00/ 0 ©1996 The Linnean Society of London