HORMONAL REGULATION OF FLOWERING IN A SYMPODIAL ORCHID HYBRID DENDROBIUM LOUISAE

Abstract

The growth habit, axillary bud differentiation and flowering behaviour in a sympodial orchid hybrid, Dendrobium Louisae cv. ‘Dark’ were studied. Flowering occurred only after termination of vegetative growth in the pseudobulb. Intermediate shoots with both vegetative and reproductive growth were produced when plants were placed in the shade. Decapitation did not stimulate floral initiation. In mature pseudobulbs, Cytokinin (benzyladenine) stimulated flowering. Gibberellic acid enhanced the cytokinin effect but was itself not effective. It is suggested that flowering in this orchid hybrid is regulated by growth substances, both qualitatively and quantitatively. Copyright © 1979, Wiley Blackwell. All rights reserved