Auxins increase the occurrence of leaf-colour variants in Caladium regenerated from leaf explants

Leaf explants of Caladium 'Pink Cloud' were cultured in vitro on MS medium containing various auxins (NAA, IBA, IAA, 2,4,5-T and 2,4-D) in combination with cytokinin (BA). NAA gave the most vigorous in vitro propagation of this plant, and only 15% of the plants were leaf-colour variants on the medium containing 0.5 mumol NAA. Leaf colour variation was observed in all plants regenerated on the medium containing 2,4-D at 0.5-4.5 mumol. In hormone-free medium, only a few leaf-colour variants (6%) occurred, but the rate of plant regeneration was very low. Application of 0.5 mumol NAA together with 4.5 mumol BA seemed to be the most appropriate for in vitro propagation of Caladium 'Pink Cloud' with only a few leaf-colour variants. (C) 2003 Elsevier B.V. All rights reserved.