1. Introduction
Certain plant species propagated by in vitro culture over a long period exhibit variants
in regenerated plants. Tissue culture-derived variation is highly undesirable in micropropagation.
Such changes are disadvantageous for the commercial grower, whose objective
is to produce a large number of uniform plants. Caladium plants have been propagated in
vitro by using the young leaf tissue for 20 years (Sahavacharin, 1982). However, cultivar
dependent variation has been observed during tissue culture, and this occurs frequently in
‘Pink Cloud’ regenerated in vitro (Zhu et al., 1993a).