A rapid and efficient method for plant regeneration and establishment in soil for three ornamental flowering bulbous plants from different explants was conducted. Corm segments, twin scales and immature flower explants of Freesia, spider lily and amaryllis were excised and cultured in vitro. Explants were cultured on Murashige and Skoog medium (MS) supplemented with different combinations of cytokinins: benzyladenine (BA ) and thidiazuron (TDZ) and auxins: 2,4 dichlorophenoxyacetic acid (2,4-D) and naphthaleneacetic acid (NAA). Multiple shoots were produced from primary explants or derived callus. Regenerated shoots were then transferred into shoot-proliferation medium for further multiplication. Nature and concentration of the growth regulator as well as type and genotype of explants affected shoot regeneration. Produced shoots were transferred into corm and bulb-induction medium containing 90 g/l sucrose and 2 mg/l paclobutrazol (PP333). Corms were stored for the next culture season in soil while bulbous shoots of spider lily and amaryllis were preserved in vitro for 40 month. Corms, bulbs and bulbous shoots were transferred directly, without acclimatization, into soil and normal phenotypic plants were effectively established in soil. This study described a simple method for rapid propagation, corm and bulb formation, in vitro preservation and successful establishment of regenerated plants in soil.
Abbreviations: ABA: abscisic acid; BA: benzyladenine; MS: Murashige & Skoog,s (1962) medium; CCC: chlormequat chloride; GA3: gibberellic acid; NAA: naphthaleneacetic acid; PP333: [paclobutrazol: 1-(4-chlorophenyl)-4,4- dimethyl-2-(1H-1,2,4 triazol-1-ly) pentan-3-ol]; SA: salicylic acid; TDZ: thidiazuron: [N-phenyl-N-(1,2,3 thiadiazol-5-yl)urea)]; 2,4-D: 2,4 dichlorophenoxyacetic acid.