Abstract
Hippeastrum hybridum Hort. is a well known ornamental plant, difficult to propagate by conventional methods such as twin scaling because of low propagation rate and virus diseases. The regeneration ability of various parts of the plant such as bulb scales as the source of clonal propagation is of interest. The regeneration of new plants from excised bulb scales in vitro has been previously reported, but these methods are not suitable for production of large number of plantlets for commercial cultivation.
Herein, the effects of abscisic acid (ABA) and light irradiation on the regeneration and growth of Hippeastrum hybridum in shake culture were investigated. The bulb segments were inoculated in MS liquid medium supplemented with various concentrations of ABA and cultured at 21°C for 13 weeks under continuous irradiation or complete darkness. Cultures proliferated well in the medium without ABA. Production of plantlets was inhibited especially at high ABA concentrations (1 to 10 mg/l), and at worst inoculated bulb segments became deteriorated. To stimulate the regeneration and growth of Hippeastrum hybridum in vitro, use of MS liquid medium with or without ABA (0 to 0.1mg/l) under continuous light conditions was required. Bulb segments cultured in a 10l glass jar fermentor containing 5l of MS liquid medium without ABA under continuous light conditions showed sufficient propagation.
