In vitro propagation of Hippeastrum × chmielii Chm. - influence of flurprimidol and the culture in solid or liquid medium and in temporary immersion systems

The in vitro propagation of the new hybrid Hippeastrum x chmielii was analysed in this study. Propagation on solid medium, permanent immersion (flasks) and in a temporary immersion system (TIS) using quarters of in vitro grown bulblets as explants was compared. The TIS was constructed as twin-flasks system, the components of which were inexpensive. Within 4 weeks of culture on solid medium 3.9 new bulbs were formed per initial bulb and by using liquid culture systems this number was increased to 6.3-6.5. The number of daily immersions in TIS only slightly influenced the propagation rates and no significant differences to the permanently immersed treatments were observed. By adding flurprimidol (0.1-1.0 mg l-1) to the medium the propagation rate nearly doubled in liquid as well as in solid medium. Moreover, the size of the newly formed bulbs was increased by this inhibitor of gibberellic acid biosynthesis. Flurprimidol strongly reduced the elongation of the leaves while root formation was enhanced.