Ornithogalum:: from diploid to tetraploid

Ornithogalum L. is a popular cut flower genus of the Hyacinthaceae family. Only a few southern African species are used in breeding programs. Poliploidization can solve some incompatibility problems existing in breeding with O. thyrsoides and O. dubium: the two species commonly used. Polyploids could also contribute more variation. Since Ornithogalum (2n=12) is a bulbous plant, different in vitro colchicine treatments were evaluated when meristematic tissue is more exposed. Explants were exposed to different colchicine concentrations (0.1, 0.2 and 0.3%) at various exposure times (24, 48 and 72h). In vitro colchicine treatments proved to be very successful: 54-89% tetraploids. The treatment that applied 0.2% colchicine for 48h was the most effective. Various Ornithogalum hybrids that were treated resulted in 17-100% tetraploids in the regenerated plants. Therefore in vitro colchicine treatment of Ornithogalum can be seen as a very effective method to produce tetraploids.