POLYPLOIDY INDUCTION AND IN VITRO BULB PROPAGATION OF LILIUM ORIENTAL HYBRIDS

In in vitro culture, Lilium 'oriental hybrids'was treated with colchicine at different concentrations and time duration. The highest induction frequency (50%) was achieved with colchicine at 50% for 24 h. Stable polyploid plants were obtained through the application of the adventitious bud technique. Compared with the normal diploid plants, the colchicine-induced tetraploid plants had thicker leaves and larger leaves, darker leaf color, larger stomata and fewer stomata per unit area. Cytological observation confirmed them to be tetraploids with a chromosome number of 2n = 4x = 48. A few octoploids were found with a chromosome number of 2n = 8x = 96, whose stomata were extra-ordinarily large.