Effects of naphthaleneacetic acid and benzyladenine on growth of bulblets regenerated from white callus of mother scale of Lilium japonicum Thunb

White callus induced from mother scale of Lilium japonicum Thunb. was cultured on MS-medium without plant hormones under continuous 2000 lx at 25 °C in vitro. A bulblet regenerated on the white callus was used for treatments. 1. Small bulblets, 15 to 18 mg (FW), were imbedded on MS-media containing of NAA (0.2, 1.0 and 5.0ppm) and BA (0.2, 1.0 and 5.0ppm), and then cultured for 8 weeks. The grown bulblets could be classified into three types; normal type, abnormal type-I and abnormal type-II. The morphology of normalbulblets was comparable to bulblets that formed on mother scales cultured in vitro. The bulblets of abnormal type-I were globular and the scale grew more slowly than that of normal ones. Scale of the type-II became dropsy and grew very slowly. 2. The regenerated bulblets which were cultured on a medium of 0.1 ppm NAA and 0.01 ppm BA gained the most fresh weight and had the most and longest roots per bulblet compared to the other treatments. Leaf emergence was advanced by the medium of 0.01 ppm NAA and 0.1 ppm BA. Histologically, root tips of bulblets grown on the medium of 1.0 ppm NAA and no BA for 8 weeks had two central cylinders, and a large hollow core in the cortex. Cracks in the epidermis also developed on this medium. 3. When the bulblets with scale leaves were cultured on the medium of 0.1 ppm NAA and no BA for 4 weeks, they has grown into a plantlet with roots. We conclude that the combination of 0.1 to 0.01 of NAA and BA, respectively, were optimum for the growth and rooting of bulblets.