EFFECTS OF NAPHTHALENEACETIC ACID AND BEN ZYLADENINE ON THE GROWTH OFWHITE CALLUS AND FORMATION OF BULBLET FROM CALLUS INDUCED FROM MOTHER-SCALE OF LILIUM-JAPONICUM THUNB

To propagate efficiently bulblets of Lilium japonicum Thunb., two expe riments were conducted : Experiment 1. White calli, induced from scale s of a mother bulb were cultured on MS-media containing various concen trations of NAA (0, 0. 01 and 0. 1 ppm) and BA (0, 0.25, 1.0 and 2.5 p pm) at 25-degrees-C under 300 Ix of continuous light for 8 weeks. The optimum concentration for the growth of white callus was the combinati on of 0.01 ppm NAA and 1.0 ppm BA. The significant.differences occurre d between treatments. Experiment 2. The effects of NAA and BA on regen eration of bulblets from the white callus were examined. The white cal lus (about 64 mm3) was cultured in MS-media containing various concent rations of NAA (0, 0.01 0.1 and 1.0 ppm) and BA (0, 0.01 and 0.1 ppm) at 25-degrees-C under 2000 lx of continuous light for 12 weeks. Advent itious globular buds formed on the callus on hormone-free medium after 3 weeks in culture. Bulblets developed from the adventitious buds aft er 6 weeks. The combination of 1.0 ppm NAA and no BA suppressed bulble t formation but induced only roots from the callus. Conversely, 0.1 pp m NAA and 0.1 ppm BA promoted the growth of the white callus and the f ormation of abnormal bulblets. Consequently, the media with no or low concentrations of plant growth hormones were optimal for the normal bu lblet formation.