Lilium jeponicum growing in the experimental field were collected in e
arly May and segments of their scales, leaves and stems of the plants
were cultured in vitro on a basal medium consisting of Murashige and S
koog's inorganic salts (1962) supplemented with several organic nutrie
nts. Young leaf-segments were a suitable source for propagation, becau
se they were least contaminated and almost had the same capacity as sc
ale seg ments for bulblet regeneration. Bulblets were proliferated by
culturing whole scales or segments on the basal medium supplemented wi
th 0.1 mg . liter(-1) NAA and 0.01 mg . liter-1 BA. A cold treatment a
t 4 degrees C for more than 12 weeks broke the dormancy of in vitro cu
ltured bulblets. In vitro light conditoin affected both post-in vitro
bulblet-rot infection and plant growth in soil. The bulblets incubated
in the dark were more susceptible to soil-born organisms than were th
ose incubated in the light. Nearly all the bulblets of more than 400 m
g in weight grew into plants with elongated axes (epigeous type plant;
ETP). The ETP plantlets required at least 2 years' cultivation before
they flowered.