The effects of environmental conditions on sprouting of microprogated lily bulblets with various levels of dormancy

We have examined the effects of environmental conditions on the sprouting of micropropagated bulblets of Lilium speciosum with various levels of dormancy. After planting at low temperature (15°C) or in vitro, a higher percentage of bulblets sprouted than after planting at high temperature (20 or 25°C) or in soil. Dormancy was relative, i.e. bulblets with deep dormancy were capable of sprouting at a limited range of conditions and bulblets with low or no dormancy at a wide range. The promotive effect of the in vitro cultivation was, to a large extent, caused by exposure of the bulblets to light which was absent after planting in soil because of coverage by a layer of soil.