THE EFFECTS OF ENVIRONMENTAL-CONDITIONS ON SPROUTING OF MICROPROGATEDLILY BULBLETS WITH VARIOUS LEVELS OF DORMANCY

We have examined the effects of environmental conditions on the sprout ing of micropropagated bulblets of Lilium speciosum with various level s of dormancy. After planting at low temperature (15 degrees C) or in vitro, a higher percentage of bulblets sprouted than after planting at high temperature (20 or 25 degrees C) or in soil. Dormancy was relati ve, i.e. bulblets with deep dormancy were capable of sprouting at a li mited range of conditions and bulblets with low or no dormancy at a wi de range. The promotive effect of the in vitro cultivation was, to a l arge extent, caused by exposure of the bulblets to light which was abs ent after planting in soil because of coverage by a layer of soil.