Plantlets with both shoots and roots were transferred to plastic
pots (10 cm ? 18 cm) containing an artificial soil mixture of peat
moss, vermiculite, and perlite (2:3:1 v/v) and covered with a
transparent polyvinyl film. The potted plants were cultivated in a
growth room (40 m mol/m 2 /s, 16 h photoperiod, 25 ? 1 ? C). After
3 wk, the plants were hardened by removing the polyvinyl film
gradually on a daily basis for 1 wk, and then the film was removed.
After 3 mo of culture, the survived plants without wilting were
counted. The acclimated plants were transplanted to glasshouse
conditions or kept in the growth room for another 4e6 mo.