The encapsulation-dehydration and vitrification techniques were experimente
d for freezing apices of pineapple in vitro plantlets. Positive results wer
e achieved using vitrification only. Optimal conditions included a 2-d prec
ulture of apices on medium supplemented with 0.3M sucrose, loading treatmen
t for 25 min in medium with 0.75M sucrose + 1M glycerol and dehydration wit
h PVS2 vitrification solution at 0 degrees C for 7 h before rapid freezing
in liquid nitrogen. This method resulted in 65, 35 and 25% survival with ap
ices of varieties Puerto Rico, Perolera and Smooth Cayenne, respectively. R
ecovery of cryopreserved apices took place directly, without transitory cal
lus formation.