Abstract: In vitro-grown shoot tip s of Stachys floridana Schuttl. ex Benth. were successfully cryopreserved by the encapsulation - vitrification method. Excised 5 mm shoot tip s, subcultured 4 times and domesticated at 5 ℃ for 14 d, were precultured for 1 d in liquid MS medium supplemented with 0.5 mol·L - 1 sucrose. Precultured shoot tips loaded with a mixture of improved MS and 2PVS₂ for 20 min at 25 ℃ were directly dehydrated with a highly concentrated vitrification solution ( PVS₂ ) for 4 h at - 20 ℃ and exchanged fresh PVS₃ prior to immersion in liquid nitrogen for 24 h. After rewarming at 40 ℃ for 1 min, the cryopreserved tips were washed twice in imp roved MS liquid medium supp lemented with 1.2 mol·L - 1 sucrose for 2 ×10 min and then post-cultured on regeneration medium in dark for 20 d, the rate of root recovery amounted to about 63.7%

Key words: Key words: S tachys f loridana Schuttl. ex Benth., vitrification, shoot2tip, cryop reservation, regenera2tion p lantlet