IN VITRO PROPAGATION AND CRYOSTORAGE OF SYZYGIUM FRANCISSI (MYRTACEAE) BY THE ENCAPSULATION-DEHYDRATION METHOD

摘要

An efficient procedure for the in vitro propagation and cryogenic conservation of Syzygium francissi was developed. The maximum number of shoots per explant was obtained on a Murashige and Skoog (MS) medium supplemented with 4.5 μM benzyladenine and 0.5 μM indole-3-butyric acid (IBA). The in vitro-propagated shoots produced roots when transferred to MS medium containing IBA, indole-3-acetic acid, or naphthaleneacetic acid at various concentrations. Rooted micro-shoots were transferred to a coco-peat, perlite, and vermiculite (1:1:1) mixture, and hardened off under greenhouse conditions. Ninety-five percent of rooted shoots successfully acclimatized in the greenhouse. Shoot tips excised from in vitro-grown plants were successfully cryostoraged at -196 ℃ by the encapsulation-dehydration method. A preculture of formed beads on MS medium containing 0.75 M sucrose for 1 d, followed by 6 h dehydration (20% moisture content) led to the highest survival rate after cryostorage for 1 h. This method is a promising technique for in vitro propagation and cryopreservation of shoot tips from in vitro-grown plantlets of S. francissi germplasm.