The survival of in vitro shoot tips of Garcinia mangostana L. after cryopreservation by vitrification

Abstract

This report highlights the first successful cryopreservation protocol for shoot tips of Garcinia mangostana L. achieved by using vitrification technique. We investigated the effects of different temperatures and exposure periods to a plant vitrification solution 2 (PVS2), sucrose concentrations and preculture periods, and unloading treatments in steps of the vitrification protocol on the survival of G. mangostana shoot tips after cryopreservation. Exposure to PVS2 for 25 min gave beneficial effects with 10.4 ± 1.8 % survival at 0 °C with average water content of 1.1 ± 0.3 g g−1 dry mass. Survival was 13.7 ± 5.5 % when using preculture medium with full-strength Murashige and Skoog (MS) medium supplemented with 0.6 M sucrose for 2 days. A significant difference was observed in survival of shoot tips when treated with various sucrose concentrations in preculture which strengthens their importance towards enhancing survival of shoot tips after cryopreservation. MS with 0.4 M sucrose and 2 M glycerol applied as an unloading solution increased the survival of shoot tips to 44.1 ± 6.5 %. Experiments on the effect of ascorbic acid were also conducted for each step of vitrification. Our results showed higher survival of 45.8 ± 3.8 % but there were no significant effects compared with the control (without ascorbic acid). Further study on the recovery dark/light period was conducted. Survival of shoot tips significantly increased to 50.0 ± 16.7 % when subjected to 7 days in the dark before transferring to 16 h/8 h light/dark photoperiod. These studies strengthen suggestions that cryopreservation through vitrification is possible for ex situ conservation of germplasm of this tropical recalcitrant species.