Shoot-tips vitrification protocol for red chicory (Cichorium intybus L.) lines

Abstract

Shoot tips from in vitro stock plants of red chicory ‘Rosso di Chioggia’ line were cryopreserved by one-step vitrification. After two days of cold-hardening on hormone-free MS medium and loading for 30 min in a mixture of 2 M glycerol and 0.4 M sucrose at 25°C, shoot tips were dehydrated with PVS2 vitrification solution at 0°C for 60 min and plunged directly into liquid nitrogen. The post-thaw survival of shoot tips was achieved 79% when was cultured on recovery medium containing 0.5 mM BA. Observed regrowth, after six weeks of culture in the same medium composition, was 100%. Rooted cryopreserved microshoots showed good quality when transferred to the greenhouse. Preliminary results proved that the genetic fidelity of the cryopreserved line was maintained. The same vitrification protocol was then applied to three other red chicory lines, ‘Rosso di Treviso precoce’, ‘Rosso di Treviso tardivo’ and ‘Castelfranco’. A simple and effective protocol for the cryopreservation of red chicory shoot tips has been successfully developed as a result of this study.