Survival and genetic stability of Dendranthema grandiflora Tzvelev shoot apices after cryopreservation by vitrification and encapsulation-dehydration.

The aim of this study was to compare the genetic stability of chrysanthemum (cv. Pasodoble) apices cryopreserved using two different methods: encapsulation-dehydration and vitrification. The assessment of the genetic stability was developed using RAPDs markers. Assessment of stability was evaluated in pot-cultivated mother plants (from which buds were excised for micropropagation), in shoots (leave tissue) from which apices were extracted for cryopreservation, and in shoots regenerated from cryopreserved apices 30 days after recovery and after further 3 months in culture. Throughout the process the origin of the apices (in vitro-shoot from which they were excised) was recorded. Twenty one regenerants cryopreserved by vitrification and 25 by encapsulation-dehydration were assessed. Only one cryopreserved regenerant from the encapsulation-dehydration method showed a different band pattern. These results support the necessity of monitoring the genetic stability of the regenerants obtained after cryopreservation, as this is a very useful technique for the conservation of plant genetic resources.