Cryopreservation at the 'Institut National d'Horticulture' of Angers: past, present and future

In order to guarantee safe, long-term conservation of the National Institute of Horticulture Pelargonium collection, apex cryopreservation studies have been undertaken since 1999. The first results were obtained on apices of P. xpeltatum 'Balcon Lilas', using an encapsulation-dehydration process. Various steps of this process (preculture, dehydration, rewarming) were studied in order to simplify and optimize this protocol. A newly determined protocol was tested on 20 genotypes representative of the diversity of our collection. Apex survival was obtained for 19 of them, and variability in cryopreservation tolerance was observed with survival rates between 28% and 84%. Plants for various genotypes were obtained after cryopreservation however some difficulties slowed down the establishment of an efficient and reliable cryogenic protocol. In 2005, studies were undertaken in order to adapt the droplet-vitrification procedure to Pelargonium. A reproducible process was obtained optimizing the duration in the loading solution and in plant vitrification solution 2. This success permitted us to continue studies on the quality of the regenerated plants with regard to their conformity and sanitary status.