Multiplication and cryopreservation of vanilla (Vanilla planifolia ‘Andrews’)

Abstract

A simple and efficient method for multiplication of vanilla (Vanilla planifolia) was developed using in vitro fragmented explants (IFEs) as propagules. IFEs were obtained after dissecting apices from in vitro propagated clusters of plantlets, by cutting the remaining base of these plant clusters into segments of about 1 cm in length. After 4 months of culture on multiplication medium, 100% of IFEs produced up to 15 new shoots per explant, providing an efficient additional method for in vitro propagation of vanilla that maximizes the use of available material. Cryopreservation of apices from in vitro grown plants was achieved using the droplet vitrification protocol. Maximum survival (30%) and further regeneration (10%) of new shoots were obtained for apices derived from clusters of in vitro plantlets produced from microcuttings through a three-step droplet vitrification protocol: 1-d preculture of apices on solid MS medium with 0.3 M sucrose; loading with a 0.4 M sucrose + 2 M glycerol solution for 20–30 min; and exposure to plant vitrification solution PVS3 for 30 min at room temperature. Even though the cryogenic protocol needs to be optimized to improve results, this work represents the first successful report of cryopreservation of vanilla apices.