Cryopreservation of Pineapple Shoot Tips by the Droplet Vitrification Technique.

Cryopreservation is a technique that allows the conservation of many species for long periods. Among the protocols used for cryopreservation, droplet vitrification has shown efficient results in preserving shoot tips of various wild and cultivated pineapple genotypes. The method consists of extraction of shoot tips from plants grown in vitro, dehydration for a period of 48 h in a preculture medium supplemented with a high concentration of sucrose, treatment in a plant vitrification solution (PVS2), and immersion in liquid nitrogen. The method described in this chapter has produced survival and regeneration indices of around 70%, depending on the genotype and physiological conditions of the initial explants. The objective of this chapter is to describe in detail a droplet vitrification protocol for shoot tips that is easy to perform for cryopreservation of pineapple germplasm.

Cryopreservation of Pollen Grains of Pineapple and Other Bromeliads.

Cryopreservation of pollen grains is an efficient technique to overcome asynchronous flowering and to support actions for genetic improvement and conservation of important alleles. It can be used both by germplasm curators and plant breeders. In the case of Bromeliaceae, a family with wide diversity but also high vulnerability, the form of conservation can be crucial to prevent the increasing problem of genetic erosion. This chapter describes a method of cryopreservation of pollen grains of different Bromeliaceae species, including pineapple, after dehydration with silica and subsequent immersion in liquid nitrogen. The efficiency of this protocol has been demonstrated by the high pollen viability percentage and production of seeds after in vivo pollination with cryopreserved grains. The protocol can be used for cryopreserving pollen of many species of bromeliads and is easy to perform.