Encapsulation of in vitro-derived explants: an innovative tool for nurseries.

The encapsulation technology consists of the inclusion of some millimeter-long plant portions in a nutritive and protective matrix. This technology represents a further and promising tool for exchange of plant material between private and public plant tissue culture laboratories, for short- and medium-term storage of valuable plant material and for use of in vitro-derived or micropropagated propagules directly in farm or in nurseries. After encapsulation, transport, storage and sowing in aseptic conditions, the enclosed explants (capsules) may evolve in shoots (regrowth) and be employed for subsequent micropropagation or culture in vitro. When the encapsulated explant evolves in plantlet (conversion) in in vitro or in vivo conditions, the product of the encapsulation is defined as synthetic seed or artificial seed or synseed. The different evolution of the encapsulated plant material depends on tissue or plant material, genotype, nutritive and culture conditions, and treatments before or after encapsulation. In order to make economical the application of the encapsulation technology in the commercial nursery, research is looking for efficient automation or mechanization of the procedure and for preparation of the encapsulable explants.