Grapevine (Vitis spp.)

Grapevine somatic embryogenesis is a precious tool in breeding programs as well as in functional genomics studies, embryo tissues being the best sources for regeneration of genetically modified plants. It has also been proposed as a strategy aimed at induction of somaclonal variation, separation of periclinal chimeras, cryopreservation, virus eradication. A reliable technique for the production of somatic embryos and regenerated plantlets from an ample number of Vitis genotypes is an essential pre-requisite for any application of somatic embryogenesis. Main developmental phases can be identified: (a) Induction of callogenesis and embryogenic competence in cultured explants; (b) Culture of embryogenic calli and expression of the embryogenic program; (c) Long term culture of embryogenic callus and preservation of the embryogenic ability of the cultures or re-initiation of embryogenic calli from somatic embryos; (d) Development of somatic embryos into plantlets. The protocol for grapevine plant regeneration via somatic embryogenesis described in this chapter proved efficient for many cultivars; details are also given on the steps requiring further protocol refinements.