Abstract

Genetic transformation provides the means for adding single horticultural traits in existing cultivars without modify their commercial characteristics. This capability is particularly valuable for perennial plants and fruit tree species, in which conventional breeding is hampered by their long generation time and juvenile periods, complex reproductive biology, high levels of heterozygosity, limited genetic sources and linkage drag of undesirable traits from wild relatives. In addition, gene transfer technologies for fruit tree species take the inherent advantage of vegetative propagation used for their reproduction, which allowed for the application of a high scale production of the desired transgenic line starting from one successful transformed line. Despite this opportunity, final setting of transformation protocols in this type of species, endures major limiting factors preventing the development of new varieties: a) explants recalcitrance to regenerate adventitious transformed shoots and b) a limited regeneration capability, usually extended to just few genotypes (i.e. cultivar dependence). This chapter illustrates the road between the establishment of transformation methodologies on particular species of Vitis spp. and Prunus spp. and their use as technical baselines for achievement of transformation procedures in new, eventually more recalcitrant, cultivars or genus members.