Genetic Transformation Of Cherry Trees

Strategies for genetic transformation have been developed using organogenesis methods adapted to Inmil(R)(GM 9) and Damil(R)(CM 61/1) dwarfing rootstocks and to sweet cherry 'Summit'. Meristems from in vitro shoots were bombarded with plasmid carrying bar and gus genes, and subsequently formed shoots. A. rhizogenes-mediated transformation with bar gene was applied to in vitro shoots and adventitious shoots were regenerated from the roots. Both techniques applied without any screening agent provided chimeral regenerants. Stable transformants of Inmil(R) and Damil(R) rootstocks regenerated from rol positive roots have been propagated by axillary branching and are growing in greenhouse culture conditions.A.tumefaciens-mediated transformation, described previously for the genetic transformation of P. autumno rosa with the uidA (Gus)-gene, was applied successfully to embryogenic calli of Inmil(R). Clones regenerated and subcultivated in the presence of kanamycin (100 mg/l) expressed gus activity. These clones differ from one another by the presence of 35S or calmodulin promoters. Their ability to form somatic embryos and adventitious shoots could be used for further analysis of organogenesis.