General Conference abstract: SVPW fall symposium, Belgium, December 8 2023
Any in vitro based breeding technique depends on the availability of a sufficiently performant regeneration system. This will be demonstrated with some case studies. Coculture of plant material with wild strains of Rhizobium rhizogenes can produce so-called hairy roots, that contain rol genes. In vitro induction and regeneration of these roots is indispensable for the production of plants with rol genes that often exhibit interesting phenotypes. Protoplast-based CRISPR gene targeting holds some advantages over other approaches, but depends on a cell-to-plant regeneration protocol that is often very genotype specific. Asymmetric protoplast fusion may be used as a tool to transfer mitochondria between species, leading to CMS in the acceptor species. Regeneration of the desired cybrids is not evident because of cytoplasmome instability and preferential regeneration of unfused protoplasts. Over the last years, we have developed protocols for Chrysanthemum, Solanum, Cichorium and other species to enable the incorporation of the aforementioned tools in their breeding schemes as complementary tools with traditional breeding.