Protoplast-Fusion Derived Cybrids in Solanaceae

The term ‘cybrid’ is neat and concised but ill-defined. For this review this term shall include protoplast-fusion derived cells and plants in which most or all the nuclear genome of one (organelle-donor) fusion partner is eliminated while this partner does contribute some or all the organelle’s (chloroplast and/or mitochondria) genomes. There exist efficient procedures to suppress the contribution of the nuclear genome from the donor fusion-partner as well as a choice of procedures to select fusion-derivatives containing the plastome or chondriome components of either fusion-partner. Thus, there exists experimental tools to strongly shift the range of cybrids towards the desired one. This implies not only to cybrids but also to asymmetric hybrids. Solanaceae genera (e.g. Nicotiana, Petunia, Lycopersicon & Solanum) and species are especially amenable to protoplast-fusion. Hence there exist ample data in respect with the compatibilities between a given nuclear genome and organelles of an alien genus or species, that provide us with important theoretical and practical information.