Intertribal hybrid cell lines of Atropa belladonna (X) Nicotiana chinensis obtained by cloning individual protoplast fusion products.

After fusion of isolated mesophyll protoplasts of belladonna (Atropa belladonna) with callus protoplasts of Chinese tobacco (Nicotiana chinensis) followed by mechanical isolation and cloning of individual heteroplasmic fusion products, 13 cell clones were obtained. The hybrid nature of most of the clones has been confirmed by biochemical (studies of amylase isozymes), cytogenetic (size and morphology of chromosomes) and physiological (peculiarities of cell-growth in vitro) analyses. Study of chromosomes and isozyme patterns in the hybrid cell lines revealed the presence of both parental genomes, without an indication of chromosome elimination, six months after hybridization. In 4 cell lines shootlike structures and plantlets have been produced by means of transfer to organogenesis-inducing media. The data obtained are interpreted as new evidence for the possibility of using non-sexual hybridization for the production of intergeneric, intertribal plant hybrids which cannot be obtained by sexual crossing. From these results the potential of Atropa (X) Nicotiana hybrids as a model system for genetic studies of distantly related plant species is discussed.