The invention provides a method for the generation of a monoclonal plant cell line from a heterologous population of plant cells, comprising the following steps: (a) provision of a heterologous population of plant cells； (b) preparation of protoplasts from said heterologous population of plant cells； (c) separation of single protoplasts by subjecting the preparation of protoplasts to flow cytometric sorting； (d) regeneration of a separated single transformed protoplast until the formation of a microcolony by co-cultivation in the presence of feeder cell material； (e) removal of the microcolony from the feeder cell material and cultivation of the microcolony until the formation of a monoclonal plant cell line.
