Cisgenesis fits in the toolkit of a modern fruit breeder

Cisgenesis is the one-step introgression of a relevant gene from a crossable species into an existing cultivar, equivalent to five or six generations of backcrosses in a conventional breeding program. The enormous time gain renders this new biotechnological technique extremely interesting for breeders wishing to improve outstanding cultivars with specific extra characters, especially fruit tree breeders. It avoids the linkage drag associated with wide crosses and leaves the genetic make-up of the recipient cultivar intact. No extra marker genes are left after the transformation procedure. A cisgenic cultivar must so far in Europe be labelled as a genetically modified organism (GMO), but there are compelling reasons to exempt these cultivars from the cumbersome and expensive GMO regulations. This exemption is a “conditio sine qua non” for applying this technique by small and medium-sized enterprises which form the majority of the fruit breeding business. Wageningen UR Plant Breeding (PRI) has created, in close collaboration with Inova Fruit, ETH Zurich, Switzerland, and Plant and Food Research, New Zealand, the cisgenic trees of apple cultivar ‘Gala’ with the HcrVf2 gene for apple scab resistance or the MYB10 gene for red fruit flesh. Trees have been planted this fall in an experimental orchard at Wageningen, The Netherlands.