Direct gene delivery into isolated microspores of rapeseed (Brassica napus L) and the production of fertile transgenic plants

A procedure for direct gene transfer into isolated microspores of rapeseed (Brassica napus L.) and the production of fertile transgenic plants is presented. By modifying the microspore culture method and adopting the firefly luciferase (Luc) gene as a non-destructive marker, we could obtain stably transformed androgenetic embryos from bombarded microspores. Luc-positive embryos were easily isolated from the large non-transformed population using a high-sensitivity bioluminescent image analyzer. PCR and Southern blot analyses confirmed that the introduced transgene was integrated stably into the genome of the selected embryos. Diploidized plants obtained from the haploid embryos were self-pollinated, and all of the offspring tested were Luc-positive, indicating rapid fixation of the transgene which is characteristic of doubled haploids.