Abstract: The recovery of doubled haploid plants from anther or microspore culture is a constraint in breeding programs. In Brassica napus the extent of spontaneous diploids varied from 4 to 38 percent. The conventional diploidization of juvenile haploids with colchicine is labour intensive and requires a generation for seed multiplication. This study examines the potential from in vitro diploidization of microspores and increasing the efficiency of doubled haploid breeding programs.