Microspore culture is used extensively in severalcrop species to generate diverse populations ofhomozygous, doubled haploid lines for breeding andgenetic analyses. In our canola (Brassica napus L.) doubledhaploid breeding programme we regularly observe conjoinedmicrospore-derived embryos, most commonlytwins, joined either at the base of the hypocotyl or alongthe length of the hypocotyl axis. The aim of this study wasto determine if twinned embryos were genetically identicalor non-identical in order to gauge their value for breedingand linkage analysis. Microsatellite marker fingerprintingof 12 pairs of twinned embryos produced by microsporeculture of heterozygous F1 lines revealed that pairs of twinswere genetically identical. Based on this finding, we recommendbreeders and geneticists using microspore culturetechnology to retain only one embryo from each pair oftwinned embryos.