CHARACTERIZATION OF THE RADISH INTROGRESSION CARRYING THE RFO RESTORER GENE FOR THE OGU-INRA CYTOPLASMIC MALE-STERILITY IN RAPESEED (BRASSICA-NAPUS L.)

Bulked segregant analysis and comparative mapping were applied to iden tify molecular markers linked to the Rfo restorer gene used for the Og u-INRA cytoplasmic male-sterility system in rapeseed. These markers we re then used to localise the radish introgression on the B. napus gene tic map constructed from the cross 'Darmor.bzh' x 'Yudal'. The introgr ession mapped on the DY15 linkage group. From the comparison of this l atter group to the linkage group constructed on a F-2 progeny segregat ing for the radish introgression, it was concluded that the introgress ion had occurred through homoeologous recombination, that it was not d istal and that it had replaced a B. napus region of around 50 cM. A QT L involved in aliphatic seed glucosinolate content was located on the DY15 linkage group at a position corresponding to one end of the intro gression. The DNA markers identified in this study are being used in m ap-based cloning of the Rfo gene and in marker-assisted selection.