Marker-assisted selection of restored male-fertile Brassica napus plants using a set of dominant RAPD markers

Bulked segregant analysis was used to identify RAPD markers in oilseed rape (Brassica napus L.) that were linked to a male fertility restorer gene for Ogura cytoplasmic male sterility. After screening for polymorphisms using 960 primers, 14 RAPD markers were mapped to a 25 cM region including the restorer locus, a mapping population of 242 F-2 individuals being employed. The map was used to select 11 markers that were investigated for polymorphisms between the restorer donor line and 46 recipient lines. A set of four RAPD markers, one in coupling phase with the restorer allele and three with the non-restorer allele, which were informative in all 46 combinations, were used in marker assisted selection of plants homozygous for the restorer allele. A total of 906 homozygous restored plants were found among the 4605 BC1F2 plants analysed. Phenotypic data of a subset of the classified plants was compared with the RAPD data and the expected number of recombinants was calculated from the map data. A close correspondence between the expected and observed numbers of plants with a deviating phenotype was found. Thus, use of a set of dominant RAPD markers provides a way obtaining reliable data for marker-assisted selection.