title: Linkage between an isozyme marker and a restorer gene in radish cytoplasmic male sterility of rapeseed (Brassica napus L.).
abstract: Co-segregation studies of isozyme markers and male fertility restoration showed that a restorer gene from radish was introduced into rapeseed along with an isozyme marker (Pgi-2). The radish chromosome segment carrying these genes was introgressed into rapeseed through homoeologous recombination, substituting for some of the rapeseed alleles. By crossing heterozygous restored plants to male-sterile lines and to maintainers, tight linkage was found between the restorer gene and the marker. The recombination fraction was estimated at 0.25 ± 0.02%. Although few restored plants lacked the radish isozyme marker, it was still possible to distinguish male-fertile from male-sterile plants by their PGI-2 patterns. Furthermore, homozygous and heterozygous restored plants could be separated by specific PGI-2 phenotypes. Thus, the Pgi-2 marker is now currently used in restorer breeding programs.
authors.affiliation: Station d'Amélioration des Plantes, INRA, BP 29, F-35650, Le Rheu, France.
authors.forename: R
authors.initials: R
authors.lastname: Delourme
authors.forename: F
authors.initials: F
authors.lastname: Eber