Identification of a BIBAC clone that co-segregates with the petunia restorer of fertility (Rf) gene

Molecular markers closely linked to the Restorer of fertility (Rf) locus in petunia were sought by conducting a bulk segregant analysis. The co-segregation of markers and Rf was tested on a large BC1 population produced from two different parental lines carrying Rf. The recombination frequency between OP704 and ECCA/MACT, the two most distal markers utilized in the fine-scale mapping. was significantly different in populations derived from parents that carry different nuclear backgrounds. The fine mapping identified an amplified fragment length polymorphism (AFLP) marker that co-segregates with Rf. A petunia BIBAC library (four genome equivalents), with an average insert size of 70 kb, was constructed and screened with the linked marker. A contiguous map was constructed from three different BIBAC clones that hybridized to the marker. As a result, we have identified a 37.5-kb BIBAC clone that co-segregates with Rf.