Identification of a sequence-tagged site (STS) marker linked to a restorer gene for Ogura cytoplasmic male sterility in radish (Raphanus sativus L.) by non-radioactive AFLP analysis

To identify DNA markers linked to a fertility restorer ( Rf) gene for Ogura cytoplasmic male sterility in radish ( Raphanus sativus L.), a non-radioactive, amplified fragment length polymorphism (AFLP) analysis was performed on bulked DNA samples from male-sterile and male-fertile radishes. Ten male-fertile and 10 male-sterile plants selected arbitrarily from an F2 population made by selfing of F1 plant from a cross between a male-sterile (`MS-Gensukeʹ) plant and a restorer (`Cometʹ) plant were used as material. Using 32 AFLP primer pairs, one AFLP fragment (AFLP190) which is specific to the bulked DNA samples from male-fertile F2 plants was identified. AFLP190 was characterized by molecular cloning and nucleotide sequencing, and was converted to a sequence-tagged site (STS) marker, STS190. A linkage analysis performed in 126 individuals of two independent F2 populations showed tight linkage of STS190 to the Rf gene. The rate of recombination between the marker and Rf was estimated to be less than 1%, making STS190 1.2 cM from the gene.