A codominant DNA marker closely linked to the rice nuclear restorer gene, Rf-1, identified with inter-SSR fingerprinting

A new molecular marker (OSRRf) closely linked to the nuclear restorer gene (RS-I) for fertility in rice has been found. The RS-I gene is essential for hybrid rice seed production. A PCR-fingerprinting technique using simple sequence repeats (SSRs) was applied to compare two near-isogenic lines with (MTC-10R) or without (MTC-10A) the Rf-l gene. Of 76 inter-SSR primers tested, only one primer, (AG)(8)YC, generated polymorphisms. The tetranucleotide repeats generating polymorphisms were found within each amplicon. The genetic distance between OSRRf and Rf-l was 3.7 +/- 1.1 cM. As in the case of a codominant marker, this marker will be applied not only to breeding both restorer lines and maintainer lines, but also to the purity management of hybrid rice seeds.