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 ess ential 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 7 6 inter-SSR primers tested, only one primer, (AG)(8)YC, generated poly morphisms. The tetranucleotide repeats generating polymorphisms were f ound 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 marke r will be applied not only to breeding both restorer lines and maintai ner lines, but also to the purity management of hybrid rice seeds.