A RAPID PCR-AIDED SELECTION OF A RICE LINE CONTAINING THE RF-1 GENE WHICH IS INVOLVED IN RESTORATION OF THE CYTOPLASMIC MALE-STERILITY

Cytoplasmic male sterility (CMS) is widely known in higher plants, the mechanism of which is believed to involve incompatibility between nuc lei and cytoplasms. In rice lines with the CMS trait, fertility is res tored by the aid of a nuclear-encoded gene, Rf-1, whose locus has been determined in chromosome 10. We found a particular PCR-amplified frag ment, designated fL601, that specifically amplified using the DNAs fro m Rf-1 lines tested as templates. RFLP mapping of the fL601 locus reve aled that there are two loci for the fL601, and that both are tightly linked to the Rf-1 locus. Progeny analysis also showed high frequency of their co-segregation. Southern analysis of the genomic DNA demonstr ated that the Rf-1 lines shared a unique sequence in the fL601 region. These results enabled us to construct a system for specific detection of the corresponding regions. Utilizing this detection system, we est ablished a simple PCR-mediated selection method for the Rf-1 lines, wh ich may facilitate the breeding for hybrid rice.