Fine mapping of the first multi-fertility-restoring gene, Rf(multi), of wheat for three Aegilops plasmons, using 1BS-1RS recombinant lines.

Fertility-restoring genes, Rfv1, Rfm1 and Rfn1, respectively, for the male sterile cytoplasms of Aegilops kotschyi, Ae. mutica and Ae. uniaristata to common wheat were located on the same locus of Pavon wheat 1BS arm. The male sterile cytoplasm (plasmon) and the fertility-restoring gene are essential genetic components for breeding hybrid seed crops. This article represents information on the genetic similarity of three Aegilops plasmons usable as the male sterile cytoplasm for hybrid wheat and provides an evidence on the possible genetic unity of three fertility-restoring genes reported for these plasmons by their genetic mapping using the 1BS-1RS recombinant lines of Pavon 76 wheat on to a single subsegment of the 1BS chromosome arm less than 2.9 cM in size: the locus is designated Rf (multi) , meaning "Restoration of fertility in multiple CMS systems". Unresolved problems were discussed in the use of the present cytoplasmic male sterility-fertility restoration system for hybrid wheat breeding.