Tagging of Fertility Restorer Loci Using Recessive Class Analysis in Wild Abortive Cytoplasmic Male Sterility System in Rice

Tagging of restorer genes for wild abortive (WA) of cytoplasmic male sterility was carried out by studying 10000 individuals from an F2 population of a cross between IR58025A × IR42686R. This study was primarily carried out to reduce the distance of the already known markers for RF gene. This F2 population was identified to be unique as four RF genes could be tagged to SSR markers on chromosomes 1, 7, 10, & 12. The RF3 gene on chromosome 1 was flanked on either side with RM443 and RM315 at a genetic distance of 3.3 and 20.2 CM, respectively. RF6 located on chromosome 10, was flanked with tightly linked SSR markers on either side at a genetic distance of 2.2 and 4.3 CM. Here a new molecular marker RM519 is reported to be linked to RF7 on chromosome 12 at a genetic distance of 7.8 CM. Moreover, RM6344 was confirmed to be linked to RF4 on chromosome 7 at a genetic distance of 12.2 CM. Tagging of closely linked flanking SSR markers to four RF genes will be extremely useful for breeders to have this source screened. In addition, pyramiding of each RF genes with other known sources will be an excellent provision for developing super restorers