Molecular mapping of the Rf 3 fertility restoration gene to facilitate its utilization in breeding confection sunflower

The inheritance of a previously identified dominant Rf gene in the confection sunflower line RHA 280 has been determined and designated as Rf 3 . This study reports the mapping of the Rf 3 locus using an F2 population of 227 individuals derived from CMS HA 89-3149 × RHA 280. Bulked segregant analysis with 624 pairs of simple sequence repeat (SSR) primers and sequence tagged site (STS) primers identified two polymorphic SSR markers each of linkage groups (LGs) 7 and 11 from a previous map. Results on 90 F2 individuals with 42 polymorphic markers of LGs 7 and 11 indicated that the Rf 3 gene was linked with eight markers on LG 7, including five SSR markers (ORS328, ORS331, ORS928, ORS966, and ORS1092) and three expressed sequence tag (EST)-SSR markers (HT619-1, HT619-2, and HT1013). Further analysis of the total F2 population of 227 individuals identified a co-dominant marker, ORS328, linked to Rf 3 at a genetic distance of 0.7 cM on one side, and a female-dominant marker HT1013 at 12.6 cM proximal to Rf 3 on the other side; a genetic distance of 47.1 cM for LG 7 was covered. This is the first report of an Rf gene from the confection sunflower. The closely linked marker to Rf 3 will facilitate marker-assisted selection, and provide a basis for cloning of this gene.