Genetic mapping for the Rf1 (fertility restoration) gene in sunflower (Helianthus annuus L.) by SSR and TRAP markers

The Rf1 gene in sunflower can effectively restore the pollen fertility of PET1 cytoplasm in male-sterile lines and has been widely used in commercial hybrid production. Identifying molecular markers tightly linked to this gene will be useful in marker-assisted selection to develop maintainer and restorer lines. Rf1 has been mapped to Linkage Group (LG) 13 of the public sunflower simple sequence repeat (SSR) map by aligning maps constructed from different populations and only one SSR marker was reported to be loosely linked to Rf1. This paper reports the result of applying target region amplification polymorphism (TRAP) and SSR markers to map and develop a sequence-tagged site (STS) marker tightly linked to Rf1 using two populations derived from a cross between two U.S. public sunflower lines, RHA439 and cmsHA441. An SSR marker, ORS511, was 3.7 cM from the Rf1 gene and a TRAP marker, K11F05Sa12-160, was linked to Rf1 at a distance of 0.4 cM. This TRAP marker was converted to an STS marker for using in sunflower breeding.