Restorer breeding in sweet pepper: Introgressing Rf allele from hot pepper through marker-assisted backcrossing

Lack of a strong and stable restorer-of-fertility (Rf) allele in sweet pepper (Capsicum annuum L.) has been a hurdle in commercial exploitation of cytoplasmic male sterility (CMS) system for cost-effective production of sweet pepper hybrid seeds. A known sequence characterized amplified region (SCAR) marker (CRF-S870) associated with a fertility restoration phenotype (Rf locus) in hot pepper was validated in a strong restorer hot pepper inbred line (AVPP9905). The CRF-S870 marker was successfully used in marker-assisted backcrossing (MAB) to transfer Rf allele from hot pepper line AVPP9905 to several sweet pepper genotypes. The fertility restoration ability of 21 BC4F2 sweet pepper plants obtained through marker-assisted backcrossing was found to be normal, as CMS based plants derived from the backcrossed male plants upon selfing produced a normal amount of fruit with sufficient selfed seeds. The development of restorer lines in sweet pepper is expected to open commercial exploitation of CMS hybrid technology in sweet pepper.