This disclosure concerns high-resolution mapping and candidate gene cloning of Rf4, a maize restorer of fertility gene that restores fertility to C-type cytoplasmic male sterility. The disclosure also relates to molecular markers that are tightly-linked to, or reside within, the Rf4 gene. In some embodiments, methods are provided whereby hybrid seeds may be produced from crosses of a male plant comprising nucleic acid molecular markers that are linked to or that reside within the Rf4 gene and a female plant carrying C-type CMS.
