Like rd1; anthocyanin interactions. Mapping of rd3 reported by Matz et al., 1991, changed to rd4 31 Jan 96 to avoid confusion with earlier Stock Center designation of rd3, an allele of ct2. Genetic 2005 3 coordinates determined from these recombination and map data: (rd4 -5- bnl6.06a); (rd4 -5- bnl5.14); see MaizeGDB ID:165110; 165114 . This gene was originally curated in MaizeGDB Database and the map position was displayed on the maize bins map if feasible.