Recent progress in genomic analysis has made genome-wide genetic and molecular scanning a realistic approach for the study of intra-specific mating incompatibility in crucifers. We describe the development of a directed genetic screen in Brassica and the isolation of a panel of induced mutations to self-compatibility which should facilitate the molecular cloning and functional analysis of loci required for self-incompatibility. Transfer of knowledge gained by the analysis in Brassica to other crucifers is accomplished by comparative mapping of the relevant loci in Brassica,Arabidopsis and related species. These approaches hold the promise of elucidating the genetic basis of mating system transitions within the crucifer family.