Sporophytic self-incompatibility genes and mating system variation in Arabis alpina

Sporophytic self-incompatibility (SI) prevents inbreeding in many members of the Brassicaceae, and has been well documented in a variety of high-profile species. Arabis alpina is currently being developed as a model system for studying the ecological genetics of arctic-alpine environments, and is the focus of numerous studies on population structure and alpine phylogeography. Although it is highly inbreeding throughout most of its range, populations in central Italy have been identified that show inbreeding coefficients (F(IS)) more typical of self-incompatible relatives. The purpose of this study was to establish whether this variation is due to a functioning SI system.