Variation in mating systems is common across angiosperm taxa, leading to a trade-off between inbreeding avoidance and reproductive assurance. Tedder et al. examine European populations of the alpine perennial, Arabis alpina, which is currently being developed as a model system for studying the ecological genetics of arctic–alpine environments, and show that mating system variation ranges from autonomous self-fertilization to self-incompatibility. Inbreeding avoidance is linked to a sporophytic self-incompatibility system.
