PREGAMIC AND POSTGAMIC SELF-INCOMPATIBILITY SYSTEMS IN CROCUS (IRIDACEAE)

Ovule fertilization and seed set were investigated in Crocus thomasii and Crocus vernus subsp. vernus, after different matings. The results gave evidence for a strict ovarian barrier in C. thomasii, which prevents self-fertilization either in self- or mixed- and double-pollination. In C. vernus the ovarian barrier to selfing is not so effective, but a further incompatibility reaction is expressed after self-fertilization resulting in a complete failure of embryogenesis. The implications of the present observations in respect to the mechanisms of pregamic- and postgamic rejection, indicate that a gametophytic system of self-incompatibility controls the ovule fertilization, and a not yet defined system of self-incompatibility controls embryogenesis.