ABSTRACT
Types of self incompatibility In many hermaphrodite and monoecious plants there is a physiological self incompatibility (SI) in which a plant’s own pollen is rejected. There are several known types of SI: gametophytic systems involving recognition of determinants of the pollen tube by the style; sporophytic systems in which proteins of the pollen surface are recognized; and ovarian systems in which the tubes reach the ovule but the ovule is aborted.
