S-RNases from self-incompatible and -compatible apple cultivars: purification, cloning, enzymic properties, and pollen tube growth inhibitory activity.

Four S-RNases (RNase associated with self-incompatibility) were purified from the styles of two apple cultivars (Malus domestica), a self-incompatible cv., Starking Delicious (SD), and a self-compatible cv., Megumi (MG).