CHARACTERISTICS OF THE RESISTANCE OF THE PEACH CULTIVAR RUBIRA TO MYZUS-PERSICAE SULZER

This work relies upon the comparison of the timing of aphid behaviour when young plants are infested for the first or second time by the fun datrigeniae apterae of Myzus persicae. The mechanisms of plant resista nce are initiated by the feeding punctures and evolve even in the abse nce of aphids. The initiation stage is short, around 2 h, and followed by latency, around 18 h. After aphid removal the systemic acquired re sistance decreases and disappears in the following 48 h. The systemic acquired resistance appears before the emergence of local discolourati ons and necrotic areas restricted to the aphid feeding punctures. Mech anical wounding failed to initiate the systemic acquired resistance. T he results are discussed on the basis of the present knowledge of indu ced resistances and hypersensitivity to arthropods with piercing mouth parts, mites and aphids.