VIEW ARTICLE

Etiology

Role of the Cuticular Membrane in Ontogenic and Vf-Resistance of Apple Leaves against Venturia inaequalis. Claudio Valsangiacomo, Institute of Phytomedicine, Swiss Federal Institute of Technology, 8092 ETH-Zürich, Switzerland; Cesare Gessler, Institute of Phytomedicine, Swiss Federal Institute of Technology, 8092 ETH-Zürich, Switzerland. Phytopathology 78:1066-1069. Accepted for publication 7 March 1988. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/Phyto-78-1066.

Venturia inaequalis penetrated the cuticular membrane of young, actively growing leaves and fully developed leaves of scab-susceptible (Golden Delicious) and scab-resistant (Liberty) apple cultivars. Initial stromal development was similar in both cultivars; it was most frequent in the young, growing leaves and decreased with their aging. The Vf-resistance in Liberty was expressed as an inhibition of the stroma growth only after 2–3 days.