INDUCTION OF SYSTEMIC RESISTANCE IN TOMATO AND TOBACCO PLANTS AGAINSTCUCUMBER MOSAIC-VIRUS

Pre-inoculation of tomato plants (Lycopersicon esculentum Mill.) cv. ' Vollendung' and tobacco (Nicotiana tabacum L.) cv. 'Xanthi NN' with to bacco necrosis virus (TNV) induced systemic resistance against the dis ease caused by a yellow strain of cucumber mosaic virus (CMV-Y). The r esistance was evident as both delay of symptom development and reducti on of disease incidence. Furthermore, systemic acquired resistance (SA R) reduced the replication of CMV-Y in upper leaves of tomato planes. An induction period of 6-8 days between TNV pre-inoculation and challe nge inoculation with CMV-Y is necessary to enhance the resistance in u pper leaf tissues.