FORSYTHIA - A NEW HOST OF PHYTOPHTHORA-NICOTIANAE IN ITALY

During the summer of 1990, seedlings of forsythia (Forsythia viridissi ma), grown in pots in a production nursery in Campania (Italy), showed symptoms of decline associated with root and crown rot. Phytophthora nicotianae of A2 mating type was isolated from decayed tissues. Identi fication of the isolate was based on both morphological and physiologi cal characters, and on the electrophoretic pattern of total native myc elial proteins. P. nicotianae was confirmed as the causal agent of thi s decline by fulfilling Koch's postulates. Seedlings of forsythia inoc ulated with the P. nicotianae isolate developed symptoms identical to those observed in natural infections. The species inoculated was reiso lated from the basal stem and roots of symptomatic seedlings. This is the first report of P. nicotianae as a pathogen of forsythia.