Occurrence of the Strawberry Pathotype of Alternaria alternata in Italy. H Wada, Graduate Student, United Graduate School of Agricultural Sciences, Tottori University, Tottori 680, Jappan. P. Cavanni and R. Bugiani, Osservatorio per le Malattie delle Piante, Bologna, Italy; M. Kodama, H. Otani, and K. Kohmoto, Laboratory of Plant Pathology, Faculty of Agriculture, Tottori University, Tottori 680, Japan. Plant Dis. 80:372. Accepted for publication 6 December 1995. Copyright 1996 The American Phytopathological Society. DOI: 10.1094/PD-80-0372.

Recently in Italy, Alternaria black spot-like symptoms were observed on leaves and petioles of the strawberry cultivars Cesena, Dana, and Miss. The pathogen was identified as Alternaria alternata based on conidial morphology. Isolates of the fungus from Italy were pathogenic to susceptible cultivars of Japanese pear as well as strawberry among differential plants used to determine susceptibility to host-specific Alternaria toxins. Bioassay and high-performance liquid chromatography analysis showed that the fungus released host-specific AF-toxin I during spore germination. These data strongly suggest that the outbreak of Alternaria black spot of strawberry in Italy is caused by the strawberry pathotype of A. alternata.