RESUMO
In the autumn seasons of the years 2005 and 2006 millions of fennel seedlings under greenhouse in nurseries where observed in Basilicata, Calabria, Campania and Apulia Regions, southern Italy, with serious symptoms of damping off and root necrosis. The basal part of seedling stem was much thinner than the uninvaded parts above it and the crown was brown and shrink. The incidence of disease reached values ut to 100% in some blocks where the humidity was higher, and seedlings attached earlier died. Almost all fennel varieties were interested by the disease, some of them more seriously. Seedlings attached later recovered to a great extent after transplanting in open field. In this work the identification of the causal agent of this disease was made applying Koch's postulates. Moreover, for a rapid and unambiguous identification of the fungus species, the internal transcribed spacers and the 5.8 rDNA gene (ITS1-5.8-ITS2) were amplified from DNA extracted from the isolated colonies. The fragment of amplified DNA was sequenced and compared with those present in Gene Bank (NCBI). The fungus isolated after the morphological and molecular characterization was ascribed to the species Phoma glomerata (Corda) Wollenweber & Hochapfel. This is the first report of P. glomerata as agent of crown rot of fennel.