Pathogenicity variation in Fusarium verticillioides populations isolated from maize in northern Italy

One hundred and eighty one strains were selected among Fusarium verticillioides populations isolated from maize samples collected in three fields located in northern Italy. All the isolates were tested for their pathogenicity on maize seeds by assessing the seed germination percentages and the percentage infection indexes concerning seed colonization, radicle decay and coleoptile rot. Fusarium verticillioides strains did not affect seed germination even in presence of high seed colonization, but showed a variable pathogenic behavior according to the maize growth stages. Seedborne F. verticillioides population as well as strains isolated at maturity was effective in seed colonization and in inducing coleoptile rot, not causing however serious radicle decay. Only populations isolated at seedling and pre-silking stages showed high radicle decay ability. These results provide baseline information on F. verticillioides pathogenicity. They constitute an important input for further investigation of F. verticillioides biology in order to define its evolutionary potential.