Dipartimento di Scienze e Tecnologie Fitosanitarie, Universita` degli Studi di Catania, Via S. Sofia 100, 95123 Catania, ItalyIn summer 2007, a dieback was observed on European aspen (Populustremula, Salicaceae) growing in a nature reserve in Catania province,Italy.Treesshoweddeclinesymptomsofyellowing,wiltingandbrowningoftheleaves,followedbyleafdrop.Thediebackwasassociatedwithcan-kersonthebranchesortrunk.Morethan30%oftreeswereaffected;mostwere about 20 years old, with a few trees over 100 years old showingsymptoms.Afunguswasconstantlyisolatedfromaffectedbarkincubatedon potato dextrose agar (PDA). The colonies were fast growing, withimmersedlight-brownmyceliumbearingaggregateddark-browntoblackpycnidia, up to 300 lm in diameter. The conidia were aseptate, smooth,fusiform, 19–38 · 2–6 lm. The fungus was identified as Fusicoccumaesculi,theanamorphicstateofBotryosphaeriadothidea(Sutton,1980).A representative isolate (IMI 395176)was deposited atCABI Bioscience,UK, who confirmed the identity of the isolate as B. populi (syn. B. dothi-dea).The rDNA regions ITS1–5.8S-ITS2 of the isolate were amplified byPCR using universal primers ITS1 and ITS4. The sequence (GenBankAccession No.GU119957) revealed 100% homology with 21 isolates ofB.dothideainGenBank.Pathogenicitywastestedonten,2-year-oldseed-lings of European aspen. A 5 mm patch of bark was removed from thestems and replaced with PDA plugs colonized by the fungus. Ten controlplants were inoculated with sterile agar plugs. All the trees were kept intheopenair.Aftertenmonths,allinoculatedplantsshowedcankersattheinoculation point and canopy wilting. Darkening of wood and bark wasobserved 3–6 cm above and below the inoculation point. Control plantsremained healthy. Koch’s postulates were met by the re-isolation of thefungus from symptom-bearing tissues. Botryosphaeria dothidea isreported asadamaging pathogenofpoplarinChina(Wang etal.,2007).In Serbia it causes cankers on the poplar clone I-214 (Populus delto-ides · P. nigra) (Karadzˇic´ et al., 2000), and in Portugal B. populi causesdamagetoP.nigra(Phillips,2000).However,thisisthefirstfindingofthisorganismonEuropeanaspeninItaly.References