One hundred and thirty-five isolates of Fusariumoxysporum f. sp. dianthi(Fod) were obtained from diseased samples of carnation from eleven provinces of Iran. All these isolates were used for pathogenicity test on susceptible cultivar of Rendezvous. Among these, one hundred isolates were found to be pathogenic on carnation. The pathogenic isolates were grouped in three vegetative compatibility groups (VCGs) using nitrate non-utilizing (nit) mutant against a single non-pathogenic group. Within three VCGs, the biggest group (VCG 0021) contained seventy-two members and VCG 0022 and VCG 0020 contained ten and three members, respectively.The Fod VCGs representative mutants were then paired with nits of different VCGs obtained from culture collection of Dipartimento di Valorizzazione e ProtezionedelleRisorseAgroforestali (Di.Va.P.R.A) Patologiavegetale,Italy.Results were shown that Iranian Fodisolates were belonged to VCG0020, VCG0021 and VCG 0022. We found any wide genetic diversity among IranianFod isolates. Also no correlation was observed between VCGs and pathogenicity test among isolates. According to our knowledge this is the first study on the genetic diversity of Fusariumoxysporumf.sp. dianthiin Iran and it is the first time these groups have been reported in Iran.
