5

3

183-188

Abstract Chamaecyparis lawsonia, which brings beauty in parks and green space, is attacked by a variety of pathogenic agents specially fungi. In this study, some Chamaecyparis lawsonia available in parks that had disease symptoms were sampled. After sample collection, in order to isolate fungal pathogens, cuts of the infected plant tissues were placed on PDA (potato dextrose agar) and later were put on WA (water agar) for identifying. Then test of pathogenicity of these isolates on Chamaecyparis lawsonia was done inside the box with plastic stopper. To do this, cuts of colonies of 4 day fungi obtained on PDA medium were put on leaves. The final evaluation was performed after 10 days. This experiment was performed in a completely randomized design with 3 replications and 7 treatments. The results showed that isolated fungi are in 2 groups as following: Alternaria franseriae and Alternaria tenuissima. According to the results, both species were pathogenic on host. Totally, A. franseriae showed more disease severity compared to A. tenuissima on C. lawsonia.