A comparative study of Phytophthora meadii isolates from rubber (Hevea brasiliensis) plantations in Sri Lanka

Thirty-three Phytophthora meadii isolates were obtained from different Heve a brasiliensis clones grown in different climatic regions in Sri Lanka. Gro wth, morphology and pathogenicity of the isolates were compared. Growth and pathogenicity levels varied among the isolates. Some isolates obtained fro m moderately susceptible rubber clones were highly pathogenic, compared to isolates obtained from resistant clones. Highly pathogenic isolates produce d a higher number of sporangia on agar at 27 +/- 2 degrees C. It was imposs ible to group isolates according to the clone or the region from where they were obtained.