GENETIC-RELATIONSHIPS AMONG ISOLATES OF COLLETOTRICHUM-GLOEOSPORIOIDES FROM STYLOSANTHES SPP. IN AFRICA AND AUSTRALIA USING RAPD AND RIBOSOMAL DNA MARKERS

Thirty-three isolates of Colletotrichum gloeosporioides from various S tylosanthes species collected in Africa and Australia and associated w ith restricted (type A), extensive (type B) or nontypical anthracnose lesions (type C) were first compared by random amplified polymorphic D NA (RAPD) analysis. A phylogenetic tree was constructed based on 118 r eproducible polymorphic bands generated with 16 random primers, using the upgma method. Twenty-nine isolates were grouped in two main cluste rs, corresponding to types A and B, within which polymorphic subgroups were partially related to geographical origin. Strong similarities we re observed among isolates of distant origin. Four isolates presented profiles completely different from the A and B types and were grouped in two additional clusters. To assess the phylogenetic relationship am ong isolates of various types and origins at the species level, the In ternal Transcribed Spacer region (ITS 1) of the ribosomal DNA was sequ enced. Type A isolates and a restricted number of type B isolates sele cted in the RAPD clusters showed an homology of 99.4-100%. When compar ed with published sequence data, the isolates that were clustered sepa rately in the phylogenetic tree, had the exact sequence of a C. gloeos porioides strain associated with the rotting of coffee berries, or of C. kahawae, the causal agent of coffee berry disease.