GENETIC-RELATIONSHIPS AS ASSESSED BY MOLECULAR MARKERS AND CROSS-INFECTION AMONG STRAINS OF COLLETOTRICHUM-GLOEOSPORIOIDES

Morphological characterisation allows isolates of Colletotrichum gloeosporioides, Colletotrichum musae and Colletotrichum acutatum to be identified only to species level. Pathogenicity tests and random amplified polymorphic DNA (RAPD) markers distinguished a mango biotype of C. gloeosporioides from eight other isolates of C gloeosporioides obtained from five different fruit species. Using these procedures, it was also possible to distinguish C. acutatum and C. musae both from each other, and from the C. gloeosporioides isolates. In cross-infectivity studies, isolates of C. gloeosporioides displayed a wide host range with the exception of isolates from mango, which were highly virulent on mango only. Teleomorphic isolates of C gloeosporioides were clustered together by RAPD analysis. This work has demonstrated the existence of a biotype of C. gloeosporioides which shows specialisation to mango.