RAPD Analysis of Colletotrichum Species Isolated from Strawberry and the Design of Specific Primers for the Identification of C. fragariae

Strains of Colletotrichum species isolated fromdiseased strawberry plants fromdifferent countries were studied by random amplified polymorphic DNA (RAPD). Grouping and variability shown by RAPD supported the results of previous molecular studies made of Colletotrichum species. The variability was larger with C. acutatum, in which 15 different RAPD patterns were observed. Cluster analysis (UPGMA) was used to divide the C. acutatum strains into two major groups that correlated with other molecular markers previously used. Strains belonging to the first group showed a high level of similarity despite their diverse geographical origins, which probably correspond to a clonal population that resulted froma rapid and wide expansion of the strawberry trade. On the contrary, strains belonging to the second group showed a high level of genetic diversity that could indicate that they belong to lineages of older origins and/or to sexual reproducing lines. Within C. fragariae and C. gloeosporioides, two morphologically indistinguishable species, less genetic variability was observed, but both species were differentiated by RAPD patterns. A C. fragariae associated RAPD band was cloned, sequenced and used to design specific primers for this species. A PCR product of 580 bp was obtained only when DNA from C. fragariae strains was used, and this is proposed as a method for quickly and easily identifying C. fragariae stra