AFLP analysis of a worldwide collection of Phoma macrostoma

The coelomycete fungus Phoma macrostoma Montagne, is considered ubiquitous with a cosmopolitan distribution. In Canada, P. macrostoma is being assessed as a potential bioherbicide for control of dandelion, scentless chamomile, chickweed and several other weedy broadleaf species. In a previous study using RAPD analysis, minimal variation was observed among a small number of isolates obtained from Canada and Europe. Here we report the use of amplified fragment length polymorphism (AFLP) analysis to assess genetic variation within a worldwide collection of P. macrostoma. Sixty-one isolates from ten countries and 39 hosts were examined. Using cluster analysis two major groups and a number of smaller subgroups were delineated. Isolates collected in Canada from Canada thistle grouped separately from those obtained from other hosts and locations. Gene frequencies and other measures of diversity will be used to investigate forces that contribute to population structure.