| Dark septate root endophytes (DSE) are an artificial assemblage of fungi that have darkly pigmented, septate hyphae and that are frequent or distinctive intracellular associates of roots of apparently healthy plants. The distribution of DSE fungi was examined along a latitudinal transect in Canada running from the high arctic to the 49th parallel. DSE fungi were isolated from all latitudes, but the species isolated from roots changed with latitude. Patterns of genetic variation across the latitudinal transect of Phialocephala fortinii , a common DSE fungus, were also examined through analysis of amplified fragment length polymorphisms (AFLP). No clones were detected, and neighbour joining analysis of genetic distances yielded eight well-supported clusters, four of which consisted of individuals from more than one latitude. Some population subdivision was detected, with the majority of genetic variation attributable to differences between individuals within each site. Some linkage disequilibrium was detected, which may be in part a consequence of partial clonality. |
