Phylogenetic relationships within and between Epichloe and Neotyphodium endophytes as estimated by AFLP markers and rDNA sequences

Analysis of Amplified Fragment Length Polymorphisms (AFLP) in a sample popu lation of Epichloe and Neotyphodium was conducted to evaluate the usefulnes s of this technique in estimating phylogenetic relationships among these fu ngi. A total of 963 unique restriction fragments were identified with 13 se lective primer combinations. Neighbour-joining and parsimony analysis produ ced phylogenetic trees with high bootstrap support. All Epichloe festucae i solates were monophyletic, and clades of E. festucae were identified that c orrespond to the host species from which they were isolated. These groups m ay indicate the importance of coevolution in the development of the fine fe scue-E. festucae symbiosis. The grouping of E. festucae isolates from hard fescue and Chewings fescue into one clade conflicts with the current taxono my of these host grasses. Sequencing of ribosomal DNA spacer regions ITS1 a nd ITS2 was conducted for comparisons to the phylogenetic relationships est imated by AFLP. Using the maximum likelihood test, a significant difference was detected between AFLP and rDNA trees due to discrepancies in the assoc iation of anamorphs (Neotyphodium) and teleomorphs (Epichloe). This discrep ancy may be due to some mechanism of genetic recombination, such as hybridi zation or parasexual recombination, that occurs in Neotyphodium populations . It is concluded that AFLP markers are useful for producing meaningful phy logenies among a diverse group of fungi and for identifying groups of close ly related individuals that are genetically and biologically similar. Furth er investigation is needed to determine how AFLP markers change over short periods of time in populations and over evolutionary time.