PHYLOGENY OF TALL FESCUE AND RELATED SPECIES USING RFLPS

The wild species of tall fescue (Festuca arundinacea var, genuina Schreb.) represent a wide range of genetic variation and constitute potential germplasm for tall fescue improvement. Our objective was to evaluate genome specificity of the previously-identified DNA probes and to examine the phylogenetic relationship nf tall fescue six related species by using RFLP data. A total of 29 DNA probes from a PstI-genomic library of tall fescue were hybridized to EcoRI- or HindIII-digested DNA of 32 plants from six Festuca species and from Lolium perenne L. Fifteen probes hybridized to all seven species. The remaining 14 probes showed differential hybridization patterns (i.e., (+/-)), especially at the diploid and tetraploid levels. This hybridization pattern reflected genome divergence in these species. The DNA probes will be useful markers in breeding programs involving interspecific and intergeneric hybridization. Cluster analyses were performed using the average genetic distances calculated with the RFLP data from 53 probe-enzyme combinations. Gen erally, genotypes from the same species were grouped in the same cluster. These data indicated that tall fescue has a close relationship with F. pratensis Huds. (diploid), F. arundinacea var. glaucescens Boiss. (tetraploid), and L. perenne L. (diploid) and that Festuca pratensis and L. perenne had the closest degree of relationship.