COMPUTER-AIDED RAPD FINGERPRINTING OF ACCESSIONS FROM THE RYEGRASS-FESCUE COMPLEX

RAPD (Randomly Amplified Polymorphic DNA) assay of 32 cultivar accessi ons from the ryegrass-fescue (Lolium-Festuca) complex was accomplished using ten decamer primers to assess (i) the power of RAPD technology to discriminate between individual commercial accessions and to produc e cultivar fingerprinting, (ii) the degree of relatedness of accession s based on RAPD profiles in comparison with other existing classificat ions, and (iii) the possibility of automation of RAPD technology. The variation of the correlation coefficient r as the primary output from the automated RAPD-profile processing summarizes variability derived f rom DNA isolation, the RAPD reaction, and final computer-image process ing of RAPD profiles. The AII (Accession Identity Interval) of r for a ccession Festuca arundinacea cv. Lekora was determined experimentally and the value obtained was accepted as a valid interval for all the ot her accessions studied. In order to evaluate the discrimination potent ial of all ten primers together, a pooled-similarity matrix was comput ed. Employing this approach, we achieved 100% discrimination between a ll 35 accessions when using all ten primers. A dendrogram for all 35 a ccessions was obtained using average linkage cluster analysis (UPGMA - Unweighted Pair Group Method with Arithmetic Means). This procedure s uccessfully produced smaller groups of higher taxonomic homogeneity. T he relationships between the Lolium-Festuca accessions were also revea led by principal coordinate analysis (PCO) based on absorbance profile s from the RAPD assay. Again, all accessions were well separated, reco gnising even subspecies relationships. In general, PCO analysis confir med the inferences made from the UPGMA method. We successfully applied the computer-aided system of RAPD assay, based on an IBM PC computer, for discrimination of cultivars as well as for description of DNA-bas ed relationships of accessions from various taxonomic groups of the Lo lium-Festuca complex.