RAPD (Randomly Amplified Polymorphic
assay of 32 cultivar accessions 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
produce cultivar fingerprinting, (ii) the degree of relatedness of accessions
based on RAPD profiles
in comparison with other existing classifications, and (iii) the possibility
of automation of RAPD technology.
The variation of the correlation coefficient r as the primary
the automated RAPD-profile processing summarizes variability derived from
DNA isolation, the RAPD reaction, and final
computer-image processing of RAPD profiles. The AII (Accession
Identity Interval) of r for accession
Festuca arundinacea cv. Lekora was determined experimentally and
obtained was accepted
as a valid interval for all the other accessions studied. In order to evaluate
the discrimination potential
of all ten primers together, a pooled-similarity matrix was computed.
Employing this approach, we
achieved 100% discrimination between all 35 accessions when using all
ten primers. A dendrogram
for all 35 accessions was obtained using average linkage cluster
analysis (UPGMA – Unweighted Pair
Group Method with Arithmetic Means).
This procedure successfully produced smaller groups of
higher taxonomic homogeneity. The relationships between the
Lolium–Festuca accessions were also
revealed by principal coordinate analysis (PCO) based on absorbance profiles
from the RAPD assay.
Again, all accessions were well separated, recognising even subspecies
relationships. In general, PCO
analysis confirmed the inferences made from the UPGMA method.
We successfully applied the computer-aided system of RAPD assay, based
an IBM PC
computer, for discrimination of cultivars as well as for description of
DNA-based relationships of
accessions from various taxonomic groups of the Lolium–Festuca