Molecular characterization and identification of a group of local Olea europaea L. varieties

There is an urgent need for a rapid and accurate procedure to evaluate the degree of genetic diversity in Olea europaea L. In this research work, we used simple sequence repeat markers for the characterization and identification of the genetic profiles of a group of ancient olive trees, using clustering analysis (dendrogram analysis, Bayesian method) to estimate the genetic distance and relationships among individuals and “random forests” to evaluate the importance of the applied markers and create the differential profiles. As a result, by the use of ten microsatellite loci, we were able to separate 142 samples into homogeneous groups. Our results indicate a high genetic diversity within the group of local accessions. Most accessions seem to have a foreign origin, particularly from neighbouring zones, but a discrete number of them appear to be of unknown origin. We have expressed the differential genetic profiles of the identified groups in terms of “if-then-else” rules. This paper, after a comparison with classical methods, proposes a rigorous methodological approach to the purpose of characterizing olive trees. It also introduces for the olive the concept of differential genetic profiles as complementary to classic ones.