A reliable DNA extraction method for use on extra virgin olive oil based on a commercial
kit was defined, and the possibility of using this DNA for fingerprinting the original cultivar
was demonstrated. The genetic traceability of single-cultivar virgin olive oil from two
cultivars (Carolea and Frantoio) was achieved by identifying the varieties from which
they were produced. This involved the analysis of DNA sequences using a panel of
seven simple sequence repeats (SSRs) to provide genotype-specific allelic profiles. The
amplified SSR fragments and the DNA profiles from the monovarietal oil corresponded to
the profiles from the leaves of the same cultivar. The most reliable SSR in providing
correct allele sizing in distinguishing either single-cultivar olive oil samples or the different
ratios of their blends are DCA3, DCA4, DCA16, DCA17, and GAPU101, while DCA9,
GAPU59 produced less concordance against data obtained by the genetic analysis of
leaf samples. To have reproducible results, PCR product purification and selection of a
set of markers with a highly robust amplification pattern is suggested.
