Simple Sequence Repeats amplification: a tool to survey the genetic background of olive oils

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.