Chloroplast DNA polymorphisms as molecular markers to identify cultivars of Olea europaea L.
The genotyping of cultivated varieties using molecular markers is a crucial aim of modern plant breeding programmes, germplasm collection management and product traceability. Methods for DNA extraction from olive oil are now available, and the DNA extracted is suitable for PCR applications. The aim of this work was to identify simple and reliable PCR markers useful for cultivar identification and oil traceability. We chose to analyse 13 cultivars and one feral accession of Olea europaea for polymorphism in the intergenic spacer of chloroplast DNA (cpDNA). The spacer analysed in this work showed a pattern of variation that was sufficient to discriminate four out of the 13 cultivars analysed. We propose an identification protocol for these cultivars based on the amplification and subsequent sequencing of the chloroplast trnT-trnD intergenic spacer. The ability to design primers pairs capable of amplifying very small fragments makes these markers useful in traceability protocols, even where the quality, yield and size of the DNA recovered from the oil may be very low.