The development of a genetic database to identify olive cultivars

Abstract

The National Olive Variety Assessment (NOVA) collection, established at the Roseworthy Campus of the University of Adelaide, contains six replicate trees of 100 olive (Olea europaea L.) accessions grown in the same environment. The DNA fingerprints of these accessions were compared, using randomly amplified polymorphic DNA (RAPD), to those of a number of cultivars obtained from international collections. A total of 86 uniquely named accessions in the NOVA collection resulted in 58 different genotypes. Different names were synonyms for the same genotype, and homonyms were also found where accessions with the same name had different DNA fingerprints. A rapid and efficient protocol was developed to identify unknown olive genotypes using a two-stage process. Data from DNA fingerprints were added to a matrix already containing binary data from recognized standard cultivars. The estimated probability of any given RAPD profile randomly occurring at this stage ranged between 6 × 10-4 and 2 × 10-8. In the second stage, the approximate identity of the unknown genotype, revealed by the resulting dendrogram, was confirmed by comparing it with appropriate standards under identical conditions of DNA amplification and band separation. The data collected in this report form the basis of a genetic database that can be used for the identification of olive samples.