A first molecular investigation of monumental olive trees in Apulia region

- We carried out the genetic identification of 36 multi-secular olive trees from Apulia region.
- We used a set of 9 SSR markers and analyzed also the genetic structure of the population using AMOVA.
- Most of the ancient olive germplasm associate with a few known cultivars.
- Dendrogram and AMOVA analysis indicated a geographical differentiation of the population.
- For the first time we characterized monumental olive germplasm from Apulia region.

The Apulia region is the most important area for the production of olive oil in Italy. About 80% of the Apulian olive growing is traditionally managed and characterized from very old olive groves. In order to protect and exploit such ancient germplasm, a regional law was recently approved which provides the introduction of the following mention in labeling: “extra-virgin oil from the Apulian secular olive trees”. The wide ancient olive germplasm has never been identified before and the genetic discrimination may furthermore be complicated by in situ grafting practices carried out, sometimes on the branches, centuries ago. A set of nine microsatellite markers was used in order to identify 36 multi-secular olive tree samples collected from an area spanning the Brindisi, Bari and Foggia provinces. Clustering analysis conducted with 7 reference cultivars, distinguished two main groups showing a high genetic similarity between most of the multi-secular samples and two known cultivars. Locus-by-locus AMOVA seems to confirm such genetic divergence probably dating back thousands of years ago.