The ancient olive trees of Capri Island renaissance of an abandoned treasure

The ancient olive trees are the living proof of the very long tradition of cultivation, and, in most cases, their genotyping has revealed strong differences with the actual known olive varieties. Thus, in addition to their historical and cultural significance, old olives offer horticultural interest due to their genetic potential, constituting an un-exploited reservoir of olive diversity. Moreover, in the last decades several ancient orchards were abandoned generating dramatic scenarios at social, landscape and biodiversity levels. To highlight the importance of abandoned olive trees, a deep restoration was made in an Island well known for the tourism as Capri, which was important in the past for agropastoral activities. The different morphologies detected after orchards cleaning together with the huge dimensions of some olive trees, had open the possibility to seek for the ancient olive cultivation in the Capri Island. The molecular identification of both canopy and rootstock through SSR markers of 67 accessions, highlight the existence of twenty-one ancient genotypes in this island. Two of these were corresponded to the Italian and Greek known cultivars while the genetic identity of remained genotypes resulted unique, even have been compared genetically with more than 450 worldwide olive cultivars. Molecular identification has demonstrated that some of them were clonally propagated and only in two cases, the grafting scenario has been discovered. Age determination by radiocarbon (14C) dating and specific algebraic formulas, shed light on the centennial age of analyzed trees, meaning that they probably represent remnants of ancient olive cultivations, since hundreds of years ago. The outstanding performance of these trees makes really promising their agronomical evaluation and possible use in future olive breeding programs. Their ongoing propagation will avoid losing this priceless olive germplasm and will re-constitute olive orchards with autochthonous and well-adapted varieties in the Capri Island restarting the extra virgin olive oil production after decades of abandonment.