A Hot Spot of Olive Biodiversity in the Tunisian Oasis of Degache

Tunisia is one of the world’s largest producers of olive oil, and it preserves pools of olive genetic diversity that are still unexplored. In order to cover the region’s gaps for exploring new olive germplasm, a governmental program of the Olive Institute, the Oasis Regional Center of Research of Degache, and the National Genebank of Tunisia has been focused on the continental Saharan oasis of Degache (Tozeur), in the south-west of Tunisia. The oasis still holds ancient olive trees that ensure small typical olive oil productions. Previous researches have been conducted at phenotypical level on morphological and pomological characters, highlighting a wide variability among the Degache olive germplasm. The identification, characterization, and evaluation of such genotypes could be useful to develop new olive oils characterized by high quality, historical memory, and connection with the local culture label such as the Controlled Designation of Origin (AOC) and Indication of Provenance (IP). To reach the right valorization of Degache olive genotypes, it is necessary to ensure their varietal correspondence. Thus, the main objectives of this study were: (i) the molecular characterization and identification of 47 olive accessions grown in the oasis of Degache, in south west of Tunisia; (ii) the validation of results in comparison with cultivars from official collections of the National Gene Bank of Tunisia; (iii) the exploration of the relationships between Degache genotypes and other Mediterranean germplasm; (iv) the enrichment of reference collections of Tunisian olive varieties.