Genotyping of Sicilian grapevine germplasm resources (V. vinifera L.) and their relationships with Sangiovese

Sicilian viticulture is one of the most important and ancient forms in Italy. This region has a vocation for viticulture and includes important autochthonous cultivars known throughout the world, such as Nero d’Avola and Frappato, alongside other varieties, which are interesting from a local point of view. In this work, seventy-two representative Sicilian accessions were analyzed by 11 SSR molecular markers and the genetic diversity among major and minor/rare autochthonous varieties was explored. There is strong evidence that Sangiovese has been cultivated in Southern Italy and several Italian cultivars having a first-degree relationship with Sangiovese were identified. The Sicilian samples showing a parent–offspring relationship with this variety at 11 SSR loci were selected and the parentage analysis was investigated increasing the number of SSR loci up to 33. The genetic analysis revealed 46 SSR unique profiles: 11 cases of synonymies and 6 cases of new identifications were found. The genetic variability appeared higher for the minor/rare autochthonous cultivars than for the major ones. Using a model-based approach implemented in the software STRUCTURE, we identified four genetic groups that could be related to geographic origin and highlighting different centres of diversification. The parentage analysis revealed four Sicilian autochthonous accessions (Arbanello, Bianca, Lievuso and Visparola) showing a parent–offspring relationship with Sangiovese overall 33 analyzed loci. Carricante showed a second-degree relationship with Sangiovese. Indeed, the analysis provided evidence that Lievuso is progeny of “Sangiovese × Mantonico di bianco”. These findings confirmed and supported the major influence of Sangiovese in the evolution of the Sicilian ampelographic assortment.