Identification and characterization of Vitis vinifera subsp. sylvestris populations in north-western Italy

Abstract

The Italian peninsula, for its favorable environmental and geo-morphological conditions, can be considered an ultimate area for survival and development of Vitis vinifera subsp. sylvestris (Gmelin) Hegi, even though severely affected by human impact. Large surveys started in early 1990 throughout the country. At the time few regions, like Piedmont located in the north-west of the country, were considered lacking of wild vinifera. More recent prospection started several years ago, leading to the discovering of five vinifera sylvestris populations plus other sites with few individuals. The sites of discovery were described for their ecological features and the identified plants were referenced and characterized by morphology (18 descriptors from the OIV list) and genetics (14 n-SSR loci). The esteemed consistency of each population ranged from 20 to 150 individuals. Morphological and biological traits (dioecious plants, females producing very small roundish black berries), as well as genetic profiles, indicated the observed plants are true vinifera sylvestris. As to the ecological requirements, plants were confirmed to be highly dependent on water availability into the soil. The neighbor-joining (NJ) dendrogram resulting from SSR allelic pattern of the individuals belonging to the five populations and to one location with isolated plants, indicated population's genetic similarity broadly reflects site's geographic distance. Considering the numerous reports in the past, spreading and consistency of wild grape germplasm from the region of Piedmont severely decreased over a period of 100-150 years. The relative short distance from wild population's sites and vineyards must also be regarded as a worrying condition because of contamination risks. All means to avoid the loss of this native Vitis germplasm must be undertaken by protection policy and proper land management.