Characterization of the Brachetto grapevine cultivars using molecular markers.

In recent years in Piemonte, a North-west Italian Region, the cultivation of grapevine cultivars bearing black aromatic berries have increased in size for the popularity of the wines they give. “Brachetto” is usually considered one of the most interesting among them and its transformed product is highly demanded by consumers as a dessert wine. Yet, it was found that under the name of “Brachetto” different cultivars are grown in different areas of Piemonte, all of them yielding more or less aromatic grapes. Thus, now the name of each “Brachetto” variety is usually added with the name of the place where it was found; 4 cultivars have been described so far: “Brachetto di Montabone”, “Brachetto di Nizza Monferrato”, “Brachetto del Roero” and “Brachetto d’Acqui”, the last being the only one officially authorized for planting in Piemonte for the production of the corresponding DOC wine, which has superior characteristic as compared to the other “Brachetto” wines. The matter of identification of the “Brachetto” cultivars, has both technological and legal relevance, and a study for characterizing the group has been carried out using molecular markers in order to provide an objective method for cultivar identification. Isoenzymes, RAPD (Random Amplified Polymorphic DNA) and SSR (Simple Sequence Repeat) markers were studied on samples from the 4 known cultivars, analysing 2 clones for each of them. Results showed that all the cultivars can be easily distinguished and in general a high level of polymorphism was found, in particular by the DNA analysis. Different laboratories can use each tecnique as a tool for cultivar identification, according to the equipment they have available.