'Ribolla Gialla' from North Eastern Italy, 'Rebula' from Northern Balkans and 'Robola' from Ionian Islands : do they belong to the same population variety or are they genetically different?

‘Ribolla Gialla’ is an extremely old grape cultivated in the Italian region Friuli-Venezia Giulia in the provinces of Gorizia and Udine. Once part of the Venetian Republic, Friuli-Venezia Giulia has been for long time an important stop along the Mediterranean spice route from the Byzantine Empire to the trading centre of Venice. During the Middle Ages, travellers passing through this area are supposed to have brought grapevines from the Balkans and Anatolia. After the splendours and reputa¬tion gained by ‘Ribolla’ wines in the past centuries, the beginning of the 1900s marked a difficult period for wine production, with a decrease in reputation. In the 1960s the interest in the cultivation of (Vitis vinifera L.) ‘Ribolla’ decreased, in the Italian wine¬growing regions, leaving place for the cultivation of ‘Tocai Friulano’, ‘Pinot bianco’ and ‘-grigio’, ‘Sauvignon’, ‘Traminer’ and ‘Riesling’. Despite the historical documents reporting the longstanding tradition of ‘Ribolla’ cultivation and winemaking in Friuli-Venezia Giulia, the origin of this cultivar is still questionable. The neighbour winegrowing regions, especially Primorska in Slovenia, have under cultivation a white cultivar called ‘Rebula’, and in Greece, on the Ionic islands of Kefalonia a white cultivar named ‘Robola’ is produced. The aim of this work was to study the genetic structure of these 3 groups of grapevine cultivars and verify the existence of genetic relationships linking these accessions, which share the same name. For this purpose 21 SSR loci were tested to fingerprint 22 ‘Ribolla’-‘Rebula’-‘Robola’ accessions uniformly distributed in the 4 areas of cultivation. Data obtained proved the existence of some synonyms and some mistakes. The sharing of many alleles in the 21 SSR analysed may suggest some possible relationships among ‘Ribolla’-‘Rebula’ and ‘Robola’ accessions.