Revival of neglected Istrian grapevine varieties: genetic authentication, ampelographic characterization and wine style definition of Duranija, Surina, Garganja and Hrvatica

Abstract

Several traditional grapevine varieties that were historically widespread in Istria region (Croatia) until the mid-20th century have undergone severe genetic erosion following profound changes in viticultural practices from the 1960s. Duranija, Surina, Garganja and Hrvatica, once integral components of regional viticulture, were progressively displaced by varieties characterized by more uniform and reliable ripening, ultimately leading to their near disappearance from commercial production and the wine market.

The present study aimed to genetically authenticate these neglected varieties through SSR genotyping of individual vines collected from various different old-sourced vineyards and to support their conservation and sustainable reintroduction as valuable elements of regional grapevine germplasm. Atotal of nine different old vineyards were surveyed and 20 vines were genotyped. The resulting allelic profiles were compared with those in the SSR database of native Croatian varieties and the international VIVC database. For two samples, the SSR profiles did not match any of the four investigated varieties, highlighting the need to establish their true-to-type identity. The obtained molecular profiles confirmed that all four varieties represent unique and distinct genotypes, clearly differentiated from internationally cultivated varieties, thus validating their status as autochthonous Istrian grapevine genetic resources.

Molecular data were integrated with detailed ampelographic descriptions and phenotypic observations to assess varietal characteristics and key agronomic traits relevant for reintroduction. On this basis, experimental vinifications were conducted in order to define technologically appropriate and economically viable wine styles for each genotype. Duranija was identified as suitable for producing fresh, young white wines intended for early consumption, Surina for sparkling wine production with potential for both short- and long-term ageing, Garganja for high-acid base wines intended for long-aged sparkling wines, and Hrvatica for rosé wine production, either as still wines or sparkling wines.

This integrated approach demonstrates how molecular characterization combined with applied viticulture and oenology can effectively counteract genetic erosion and facilitate the on-farm conservation and commercial revival of endangered grapevine germplasm. As a direct outcome of this work, all four varieties have recently been replanted in Istria, contributing to the preservation of viticultural biodiversity and the long-term safeguarding of regional genetic heritage.