Cultivar Identity, Intravarietal Variation, and Health Status of Native Grapevine Varieties in Croatia and Montenegro

Croatia and Montenegro (located in southeast Europe) host numerous native (autochthonous) minor grapevine (Vitis vinifera L.) varieties that might irreversibly disappear in the near future because of limited conservation efforts and lack of virus-free propagation material. To prevent their disappearance and help sustain these native populations, a collaborative project was launched to gather and evaluate extremely rare and neglected native grapevine genotypes by establishing true-to-type and virus-tested stock material, ready to use for nurseries. During several field expeditions, 284 grapevine accessions collected in 22 different locations in Croatia and Montenegro were subjected to ampelographic in situ description, genetic identification by nine simple sequence repeat (SSR) markers, serological testing for the presence of common grape viruses, and intravarietal variability assessment by sequence-specific amplification polymorphism (S-SAP) markers. We observed 53 unique SSR profiles, of which 25 genotypes have not been previously reported and are thus worthy of further research. Comparison of these genetic profiles with those from some very rare and poorly described accessions within the European Vitis Database and other published studies revealed several previously unknown synonyms and homonyms, which helped properly name some of the profiles and provided novel information on the history of these cultivars and their distribution in the region. Virus testing revealed high frequencies of infection with Grapevine leafroll-associated viruses 1 and 3 and indicated the urgent need for sanitary selection. Assessment of intravarietal genetic variation indicated the presence of accumulated mutations, which strongly suggests a need for clonal selection.