Goran Zdunić

Genetic Characterization of Grapevine Cultivars Collected throughout the Dalmatian Region

Eleven SSR loci were used to identify 76 accessions of presumed native Dalmatian grapevine cultivars (Vitis vinifera L.). Plant material was collected throughout the Dalmatian region and used to reestablish a grape germplasm collection in Dalmatia, the Adriatic region of Croatia. The 76 accessions had 63 unique genotypes, of which 35 are published here for the first time. Twelve synonyms were found within the Dalmatian cultivars and 11 Dalmatian cultivars matched previously published genotypes, mainly from neighboring countries, suggesting historic exchange of grapevine cultivars. Several cultivars with similar names had different SSR profiles, making them homonyms. Genetic distance analysis revealed five groups of cultivars and confirmed several distinct grape gene pools in Croatia.

Genetic Diversity of Wild Grapevine [Vitis vinifera L. subsp. sylvestris (Gmel.) Hegi] in the Eastern Adriatic Region

The genetic diversity of wild grapevine [Vitis vinifera L. subsp. sylvestris (Gmel.) Hegi] in the eastern Adriatic region, which includes Croatia and Bosnia and Herzegovina, has previously not been documented. Natural populations of wild grapevine were identified in their natural habitats, and their genetic diversity was studied and compared with both local and widespread European cultivars. Ninety-two grapevine genotypes were determined at 21 nuclear microsatellite loci, including 53 wild grapevine individuals, 32 diverse local Croatian and west European cultivars, and seven commonly used rootstocks. Two hundred thirty-nine alleles were detected, with a mean of 11.4 alleles per locus and high heterozygosity, ranging from 0.461 to 0.897 for observed heterozygosity and from 0.391 to 0.837 for expected heterozygosity. The genetic diversity of the wild grapevines was slightly lower than that observed in cultivars. Distance- and model-based cluster analysis differentiated three main groups, indicating clear separation between wild, cultivated, and rootstock accessions. This study greatly contributes to knowledge of genetic diversity in local wild grapevine populations in Croatia and Bosnia and Herzegovina, and provides necessary information for their conservation and further characterization.

Volatile compounds in Prošek dessert wines produced from white and red grapes.

Budic-Leto I., Humar I., Zdunic G., Hribar J., Zlatic E. (2015): Volatile compounds in Prosek dessert wines produced from white and red grapes. Czech J. Food Sci., 33: 354–360. Prosek dessert wines produced from dried grapes of two native Croatian varieties, one white and one red, had complex volatile compositions. Various categories of volatile compounds were identified using headspace solid-phase micro extraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS). Sixty-one individual volatile compounds of Prosek were identified. Of these, nine compounds comprised over 95% of the total peak area of volatile aromas detected in Prosek: five esters and four alcohols. The remaining volatile compounds consisted of 11 alcohols, 11 esters, 10 terpenes, 8 aldehydes, 10 ketones, 4 acids, 1 lactone, and 1 norisoprenoide. Only 13 of the 61 aroma compounds showed significant differences between the varieties investigated. These results suggest that the charac teristic aroma of Prosek is very complex and determined predominantly by the unique process of the grape drying.

Assessment of wild grapevine (Vitis vinifera ssp. sylvestris) chlorotypes and accompanying woody species in the Eastern Adriatic region

The Eastern Adriatic region, encompassing Croatia and Bosnia and Herzegovina, is considered an important area of natural populations of wild grapevines (Vitis vinifera ssp. sylvestris). The wild grapevine arises in the Eastern Adriatic region in a contact zone of the EU-Mediterranean and the sub-Mediterranean characterized by typical karst relief. This study focuses on the chloroplast DNA (cpDNA) analysis of wild grapevines and the biodiversity of accompanying woody species to better understand the genetic variation of the sylvestris populations of the Eastern Adriatic region and to investigate how this variation fits within today’s wild grapevine distribution in the European continent. The allelic variation at nine cpDNA microsatellite loci of wild individuals was used to characterize haplotype diversity in 53 individuals from four population sites. All individuals were grouped into two chlorotypes: A and D, D being the rare haplotype among wild populations on the European continent. In total, 52 woody plant species were identified. However, the studied vegetation structures have been affected by permanent human pressure on natural resources and the preservation status of the collection sites. Based on our results, we conclude that the investigated areas were probably shelter zones for wild grapevine preservation during the unfavorable glaciation era.

Estimate of intravarietal genetic variation as a prerequisite for successful clonal selection in grapevine

ESTIMATE OF INTRAVARIETAL GENETIC VARIATION AS A PREREQUISITE FOR SUCCESSFUL CLONAL SELECTION IN GRAPEVINE

Polyphenolic potential of the rare croatian cultivar 'dobricic' (vitis vinifera l.)

Croatia is very rich in grapevine (Vitis vinifera L.) biodiversity and many native cultivars have been grown from ancient times, mostly along the Dalmatian coast. Many of the old native cultivars have almost vanished and ?Dobricic? is one of them. This cultivar has a great potential to be used in planting new vineyards, but its oenological characteristics still have not been defined and its wine is still not available on the Croatian market. Polyphenolic compounds are of profound significance for determining technological and nutritional values as well as sensory properties of grape cultivars and wines. In this work, the phenolic potential of ?Dobricic? grapes has been evaluated. Two different vineyards with this cultivar were considered. Three samples from each vineyard were taken at the time of harvest. Simulated maceration assays were carried out in model wine solutions containing 12% ethanol, 5 g/L of tartaric acid and 50 mg/L of SO2, neutralized with 0.3 M NaOH to pH=3.2 in order to investigate the composition of the polyphenols that were extracted from the grape into the wine. For each sample, separate extraction assays were performed using the grape skin and seeds. The results show that grape extract of this rare native cultivar contains appre-ciable amount of total phenols, proanthocyanidins and catechins as well as antho-cyanins. It was determined that grape skin is rich mainly in high-molecular-mass proanthocyanidins and anthocyanins. The skin contained higher concentration of low-molecular-mass proanthocyanidins than the seeds, as determined by vanillin index.