Over the past two centuries, introgression through repeated backcrossing has introduced disease resistance from wild grape species into the domesticated lineage Vitis vinifera subsp. sativa. Introgression lines are being cultivated over increasing vineyard surface areas, as their wines now rival in quality those obtained from preexisting varieties. There is, however, a lot of debate about whether and how wine laws defining commercial product categories, which are based on the classification of V. vinifera and interspecific hybrid grapes, should be revised to accommodate novel varieties that do not fit either category. Here, we developed a method of multilocus genotype analysis using short–read resequencing to identify haplotypic blocks of wild ancestry in introgression lines and quantify the physical length of chromosome segments free–of–introgression or with monoallelic and biallelic introgression. We used this genomic data to characterize species, hybrids and introgression lines and show that newly released resistant varieties contain 76.5–94.8% of V. vinifera DNA. We found that varietal wine ratings are not always commensurate with the percentage of V. vinifera ancestry and linkage drag of wild alleles around known resistance genes persists over at least 7.1–11.5 Mb, slowing down the recovery of the recurrent parental genome. This method also allowed us to identify the donor species of known resistance haplotypes, define the ancestry of wild genetic background in introgression lines with complex pedigrees, validate the ancestry of the historic varieties Concord and Norton, and unravel sample curation errors in public databases.

ISHS XI International Conference on Grapevine Breeding and Genetics GRAPEVINE GENOTYPES WITH COMBINED DOWNY AND POWDERY MILDEW RESISTANCE

The starting point for every viticultural and wine-producing country with respect to local grapevine varieties is their identification, inventory, preservation and development of genetic resources of those varieties. There are currently 224 grapevine va?rieties cultivated in Serbia for the purpose of commercial production of grapes and wine. Out of that number, 31 wine varieties are local. Vineyards under those varieties can be dif?ferentiated by their importance for production of grapes and wine, and by the level of their endangerment, that is, sustainability in conditions caused by climate changes. This paper presents the creation, that is, the modeling of the Method for Vineyard Sustainability Clas?wine grapevine varieties on grounds of their endangerment and sustainability, based on 20 examined and categorized individual vineyard sustainability parameters; to carry out comsification (MVSC). The purpose of MVSC classification is: to valorize vineyards with local prehensive classification into one of the four established vineyard sustainability classes (Class A - very endangered vineyards, Class B - endangered vineyards, Class C - sustainable vineyards and Class D - very sustainable vineyards); spatial identification and presentation of vineyards based on determined vineyard sustainability class through application of GIS technology; and finally, application of Network Analysis (NA), prioritization of examined parameters and, therefore, vineyards. A total of 10,402 vineyards under local grapevine wine varieties were used for modeling, and it was determined that 29 vineyards with the total surface of 1.2 hectares should be classified in Class A, while 2,883 vineyards with the total surface of 158.2 hectares should be classified in Class B. With respect to the strength of 20 individual vineyard sustainability parameters, it was determined that the parameter Structure of the vine rootstock (SVR) has the greatest impact, and priority in selection of vineyards in different sustainability classes should be given to vineyards without rootstocks. In accordance with the scientific justification of obtained results, the MVSC enables comprehensive clas?sification of the potential for sustainability of genetic resources of local grapevine varieties in Serbia, and it can be applied in other countries and wine-growing areas, as well as to other groups of grapevine varieties.

The conducted research aims to ascertain the variations in macro and microelement content within the soil-to-leaf relationship in small vineyards. The vineyard block (1.2 ha), located in Sremski Karlovci, Serbia, planted with Grasac (Riesling Italico), was divided into 20 subplots. Each subplot served as an individual location for soil and leaf sampling. Soil samples were collected at three depths, while leaf sampling occurred at two phenophase (end of flowering and at ripening), with separation into petiole and blade parts. Vari?ability of soil physico-chemical characteristics between subplots was determinate, with the greatest variability in the 30-60 cm soil layer. The soil generally displayed low levels of organic matter and available P, K, Zn and B. Erosion processes were indicated by the spatial distribution of physico-chemical parameters. Differences in nutrient contents were noted among leaf parts and phenophases, aligning with existing literature. Comparing leaf nutrient status to optimal values from literature, N and P content was found at lower limits, confirming K and B deficiencies. Identically, fertilization recommendations can be inferred from soil and foliar analyses, primarily for N, K and B. Additionally, based on soil analysis, a slight increase in P and Zn application is advisable. Established correlations among all observed variables revealed connections between soil parameters, across all depths, and nutrients in the leaf blade at the end of flowering. It is notable to say that nutrient content in soil, particularly N, K, Mn and Zn, exhibited statistically significant positive correlations with its content in the leaf blade, respectively. Further research is necessary to lay the foundation for the development of ac?curate and reliable criteria for diagnosing nutrition, not only for the whole species but also among grapevine leading varieties. Given the significant variations in nutrient requirements and accumulation among these genotypes, this research will be instrumental in ensuring op?timal nutrient supply while minimizing deficiencies or excesses.

After harvest, table grape berries undergo physical and chemical changes even with optimal storage conditions, and postharvest fruit quality retention varies among varieties. This study evaluated four varieties over a two-year period: Lasta, Lyana, recently released seedless variety Nada, and the widely cultivated Muscat Hamburg. At harvest, variety x year interaction affected yield, berry weight, and berry size, while differences among varieties were observed for rachis weight (p < 0.001) and the number of berries per cluster. During storage and shelf life, analyzed separately by experimental year, no berries with mechanical disorders or decay incidence were observed. Weight loss increased during storage in all the varieties, and this was particularly pronounced during the shelf-life period. Berry firmness ranged from 5.7 to 27.8 N/mm² depending on variety and storage duration. After 28 days of cold storage, increased berry firmness compared with harvest was recorded only in variety Nada. In 2024, Nada exhibited the highest total soluble solids content at harvest and, after 28 days of cold storage, reached 28.2%, significantly exceeding its harvest value and the SSC of the other varieties at the same evaluation time. Varieties showed different potential for cold storage. After 28 days in cold storage, sensory acceptance scores for Lasta and Nada decreased significantly compared to harvest, mainly due to increased rachis browning and berry skin shriveling. Muscat Hamburg showed the lowest rachis browning during storage. This study demonstrates the importance of selecting table grape varieties adapted to diverse environmental conditions and capable of maintaining postharvest quality during cold storage and shelf life.

The aim of this work was to investigate the differences in yield and grape quality among three grapevine cultivars Dionis, Morava and Panonia during the period 2015-2022. The results suggest that season highly affects grape quality of all tested cultivars. Among the all tested cultivars, Morava had the lowest variation in bunch weight, while the lowest variation in acidity was demonstrated by Panonia. On average, these cultivars had satisfying yield (0,91-1,41 kg/m2) and even the production was performed according to ecological principles, without the use of pesticides. Colored cultivar Dionis and its parent Panonia, showed high sugar content in the grape must. Panonia and Morava had significantly higher acidity of the must (8.4 and 7.8 g l-1), compared to Dionis (6.30 g l-1).