Genome Scan Analysis for Advancing Knowledge and Conservation Strategies of Primitivo Clones (Vitis vinifera L.)

The success of the Primitivo variety underscores the critical need for the managing of clone genetic conservation, utilization, and improvement. By combining genomic and environmental data, breeders can better predict the performance of varieties, thereby improving breeding efficiency and enabling more targeted development of high-quality grapevine cultivars. In this study, 35 Primitivo clones were analysed, including selected and certified clones that have been propagated over several years in Apulia. Genetic variability among the Primitivo clones was assessed through genotyping by sequencing. Using 38,387 filtered SNPs, pairwise identity-by-state (IBS) analysis demonstrated the uniqueness of the 35 clones (IBS < 0.75), indicating a high degree of variability among the samples. Genetic diversity analysis revealed three primary groups, which were differentiated based on geographic origin. The clones from Gioia del Colle were grouped into two distinct clusters, which aligns with the observed variation in grape-related traits. The fixation index (F_ST > 0.50) identified numerous loci putatively associated with stress responses and developmental traits, including genes involved in key plant biological processes, stress response regulation, and adaptation to environmental conditions such as glutamate receptors, auxin, and ethylene signalling.