Biodiversity for Sustainable Viticulture: Seed Morphometry in Portuguese Cultivars of Vitis vinifera L.

Seeds are the result of sexual reproduction, containing the embryo that stores genetic information from past generations, surrounded by protective and nutritional tissues. In Vitis, seed morphology provides valuable insights into varietal diversity and domestication processes. In the context of transitioning toward sustainable viticulture, understanding varietal diversity provides key insights into crop evolution and adaptation. This study explores relationships in seed morphology among 91 varieties conserved in the Portuguese Ampelographic Collection (PRT 051 in FAO). Based on images of well-oriented seeds, outline geometry was described using Fourier coefficients and curvature values measured at key points along the outline. Seeds were classified according to their similarity to four reference models: Sylvestris, Hebén, Traminer, and Koenigin der Weingaerten. A high proportion of cultivars showed strong similarity to the Koenigin der Weingaerten model, suggesting an advanced stage of domestication. In contrast, very few cultivars matched the Sylvestris model. Significant differences in curvature values were observed among groups. The results confirm known pedigree relationships and the key role played by ancient varieties and provide new insights into the evolution of seed morphology during grapevine domestication. Among cultivars resembling the Koenigin der Weingaerten model, some result from crosses involving Iberian and European varieties, suggesting that the different Vitis haplotypes may be associated with progressive stages during the process of domestication that define the current resilience of Mediterranean grapevines.