Seed Morphological Changes Associated with the Domestication of Vitis Cultivars

Background: The transition from wild Vitis vinifera subsp. sylvestris to cultivated grapes led to major changes in seed shape, known as the “domestication syndrome.” While traditional measurements distinguish these groups, high-resolution geometric analysis provides a more precise way to track domestication and variety stability. Objective: This study uses a multi-parametric approach—combining Fourier descriptors, curvature analysis, and the J-Index—to quantify seed shape variation across 121 Vitis populations. Methods: We analysed 48 varieties, including wild species and three major cultivated lineages (Iberian, Central European, and Muscat). Results: Principal Component Analysis (PCA) successfully separated wild and cultivated groups. The first three components explained 79% of the variation, driven mainly by seed elongation and curvature. The J-Index proved to be a highly stable metric; it remained consistent across different harvest years (2020–2025) for ‘Hebén’ and across different locations for ‘Cabernet Sauvignon.’ Cultivated seeds showed a consistent decrease in solidity and a significant increase in lateral curvature compared to wild seeds. Conclusion: Our findings confirm that the J-Index is a robust tool for identifying grapevine varieties. The stability of these geometric traits across different years and environments suggests that clonal propagation effectively “freezes” the morphological identity of grapevine lineages.