Ampelography, the botanical discipline dedicated to the identification and classification of grapevine cultivars, was grounded on the description of morphological characters and more recently is based on the application of DNA polymorphisms. New methods of image analysis may help to optimize morphological approaches in ampelography. The objective of this study was the classification of representative cultivars of Vitis vinifera conserved in the Spanish collection of IMIDRA according to seed shape. Thirty eight cultivars representing the diversity of this collection were analyzed. A consensus seed silhouette was defined for each cultivar representing the geometric figure that better adjusted to their seed shape. All the cultivars tested were classified in ten morphological groups, each corresponding to a new model. The models are geometric figures defined by equations and similarity to each model is evaluated by quantification of percent of the area shared by the two figures, the seed and the model (J index). The comparison of seed images with geometric models is a rapid and convenient method to classify cultivars. A large proportion of the collection may be classified according to the new models described and the method permits to find new models according to seed shape in other cultivars.

Ampelography, the botanical discipline dedicated to the identification and classification of grapevine cultivars, was grounded on the description of morphological characters and more recently is based on the application of DNA polymorphisms. New methods of image analysis may help to optimize morphological approaches in ampelography. The objective of this study was the classification of representative cultivars of Vitis vinifera conserved in the Spanish collection of IMIDRA according to seed shape. Thirty eight cultivars representing the diversity of this collection were analyzed. A consensus seed silhouette was defined for each cultivar representing the geometric figure that better adjusted to their seed shape. All the cultivars tested were classified in ten morphological groups, each corresponding to a new model. The models are geometric figures defined by equations and similarity to each model is evaluated by quantification of percent of the area shared by the two figures, the seed and the model (J index). The comparison of seed images with geometric models is a rapid and convenient method to classify cultivars. A large proportion of the collection may be classified according to the new models described and the method permits to find new models according to seed shape in other cultivars.

The main phenological stages (budburst, flowering, veraison, and ripeness) of 53 Spanish minority varieties were studied to determine their potential to help winegrowers adapt to climate change conditions. In total, 43 varieties were studied in the same location in Spain (Alcalá de Henares, in the Madrid region) and 10 varieties in 5 other regions (Galicia, Navarre, Catalonia, Extremadura, and Andalusia). Other traits of agronomic and oenological interest, such as yield and acidity, were also monitored. The results allow for the grouping of the varieties into several clusters according to the time of ripeness (very early—only for red varieties—and early, intermediate, and late, for both red and white varieties) and yield (high, medium, and low). The total acidity in the grape juice ranged from 3 to 11 g of tartaric acid/L. The average temperatures were higher (up to 3–4 °C during summer) compared to historical averages during the 1957–2021 time period. Advanced phenology phases and reduced acidity are regarded as negative effects of climate change for winegrowing practices. Since some minority varieties showed late or intermediate ripening, high acidity, and high (1 Kg/shoot) or medium (0.5 Kg/shoot) yield, our findings suggest that they may be cultivated in the coming years by winegrowers as an approach to mitigate climate change effects.

Seed morphological description requires quantitative methods for further comparison. Here, traditional measurements, curvature analysis, and the J-index (percentage of similarity to a geometric model) were applied to the average contours (Acs) of 271 Vitis cultivars from the Spanish collection at IMIDRA (Madrid, Spain), including 9 different Vitis species and several sylvestris seeds (i.e., those derived from plants that once grew in the wild). Acs are graphical representations of the shape in seed populations, which can be obtained either from image analysis programs or computationally opening the way to quantitative analysis. A geometric model is a geometrically defined, closed curve, used as a reference for shape quantification. Based on existing differences between the Hebén cultivar (collected in 2020 and 2024; Hebén model, for morphotype 1) and the European varieties Chenin and Gewurztraminer (Chenin model, for morphotype 2), we created two models. The comparisons were based on a J-index, resulting in four groups: Group 1 contained all seeds with values lower than 90 for both models and included all Vitis species other than V. vinifera and most sylvestris seeds; Groups 2 and 3 contained seeds with J-index values higher than 94 for the Hebén and Chenin models, respectively. Group 4 consisted of seeds not included in the other groups. Based on J-index values, differences in curvature and solidity, and PCA analysis with Fourier coefficients, this work defines two new morphotypes associated with the Hebén (Group 2) and Chenin (Group 3) models, related to Iberian and Western European varieties, respectively.

In this study, a total of 34 Spanish minority varieties were studied during four seasons from 2020 to 2023, and their behavior was characterized according to their main phenological stages (bud break, bloom, veraison, and maturity) and complete cycle. We focused on the varieties prospected in the central Spanish plateau and conserved in the “El Encín” grapevine collection, aiming to identify the potential for adaptation of these varieties and for them to be considered by winegrowers as an alternative to current climate change conditions. The growing degree days required for the expression of the phenological stage, and the duration of each stage, were compiled. Characteristics of oenological interest were also monitored, such as °Brix, pH, and titratable acidity in must at the time of harvest. This study was carried out in years with atypical snowfall and cold spells (winter 2021), as well as with heat waves (summer 2022), with average temperatures 3–5 °C higher than normal and absolute maximum temperatures over 40 °C. Both cases also exceeded records of historical series (1957–2019). Veraison has been identified as the stage most susceptible to damage from high temperatures, in addition to the maturation and duration of the complete cycle. The varieties were classified into five groups according to the duration of each phenological stage (very early, early, medium, late, and very late). Some varieties with late or very late maturation and with must characteristics of 20–23 °Brix, 3–5 g/L of titratable acidity, and pH 3.5–4.5, as well as others, retained stability in their phenological periodicity and must quality. The results suggest that special attention should be given to thoroughly evaluating these varieties, and that the strategies contemplated should be considered as a feasible cultivation alternative in viticulture to mitigate the effects of climate change.

Seeds of different Vitis cultivars (V. vinifera subsp. vinifera) have an interesting diversity of shapes, ranging from the small seeds of high solidity and low aspect ratio in some species of Vitis and V. vinifera subsp. Sylvestris to other morphological types with elongated stalks, characteristic of the more recent cultivars, suggesting a transition with alterations in seed shape associated with groups of cultivars. J-index analysis is a morphometrical technique that measures the percentage similarity of seed images with geometric models. Three models based on the outlines of reference cultivars (a model based on the Spanish female cultivar Hebén; and mixed models for French and German Chenin and Gewürtztraminer, both related to Savagnin Blanc; and Regina dei Vigneti and Muscat Hamburg, related with the Muscat group) have been applied to select the average outlines (Aos) resembling these models from a collection of cultivars maintained at IMIDRA. Three groups resulted, called Hebén, Chenin, and Regina, with 15, 25, and 18 cultivars, respectively. Principal component analysis (PCA) with the Fourier coefficients of the Aos for these cultivars and seeds of other species of Vitis and V. vinifera subsp. sylvestris showed differences between groups. Specific Fourier coefficients were related with geometric properties of the seeds, circularity, roundness, aspect ratio, and solidity as well as with diverse measurements of curvature allowing to establish hypothesis about the change in geometric properties along the evolution of cultivars.