Among the more than 500 known species of Passiflora, 19 of them are native to Argentina. In the framework of a breeding program to obtain ornamental varieties from native species, the objective of this work was to know the anatomical and colorimetric components that determine flower color in Passiflora species and their hybrids. For this, anatomical studies of the cellular components of the epidermis of the petals were carried out and the colorimetric values ​​on the CIEL*a*b* scale were analyzed in 4 species (P. alata, P. cincinnata, P. amethystina and P. caerulea) and 6 hybrids of crosses with P. alata. All the plants presented intracellular structures with irregular spindle-shaped to granular morphology, identified as anthocyanic vacuolar inclusions (AVIs). AVIs were also found as colored solid bodies in spherical, rod and irregularly folded shapes in the epidermal cells of the petals of P. alata and with spherical to elongated morphologies in P. cincinnata and in the P. alata x P. cincinnata hybrid. These structures were found in cells with accumulation of pigment in the vacuole. No correlation was found between the presence of solid AVIs and the colorimetric parameters. The presence of solid AVIs only in the hybrid among the species with this character, suggests that inheritance would be quantitative, expressed as a threshold characteristic.

The color of the flowers is the result of complex metabolic pathways genetically regulated and represents a relevant feature in breeding ornamental plants. The aim of this work is to study flower color in Passiflora species and to compare them with interspecific hybrids values to evaluate the inheritance of this character. Five parental species of Passiflora and five interspecific hybrids with P. amethystina were analyzed. A Minolta CR-321 colorimeter was used to take color values in the flowers (CIELab scale). The colorimetric components were estimated from three petals per flower and three flowers per genotype, analyzing the data by ANOVA and tested by BSS. The results on the flowers of the species showed that the L value (color luminosity) was statistically lower in P. amethystina (40.23) and higher in P. elegans (90.79), this would indicate that the former possesses the most intense and the latter, the lightest. In both, a-scale (green-red) and b-scale (blue-yellow), P. caerulea (a = -10.69 and b = 24.69) and P. amethystina (a = 33.21 and b = -33.33 ) were positioned at opposite ends. Hybrids between P. amethystina and the other four species presented intermediate colorimetric values to those of their parents, except P. amethystina x P. elegans. In the hybrids of this cross, the luminosity values (L = 39.7) and green-red scale (a = 34.1) were statistically similar to those of P. amethystina. The results would suggest a quantitative inheritance of the character with genetic interaction between the parental species, altering the expression in hybrids. The color of the flowers in P. amethystina would be the result of the combination of the tonality of the vacuolar content and the number of colored cells interspersed with those that reserve colorless substances, but there would also be a contribution of chlorophyll in the cytoplasm of the epidermal cells of the petals.

Color is a major factor in consumer's (consumer's preference) buying choices, and pigments responsible for color have functional properties. The aim of this work were to determine the existence of a maternal effect, and whether there is association between skin and flesh color of the sweet potato (Ipomoea batatas L. Lam) tuberous root. There were genotypes with higher and lower values of color than their progenitors. The direction of the crosses did not affect color variables, what suggests that there was not a maternal effect. Skin with anthocyanic pigments was incompletely dominant over white/cream skin, meanwhile white/cream flesh was incompletely dominant over orange flesh. Flesh and skin color were associated, being "skin with anthocyanins with white/cream flesh" the most frequent combination and "white/cream with orange skin or flesh" the less frequent. This work is part of the development of a linkage map which will allow the relative localization of reported genes involved in pigment synthesis in tuberous roots of sweetpotatoes.