Browsing by Author "Gomez, Miguel"

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    Characterisation of seed dormancy of 12 Chilean species of Nolana (Solanaceae) from the coastal Atacama Desert
    (CAMBRIDGE UNIV PRESS, 2021) Hepp, Josefina; Gomez, Miguel; Leon Lobos, Pedro; Montenegro, Gloria; Vilalobos, Luis; Contreras, Samuel
    The genus Nolana (Solanaceae) comprises numerous species endemic to the coastal Atacama Desert of Chile and Peru of high ornamental potential and conservation value. The environments in which these species have evolved and are present today correspond to particular conditions in the midst of a hyper-arid habitat, so the study of their germination requirements and characterisation of seed dormancy becomes important in terms of conservation but also for ecological and evolutionary purposes. Different treatments were performed on mericarps of 12 species of Nolana: control (intact seeds imbibed in distilled water), scarification in funicular plug and distilled water and scarification in funicular plug and addition of GA(3) (500 ppm); their permeability to water was also tested. It was determined that the species did not present physical dormancy, as had been previously reported, but rather physiological dormancy (PD). Germination results after treatments were not homogeneous among all 12 species, indicating differences in their dormancy levels. Also, the important role of the endosperm in the prevention of germination for the studied Nolana species was highlighted. Regarding the relationship between the level of PD (expressed as the percentage of germination for the most successful treatment) and the latitudinal distribution of the species or their phylogenetic closeness, it was determined that, for the studied species, their proximity in terms of clades was more relevant than their latitudinal distribution.
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    Histochemical Analysis of Anthocyanins, Carotenoids, and Flavan-3-ols/Proanthocyanidins in Prunus domestica L. Fruits during Ripening
    (AMER CHEMICAL SOC, 2020) Vio Michaelis, Sofia; Feucht, Walter; Gomez, Miguel; Hadersdorfer, Johannes; Treutter, Dieter; Schwab, Wilfried
    As a result of the high variability of fruit properties in the European plum Prunus domestica, a histochemical analysis of fruits at different stages of development was performed to understand the ripening process in cv. 'Colora' (yellow-red skinned) and cv. 'Topfive' (purple skinned). Histological analysis showed that carotenoids in the fruit had two different origins. In the fruit flesh, they derived from chloroplasts that turned into chromoplasts, whereas carotenoids in the fruit skin derived probably from proplastids. Flavan-3-ols and proanthocyanidins showed differential localization during ripening. They were visible in the vacuole in different fruit tissues or organized in tannosomes in the fruit flesh. Tanninoplasts were observed only in hypodermal cells of 'Colora'. Toward maturity, anthocyanins were detected in the epidermis and later in the hypodermis of both cultivars. The study forms a basis for the analysis of the biosynthesis of secondary metabolites in European plums and their biological effects.
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    Nutritional and antioxidant potential of Chilean native fruits: lleuque (Prumnopitys andina) and copihue (Lapageria rosea)
    (VUP FOOD RESEARCH INST, BRATISLAVA, 2021) Giovagnoli vicuna, Claudia; Velasquez, Patricia; Montenegro, Gloria; Espejo, Jaime; Gomez, Miguel; Cabrera barjas, Gustavo; Giordano, Ady
    Nutritional and antioxidant properties of pulp and seeds of lleuque (Prumnopitys andina) and copihue (Lapageria rosea) were investigated. Proximal analysis revealed that the pulps are rich in carbohydrates, whereas the seeds are a good source of fibre. Both pulps exhibited higher phenolics content (PC) and flavonoids content (FC), as well as antioxidant capacities, compared to seeds. The data showed that PC correlated with antioxidant capacity the strongest, followed by FC and anthocyanins content. It was observed that global antioxidant score and relative antioxidant capacity index represented the antioxidant capacity behaviour of the extracts. According to the polyphenol antioxidant coefficients calculation, PC was an important contributor to antioxidant capacity of all extracts. The results of this study confirmed that the native Chilean fruits lleuque and copihue are an excellent source of antioxidants.
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