Search Results (3)

In Europe, the cultivation of blood oranges for fresh consumption is increasing due to their excellent organoleptic and nutraceutical properties, which give this fruit the status of functional food. Blood orange has a higher content of bioactive compounds, which confer additional benefits for human health. The main morphological and qualitative parameters were studied together with the content of primary metabolites by ¹H NMR and secondary metabolites by HPLC-ESI-DAD-MSⁿ from eight varieties of blood orange grafted on Citrus macrophylla. Tarocco Dalmuso was the variety with the highest values of weight (350.6 g), caliber (86.4 mm and 88.6 mm) and juice content (214.2 g). Tarocco Gallo obtained the most interesting qualitative parameters (13.95 °Brix; 22.75 MI). The most intense red juice was in Sanguinelli (a^* = 9.45) and, in crust, it was in Tarocco Scirè (a^* = 40.13). The most abundant primary metabolites were proline, aspartate and asparagine, citric acid and sucrose. The results showed that the juice of the Moro had the highest levels of total flavones and flavanones (90.07 and 592.88 mg L⁻¹, respectively), and Sanguinelli in total anthocyanins (101.06 mg L⁻¹). To conclude, Tarocco Dalmuso obtained the best values of agronomic parameters, and Moro and Sanguinelli in the content of phenolic compounds. Full article

Rootstock choice has important effects on the horticultural and pathological traits of the citrus cultivars. Thus, the scion/rootstock combination can affect tree vigour, nutrition, and stress resistance; it can also have positive influences on the fruit quality traits. Although the study of rootstock effects has been a relevant research topic in citrus for many years, the main body of such study has been conducted at the biochemical level, while little effort has been directed to the determination of the rootstock influences at the molecular level. A comparative study of three combinations of scion and rootstock shows a positive correlation between the regulation of the fruit quality-related genes and the accumulations of bioactive compounds, as well as with acid degradation. Monitoring the anthocyanin accumulation during ripening shows the scion/rootstock combination can increase anthocyanin synthesis in the fruit, as well as vitamin C accumulation and acid degradation. Our results show that the rootstock genotype can exert important influences on citrus fruit quality by affecting gene expression in the scion. New insights into the molecular interactions between scion and rootstock may help unravel the systems through which rootstocks exert their influences on the regulatory networks in the scion, so as to influence relevant agronomic traits. This information should result in an improved rootstock breeding selection and definition of scion/rootstock combinations to enhance fruit quality traits. Full article

In Citrus, flower induction represents the transition from vegetative to reproductive growth. The regulation of flower induction is mainly triggered by exposure to low temperatures and water-deficit stress, which activates the signaling cascade leading to an increased expression of the citrus orthologs of the FLOWERING LOCUS T (CiFT). In this study, the relationship between rootstock and flower induction under Mediterranean field conditions was investigated by monitoring the expression levels of the floral promoter CiFT2 in leaves of the pigmented sweet orange “Tarocco Scirè” grafted onto “C35” citrange and “Swingle” citrumelo rootstocks. The latter two are known to confer, respectively, high and low yield efficiency to the scion. In both rootstock/scion combinations, CiFT2 showed a seasonal expression with a peak during the inductive period in January triggered by cold temperature. The “Tarocco Scirè”/”C35” citrange combination showed the highest expression levels for CiFT2; this increased expression was correlated with yield and a higher number of flowers in the following spring, suggesting a significant effect of rootstocks on flower induction mediated by the overexpression of the CiFT2 gene. Full article