## 3 Results
### Nutraceuticaltical Compounds and Antioxidant Capacity
Different letters for the factors grafting and landrace, or their interaction, indicate significant differences at \(p<0.05\) using the LSD test. No letter indicates the non-significance of the \(F\) ratio. ns: \(p>0.05\); **: \(p\leq 0.05\); **: \(p\leq 0.01\). Antioxidant capacity was determined by the DPPH assay and was higher in the red fruit compared to the green ones (\(p\leq 0.001\), Student's \(t\)-test). Grafting generally reduced this parameter in both colored fruit (Figure 3E,F). The highest antioxidant capacity values were found in both the green (3.84 mg TE g\({}^{-1}\) FW) and red (11.1 mg TE g\({}^{-1}\) FW) fruit produced by the \"Valencia\" plants, followed by \"Sueca,\" whereas the lowest antioxidant capacity was recorded in fruit from \"Cuerno.\" A significant grafting and landrace interaction was observed only for the red fruit, which became evident as the highest antioxidant capacity was reported in the fruits produced by grafted and ungrafted \"Valencia\" plants, and by the ungrafted \"Sueca\" plants (Figure 3F). The lowest antioxidant capacity values were detected in the fruits from the grafted \"Cuerno\" plants. The most evident result was the lower Chl a and b content in the red vs. The green fruit (\(p\leq 0.001\); Student's \(t\)-test) (Figure 4A,B). In the green fruit, this concentration was not influenced by grafting, but was strongly impacted by landrace, with the fruit from \"Cuerno\" presenting the highest content, followed by \"Valencia\" and finally by \"Sueca.\" The interaction between the two variability factors was evidenced as the highest Chl a and b content was detected in the ungrafted \"Cuerno\" fruit, followed by the grafted \"Cuerno,\" \"Valencia,\" and ungrafted \"Valencia\" (Figure 4A). In the red fruit, no variability factor induced significant differences in Chl a and b content (Figure 4B). Not even did carotenoid content change in the green and red fruit because of grafting, but marked differences were found  
Figure 2: Titratable acidity (**A**,**B**) and pH values of pepper juice (**C**,**D**) in the green (**A**,**C**) and red (**B**,**D**) fruit produced by pepper landraces “Cuerno” (C), “Valencia” (V), and “Sueca” (S) grafted (G) or ungrafted (U) onto rootstock F1 NIBER®. Values are the mean \(\pm\) SE of three fruits per replicate (3 replicates) per landrace. Means were subjected to a two-way ANOVA with grafting and landrace as sources of variability. Different letters for the factors grafting and landrace, or their interaction, indicate significant differences at \(p<0.05\) using the LSD test. No letter indicates the non-significance of the \(F\) ratio. among landraces: the green fruits produced by \"Cuerno\" and \"Valencia\" had a higher carotenoid content, with both \"Cuerno\" together with \"Sueca\" in the red fruit (Figure 4C,D). Figure 3: Total phenols (**A**,**B**), ascorbic acid amount (**C**,**D**) and antioxidant capacity (**E**,**F**) in the green (**A**,**C**,**E**) and red (**B**,**D**,**F**) fruit produced by the three pepper landraces “Cuerno” (C), “Valencia” (V), and “Sueca” (S) grafted (G) or ungrafted (U) on rootstock F1 NIBER®. Values are the mean \(\pm\) SE of three fruits per replicate (3 replicates) per landrace. Means were subjected to a two-way ANOVA with grafting and landrace as sources of variability. Different letters for factors grafting and landrace, or their interaction, indicate significant differences at \(p<0.05\) using the LSD test. No letter indicates the non-significance of the F ratio. As expected, the lycopene concentration was higher in the red versus the green fruit. The mean value, independently of grafting and genotype, was 2.78 mg g\({}^{-1}\) FW compared to one of 16.39 mg g\({}^{-1}\) FW in the red fruit (\(p\leq 0.001\), Student's \(t\)-test; Figure 4E,F). Although in lycopene content the green fruit was low, significant differences were found for grafting and landrace, but not for their interaction (Figure 4E).