Abstract
During 2019 and 2020, we examined the influence of two traditional rootstocks (Mazzard seedlings and clonal Colt) on fruit size, phenolics content, and antioxidant capacity of eight commercial sweet cherry cultivars. Rootstocks significantly affected only fruit weight (FW), total anthocyanin content (TAc) and total phenolics content (TPC), being higher on Colt than on Mazzard by 5.33, 6.45 and 6.29%, respectively. Their influence on other parameters was not significant. However, the cultivars exhibited significant differences for all parameters between and within rootstocks, although their behavior was not consistent in many cases. ‘New Star’ on Mazzard and ‘Germersdorfer’ on Colt had the highest FW, whereas the highest vitamin C (Vit C) was registered in ‘June Early’ on both rootstocks. The condensed tannins (CT) and gallotannins (GT) were highest in ‘Summit’ on both rootstocks. In general, ‘Hedelfinger’, partially ‘New Star’ and ‘Lapins’, may be considered superior due to their phenolic compound contents and antioxidant activity. Contrary, ‘Summit’, ‘Stark Hardy Giant’ (‘SHG’) and ‘Sunburst’ may be considered less promising in the context of most evaluated properties. Among others, Pearson’s correlations showed that FW negatively correlated with TAc, TPC, total flavonoid content (TFC) and DPPH scavenging activity, which means that smaller fruits are a richer source of phenolic compounds and have a stronger antioxidant capacity than larger ones. Also, positive correlations were found between TPC and TFC, and TAc versus TAC. The principal component analysis (PCA) has proven to be a good statistical tool for segregating cultivars with the best and/or weakest properties.