Accumulation Characteristics of Flavonoids and Contribution to Antioxidant Capacity in Wild and Cultivated Kiwifruits

This study aimed to clarify flavonoids accumulation characteristics and their contribution to antioxidant capacity in wild type (WT) kiwifruit (Actinidia deliciosa) and three cultivated varieties (Xuxiang, XX; Yazui, YZ; Hongyang, HY). Integrating untargeted metabolomics and traditional biochemical analysis, we compared morphological, biochemical, and metabolic differences, analyzed flavonoid profiles, and screened core flavonoids linked to antioxidant activity. Results showed cultivated varieties exhibited superior fruit shape, sweetness (TSS/SS), total phenols, flavonoids, and DPPH scavenging activity (HY highest). Flavonoid metabolic profiles differed significantly: WT enriched stress-resistant flavonoids (e.g., Leucocyanidin), while cultivated varieties showed specialized accumulation (e.g., flavonol glycosides in HY). Fourteen core flavonoids (e.g., Kuwanon D, Hyperoside) strongly correlated with antioxidant activity were identified. This study reveals domestication’s impact on kiwifruit metabolism, providing theoretical support for directed breeding of high-nutrition varieties and wild germplasm utilization.