Abstract:

【Objective】 The aim of this study was to investigate the flavonoid composition and content in fruits of apple germplasm resources (AGRs), to discover AGRs rich in flavonoids, and to provide a basis for exploitation of flavonoids in fruits of AGRs and for breeding apple cultivars rich in flavonoids. 【Method】 Flavanoids in fruits of 22 AGRs were determined by RP-HPLC. 【Result】 There were 34 Flavonoids were detected (including 5 flavanols, 6 dihydrochalcones, 15 flavonols, and 8 anthocyanins), among which 18 flavonoids were not reported in fruits of apple cultivars. There were 16-30 flavonoids in fruits of 22 AGRs, of which 14 were common flavonoids. Total content of 5 flavanols detected was 10.4-2 764.9 mg?kg-, and over 1 700 mg?kg-1 in fruits of 5 AGRs. Total dihydrochalcones were 58.1-1 077.5 mg?kg-, and more than 450 mg?kg-1 in fruits of 7 AGRs. Total flavonols were 52.9-645.6 mg?kg-, and higher than 200 mg?kg-1 in fruits of 6 AGRs. Anthocyanins only exisited in red fruit, the total of which was 0.3-284.8 mg?kg-, and beyond 150 mg?kg-1 in fruits of 6 AGRs. 14 AGRs (except S, S4, S6, S10, S13, S14, S15, and S17) all had abundant flavanols included oligomeric and polymeric proanthocyanidins. There was a special flavanol (RT=42.43 min) in fruits of S18 with content of 1 350.7 mg?kg-1. S4, S6, S7, S1, and S22 were AGRs high in dihydrochalcones. S, S4, S9, S14, S17, S18, and S20 were AGRs high in flavonols. And S, S, S3, S5, S9, and S22 were AGRs high in anthocyanins. 【Conclusion】 Flavonoids in fruits of AGRs studied were very rich and showed significant diversity. There were 16 AGRs were high in flavonoids with total flavonoids (TF) above 10 000 mg?kg-1. These AGRs with abundant flavonoids can be used to exploit flavonoids in the fruit and to breed apple cultivars high in flavonoids.

Key words: apple')">apple, germplasm resource, fruit, flavonoids, diversity, composition, content