Comparison of anthocyanins in non-blotches and blotches of the petals of Xibei tree peony

A comparison in non-blotches and blotches of 35 cultivars of Xibei tree peony was investigated to explore flower coloration of Xibei tree peony (the second cultivar group in Chinese tree peony). With high performance liquid chromatography (HPLC) analysis, six anthocyanins including peonidin 3,5-di-O-glucoside (Pn3G5G), peonidin 3-O-glucoside (Pn3G), cyanidin 3,5-di-O-glucoside (Cy3G5G), cyanidin 3-O-glucoside (Cy3G), pelargonidin 3,5-di-O-glucoside (Pg3G5G), and pelargonidin 3-O-glucoside (Pg3G) were detected in non-blotches and blotches of petals. Total anthocyanins (TA), total flavones and flavonols (TF), and the copigmentation index (CI) were also analyzed. Cyanidin-based glycosides, which accumulated abundantly at the basal petal, resulted in blotch formation. Some peculiar cultivars with only one kind of anthocyanins or without anthocyanins in non-blotches were found in this study. For example, 'Feng Zi Xiu Se', 'Ou Duan Si Lian', and 'Xi Wang' contained only Pn3G5G; 'Bing Shan Cang Yu' and 'Jin Bo Dang Yang' contained only Cy3G; while no anthocyanins were found in 'Bing Shan Xue Lian'. Several cultivars were rich in Pg-based glycosides, such as 'Ni Hong Huan Cai', and 'Ju Yuan Shao Nv'. These cultivars would be excellent parents for creating new cultivars with novel flower color in the future.