Petal coloration and pigment constitution in 38 tree peony cultivars (cvs.) from Daikon Island in Shimane Prefecture were observed.
Hues of flower color ranged from red through reddish purple to purple in most cvs. Chromas and values ranged from dull to deep or dark in red-flowered cvs., very pale to dull in pink-flowered cvs. and deep to dark in purple-flowered cvs.
As regards pigmentation, both 3, 5-diglucoside (3G5G) and 3-glucoside (3G) of pelargonidin (Pg) were dominant in almost all of the red-flowered cvs. Pink-flowered cvs. mainly contained the 3G5G of Pg or peonidin (Pn) but the amounts of anthocyanins were low. In purple-flowered cvs., Pn3G5G was dominant but some deep-colored cvs. had a high Cy3G content. Furthermore, as the petal color became bluer, the Pg3G and Pg3G5G contents decreased and, conversely, the Pn3G and Pn3G5G contents increased.
Based on the pigmentation in tree peony cvs. from Daikon Island, Pg3G-rich 'Hohki', 'Shin Shima no Kagayaki' and 'Kohki Jishi' are recommended as useful parental cvs. to obtain more vivid red colors, and 'Hohrei' with a high Pn3G5G content may be used as a parent to obtain bluer colors in future breeding.