Abstract
Flowers of the tree peony, Paeonia suffruticosa, and its interspecific hybrids with P. lutea, and P. delavayi, which originated in China and which were introduced by American and French breeders, were assayed for anthocyanins to trace their development.
Petal hues of all Japanese cultivars (Paeonia suffruticosa) were distributed within the blue-red scope on Commision Internationale de l'Eclairage (CIE) (L*, a*, b*) color coordinate. Red-dish purple cultivars had high values of both blue and red, whereas pink or white cultivars had low values. Dark red or deep red-purple cultivars contained a large amount of anthocyanins in the petals, whereas pink or white cultivars contained a slight amount. Therefore, there was a high negative correlation between petal lightness (Hunter's L value) and petal anthocyanin contents.
All dark red or deep red-purple Japanese cultivars contained 6 anthocyanins, peonidin 3, 5-diglucoside (Pn3G5G), peonidin 3-glucoside (Pn3G), cyanidin 3, 5-diglucoside (Cy3G5G), cyanidin 3-glucoside (Cy3G), pelargonidin 3, 5-diglucoside (Pg3G5G) and pelargonidin 3-glucoside (Pg3G). Vivid red cultivars lacked Cy3G/Cy3G5G but contained large amounts of Pg3G/Pg3G5G. Some pink cultivars lacked Pn3G and Pg3G as well as Cy3G/Cy3G5G.
Of the 6 anthocyanins present in the Japanese cultivars, the Chinese cvs. of P. suffruticosa and P. suffruticosa var. spontanea generally lack Pg3G, which may account for the absence of the vivid red color.
American and French interspecific hybrids between P. suffruticosa and P. lutea and P. delavayi lack Pg3G and Pg3G5G. The lack of pelargonidins gave rise to hybrids with crimson or scarlet flowers; but in the presence of a yellow chalcone, peonidin and cyanidin in some cultivars gave rise to orange or maroon flowers. The yellow pigment is inherited from the P. lutea and P. delavayi.
