The domestication syndrome within Hybrid Perpetuals roses: the effect of unconscious selection on flavonoids

Cultivated Gallicanae x Chinenses hybrids of roses, namely Hybrid Perpetual s, were compared with their parents as to morphology, petal colour, flavono l and anthocyanin metabolism. Morphology exhibited clear patterns of hybrid ity. An objective measure of petal lightness (L) indicated that Hybrid Perp etuals were submitted to a selection pressure favouring dark-flowered culti vars. When compared to the parental flavonoid metabolisms, Hybrid Perpetual s exhibited increased synthesis of anthocyanin and quercetin. High amounts of anthocyanin in Hybrid Perpetuals resulted from the selection of deeper-c oloured flowers. High amounts of quercetin were correlated with enhanced an thocyanin synthesis, so that this originality of the flavonol metabolism wa s interpreted on biogenetic ground as a repercussion of this same selection pressure. Finally. the patterns of variation of flavonol glycosides within the Hybrid Perpetuals reflected the indirect selection pressure for the qu ercetin end-products, and with the ancestral hybridizations for the kaempfe rol derivatives. (C) 2001 Elsevier Science Ltd. All rights reserved.