BMC Genomics 2006, 7:12 http://www.biomedcentral.com/1471-2164/7/12 in [39]. Anthocyanins were detected by a LC-95 spectro- photometric detector (Perkin Elmer) operating at 520 nm. Anthocyanin content was expressed as mg/L of malvidin 3-glucoside upon the construction of a standard curve. The composition of monoglucoside anthocyanins was used for calculating the ratio of tri-/di-substituted deriva- tives. Berry colour was measured with an X-Rite 948 Chro- mameter (X-Rite) and averaged over 160 berries at each sampling date. Colorimetric specification was referenced to the CIELab scale. Hue angle (H°) and chroma (C*) were calculated according to [40]. Authors' contributions SDC participated in the design of the study, carried out gene cloning, expression profiling, field experiments and analyses of metabolites, participated in the interpretation of the results. 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