Identification of candidate genes related to anthocyanin biosynthesis in red sarcocarp hawthorn (Crataegus pinnatifida)

•Anthocyanin biosynthesis in red sarcocarp hawthorn formation have not been reported.•21 anthocyanin metabolites expressed differently between red sarcocarp cultivar ‘Xinglongzirou’ and white sarcocarp cultivar ‘Bairangmian’.•Structural genes Cp4CLL7, CpDFR, and CpLAR and transcription factors CpERF1B, CpARF7, CpIAA27, CpMYB4, and CpbHLH18 involved in hawthorn anthocyanin biosynthesis were firstly identified. The red sarcocarp hawthorn (Crataegus pinnatifida) ‘Xinglongzirou’ (XZ) is the unique red sarcocarp resource among the cultivated hawthorn varieties in China, which has important production and breeding value and is also an important material for the research of hawthorn anthocyanin biosynthesis. So far, no genes related to anthocyanin biosynthesis in hawthorn have been reported. In this study, anthocyanins and the genes responsible for their synthesis were identified by comparing the red ‘Xinglongzirou’ and white ‘Bairangmian’ sarcocarp varieties. Sarcocarp color measurement and phenotype observation revealed that anthocyanin biosynthesis began 90 days after full-bloom (DAFB90), color turning at DAFB110, and maturation at DAFB150. Liquid chromatography-tandem mass spectrometry identified 21 anthocyanin metabolites expressed differently between ‘Xinglongzirou’ and ‘Bairangmian’ (P