Abstract: Using the total RNA from the leaves of Malus crabapple‘Royalty’as the template, the full cDNA of CHS（Chalcone synthase）gene（1 529 bp）was cloned by reverse transcription polymerse chain reaction（RT-PCR）and rapid-amplification of cDNA ends（RACE）. The gene was named McCHS, containing
an open reading frame（1 167 bp）and encoding a protein of 389 amino acids. The expression of McCHS and the content of anthocyanin was determined by Real-time quantitative PCR and spectrophotometer
respectively in the mature and young leaves of ‘Flame’（green young and mature leaf），‘Radiant’（red young leaf and green mature leaf），‘Prairifire’（red young leaf and green mature leaf），‘Royalty’（purple
young and mature leaf）. The results showed that McCHS was expressed in both mature leaves and young leaves of the above four cultivars. It was in the young leaves of all the four cultivars that the variation in the
McCHS expression was similar to that in the anthocyanin content. The same trend was found in the mature leaves of most cultivars with the exception of ‘Radiant’, which may have other enzymes and transcriptionfactors involved in the anthocyanin synthesis in its mature leaves.

Key words: Malus, crabapples, chalcone synthase, anthocyanin, real-time quantitative PCR