Abstract: By using PCR method, partial sequences of chalcone synthase (CHS)gene exon 2 were amplified from genomic DNA of Tutcheria spectabilis (Theaceae). After cloning and sequencing, 12 sequences ranging from 740 bp to 780bp were obtained. Comparing these sequences, with the ones of Medicago sativa and Pinus sylvestris from EMBL database, it reveals a similarity higher than 70% at the nucleotide level, and they are the members of CHS gene family. The result indicates that these sequences consist of five diffrent gene copies in three groups. In group 1,the CHS genes lost their functions because of indels of bases, then turning into pseudo-genes, which is reported here for the first time;In group 2, the gene copies provide new functions because of the mutation of the amino acid in active sites; In group 3, the copies have the same function of CHS genes. It is suggested that the CHS gene family in Theaceae is large, which has complex evolutionary mode.

Key words: Theaceae