Abstract: PCRs were performed on genomic DNAs of four pear cultivars Sand pear,Huangguan pear,Xueli pear,Yali pear using primers derived from sequences of previous published PPO.The target bands were recovered and purified.The fragments were ligated with the plasmid of p GEM-T Vector by the method of direct TA cloning.The mixtures of ligation were transformed into DH-5α and the positive clones were screened and sequenced.Phylogenetic tree analysis of the plantPPOgene sequences were made by the software of Clustalx and DNAStar.The results showed these enzymes coding region each containing 1 782 oligodeoxynucleotides and the obtainedPPOgene of Yali pear was registered in Genbank,whose accession number is EU048225.The five types pear shared high sequence homology of 98 %.ThePPOgenes were divided into two groups based on phylogenetic tree analysis of the plantPPOgene sequences.ThePPOgenes of the pears can be clustered in the same group with most other woody plants according to phylogenetic tree analysis.

Key words: Pear, Polyphenol oxidase gene, Cloning, Sequence comparison

CLC Number: 

• Q785