Abstract: For exploiting retrotransposon gene resource,and analyzing diversity and phylogenetic evolution of retrotransposons in Sabina vulgaris genome,twenty-two of fragments encoding reverse transcriptase of Ty1-copia-like retrotransposon were cloned by degenerate-PCR.The length of the nucleotide sequences excluding primer varied from 239 to 247 bp,and homology ranged from 49.6% to 98.4%,showing high heterogeneity.Phylogenetic analysis of the nucleotide sequences showed that the twenty-two sequences consisted of five families.When they were translated into amino acids,stop codon mutation was found in seven sequences,and frameshift mutation was found in four sequences.The alignment analysis of amino acid sequences of Ty1-copia-like reverse transcriptases from S.vulgaris and other plant species suggested that they may have the same origin.These results demonstrated diversity of retrotransposon in S.vulgaris genome,and could prove to be useful for further study on genetic diversity and cultivar identification of S.vulgaris.

Key words: Sabina vulgaris, retrotransposon, reverse transcriptase, diversity