广藿香与土藿香的DNA序列分析及其分子鉴别

DNA SEQUENCING AND MOLECULAR IDENTIFICATION OF PATCHOULI AND ITS SUBSTITUTE WRINKLED GIANTHYSSOP

AIM To analyze sequences of the nuclear ribosomal RNA small subunit (18S rRNA) gene and the chloroplast mat K gene of crude drug Patchouli ( Pogostemon cablin ) in order to provide molecular evidence for identification of Patchouli drug. METHODS To sequence the entire 18S rRNA gene and partial mat K gene of Patchouli from Guangzhou and its substitute Wrinkled Gianthyssop ( Agastache rugosa ) from S ichuan using PCR direct sequencing and to detect the homology of two gene sequen ces between these two crude drugs. RESULTS The complete 18S rRNA gene sequence is 1 805 bp in length for Patchouli from Guangzhou whereas 1 794 bp for Wrinkled Gianthyssop from Sichuan. The 3′ end sequence of mat K gene is 521 bp (747～ 1 268 nt from upstream of ma t K gene) for these two crude drugs. Based on multiple sequence alignment, it i s found that there are 18 variable sites and 11 aligned gap sites in 18S rRNA se quence, 49 variable sites in 3′ mat K sequence between these two crude drug s. The homology is 98 4% for 18S rRNA and 90 6% for 3′ mat K between two crude drugs, respectively. CONCLUSION DNA sequencing can provide an accurate and reliable tool in the crude drug ident ification of Patchouli and its substitute Wrinkled Gianthyssop.