广藿香与土藿香的DNA序列分析及其分子鉴别

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.