广藿香的基因序列与挥发油化学型的相关性分析

DNA PROFILING OF POGOSTEMON CABLIN CHEMOTYPES DIFFERING IN ESSENTIAL OIL COMPOSITION

目的 探讨“南药”广藿香Pogostemoncablin (Blanco)Benth .不同产地间的叶绿体和核基因组的基因型与挥发油化学型的关系 ,为广藿香道地性品质评价、规范化种植提供分子依据。方法 用PCR直接测序技术对广藿香6个产地样本的叶绿体matK基因和核 18SrRNA基因核苷酸序列进行测序分析研究。结果 广藿香 6个样本的matK基因序列长均为 12 4 5bp ,编码 4 15个氨基酸成熟酶。 18SrRNA基因序列长为 180 3～ 180 5bp。根据排序比较 ,广藿香 6个样本间的matK基因序列存在 4 7个变异位点 ,18SrRNA基因存在 17个变异位点 ,非加权组平均法构建的系统分支树表明广藿香基因序列分化与其产地、所含挥发油化学变异类型呈良好的相关性。结论 结合挥发油分析数据 ,基因测序分析技术可作为广藿香道地性品质评价方法这一以及规范化种植过程关键技术“物种鉴定”

AIM To provide molecular evidence for quality evaluation and GAP production of Pogostemon cablin (Blanco) Benth. cultivated in different regions in Guangdong and Hainan provinces, China, by comparing two sequences (1 2 kb of plastid mat K gene and 1 8 kb of nuclear 18S rRNA gene) and two chemotypes (Pogostone type and Patchouliol type in essential oil composition). METHODS PCR direct sequencing was applied to detemine the mat K and 18S rRNA sequences for six samples of Pogostemon cablin from different localities. RESULTS The mat K sequences of six samples of Pogostemon cablin from different regions of cultivation are 1 245 bp in length, which coding 415 amino acids of protein (maturase), and 18S rRNA sequences are 1 803～1 805 bp in size. Based on multiple sequence alignment, there are 47 variable sites in the mat K sequence of these six samples, 17 in the 18S rRNA sequence. The cluster tree reconstructed by UPGMA method shows that the sequence divergence both in mat K and 18S rRNA genes among six samples of Pogostemon cablin was well correlative with their regions of cultivation and intraspecific chemotypes of essential oil composition. CONCLUSION Combining with chemical and biogeographical data, DNA sequencing can become a powerful tool in the key technique species identification of quality evaluation and GAP production of Pogostemon cablin .