伞形科常用中药品种rDNA序列特征及其标记方法研究

Molecular Characteristic Marker Method of 27 Breeds of Common Umbelliferae Chinese Herb Medicinal Plants by Sequencing rDNA

目的：探讨伞形科27种常用中药指纹图谱鉴定的分子特征标记，探索筛选标记方法。方法：扩增伞形科27种植物的rDNA序列，限制性内切酶消化，聚丙烯电泳，其中6个品种测定rDNA序列。结果：PCR获得的rDNA序列片段包括ITS1、ITS2、5．8S全长序列以及18S、26S部分序列。将PCR产物经限制性内切酶MSPI消化后的电泳图，27个品种出现了16种特征性图谱，其中有11个品种的图谱与其他品种不相同；经限制性内切酶HaeⅢ消化后出现5种特征性图谱，其中有3个品种的图谱不与其他品种相同。6个品种经测序，获得了长度为652～656bp的基因序列。根据rDNA序列构建的相似系统树，限制性内切酶消化电泳图相同的三组品种，序列相似度高。结论：rDNA序列特征是伞形科中药鉴别的有效分子标记，序列测定法优于限制性内切酶切片长度多态性的分子标记方法。

Objective ： To probe a molecular marker method of accrediting fingerprinting of 27 kinds of common Umbelliferae Chinese herb medicinal plants by sequencing rDNA. Method ： The rDNA sequences of the 27 breeds of common Umbelliferae Chinese herb medicinal plants were amplified, and were digested by restriction endonuclease, and were seperated via polypropylene electrophoresis, at last 6 breeds of them were sequenced. Results： The rDNA sequence fragment we gained concluded ITS1, ITS2, 5.8S complete sequence and 18S, 26S part sequence. On the electrophoresis map of PCR products digested by restriction endonuclease MSP I , 27 breeds appeared 16 kinds of characteristic map, 11 of them differ from others; and PCR products digested by restriction endonuclease Haelll, there appeared 5 kinds of characteristic map among 27 breeds, 3 of them differ from others. The sequenced result of 6 breeds showed genes whose length extented from 652bp to 656bp were acquired. These sequences of 3 breeds which showed the same electrophoresis map after digested by restriction endonuclease Haelll exhibited great similarity according to similar phylogenetic tree constructed on rDNA sequence. Conclusion： The rDNA sequence character is effective molecular marker for classifying the different Umbellerae Chinese herb medicinal plants. And the method of sequencing rDNA surpassed that of restriction fragment long polymorphism （RFLP）.