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目的应用ITS2序列对降香药材及其混伪品进行DNA条形码鉴定。方法以降香药材及其常见混伪品为研究对象,PCR扩增降香及其混伪品的ITS2序列并进行双向测序,利用软件MEGA5.0对ITS2序列的长度、GC含量等分析比对,基于K2P模型计算遗传距离,通过中药材DNA条形码鉴定系统和构建邻接树(NJ树)法对降香药材及其混伪品进行鉴定。结果降香药材的ITS2序列长度为216 bp,GC含量为68.5%,种内无变异位点,降香与其混伪品的种间最小遗传距离为0.009,大于降香种内最大K2P距离。结论中药材DNA条形码鉴定系统和构建邻接树均可以准确区分降香药材及其混伪品。
Objective To identify DNA samples of Rhodiola rosea and its adulterants by ITS2 sequence. Methods The medicinal materials of Rhodiola and their common compounds were used as research objects. The ITS2 sequences of Rhodiola and its adulterants were amplified by PCR and sequenced bidirectionally. The length and GC content of ITS2 were analyzed by software MEGA5.0. Based on the K2P model, genetic distance was calculated. The Chinese medicinal herbs DNA barcode identification system and the construction of the adjacent tree (NJ tree) method were used to identify the medicinal materials and their adulterants. Results The length of ITS2 sequence was 216 bp and the GC content was 68.5%. There was no variation in the species. The minimum genetic distance between the two species was 0.009, which was greater than the maximum K2P distance within the desiccated species. Conclusion Chinese herbal medicines DNA barcode identification system and construction of adjacent trees can accurately distinguish hypoglycemic herbs and their adulterants.