February 2016
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23 Reads
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3 Citations
Objective: To evaluate the suitable candidate DNA barcoding of plants in Rehmannia Libosch. ex Fisch. et Mey., and unravel the origin of cultivated R. glutinosa. Methods: Nuclear DNA ITS and chloroplast gene psbA-trnH, rbcL, and matK sequences of species in Rehmannia Libosch. ex Fisch. et Mey. were amplified and sequenced. The Kimura 2-Parameter (K2P) distances were calculated. Identification analyses were performed using Nearest Distance, BLAST1, and Neighbor-Joining (NJ) methods. Results: A comparison on the sequences within species in Rehmannia Libosch. ex Fisch. et Mey. indicated that the rbcL sequences were identical, the matK sequences were similar by 99.9%-100%. All inter-specific distances (ITS and psbA-trnH data) were far higher than all intra-specific genetic distances. Minimum interspecific distance (ITS and psbA-trnH data) were higher than coalescent depth. The NJ trees (ITS, psbA-trnH, and combined data) indicated that all population of R. glutinosa formed a monophyletic clade [Bootstrap (BS)=96%, 55%, and 58%]. The clades including R. glutinosa and R. solanifolia were clustered with R. piasezkii and R. elata in ITS and combined trees (BS=55% and 68%), and clustered with R. piasezkii and R. chingii in psbA-trnH tree (BS=80%). The NJ trees (ITS, psbA-trnH, and combined data) supported that three cultivated varieties of R. glutinosa were clustered with wild populations from Wenxian, Zhengzhou, Nanyang, and Beijing (BS=51% and 69%). Conclusion: Chloroplast genes rbcL and matK can not be used to identify the medicinal plants of Rehmannia Libosch. ex Fisch. et Mey. ITS and psbA-trnH are two efficient barcodes for authentication of R. glutinosa and its relative species. R. piasezkii and R. chingii may be as both parental species of tetraploid R. glutinosa. Furthermore, it appears that native wild populations are involved in the origin of cultivated R. glutinosa in Wenxian county. © 2016, Editorial Office of Chinese Traditional and Herbal Drugs. All right reserved.