title: Identification of Hippophae species (Shaji) through DNA barcodes.
abstract: BACKGROUND
  The morphological identification of different Hippophae species (Shaji) was difficult. This study aims to discriminate between medicinal and non-medicinal Hippophae species by DNA barcodes, the ITS2, psbA-trnH, and a combination of ITS2 and psbA-trnH (ITS2 + psbA-trnH).
  
  
  METHODS
  DNA was extracted from the dried fruit samples. Primer pairs ITS2F/3R for ITS2 and psbAF/trnHR for psbA-trnH were used for PCR amplification. The purified PCR products were bidirectionally sequenced. Genetic distances were calculated according to the Kimura 2 parameter model and phylogenetic tree was constructed based on neighbor-joining (NJ) method, barcoding gap was also analyzed to assess identification efficiency.
  
  
  RESULTS
  Amplification and sequencing efficiencies for both ITS2 and psbA-trnH were 100 %. Sequence data revealed that ITS2 + psbA-trnH was the most suitable candidate barcode at the species and subspecies level. The closely related Hippophae species were effectively differentiated in the NJ tree.
  
  
  CONCLUSIONS
  The combination of the two loci, ITS2 + psbA-trnH is applicable to the identification of medicinal and non-medicinal Hippophae species.
authors.affiliation: College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137 China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700 China.
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.affiliation: College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137 China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Liu
authors.affiliation: School of Chemical Engineering, Wuhan University of Technology, Wuhan, 430070 China.
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137 China.
authors.forename: Yilong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: School of Chemical Engineering, Wuhan University of Technology, Wuhan, 430070 China.
authors.forename: Ming
authors.initials: M
authors.lastname: Song
authors.affiliation: College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137 China.
authors.forename: Gang
authors.initials: G
authors.lastname: Fan
authors.affiliation: School of Chemical Engineering, Wuhan University of Technology, Wuhan, 430070 China.
authors.forename: Xia
authors.initials: X
authors.lastname: Liu
authors.affiliation: Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700 China.
authors.forename: Li
authors.initials: L
authors.lastname: Xiang
authors.affiliation: College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137 China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang