Identification of Hippophae species (Shaji) through DNA barcodes

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. CONCLUSION The combination of the two loci, ITS2 + psbA-trnH is applicable to the identification of medicinal and non-medicinal Hippophae species.