[Molecular identification of Hibiscus syriacus and its adulterants using ITS2 barcode]

To identify Hibiscus syriacus and its adulterants using DNA barcoding technique.

Nine samples of five species were PCR amplified and sequenced, and twelve samples were downloaded from the GenBank. The intra-specific and interspecific K2P distances were calculated, and neighbor-joining( NJ) tree was constructed by MEGA 5.0.

The results showed the intra-specific genetic distances of Hibiscus syriacus were ranged from 0.009 to 0.056, which were far lower than inter-specific genetic distances between Hibiscus syriacus and its adulterants (0.236 - 0.301). Variable sites within Hibiscus syriacus ranged from 2 to 9 which were far less than the adulterants (45 - 52); Different samples of Hibiscus syriacus were gathered together and could be distinguished from its adulterants by NJ tree.

ITS2 can discriminate Hibiscus syriacus from its adulterants correctly. The ITS2 region is an efficient barcode for authentication of Hibiscus syriacus and its adulterants.