Application of genetic marker and real-time polymerase chain reaction for discrimination between Forsythia viridissima and Forsythia suspensa.

Forsythiae Fructus has been used as a herbal medicine for a fruit of Forsythia viridissima LINDLEY or Forsythia suspensa VAHL (Oleaceae). In Korea, the fruit of Forsythia viridissima is used and in China, the fruit of Forsythia suspensa is used generally. There are differences in the amount and distribution of constituents between Forsythia viridissima (FV) and Forsythia suspensa (FS). Accordingly, a discrimination of these two herbal drugs is needed. In this study, we designed FV genetic marker based on the internal transcribed spacer (ITS) sequence of nuclear ribosomal DNA that can discriminate Forsythia viridissima and Forsythia suspensa and species-specific amplification product 252 bp was confirmed. Using the real-time polymerase chain reaction (PCR) (allelic discrimination) analysis, an accurate discrimination between Forsythia viridissima and Forsythia suspensa was accomplished. Accordingly, with the use of PCR analysis based on ITS region sequence of ribosomal DNA and the real-time PCR analysis which can efficiently discriminate between Forsythia viridissima and Forsythia suspensa was developed.