Characters of nrDNA ITS region sequences of fruits of Alpinia galanga and their adulterants.

The fruits of Alpinia galanga (L.) Sw. are used as a traditional Chinese medicine; but the dry fruits of A. conchigera, A. suishaensis, A. maclurei and A. polyantha are also used as the medicine in local areas. Because dry fruits of these related plants are similar to those of Alpinia galanga (L.) Sw. in odor, morphological characters and chemical components, and even anatomical characters, it is difficult to identify the medicine. Nuclear ribosomal DNA internal transcribed spacer (ITS) regions of the five taxa were directly sequenced using an automated sequencer. Sequence analysis showed that the ITS 1 ranges from 177 to 178 base pairs (bp), and the ITS 2 from 225 to 234 bp. The size of the 5.8S coding region is 164 bp for all species. Also, the pairwise sequence divergence is higher and some molecular markers were determined. According to these molecular markers, Alpinia galanga (L.) Sw. and the related species can easily be distinguished from each other. Therefore, evidence from nrDNA ITS sequence variation can identify the medicine at the DNA level.