Internal Transcribed Spacer Sequence Based Identification and Phylogenie Relationship of Herba Dendrobii

Abstract

Herba Dendrobii, commonly known as "Shi-hu", has been used as a precious traditional Chinese medicine. It is expensive and adulteration are common clue to high demand. The method to distinguish the herb from adulterant species is necessary. In the present study, internal transcribed spacers (ITS) region-based analysis was employed to ascertain the phylogenetic relationship among the 11 Dendrobium and two adulterant species Pholidota articulata and Flickingeria comate. Results showed that the length of the ITS regions among the thirteen species ranged from 635 to 641 bp and the GC ratio in ITS (ITS1 + 5.8S + ITS2) regions ranged from 50.55% to 57.25%. Dendrobium species was significantly different from one another by an average of 13.20% and from P. articulata and F. comate by 42.00% and 29.00% respectively. The molecular phylogenetic trees indicated that most of Dendrobium species are closely related and share common clad while both the adulterants outgroup and have separated clad. Therefore, ITS regions can be used as a molecular marker to differentiate medicinal Dendrobium spp. from one another and also from adulterants.