MORPHOLOGICAL AND DNA MOLECULAR EVIDENCE FOR AUTHENTICATION OF DENDROBIUM FLEXICAULE FROM ITS ALLIED SPECIES OF DENDROBIUM

AIM To define morphological and molecular characters to distinguish Dendrobium flexicaule from its allied species D.flexicaule (Henan population), D.moniliforme (Henan population), D.huoshanense (Huoshan population) and D.officinale (Tiantai population). METHODS The morphological characteristics of D.flexicaule (population of Henan) and its allied species are compared. The sequences of rDNA ITS regions are exploited to explore the evidence for authenticating D.flexicaule (population of Henan) and its allied species. RESULTS The morphological characteristics of the herb of D.flexicaule (Henan population) and its allied species are summed up. Although the morphological difference is not much, the sequence difference of ITS regions among the four rDNAs is obvious and stable. The absolute genetic distance between the ITS region of D.flexicaule and D.officinale is 7 while that between the ITS region of D.flexicaule and D.moniliforme is 40 and that between the ITS region of D.flexicaule and D.huoshanense is 42. Seven sites of ITS region are defined as DNA character to identify D.flexicaule from the other three allied species. CONCLUSION The morphological characters and rDNA ITS sequences can be used to authenticate accurately D.flexicaule from three allied species of Dendrobium.