DNA BARCODING OF SPECIES IN GENUS Dendrobium SECTION Dendrobium (ORCHIDACEAE) USING matK SEQUENCES

Application of the matK gene to distinguish the Dendrobium species, particularly for sterile specimens, showed that it is a powerful tool for DNA barcoding. 30 taxa from Dendrobium section Dendrobium, 7 from section Densiflora, 4 from section Breviflores and 1 from section Stuposa were sampled for phylogenetic study. The results showed that the section Dendrobium was a monophyletic group based on matK gene sequences. According to the phylogenetic tree, it demonstrates that seven species of the section Densiflora, namely D. chrysotoxum, D. farmeri, D. griffithianum, D. jenkinsii, D. palpebrae, D. sulcatum, and D. thyrsiflorum, four species of the section Breviflores, D. dantaniense, D. hercoglossum, D. linguella and D. umbonatum, and D. stuposum of the section Stuposa were better placed in the section Dendrobium. The tree further showed that the Dendrobium section Dendrobium can be divided into 2 clades with high bootstrap support.