Genetic characterization of the nine medicinal Dendrobium species using RAPD

The nine species of Dendrobium were distinguished from each other by the banding pattern generated by the sixteen 10-mer oligonucleotide primers in the random amplified polymorphic DNA (RAPD) reaction. Distinctive bands generated from the nine species were observed. RAPD analysis was also applied to estimate the genetic relationship among the nine species. A dendrogram was constructed based on a data matrix of 323 polymorphic bands originated by the sixteen random primers. Four groups were identified, one consisting of Dendrobium huoshanense and Dendrobium loddigesii, the second consisting of Dendrobium bellatulum and Dendrobium fimbriatum. The third cluster contained Dendrobium candidum, Dendrobium densiflorum and Dendrobium exile. The rest were grouped in the fourth cluster. The principal coordinate analysis (PCA), that is, the plot drawn on the basis of the RAPD data, clearly distinguished the nine species into four groups, which also support the notion in the dendrogram described above.