Chiang Mai Journal of Science

 Genus Cinnamomum is an important plant group containing aromatic oils in its leaves and bark. These oils are widely used in flavoring agents for foods, cosmetic and pharmaceutical preparations, and in other traditional and prepared forms. The Cinnamomum diversity in Thailand was investigated and identified in areas where it naturally grows. There were seven known species, seven unknown species, one traditional form, and two prepared forms included in this research. The unknown species which had no reproductive parts were identified firstly by comparing their random amplified polymorphic DNA (RAPD) banding patterns to the known species. The 15 different primers produced a total of 983 bands, which were successfully used to construct a dendrogram that distinctly separates species with genetic similarity values ranging from 0.56 to 0.84 accordingly to show different leaf characters. DNA barcodes with matK, rbcL, and rpoB gene regions were constructed in all studied samples. Compared to some sequences from GenBank, the genetic distances in the regions were 0.00 to 0.52, 0.00 to 0.36, and 0.00 to 0.30, respectively. Considering these values, some different species showed no genetic distances. To summarize, the three regions cannot be used to identify these Cinnamomum species as there are no distinct sequence variations between many different species.