Comparative analysis of the complete chloroplast genomic sequence and chemical components of Cinnamomum micranthum and Cinnamomum kanehirae

Cinnamomum micranthum (Hayata) Hayata is a tree species that is often confused with Cinnamomum kanehirae Hayata, which is an endemic species in Taiwan and the sole natural host of the valuable medicinal fungus Antrodia cinnamomea. However, the two species are highly similar in morphology and difficult to distinguish based on traditional vegetative structures or wood anatomical methods. The aim of the present study was to identify of these two species by DNA and chemical analysis. The complete chloroplast genome of C. micranthum has been determined and compared with that of C. kanehirae. The leaf methanol extracts of these species were also analyzed by ultra-performance liquid chromatography (UPLC). The length of the C. micranthum chloroplast genome was 152675 bp, i.e. 25 bp shorter than that of C. kanehirae. In phylogenetic analysis, C. micranthum was more closely related to C. kanehirae than other six Lauracea species. Six validated insertion/deletions of bases in the DNA (InDels) are suitable for differentiation of the two species. Moreover, high amounts of linalool and sesamin were present in the leaves of C. kanehirae, but not in C. micranthum. Overall, this study provided new insight for distinguishing the two species on the basis of the chemical composition of the leaves and the InDel markers.