A comparison of nrDNA internal transcribed spacer (ITS) loci for phylogenetic inference and authentication among Cinnamomum osmophloeum and related species in Taiwan

Abstract

Cinnamomum osmophloeum, an indigenous species of Taiwan, can be utilized for valuable products such as a food, a spice and a traditional Chinese medicine. This study compares the ribosomal DNA (nr DNA) internal transcribed spacer (ITS) sequence of C. osmophloeum to that of several other species with similar external morphology, such as Cinnamomum burmannii, Cinnamomum insularimontanum, Cinnamomum macrostemon and Cinnamomum subavenium. Phylogeny of ITS sequences shows that C. osmophloeum is more closely related to C. burmannii than the other species, while C. insularimontanum, C. macrostemon, and C. subavenium are phylogenetically relevant to each other. By comparing ITS sequence between C. osmophloeum and C. burmannii, specific primers were designed for the multiplex-PCR to differentiate them. Based on ITS sequence differences, all tested Cinnamomum spp. can be properly authenticated. A 125 bp band specific for C. osmophloeum and a 204-bp C. burmannii-specific band were successfully amplified by polymerase chain reaction (PCR) using the respective primers described above. The two species then can be identified at the molecular level according to the sizes of their respective PCR products as determined by gel electrophoresis.

Identification and monitoring of Korean medicines derived from Cinnamomum spp. by using ITS and DNA marker

“…According to the pharmacopoeias of Korea, China, Taiwan, and Japan, C. cassia is the only officially permitted Cinnamomum species that can be used as a source of traditional medicine (Korea Institute of Oriental Medicine 2016). However, the major of areas in which Cinnamomum plants are grown are distributed in tropical and subtropical Asia and Australia (Ho et al 2015). Consequently, the Cinnamomum markets in many countries, including Korea, are completely dependent on imported products.…”

“…However, as previously mentioned, Cinnamomum is primarily found in tropical and subtropical Asia and Australia, and therefore the collection of specimens for examination has been limited. Several techniques used to identify Cinnamomum plants have been reported, including those based on RAPD (Joy and Maridass 2008; Sudmoon et al 2014), chloroplast DNA (e.g., trnL - F, trnL intron, matK, rbcL and trnH - psbA ) sequences (Sudmoon et al 2014; Kojoma et al 2002; Abeysinghe et al 2009; Swetha et al 2014a, b), and ITS nucleotide sequences (Ho et al 2015; Abeysinghe et al 2009). However, most of the research has focused on specimens from a limited number of species.…”