DNA profiling of Acorus calamus chemotypes differing in essential oil composition

The phylogenetic relationship of Acorus gramineus and three types of Acorus calamus was analyzed by comparing the 700 bp sequence of a 5S-rRNA gene spacer region. Although there was no intra-specific variation in the essential oil profile of A. gramineus which contained a phenylpropanoid (Z-asarone) as a predominant constituent, A. calamus was classified into two chemotypes: chemotype A in which Z-asarone is a major essential oil constituent and chemotype B which contained sesquiterpenoids predominantly. An intermediate type (M) of these two chemotypes in various ratios was also observable. The NJ tree constructed based on the sequences revealed that A. gramineus was clearly distinguished from any of the chemotypes of A. calamus and that the phylogenetic relationship predicted by the spacer region data correlated well with the essential oil chemotype pattern of A. calamus.