Genetic profiling of Sasa species by analysis of chloroplast intron between rbcL and ORF106 and partial ORF106 regions.

Kuma-zasa is Japanese folk medicine derived from plants of genus Sasa, family Bambusaceae. Although the plants of origin of Kuma-zasa were reported to be Sasa palmata, S. senanensis, S. yahikoensis, and S. kurilensis, authentication of those plants was difficult because of similarity in morphology. Several methods for the classification of genus Sasa are available, but none involve a genetic approach. Here, we performed the genetic profiling of genus Sasa, including the four species used medicinally. Thirteen sequences were observed in chloroplast DNA intron between rbcL and ORF106 and partial ORF106 regions of 34 specimens of 16 Sasa species and one specimen of Phyllostachys pubescens. We observed differences in alignment in this region among the specimens. The analyzed lengths varied from 759 to 821 bp depending on the specimen. There were nine base substitutions, eight successive thymines or adenines, and one to three repeat units of 31 bp. Moreover, we could not find species-specific alignment: different alignments were observed in specimens of the same species, while the same alignment was observed in specimens of different species. In the phylogenetic tree reconstructed by maximum parsimony analysis, medicinally used species did not form a cluster, although most of them were positioned close to each other. The genetic profiling of Sasa species would be of use in determining the botanical origin of the herbal medicine derived from the leaves of Sasa plants.