Species-Level Diversity in the Botanical Origin of Asparagi Radix (Asparagus cochinchinensis and its Allied Species: Asparagaceae) Distributed in China and Japan Revealed by DNA Barcoding

Abstract

To clarify species-level diversity in the botanical origin of Asparagi radix distributed in markets in China and Japan, we developed an identification method using DNA barcoding markers for Asparagus cochinchinensis and its allied species, and performed market investigations. Nucleotide sequences of the ITS regions were determined in 107 accessions of 21 Asparagus species, along with partial trnL-trnF intergenic spacer regions from a limited number of species. The examined species were discriminated from each other, except A. meioclados and A. trichoclados. Among 238 accessions of Asparagi radix distributed in markets, the most common origin was A. cochinchinensis (56%), followed by A. subscandens (25%), A. taliensis (16%), A. lycopodineus (2%), and A. meioclados or A. trichoclados (0.4%). All species were found in Chinese markets, whereas only three species, A. cochinchinensis, A. taliensis, and A. subscandens, were found in Japanese market. While four species were found to consist of only wild origin, A. cochinchinensis and A. taliensis were found to have both wild and cultivated origins. More than half of the A. subscandens-derived crude drugs in the Chinese markets was estimated to be sourced from Myanmar based on the intraspecific barcoding variation, even though 55 out of 60 samples were sold as products originating from China.