Asahina Haruka, Shinozaki Junichi, Masuda Kazuo, Morimitsu Yasujiro, Satake Motoyoshi
Laboratory of Food Chemistry, Faculty of Humanities and Sciences, Ochanomizu University, 2-1-1 Ohtsuka, Bunkyo-ku, Tokyo, Japan.
J Nat Med. 2010 Apr;64(2):133-8. doi: 10.1007/s11418-009-0379-8. Epub 2010 Feb 6.
Species identification of five Dendrobium plants was conducted using phylogenetic analysis and the validity of the method was verified. Some Dendrobium plants (Orchidaceae) have been used as herbal medicines but the difficulty in identifying their botanical origin by traditional methods prevented their full modern utilization. Based on the emerging field of molecular systematics as a powerful classification tool, a phylogenetic analysis was conducted using sequences of two plastid genes, the maturase-coding gene (matK) and the large subunit of ribulose 1,5-bisphosphate carboxylase-coding gene (rbcL), as DNA barcodes for species identification of Dendrobium plants. We investigated five medicinal Dendrobium species, Dendrobium fimbriatum, D. moniliforme, D. nobile, D. pulchellum, and D. tosaense. The phylogenetic trees constructed from matK data successfully distinguished each species from each other. On the other hand, rbcL, as a single-locus barcode, offered less species discriminating power than matK, possibly due to its being present with little variation. When results using matK sequences of D. officinale that was deposited in the DNA database were combined, D. officinale and D. tosaense showed a close genetic relationship, which brought us closer to resolving the question of their taxonomic identity. Identification of the plant source as well as the uniformity of the chemical components is critical for the quality control of herbal medicines and it is important that the processed materials be validated. The methods presented here could be applied to the analysis of processed Dendrobium plants and be a promising tool for the identification of botanical origins of crude drugs.
采用系统发育分析对5种石斛属植物进行了物种鉴定，并验证了该方法的有效性。一些石斛属植物（兰科）已被用作草药，但传统方法难以鉴定其植物来源，阻碍了它们在现代的充分利用。基于新兴的分子系统学领域作为一种强大的分类工具，利用两个质体基因的序列，即成熟酶编码基因（matK）和1,5-二磷酸核酮糖羧化酶大亚基编码基因（rbcL），作为石斛属植物物种鉴定的DNA条形码，进行了系统发育分析。我们研究了5种药用石斛属植物，即流苏石斛、细茎石斛、金钗石斛、美丽石斛和台湾石斛。由matK数据构建的系统发育树成功地将每个物种彼此区分开来。另一方面，rbcL作为单一位点条形码，其物种区分能力不如matK，这可能是由于其变异较小。当将保存在DNA数据库中的铁皮石斛matK序列的结果结合起来时，铁皮石斛和台湾石斛显示出密切的遗传关系，这使我们更接近于解决它们的分类学身份问题。鉴定植物来源以及化学成分的一致性对于草药的质量控制至关重要，并且对加工材料进行验证很重要。这里提出的方法可应用于加工后的石斛属植物分析，并且是鉴定生药植物来源的一种有前途的工具。
