A Pharmacophylogenetic Study Of Atractylodes DC.

Atractylodes DC., an important group of medicinal plants, whose rootstocks can be used as medicines, with the exception of A. carlinoides on account of small rootstocks. Atractylodes DC., a small genus of Asteraceae only distributing in East Asia, can be widely found in China. Due to large amount of varieties and transitional types of Atractylodes DC., for a long time scholars have quite different ideas of its classification. For that reason, under the guidance of pharmacophylogenetics, the author made an investigation on resources of medicinal plants of Atractylodes DC. in five provinces. The methods of morphology, anatomy,numerical taxonomy, molecular biology, and chemotaxonomy and method so forth were applied in this thesis. We got following results:1. Firstly, the history of taxonomy of the genus was briefly summarized, the traditional uses,chemical constituents and bioactivities of plants in Atractylodes DC. were reviewed.2. On the basis of field survey, identification of original plant and herbarium specimens, the variation pattern of all the major-morphology characters in the genus of Atractylodes DC. in China was analyzed, and their taxonomic significance was evaluated. We found that in Dabie Mountain area there was a series of transitional forms between A. lancea and A. lancea subsp. luotianensis. A. coreana and A. chinensis var. liaotungensis look the same in external morphology, except slightly different in leave shape. There were remarkable differences in the feature of the rootstocks and florescence from the other plants of Atractylodes DC., so it was not so difficult to distinct A. macrocephala from the other species of the genus. A. carlinoides could be easily distingushed from other species of the genus by the remarkable differences in the feature of the rootstocks and leaves.3. Micro-morphological characters of roots and leaves were examined by LM. The results indicated that the characters of primary xylem and pith of the rootstocks, vascular tissue and collenchyma of midrib in the leaves, palisade ratio, stomatal number and stomatal index of lower epidermis could be taken as the evidence to classify the species of Atractylodes DC.4. We made a numerical taxonomy to the plants of Atractylodes DC. according to their 30 characters. The clustering results suggested that all 8 species were clustered into two sections, using Nearest neighbor based on the Euclidean distances. The cluster one was only A. carlinoides. The second cluster includes the other 7 species. Among the second cluster, there were several pairs of closely related plants, such as A. lancea and A. lancea subsp. luotianensis, A. coreana and A. chinensis var. liaotungensis, A. japonica and A. macrocephala. This result was relatively consistent with foreseen results of morphology and microscope identification. However, compared with A. lancea, the relationship between A. chinensis and A. coreana was relatively more closer, which is relatively different from morphological identification. In the Principal components analysis, the cumulative contribution rates rose fast and that of the first four Principal components came up to 89.75%. The feature of the rootstocks and leaves, the type of vascular tissue in the leaves, stomatal index of lower epidermis were the first and second Principal components.5. The phylogenetis relationships of the genus Atractylodes DC. were analyzed using the nuclear ribosomal ITS and three chloroplast fragments, including atpB-rbcL, psbB-psbF and trnL-trnF intergenic spacer (IGS) sequences. The results were generally consistent with ones from the morphological and numerical taxonomy. Phylogenetic analyses revealed that A. lancea subsp. luotianensis and A. lancea, A. chinensis var. liaotungensis and A. coreana form monophyletic terminal clade, respectively. The trees, within each the pairwise genetic distances, did not support Hu's classification. The authers suggested that A. lancea Subsp. luotianensis should be included in A. lancea rather than be treated as a separate subspecies. A. carlinoides was placed in the basal position of Atractylodes, which had a distant relationship with the others of the genus. The results lead us to suggest that A. chinensis var. liaotungensis be put into A. coreana, A. chinensis as a subspecies of A. lancea.6. The constituents of volatile oil of Atractylodes DC. were undertaken by GC/MS combination technology. The results were generally consistent with ones from the morphological and numerical taxonomy.7. According to the comprehensive studied by the examination on 1000 herbarium specimens, field observations, gross-morphology, anatomy, numerical taxonomy, molecular systematics, and volatile oil, the taxonomic revision of Atractylodes DC. has been made. The author suggested that the genus of Atractylodes DC. should be separated to five species and one variety, namely A. lancea, A. lancea var. chinensis, A. corean, A. japonica, A. macrocephala and A. carlinoides. In addition to this, we also compiled a Key to the species of genus. 8. In addition, based on gross-morphologic, anatomic, molecular systematic, chemical and pharmaceutical information, the pharmacophylogenetics of Atractylodes DC. was investigated. According to our present research and the literature record for the chemical and pharmacological research of genus, we proposed that A. lancea and A. chinensis, A. macrocephala and A. japonica, respectively, have a close relationship because of their similarity in chemical constituents and medical use. A. carlinoides was an independent branch of the genus, because of its remarkable differences of morphology, anatomy, molecular systematics, chemical constituents.