Study On Taxonomy Of The Genus Schisandra Michaux

The methods of classical classification, integrating the study on seed morphology and leave epidemics morphology, along with phytomorphology, phytotomy, phytoembryology, palynology, phytocytotaxonomy, phytochemistry and molecular systcmatics, were used to revise and complete the former taxonomic system.On the basis of examination of more than 2000 specimens (including types) from 15 herbaria worldwide, the characters features of species,phonological phase,ecoloigical habit and the relation to close species were analyzed, recorded and described, the disputed species were compared, measured and counted in detail, the quantitative analysis to different characters was done through dot-map, the variation pattern of major morphology characters was analyzed and their significance for a better delimitation of the species was evaluated.The seeds of 10 species (96 samples) of the genus Schisandra Michaux were observed tinder light microscope and scanning election microscope. The results indicate" that: the macroslructural features of seed surface, including smooth type, rugulose type and tuberculate type, may suggest the evolutionary trend from smooth type to rugulose type, from rugulose type to tuberculate type; the microstructural features of outer epidermis can be divided into two types, viz. verrucate type and reticulate type. The former included S. grandiflora, S. chinensis, S. elongata, S. lancifolia, S pubescens, S. henryi, S. repanda, the latter included S. propinqua and .S. plena. Connected other characters, it was thought that the species which the reticulate type represents should be created coordinate classification with other species of the genus. Some differences between species were found, which can be used lor the identification to subdivision of the genus and supraspecific taxon, furthermore, their structural diversity provided taxonomic evidence and valuable information for phylogeny of the genus.Leaf epidermises of 7 species (30 samples) of. Schisandra were investigated under the light microscope. Both upper and lower epidermis cells are polygonal or irregular in shape in all species studied. The patterns of anticlinal walls are straight, arched or sinuous, and the raphal cuticular striastriae are occasionally observed on periclinal walls. Stomatal apparatus and secretory cells are found on the upper epidermis of several species and on the lower epidermis of all Species. The slomata apparatus mainly belong to the paracytic type and latercylic type; rarely anomocytic type occurs along with the paracytic one. Three types of cuticular thickening at the polar region of the guard cells are observed: slight cuticular thickening; rod-shaped culicular thickening and rarely T-shaped thickening.With data obtained from the former research and personal observation, the cladistic methods were employed for the phylogenetic analysis of data and trees were rooted byout-group comparison using, the related genus Kadsura. as result, a new system of the genusSchisamdra Michaux was reconstructed, and Schisandra Michaux was subdivided into 2 subgenus, 3 section, 2 series 10 species in this dissertation.