Anatomical Studies On Stems And Leavesi Of 14 Species Of Taxodiaceae And Cupressaceae

Applying multidisciplinary theory such as plant anatomy, plant morphology, plantphysiology, plant ecology etc, this research have studied on anatomical structure of apart of their stem and leaves in Cryptomeria fortunei Hooibrenk ex Otto etDietr, Glyptostrobus pensilis(Staunt.) Koch, Taxodium distichum (Linn.) Rich, Metasequoiaglyptostroboides Hu et Cheng, Cunninghamia lanceolata (Lamb.) Hook, Taxodiumascendens Brongn, Taiwania cryptomerioides Hayata, Taiwania flousiana Gaussen,Platycladus orientalis (Linn.) Franco,Calocedrus macrolepis Kurz,Juniperus formosanaHayata,Fokienia hodginsii (Dunn.) Henry et Thomas, Chamaecyparis obtusa (Sieb.etZucc.) Endl, Chamaecyparis obtuse (Sieb.et Zucc.) Endl.cv. 'Tetragon', which canprovide specific basis for phylogenetic classification and phylogenetic development ofCycadaceae, and it was vital significant to reveal the unity between structure and theirbiotope. The results show as follows:The structures of stems and leaves are obviously different between Taxodiaceae andCupressaceae. There are many differences of structures of stems and leaves amongdifferent genus in Taxodiaceae. They share many similar structures in Cupressaceae,especially in stem. Meanwhile, they also have some subtle distinctions in structure inCupressaceae.Writer made observations on the anatomy of structure of stems of 14 species inTaxodiaceae and Cupressaceae, including the characters of cortex, xylem, phloem andpith and so on. Based on the comparitions of the strctures of stem, the writer furtherdiscusses the relationship among those 14 species.The structures of the leaves are found in the structure of the rachises all of the 14species of in Taxodiaceae and Cupressaceae, which is an advent appearance that cycadsadapt to the environment. The fiber tracheid is found in the phloem of the stems in all of 14 species in Taxodiaceae and Cupressaceae. Most of the 14 species have resin duct intheir stems and leaves, and the resin duct only exists in Gymnosperms.By means of the observation in the optical and electronic microscope, the vessels arediscovered in all the 13 species plants which studied in this research. Thetypes of vesselare annular vessel, spiral vessel, scalariform vessel, and reticulate vessel and pittedvessel. The characteristics of the vesselsh in different family, genus or species aredifferent. The advanced vessel is observed in Gymnosperm, while they remain obviouslyprimitive. It is significance that the appearances of vessels enhanced the power, speedand efficiencies of physiological-biochemical metabolism to promote the growth andreproduction, and the stress resistance such as drought, thermal rigidity, pest and pooroil.