Studies On Morphological Anatomic Structure Of Vegetative Organs And Habitat Flexibility Of Ophiopogon Japonicus

Microstructures, submicroscopic structures and ultrastructures of root, stem and leaf of Ophiopogon japonicus (L. f.) Ker-Gawl were observed with light microscope, scanning electron microscope and transmission electron microscope. The anatomic structure, chlorophyll content, chlorophyll fluorescence kinetics parameters, and antioxidant enzymes of leaves in different habitats were compared. The main results were as follows:1. The root of Ophiopogon japonicus could be divided into two types: fibrous and tuberous roots, which were all composed of the epidermis, cortex and vascular bundle. Epidermis had 3-5 layer cells. There was 1 layer stone cell outside endodermis. The numbers of the xylem were variable from 16 to 23. The mainly differences were the shape and the size of cortex cells between tuberous and fibrous roots. The middle cortex cells expansion made the fibrous root inflate. Saponin was mainly located in cortex cell of fibrous and tuberous roots.2. The stem of Ophiopogon japonicus could be divided into three types: ordinary stem, rhizome stem and pedicel stem, which were all composed of epidermis, ground tissue and vascular bundle. Epidermis had 1-2 layers. Vascular bundles with well-developed phloem fiber were spread in ground tissue.3. The leaf of Ophiopogon japonicus was composed of epidermis, mesophyll and vein. Epidermis was covered with heavy cutin and wax. The stomatal apparatus without subsidiary cell were exclusively located on the lower epidermis between veins by the pattern of stomatal band. Outer protrusion occurred on the periclinal wall of epidermis cells of stomatal band, which resulted in relatively sunken stomata. The mesophyll was composed of palisade tissue, spongy tissue and ventilating tissue. 5 veins and well-developed phloem fiber were observed in leaf.4. Oxalate crystals were found in root, stem and leaf. These crystals were distributed in crystal idioblasts or in intercellular spaces of parenchymatous cells as needle clusters.5. The full sunshine leaf showed that the mesophyll cells were small and in good order, the spaces among cells were smaller. The chloroplasts were unevenly distributed in mesophyll cells. The shade leaf showed that large mesophyll cells arranged loosely. The chloroplasts were evenly distributed in mesophyll cells. The chloroplast thylakoids of shade leaf were arranged more compactly than that of full sunshine leaf. The full sunshine leaf had more plastoglobuli than shade leaf.6. The contents of chlorophyll a, chlorophyll b and total chlorophyll of shade leaf were higher than that of the full sunshine leaf, but the ratio of chlorophyll a/b of shade leaf was lower than that of the full sunshine leaf. The Fv′/Fm′,ΦPSⅡ,qP of shade leaf were higher than that of the full sunshine leaf, but the qNP of shade leaf was lower than that of the full sunshine leaf. The Fv/Fm,Fv/Fo,ΦPSⅡof shade leaf decreased only in winter, but the Fv/Fm,Fv/Fo,ΦPSⅡof full sunshine leaf decreased in summer and winter.7. The activities of POD and CAT of shade leaf were higher than that of full sunshine leaf, however, the activity of SOD had no difference between shade leaf and full sunshine leaf. The activity of POD had no difference in year. The activities of SOD and CAT were lower in young fresh leaf, but higher in mature leaf during fall and winter.