【作者】 谢佩松；

【导师】 韦存虚；

【作者基本信息】 扬州大学 ， 细胞生物学， 2008， 硕士

【摘要】 通过光学显微镜和电子显微镜技术,系统观察了麦冬营养器官根、茎、叶的显微、亚显微和超微结构,比较分析了不同生境下麦冬叶片解剖结构、叶绿素含量及荧光动力学、叶片抗氧化酶活性等的差异,研究结果如下:1、麦冬须根和块根解剖结构都是由表皮、皮层和维管柱组成。表皮有3-5层表皮细胞,皮层的内皮层外侧有一层石细胞,木质部一般为16-23原型。须根和块根的主要区别是中皮层细胞形态和大小发生变化,块根膨大主要由中皮层细胞体积增大造成。麦冬皂苷主要分布在须根和块根的皮层细胞中。2、麦冬普通茎、根状茎和花梗茎由外向内依次由表皮、基本组织和维管束构成,表皮1-2层,维管束散生,韧皮纤维发达。3、麦冬叶片由表皮、叶肉和叶脉构成。表皮有丰富的角质层和蜡质层;气孔器无副卫细胞,以带状分布于下表皮,周围的表皮细胞壁局部外突导致气孔相对下陷。叶肉由栅栏组织、海绵组织和通气组织组成,通气组织非常发达。叶脉5条,韧皮纤维很发达。4、次生代谢物草酸钙晶体在麦冬根、茎、叶中都存在,以针状成簇分布在晶体异细胞或薄壁细胞胞间隙中。5、麦冬阳生叶片叶肉细胞较小,排列紧密,叶绿体分布于远离叶片上表面一侧;阴生叶片叶肉细胞较大,排列疏松,叶绿体分布均匀。阳生叶片叶绿体类囊体和基粒没有阴生叶片叶绿体的类囊体和基粒排列紧密和规则,阳生叶片叶绿体内脂体小球数量比阴生叶片多。6、麦冬阴生叶片叶绿素a、叶绿素b、总叶绿素含量比阳生叶片高,叶绿素a/b比值比阳生叶片低。阴生叶片叶绿素荧光动力学参数Fv′/Fm′、ΦPSⅡ、qP的值高于阳生叶片,而qNP值低于阳生叶片;阴生叶片Fv/Fm、Fv/Fo、ΦPSⅡ仅在冬季较低,而阳生叶片Fv/Fm、Fv/Fo、ΦPSⅡ在夏季和冬季都较低。7、麦冬阴生叶片POD、CAT活性高于阳生叶片,而SOD活性在阴生叶片与阳生叶片中无显著差异。POD活性全年变化差异不大,而SOD和CAT活性在初生叶片中活性较低,秋冬季维持在较高水平。更多还原

【Abstract】 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.更多还原