【作者】 郭敏；

【导师】 强科斌； 龙瑞军；

【作者基本信息】 甘肃农业大学 ， 草业科学， 2006， 硕士

【摘要】 利用光学显微镜和电子显微镜研究了黑褐苔草(Carex atrofusca)、圆囊苔草(Carex orbicularis)、华扁穗草( Blysmus sinocompressus)叶的发育形态解剖结构和发育过程中的细胞程序性死亡现象,得出以下结论:1.在横切面上,黑褐苔草、圆囊苔草和华扁穗草叶片的解剖结构均包括表皮、叶肉、叶脉和通气结构四部分。黑褐苔草和圆囊苔草叶均呈“V”字形,华扁穗草叶呈“新月”形。2. 3种植物叶上下表皮细胞垂周壁均呈不同程度波浪状增厚。上表皮细胞均大于下表皮细胞。正对主脉的上表皮凹陷处均有泡状细胞。气孔器均为平列型。黑褐苔草叶下表皮和圆囊苔草上下表皮有硅化乳突,且圆囊苔草上下表皮细胞硅化乳突倾斜方向一致,而华扁穗草叶上下表皮均无硅化乳突。圆囊苔草叶片上下表皮均有气孔器分布,而其余两种气孔器仅分布于下表皮。3.叶肉均无栅栏组织与海绵组织的分化,叶肉细胞中均有异化细胞存在。维管束鞘两层,外层为较大的薄壁细胞,内层为较小的厚壁细胞,胞壁呈“U”形增厚。机械组织成片分布于大多数维管束上下方。成熟叶片相邻叶脉间均有气腔形成发达的通气结构,气腔面积分别约占总叶片面积的30%～40%、50%和60%。4.三种莎草科植物叶片的发育过程中,异化细胞经历分化、发育、解体三个阶段,最终形成通气结构。在此过程中,异细胞的叶绿体、线粒体、细胞核以及内膜系统均发生一系列形态结构上的变化,最终解体消失形成气腔。5.异化细胞从分化、发育到解体最终形成气腔,整个过程中异细胞和气腔周围的细胞没有炎症发生、染色质的凝缩、细胞内含物的趋边效应以及细胞壁保留到异细胞解体之后,这些特征都证明了此过程就是细胞程序性死亡。6.在黑褐苔草叶鞘中部的横切面上,从第1~4片叶子间,气腔总面积从1.16×104μm2增加到16.27×104μm2,所占的比例从10.2%增加到18.8%,气腔的数量从4变为20,均呈增长趋势,在第5～6片叶子中气腔的面积、所占比例呈稳定趋势,随后的叶片气腔面积和所占比例又不断增大,而从第5片叶子开始,其气腔数基本呈稳定趋势。更多还原

【Abstract】 This paper studied on the developmental and morphological anatomy structure and the programmed cell death of leaves of Carex atrofusca, Carex orbicularis and Blysmus sinocompressus by using light and electron microscope. The results as follows:1. In the transverse section, the morphological anatomy structure of leaves of Carex atrofusca, Carex orbicularis and Blysmus sinocompressus was evidently composed of epidermis, veins, mesophyll tissue and ventilating structure. The blades of Carex atrofusca and Carex orbicularis were V-shaped and that of Blysmus sinocompressus was crescentiform.2. The cells walls of both epidermal cells of three plants showed sinuate. The sizes of upper epidermal cells were bigger than that of lower epidermis. The bulliform cells were situated in groove of upper epidermis facing the main vein. The stomatal apparatuses were all hemiparacytic types. There were siliceous papillae on the all above lower epidermal cells of Carex atrofusca and Carex orbicularis, which was leaning toward the same direction in the Carex orbicularis, while both epidermal cells of Blysmus sinocompressus had no one. The stomatal apparatuses of Carex orbicularis were distributed on both epidermal cells, while to Blysmus sinocompressus and Carex atrofusca,which were only on the lower epidermal cells.3. The mesophyll cells of Carex atrofusca , Carex orbicularis , and Blysmus sinocompressus had no differentiations between palisade tissue and spongy tissue. The mesophyll cells contained idoblast. The vascular bundle sheath consisted of two layers of cells: the outer layer was bigger parenchyma cells, and the inner layer was composed of minor sclerenchyma cells. The model of the cell wall was U- shaped incrassation in the transverse section. The mechanical tissue was flakily situated in the upside and downside of mostly vascular bundles. There was an air-cavity among the neighboring vascular bundles forming well developed ventilating structure in the mature leaf. The area of air-cavity occupied 30%~40%, 50% and 60% of the area of the whole leaf respectively.4. The idioblast went through three processes including differentiation, development and更多还原