摘要
对鄂尔多斯半日花不同居群间营养器官进行解剖学比较和分析,发现它们都具明显的旱生植物特征。但是由于其生境不同,叶表现为宽叶与细叶两种类型生长于沟边坡下较湿润环境的植株的叶较宽,一般不反卷,称其为宽叶型;生长于干燥阳坡上较干旱环境的植株的叶较窄,常反卷为针形,称其为细叶型。宽叶型的叶比细叶型的叶宽、长、厚,但角质层比细叶型薄,表皮毛比细叶型少,外切向壁不加厚,叶肉有栅栏组织和海绵组织的区别,上表皮气孔不下陷,由大型薄壁细胞形成维管束鞘。细叶型的叶上表皮气孔强烈下陷,叶肉无栅栏组织和海绵组织的区别,由木质化或栓质化细胞形成维管束鞘。同时,将鄂尔多斯半日花与其他几种旱生、中生植物叶的解剖特征进行了比较,其解剖学特征基本同其他几种旱生植物。
We found in anatomical study that the vegetative organs of different Helianthemum ordosicum populations all have obvious xerophyte structure. The primary root is tetra-pentarchy, and the pericycle is not distinct. There are multiple vascular bundles in the primary stem, the epidermis is mulched by epidermal hair or made up of slime cells. The fascicular cambium is also not distinct. There are a circuit of big slime cells and twain layers of flat cells at the deep of cortex and they are made up of cork cambium. The xylem rays are strait. Plant has two leaf types: broad-leaf type and thin-leaf type; the former grows in comparatively moist habitat, but the later in arid habitat. The leaves of broad-leaf type are broader, longer and thicker than that of thin-leaf type, but the horny layer is thinner. Besides, the broad-leaf type s epidermal hair is fewer, the outer tangential wall is not thickened; the palisade tissue is distinguished from spongy tissue in the diachyma, the stomas of the upper epidermis are not settled, the vascular bundle sheath consists of large parenchymatous cells. Whereas, the stomas of the upper epidermis of the thin-leave type settle strongly, there are no dividing between palisade tissue and spongy tissue in the diachyma, the vascular bundle sheath consists of lignification and suberin cells. At the same time, we also have made a comparison between Helianthemum ordosicum and other xerophytes or mesophytes on the anatomic characters of leaves.
出处
《中国沙漠》
CSCD
北大核心
2005年第3期437-441,共5页
Journal of Desert Research
基金
国家自然科学基金项目(39560007
39760008)资助
