植物学课件2011植物器官的结构与生长发育.pptxVIP

Chapter Four Structures and development of Organs of Plants;Leaves Stem;第一节：种子的萌发及幼苗的形成 （自学） 1、种子萌发的条件 2、种子萌发的一般过程 3、幼苗的类型;Section 2 Morphology, structure and development of roots第二节 根的形态、结构及生长发育;Embryo root;The adventitious roots may have similar structures and functions with normal roots (定根）.;;2. Structure and development of Root根的结构和生长发育;The root cap protects the growing parts of a root as the root grows through the soil 根冠保护根的生长区域在土壤里向前运动。;In most dicots, cells of rhizodermis have a common origin with the rootcap cells as shown in Figs. A, B C). while in most monocots all cells of the root have indepen - dent origin from the rootcap, as shown in Figs. D, E F. 在大多数双子叶植物中，根表皮细胞与根冠细胞 有共同的起源，而在单 子叶植物中，所有根冠 的细胞都独立地起源于 根冠。;Dermatocalyptrogen表皮根冠原;calyptrogen根冠原;Quiescent center不活动中心;cell maturation;Root hair zone 根毛区;皮层;A complete transverse section of Ranunculus sp. root at a level showing the completion of primary growth. Note the lack of pith, accumulation of starch in cortical cells, and the absence of starch in the rhizodermis and exodermis.;A. Root epidermis and characters 根的表皮及其特征;B. Root cortex and characters 根的皮层及其特征;The Casparian strip (凯氏带）and Casparian dots （凯氏点） in the endodermis （内皮层）;凯氏带;Cotton root shows Casparian strip （凯氏带）;C. central cylinder （中柱）;Pericycle中柱鞘;Casparian strip (凯氏带） of the endodermal cells on radial wal (径向壁）;Monocots （单子叶植物） A cross section through a mature monocot root;primary xylem初生木质部;primary xylem初生木质部;Details of mature corn root structure. Rhizodermis (根被）is replaced by exodermis （外皮层）. exodermis 外皮层细胞壁加厚 Endodermis （内皮层） walls are lignified suberized （木化和栓化）;单子叶植物内皮层细胞 五面加厚， 有了通道细胞 （passage cell）;Two schemathe arrangement of the Casparian strip in the endodermis cell walls 凯氏带的结构;2.3 The secondary growth secondary structure of root in Dicots 双子叶植物根的次生生长与次生结构;Forming process of vascular cambium （1）维管形成层的形成过程（1）;Forming process of vascular cambium （2）维管形成层的形成过程（2）;Forming process of vascular cambium （3）维管形成层的形成过程（3）;Formi