桔梗根的发育解剖学研究  

Developmental and Anatomical Studies on the Root of Platycodon grandiflorum A.DC

作　　者：谭玲玲[1] 胡正海[2] 

机构地区：[1]青岛农业大学生命科学学院/山东省高校植物生物技术重点实验室,山东青岛266109 [2]西北大学生命科学学院,西安710069

出　　处：《西北植物学报》2014年第5期938-942,共5页Acta Botanica Boreali-Occidentalia Sinica

基　　金：山东省高等学校科技计划(J11LC06);山东省自然科学基金(ZR2013CQ027);青岛农业大学高层次人才启动基金(630909)

摘　　要：以桔梗(Platycodon grandiflorum A.DC)根为材料,运用石蜡切片和半薄切片法对其根的发育过程及结构进行解剖学观察,并对不同年限根的结构进行了比较。结果表明:桔梗根的结构发育过程包括原生分生组织、初生分生组织、初生生长和次生生长4个阶段。其原生分生组织由3群原始细胞组成,表现出典型分生组织的细胞学特征;初生分生组织包括根冠原、表皮原、皮层原和中柱原;初生结构由表皮、皮层和中柱组成,其中皮层薄壁细胞占主要地位,初生木质部为二原型;次生生长主要依靠维管形成层和木栓形成层的活动来完成,其次生结构从外到内由周皮和次生维管组织组成,次生维管组织占主导地位,其中以薄壁细胞为主,维管分子少量,分散在薄壁组织中。不同年限的根的结构基本相同,但它们在主根长度和直径、周皮厚度、木质部与韧皮部面积之比等方面存在差异。The development and the structures of the annual and the perennial tap roots of Platycodon grandiflorum were studied with the paraffin section and the semi-thin section.The results showed that the development of P.grandiflorum root could be divided into four stages：promeristem,primary meristem,primary growth and secondary growth.The promeristem consists of three groups of initial cells;the primary meristem is composed of calyptrogens,primordial epidermis,periblem and plerome.The primary structure includes epidermis,cortex and stele.Parenchyma cells in cortex are dominant.The primary xylem is diarch.The secondary growth depends on activities of the vascular cambium and the cork cambium.The secondary structure includes periderm and secondary vascular tissue from the outside to the inside.Parenchyma cells are prominent in the secondary vascular tissue,and only small amount of vascular elements are scattered in them.The perennial roots have the similar structure to the annual one,but there are some differences in the length and the diameter of the tap root,the thickness of periderm and the area ratio between the xylem and the phloem.

关 键 词：桔梗 根 发育解剖 

分 类 号：Q944.54[生物学—植物学]