【摘要】 应用植物解剖学方法研究了木立芦荟(AloearborescensMill.)茎的发育过程。研究结果表明,木立芦荟茎的发育包括原分生组织、初生分生组织、初生结构和次生生长4个发育阶段。原分生组织具有典型分生组织的细胞特征;初生分生组织包括原表皮、基本分生组织和原形成层束。初生结构由表皮、薄壁组织和维管束组成。初生维管束为外韧有限维管束,分散于薄壁组织内。次生加厚分生组织起源于正常的散生维管束中柱外侧的薄壁组织细胞。次生加厚分生组织切向分裂,向外侧产生的细胞分化成薄壁组织;向内产生的细胞,一部分细胞分化成为薄壁组织细胞,称为结合组织,另一部分细胞则分化成为次生周木维管束,分散于结合组织中。由表皮之内的一层薄壁组织细胞恢复细胞分裂能力,进行切向分裂,以后形成周皮。木立芦荟茎初生结构阶段的增粗主要是基本分生组织和薄壁组织细胞的分裂和体积增大的结果。在老茎中,茎的增粗主要是由次生加厚分生组织进行细胞分裂及其衍生细胞体积增大的结果。更多还原

【Abstract】 The developmental and the anatomical structures of stem of Aloe arborescens Mill.were examined with anatomical methods.The results showed that the development of the stem underwent four stages,they were promeristem,primary meristem,primary structure and secondary growth stage.Promeristem possessed the typical cell characteristics of meristem.The primary meristem consisted of protodern,ground meristem and procambial bundles,while the primary structure consisted of epidermis,parenchyma and primary vascular bundles.The primary vascular bundles,that scattered in the parenchyma,contained xylem in the inside facing the center of the stem and phloem on the outside.The secondary thickening meristem originated from the parenchyma cells,which were located the outside of the atactostele.The secondary thickening meristem divided in tangent.The new cells on the outside of the secondary thickening meristem developed into parenchyma,and the cells in the inside developed into parenchyma and amphivasal vascular bundles.The parenchymatous cells underneath the epidermis recovered the ability of mitosis and produced the perideum.In the primary structure stage,the increase of stem in diameter mainly depended on the division of parenchyma and the volume increase of the new cells,whereas in the mature stem,the increase of stem in diameter mainly depended on the division of the secondary thickening meristem and the volume increase of the new cells.更多还原