玉吊钟多细胞根毛的发育及其超微结构研究

玉吊钟气生不定根根尖区域的部分表皮细胞经分裂可形成多细胞根毛。根毛长０．０３ｍｍ左右，具单列细胞、双列细胞和叉状分枝类型，由基细胞和毛体细胞二部分组成。电镜显示，基细胞内部结构与表皮细胞相似。组成毛体的细胞都有分泌功能。在分泌活动期，细胞内形成大量内质网，并膨大成囊泡状或溢出囊泡，分泌停止，内质网即消失；其细胞结构的变化及主要由内质网参与分泌活动与蜜腺细胞在分泌活动中的结构变化类似。故推测多细胞根

A STUDY ON THE DEVELOPMENT AND ULTRASTRUCTURE OF MULTICELLULAR ROOT HAIR OF KALANCHOE FEDTSCHENKOI

Development of multicellular root hairs may occur from a part of epidermal cells of the tip ofaerial adventitious roots of Kalanchoe fedtschankoi through cell division. Length of root hairranges about 0.03 mm and is morphologically divided into three kinds,namely:the uniseriate,biseriate and dichotomously forked. Each hair is constituted by a basal cell and a trichome part. Electron microscopy shows that the internal cell structure of basal cell is the same as that ofthe epidermal cell,while all the trichome cells possess secretory function. At the stage of activesecretion, a great number of endoplasmic reticulum are formed in the cell which enlarge as vesi-cles or vesicles being exudated. Endoplasmic reticulum disappears as the secretion is at an end. By the fact that change of internal cell structure and with endoplasmic reticulum takes the mainpart in the secretory activity of the trichome cell is similar to the cell of nectary gland at its secret-ing stages, it can be assumed,therefore, that secretion is the main function of the multicellularroot hair.