木立芦荟叶内维管束发育过程的研究

Development of Vascular Bundles in Aloe arborescens Leaves

采用半薄切片和组织化学方法研究了木立芦荟(Aloearborescens)叶内维管束的发育过程,并着重于维管束鞘细胞和芦荟素细胞的来源及组织类型.结果表明:维管束由原形成层发育而来,但在分化原生韧皮部筛管时,其外侧仍保留一层原形成层细胞,以后分裂、增大成为特殊的大型薄壁细胞(芦荟素细胞),芦荟素细胞应属于韧皮部的一部分.而维管束鞘细胞则来源于基本分生组织,属于基本组织的范畴,与维管束不同源.

Semi-thin sectioning and the method c.ommonly referred in histochemistry were used to study the development of vascular bundles in Aloe arborescens leaves with emphasis on the origins and tissue types of vascular bundle sheath cells and aloin-containing cells. The results indicated that the vascular bundles developed from the procambium but while the procambium differentiated sieve tubes of protophloem it still kept a layer of procambium cells at the outer part, which later divided and enlarged to form large-size parenchyma （aloin-containing cells）, part of phloem. The vascular bundle ceils stemmed from ground meristem, belonging to ground tissue and differing from vascular bundle sheaths in origin.