合意非洲铁羽片表皮及气孔器的发育研究

用光学显微镜和扫描电镜对合意非洲铁羽片表皮及气孔器的发育过程进行观察研究。结果显示,(1)在羽片发育过程中表皮细胞变化不明显,主要是细胞伸长和壁增厚的过程;表皮的角质层连续出现。(2)气孔器发育可大致分3个阶段:保卫细胞母细胞阶段、幼保卫细胞阶段和成熟保卫细胞阶段;气孔器发育方式为单唇型或周源型;成熟气孔器属单环型。(3)在羽片发育过程中,气孔密度起初很低,后急剧升高并达到峰值,之后逐渐下降并趋于稳定。(4)有早熟气孔器。(5)羽片表皮发育成熟的方式是由基部向顶部逐步推进。

Ontogeny of Pinnal Epidermis and Stomatal Apparatus in Encephalartos gratus Prain

The ontogeny of pinna epidermis and stomatal apparatus in Encephalartos gratus Prain have been observed with LM and SEM.The results are as follows:(1)The epidermal cells change mainly in cell elongation and cell wall-thickening during the development of pinna.The epidermal cuticula occur continuously.(2)The development of stomatal apparatus can be divided into three stages:guard mother cell,young guard cell and adult guard cell;Stomata1 apparatus are haplocheilic or perigenous in origin,and the mature stomatas are monocyclic type.(3)During the development of pinna,the stomatal density is very low at first,then raises rapidly to the peak value,and finally drops gradually to the fixed one.(4)A few of stomata develop into mature earlier than others.(5) The pinnal epidermis mature from the base to the top.