白三叶营养体的形态结构

Morphology and anatomy of the vegetative plant on white clover(Trifolium repens L.)

用普通石蜡切片 ,显微镜观察 ,照相 ,观察白三叶营养体结构形态 ,扫描电镜观察叶结构。结果表明 ,一株成熟的白三叶植物 ,是由一系列不同年龄、不同发育阶段的匍匐茎组成的。一年生、二年生和三年生的匍匐茎在木质部导管的行数上明显不同。叶子为完全叶 ,属于小型叶 ,表面不具有 V型标志。叶是一个典型的异面叶 ,具栅栏组织和海绵组织。成熟的叶两面都有气孔 ,其数量叶下表面明显高于上表面 ,上表面小且凹隐。在下表面气孔完全暴露 ,多数是开放的 ,而上表面的气孔多数是关闭的。上表面蜡质成网状 ,而下表面形成蜡板或蜡片。叶柄含有 5个维管束 ,其中中间 3个较大 。

A mature plant consists of development stages and defferent ages of stolon.It's leaf was small leaf type and not V marked.The relative number of rows of tracheary elements in the various vascular bundles,the actural numbers vary with stolon ages.The anatomy of the leaf is that of typical bifacial leaf.The palisade is from one to two layers thick,the spongy mesophyll usually cosists of four layers of cell.Adult leaf have stomata on bith surfaces ,those on the lower surface being more numer ous and bigger than those on the upper surface,the guard cell of upper epidermis is smaller and slightly sunken,the stomata on upper epidermis are often ,completely sealed over,but often completely opened on lower epidermis.Wax on the lower epidermis surface is in the form of platelets or spiculrs where as that on the upper surface appears net-like.Petiole contains five vascular bundles,three of which are larger than the others.$$$$