慈姑匍匐茎的起源和球茎的膨大研究
A STUDY OF THE ORIGIN OF THE STOLON AND EXPANSION OF THE CORM OF SAGITTARIA SAGITTIFOLIA L.
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摘要: 匍匐茎的发生一般见于主茎倒二或倒三叶原基的叶腋部位。在匍匐茎发生区域的主茎一侧,匍匐茎原始细胞的基部形成壳状区;壳状区的形成对匍匐茎原基的外凸起一定作用。匍匐茎无居间分生组织;它的伸长依靠顶端分生组织细胞的横向分裂,使轴向细胞数目增多,并使细胞的轴向延伸。球茎的膨大是通过匍匐茎第8—10节基本分生组织的细胞有丝分裂,增加细胞数目,然后细胞体积的扩大来实现的。球茎中的淀粉一般为单粒淀粉;匍匐茎中的淀粉由单粒和复合两种淀粉粒组成。Abstract: The stolon arises at the second or third leaf axil from the apex. During development of a stolon, cell divisions occurred orderly alongthe basal and lateral limits of the incipient stolon primordium, forming a zone of parallel curving layers referred to as the shell zone. The stolon primordium appears to be associated with an active outward growth by the shell zone.The tunica of the stolon apex is uaually one layered. Thickening and elongation of stolon are manifested mainly by expansion and axil elongation of the cells.In the process of corm formation, figures of mitotic nuclear divisions appear in the cells of the ground tissue at several nodes of the stolon near its apex and cell expansion occurs afterwards. Simple starch grains are stored in the corm in general, but both simple and compound starch grains are formed in the stolon.