药用甘草实生苗发育结构的比较形态学研究

A Study of Comparative Morphology on Growing Structure of Medical Glycyrrhiza Seedling

药用甘草的根属肉质直根,由下胚轴、主根、侧根发育而成。下胚轴横切面初生维管束四束,髓射线较宽,束间形成层不明显,次生生长后维管束环状排列,维管射线不明显。主根初生生长四原型结构,次生生长与一般双子叶植物很相似。三个不同甘草种组织分化速度稍有变化,但其形成过程没有本质上的差异。

The root of the medical Glycyrrhiza is fleshy tap root, which is composed of the hypocotyl, the main root and the lateral root. There are four primary bundles cross section of the hypocotyl, the pith rays are wide,the interfas-cicular cambium is not apparent. After secondary growth, the bundles appear ringlike arrangement, the vascular rays are not obvious. The xylem is tetrarch in the primary structure of the main root, the secondary growth is similar to that of the common dicotyledon plant root. The tissue differentiation speeds of the three specieses of Glycyrrhiza are different, but there are not essential differences in their forming processes.