药用甘草一年生根下胚轴根茎比较形态学的研究

本文就药用甘草一年生根,下胚轴根茎的形态结构进行了比较研究。根园柱形,周皮黄棕色或暗棕色,有规则的纵沟纹及横生皮孔。平整切断面纤维性,浅黄色形成层环明显,射线放射状,中心淡黄色。根茎外形与根相似,自地上茎基部侧生出1—2条,表面具芽痕。根初生结构属于“四原型”,次生结构与一般双子叶植物根相同。其区别根增粗主要由于次生维管束,射线、轫皮射线,木射线增多,特别是射线,轫皮射线,木射线细胞显著增大的结果。根中心为射线,木射线伸入薄壁细胞所充满。我们首次发现根由下胚轴主根组成,根茎具有茎的结构特征。

A Study on the compative morphology for the annual root hypocotyl and rhiizome of medicinal licorice

In this paper a study on the compartive mor phology of the annula root and rhizome of medicinal licorice (Glycyrrhiza) has been conducted. The results show that the root shaped like a cyliuder is 40-60 cm. in length and 0.7-1.7 cm. in diameter. The pefiderm of the root is yellowish brown or dark brown. Both amphitropous lenticels aud regular wrinkly streaks on the periderm are visible. The level section of the root appears to be nemaline and yellowish white. The cambium ring in root cross section is obvious. rays extend radially and the root cen- ter is light yellowish. 1-2 rhizomes whose appedrance is similar to the root grow laterally from the base of thea boveground stem, and there are bud scars on the surface of the rhizome. The primary structure of the root of medicinal licorice is known as "Tetrarch" , and the secondary structure of the root is the same as that in the root of a Dicot. There are some significant characteris-tic differences from Dicots in the structure of root of medicinal licorice, i.e. the increae in root thickness is due to a numeral increase of the secondary vascular bundle, ray, phloem ray and xyloem ray? and especially due to the significant increase in volume of ray, phloem ray and xylem ray cells. when the root increases in thickness, the rayand xylem ray extend to the root center and the ceuter is fully occupied by parenchyma cells which orginate from those extended rays and xylem rays. In the study it is firstly observed that the root compost of hypocotyland main root rhizome belongs structurally to the stem.