广藿香根的成熟结构及挥发油的分布研究

利用常规石蜡切片、半薄切片和组织化学等方法，对广藿香根的成熟结构和挥发油的分布做了系统研究，结果表明：广藿香根的成熟结构组成类似其它植物的根，但纤细的根中有发达的木质部，其他部分相对较弱。印证了广藿香纤细根来支撑相对庞大地上部分的原因；韧皮部以外部分所含挥发油滴极少，韧皮薄壁组织细胞中含许多小油滴，挥发油主要分布于木薄壁细胞中。因此，在评价和选育广藿香的优良品种时，可以把根内木质部的粗细作为一个评价指标。

The structure of Pogostemon cablin's root and distribution of essential oil in Root

With the help of tradition paraffin method, semi-thin sectioning and histochemical method, the structure of Pogostemon cablin＇s mature root and distribution of essential oil in root were systematically studied. Our observation revealed that the mature structure of Pogostemon cablin＇ root was similar to the other plant root, but the xylem of root was well developen in the slender root; the other part of root was relative feeble; and this verified the reason that the slender root sustained huge part on land. In the part out of phloem, there was very little essential oil, there were very much little essential oil drops in phloem cells, essential oil was mainly distributed in xylem parenchyma ceils. Therefore when we evaluate or select the improved variety of Pogostemon cablin, the thicness of xylem in root can be as an evaluating index.