目的揭示广藿香茎和叶中挥发油的合成场所、转运方式和储存部位。方法超薄切片法、组织化学法。结果在广藿香茎内的薄壁细胞中,质体和线粒体内观察到电子致密度高的嗜锇物质,另外,在细胞质中观察到有一些灰色小泡,在小泡的外膜上附着一些小的、电子致密高的嗜锇滴;在液泡膜外侧,聚集着大量的附着嗜锇滴的灰泡。在叶中,情况有所不同。由于栅栏组织细胞排列紧密,体积较小,且细胞内密集大量的叶绿体,因此栅栏组织细胞内无大液泡,质体、线粒体和小液泡相邻分布,而前两者内分布有电子致密度高的嗜锇物质。结论在广藿香茎内,质体是挥发油的主要合成场所,合成的挥发油主要通过灰色小泡转运到液泡内储存。在叶中,叶绿体不仅行使光合作用功能,而且还是挥发油的主要合成场所,合成的挥发油以渗透的方式进入小液泡内储存起来。

Objective To study the synthesizing site,transporting mode,and storing position of essential oil in Pogostemon cablin stems and leaves.Methods Ultrathin slicing and histochemical methods were used.Results In parenchyma cells in the stem of P.cablin,dark osmiophilic material was observed in plastids and mitochondria,otherwise,some small gray vesicles were also found in cytoplasm.Some dark osmiophilic droplets were found to adhere to outer membrane of small gray vesicles,and many small gray vesicles with osmiophilic droplets gathered in outer membrane of large vacuole.In leaves,it was different case.Because palisade tissue cells were arranged closely,which had smaller volume and rich chloroplasts,so there was not large vacuole in palisade tissue cells.Plastids,mitochondria,and small vacuole were distributed in high density,but the first two organelles contained more dark osmilphilic substance than latter.Conclusion The plastid is the main synthesis site of essential oil,and the essential oil was mainly transferred by small gray vesicles into large vacuole to store in the stem.In leaves,chloroplast not only has photosynthesis,but also is the main synthesis site of essential oil,and essential oil is permeated into small vacuole to store.

广东省中医药管理局基金项目(F01032)；广东省科技攻关项目(2002C20147)