鹅掌楸油细胞发育过程中超微结构的变化与挥发油产生的关系

鹅掌楸Liriodendron chinense(Hemsl.)Sargent.]油细胞的发育过程可依据细胞壁的结构变化依次划分为3个阶段，即仅具初生纤维素壁层阶段、木栓质化壁层形成阶段和内纤维素壁层形成阶段。在发育早期，仅具初生纤维素壁层时，油细胞因其体积大，核仁显著，含极少淀粉粒和质体几乎无类囊体而与周围的组织细胞不同。对其3个发育阶段中内部结构变化分析表明，挥发油合成于细胞质和质体中。细胞质中，挥发油就以小滴形式产生，然后逐渐与油囊融合直接贮入油囊，与此同时，在各种细胞器中，质体的变化最为明显，质体中合成的锇物质，随质体解体进入细胞质中，再经转化通过杯形构造积累入油囊。油囊中积累的油经OsO4染色后呈灰色，且分为2层，外层较内层深，推测与油的2种来源有关。

The relationship between ultrastructure changes and produce of the oil during the oil cell development in Liriodendron chinense

The development of the oil cell in Liriodendron chinense(Hemsl.)Sargent.was distinguished into three stages according to the ultra structural changes of the cell wall.Stage 1,only the outer primary cellulose wall layer is present.Stage2,a suberin layer is formed.Stage3,the inner cellulose wall layer and cupule is formed,the oil drop attains its maximum volume,the cytoplasm becomes very dark and organelles can no longer be distinguished.During the early development,the oil cell is different from the neighboring cells in its large size,lower starch content,and its plastids,which contains only few thylakoids.The oil is produced in the cytoplasm and plastids.In the cytoplasm,the oil is occurred as small droplets or in small vacuoles then coalesced into the oil vacuoles.The biosynthesis of the oil also occurs in the plastids,then the oil moves into the cytoplasm with the disintegrating of plastids,subsequently into the oil vacuoles through the cupule.The oil drop stained with OsO 4 has two layers,the outer layer is darker in color than that of inner one.