植物器官內可擴散性物質之放射能顯像技術之嘗試

An Attempt on the Autoradiography of Diffusible Substances in Plant Organs

一項可擴散性物質之放射顯像，聯合植物全器官放射能顯像技術於本試驗中逐步達成。觀賞用柑桔（種名不祥）及椪柑（Citrus poonensis）幼菓以及仙人掌（Echinopsis sp.）小球，分別經14C，45Ca及88Rb等核種處理後，試材歷經急速冷凍，凍結切片，Saran wrap黏著，轉貼著於載玻片，昇華脫水，以及事後之乾裝裱等程序。其中運用Saran wrap之黏著，已避免運用膠帶（Scotch tape）黏著切片之缺點，而乾裝裱方法之設想，為避免水溶性物質滲失之重要步驟之一。所獲放射能顯像結果，其像斑分別展示於觀賞柑桔之幼菓之維管束（14C），椪柑果皮之澱粉粒（45Ca, 80Rb），以及仙人掌小球之維管束（14C）。其解像力，雖因切片厚達48μm，但因所採用包捲法促乳膠膜與組織間距離縮短，致使像斑與組織仍能在同一焦距下觀察。用乾裝裱及包捲法，染色宜行於曝光完成之後，而組織切片系覆蓋於乳膠膜之下，其染色不易，且不均勻，但試驗目的在了解像斑存於組織之相關位置，故染色工作可免除。本試驗所用凍結切片裝置方法應可處理小於5cm直徑之植物材料如果實，花托、球莖、鱗莖、塊根、塊莖，肉質莖甚或腫瘤等之全器官放射能顯像。

An attempt of the autoradiography of diffusible substances in combination with intact plant organ autoradiography was conducted. Small fruits of ornamental citrus and Citrus poonensis as well as the buttons of cactus (Echinopsis sp.) were treated with 14Cm 45Ca and 56Rb nuclides either on the above ground parts or in the nutrient solution. The materials were put into practices of quick freezing, freezed sectioning. Saran wrap affixing, affixed on glass slip, dried by sublimation and dry mounting procedures. Where the affixture by Saran wrap was an improvement over the usage of Scotch tape which caused the section inseparable. On the other hand, the dry mounting method performed in this experiment was an important step in avoiding the leaching of water soluble substances. The autoradiograms displayed the images in the vascular bundle of small fruit of an ornamental citrus (14C), in the starch grains of the rind of small fruit of Citrus poonensis (45Ca, 56Rb), and in the vascular bundle of cactus button (14C) respectively. The resolution was not reduced badly due to the 18μm sections. While the dry-wrapping technique which pullep the section and emulsion film closer by the action of contraction and enabled the tissue and images reachable under a same focus. Using the dry mounting and wrapping technique, staining process must be carried out after completion of exdosure. Since the section was covered beneath the emulsion film, stain showed uneven usually. It was aimed at locating the images distribution in the relative position of plant tissue, staining was unnecessary in some cases. The setups and techniques adopted may extend may extend its performance to the materials up to 5 cm diameter. Those of small fruits, receptacle, bulb, tuber, corm, tuberous root, fleshy stem as well as gall may all be practicable.