Abstract

By using light microscopy and scanning electron microscopy, the composition, shape and localization of calcium depositions in the leaves of Ficus pumila L. var. awkeotsang (Makino) Corner were studied. In the mature leaves, many calcium oxalate and calcium carbonate were accumulated. All calcium carbonate depositions (cystoliths) were found in the lithocysts of the lower epidermis. The calcium oxalate crystals were in forms of druses or prismatic crystals. Most of the druse crystals were located sporadically in the cells of palisade mesophyll, while the prismatic crystals were found in the crystal cells of the bundle sheath. The formation of these two kinds of calcium deposits was related to the levels of calcium supply. The size of calcium carbonate depositions increased with the calcium concentration, but the density of lithocysts was not affected by different concentrations of calcium supply. Nevertheless, the density of calcium oxalate crystals was higher in high calcium solutions.

中文摘要

應用光學與掃描電子顯微鏡技術來觀察愛玉子 (Ficus pumila var. awkeotsang)葉部鈣沉積物的成分、形態與分佈。愛玉子成熟葉片中，可觀察到草酸鈣與碳酸鈣的堆積。碳酸鈣鐘乳體分佈在葉片下表皮之石胞中，晶簇狀草酸鈣結晶分散於柵狀葉肉組織中，而多面體結晶則主要分佈於維管束鞘。此外，愛玉子葉片鈣結晶的形成受到所提供之不同鈣離子濃度的水耕培養液的影響，在較高濃度鈣離子培養液中，石胞內堆積多量碳酸鈣，而在低濃度鈣離子培養液中，石胞內則較少碳酸鈣堆積，然而，石胞的密度並不受不同濃度的鈣離子供應所影響。就葉肉組織中的草酸鈣結晶而言，隨著水耕培養液中鈣離子濃度之升高，其草酸鈣結晶之密度亦明顯增加。

Keyword: Calcium carbonate, Calcium oxalate, Calcium supply, Ficus pumila var. awkeotsang.