A method for isolating and preparing silica bodies in grasses for scanning electron microscopy.

Silica bodies are discrete deposits of dehydrated silica within epidermal cells. To describe these bodies completely, surrounding organic and unsilicified material must be removed. Methods generally used for isolating and preparing silica bodies were unsuitable for most grass species. An effective method for studying grasses is described here. After ashing the plant tissue, the ash was repeatedly rinsed with HCl in a specialized multiple funnel manifold and collected on Nuclepore filters. In addition, the silica bodies were sonicated for a few minutes to remove any remaining mineral impurities. Compared to conventional procedures, this method has a number of advantages: unsilicified material and mineral impurities were removed effectively, smaller quantities of plant tissue could be used, and the loss of silica bodies was minimized.

An improved method for studying grass leaf epidermis.

Leaf epidermis of grasses is elaborate and important in the systematics of the Poaceae at subfamily and genus level. Most available techniques used in preparing leaf epidermis for microscopic studies are time-consuming and often produce preparations inadequate for studying histological detail. A combination of the hand scraping and maceration methods with modifications is proposed in this paper to prepare epidermal peels comparatively rapidly. One epidermal layer was scraped off and the mesophyll tissue removed from the epidermis to be studied by maceration in HNO3. The recovered epidermal peel was neutralized in NaOH and stained with malachite green or safranin O. Preparations made by this technique are suitable for studies of epidermal features, measurements of special structures and determinations of trichome indices. This method has been used in a study investigating intraspecific variation in southern African pasture grasses.