Use of selected light microscopy techniques to investigate wood and bark

We present some possibilities to use a light microscope for investigations of wood and bark. We investigated intact tissue samples containing the wood, cambial zone and bark. They were taken from living mature beech (Fagus sylvatica L.) trees at different times of vegetation period. The samples were fixed in FEA (formalin-ethanol-acetic acid) and embedded in paraffin or epoxy resin after Spurr. We made the slices of normal mature wood and of wood in different phases of differentiation, tension wood, cambial zone and bark tissues. The sections were stained with safranin, astra blue, acridine orange and toluidin blue. We also prepared unstained sections for comparison. The sections were observed under the light microscope using bright field and polarization mode, and UV-fluorescence. We present images of sections stained with different stains and observed with different light microscope techniques. We discuss the advantages and disadvantages of all used techniques