FEATURES OF THE OF WOODY PLANTS BARK MACERATION

Аннотация

The article describes problems in preparing the woody plants bark for maceration and the ways to solve them by modifying methodological approaches. During maceration of the bark and its constituent tissues of woody plants, certain difficulties arise, especially with phloem, since this tissue is less lignified and stable than xylem, which remains relatively unchanged in its structure during ontogenesis. This fact requires an individual approach not only to different types, but also to each specific case. We use separation, that is, the selection of necessary tissue sections and tissue types (soft and hard) at each stage of maceration: selection of definite fragments for analysis, varying the exposure time for a certain type, collection and tissue fragment site, centrifugation of both hard, soft and liquid fractions. We separate, if possible, the periderm and wood, macerating only the part necessary for microscopic analysis of the bark internal structure. They are conductive phloem to reveal the characteristics of conducting living elements, non-conductive phloem for the study of sclerified elements, and elements of the cortex for the study of parenchyma, primary mechanical elements, etc. The macerating liquid includes distilled water, concentrated acetic acid, and hydrogen peroxide. We place the prepared samples, tightly closed with a ground lid, in a thermostat with a temperature of 50 °C. The exposure time in the thermostat can vary from several hours to several days. Then we thoroughly wash the macerated matter with distilled water before the odor of acetic acid disappears, with the following centrifuging and preparing the slides for analysis.