In this article we will discuss about the boulos and beakbane’s technique with experiment.
Boulos and Beakbane (1971) suggested a highly useful method of separating leaf epidermis from the mesophyll tissue. In routine type of epidermal studies, especially for investigating the details of the stomata and epidermal cells, this method is very effective in the laboratory.
In this method pieces of leaves are cut from various parts of the plant and kept in a macerating solution (H2O2 100V: glacial acetic acid: water in a proportion of 2:2:1) in oven at 70°C for 12-24 hours. When bubbles appear on the leaf surface, the peels are taken out in a watch glass.
They are washed in water. With the help of a fine hair brash (Camel’s brash) all adhering mesophyll tissues are cleaned. Peels are stained with 1% aqueous solution of safranin and then mounted in 50% glycerin and finally studied under microscope.
Exercise No. 1:
To peel off the epidermis of the given material and to stain and mount it. Identify the stomatal types and calculate the stomatal index.
Leaves of given material, forceps, brash, razor, blade, slides, cover-slips, safranin, glycerin.
For peeling off the epidermis of the given leaf fold it to break its one surface and pull the other surface gently by holding a thin piece of peel with the forceps. Put the pieces of such peels on the slide, stain them with 1% aqueous solution of safranin, mount in 50% glycerin and study under low and high power of microscope.
In the same way, remove the epidermal peel of the other surface of the leaf, stain and mount them also in the same way as discussed above.
Observations and Result:
Study the details of the epidermis of both the surfaces of leaf, compare the stomata with Fig. 137 and find out the type to which they belong and draw the diagrams. In general, the stomata in dicotyledonous plants remain scattered irregularly whereas in monocotyledons they remain arranged in parallel rows.
Count the number of stomata and number of epidermal cells per unit area and calculate the stomatal index by the following formula:
Stomatal Index (SI) = S/E + S × 100
where ‘S’ represents the number of stomata per unit area and ‘E’ represents the number of epidermal cells per unit area.