English: Preparation of native microscope slide from Marchantia polymorpha thallus

The species Marchantia polymorpha is a moss that belongs to the group of thallus mosses. In order to make a native microscope slide from the thallus of this species, the following is needed: object and cover glass, a water dropper, a razor blade, tweezers and a sample of the plant material. The procedure for making the native microscope slide is as follows. On the object glass, which has previously been well washed and wiped, drip a large drop of water centrally and a smaller drop of water peripherally. Cut the thallus with a razor to flatten the surface. The plant material is placed at eye level and with a razor, with alternating movements of the hand to the left – right, a thin transverse section is made from the flattened part of the thallus. Using tweezers, the section is placed in the central drop of water on the object glass. With a cover glass, placed at an angle of 45°, the peripheral drop of water is stretched towards the central one. After the water droplets coalesce, the cover glass is lowered onto the object glass. The native microscope slide, prepared like this, is ready for microscopе.

On the upper, dorsal side of the thallus is the upper epidermis made up of one row of cells. It is covered with an almost impermeable cuticle. Under it are air chambers, separated from each other by partition walls. Inside they are filled with assimilation cells rich in chloroplasts. The process of photosynthesis is carried out in this part of the thallus. Each air chamber communicates with the external environment through an air pore that has a barrel shape. Ventrally, in the lower part of the thallus is the lower epidermis. Additionally, there are rhizoids and ventral scales. Rhizoids are single-celled structures that have a similar function to root hairs in more developed plants. They hold the thallus to the substrate and supply it with water. Ventral scales, unlike rhizoids, are multicellular structures, made up of many cells. Their function is to retain moisture while reducing the amount of water in the soil.

Prepared and performed by Angela Ivanova, Institute of Biology, FNSM, Ss. Cyril and Methodius University, Skopje, Macedonia.