The use of tissue culture method for the study of lichenized fungi (Lobariaceae Chevall., Parmeliaceae Zenker.) of the European part of Russia

Lichenized fungi as a multicomponent biological system are an interesting but difficult research object. In view of the complex interaction of the myco- and photobiont, the slow growth of natural thalli, their exceptional exactingness to environmental factors, the study of the biological characteristics of lichens is significantly difficult. This article discusses the problem of studying the anatomical and morphological structure of the myco- and photobiont of lichenized fungi using the tissue culture method on the example of rare species (Lobaria pulmonaria) and species with pharmaceutical potential (Usnea dasopoga, Cetraria islandica). The authors proposed a method for cultivating of myco- and photobionts of these species on synthetic nutrient media for the purpose of further research on the characteristics of lichenized fungi. Fragments of thalli, apothecia (for C. islandica), and soredia (for U. dasopoga and L. pulmonaria) were used as donor material. For the introduction of the photobiont under sterile conditions, a homogenate of the thallus region was prepared. Pure cultures of the myco- and photobiont of L. pulmonaria, U. dasopoga, and C. islandica were obtained on three types of hormone-free nutrient media, namely MS nutrient medium, modified MS medium with a reduced nitrogen content, Czapek medium. The verification of the research results was carried out taking into account the microscopy of the obtained cultures of myco- and photobionts. Using microscopy, the dimensional characteristics of the obtained mycobionts were determined. The diameters of the hyphae of L. pulmonaria, U. dasopoga, and C. islandica were 4.3–4.4 µm, 4.6 µm, and 4.1–4.3 µm, respectively, which corresponds to the size of the hyphae in natural samples. The use of the tissue culture method makes it possible to study and analyze the biological characteristics of lichenized fungi as a multicomponent biological system, as well as to contribute to the preservation of rare species and their components in the Red Data Book; while optimizing the method of cultivating myco- and photobiont on synthetic nutrient media, to reduce the anthropogenic load on natural populations of lichens when using them as medicinal raw materials.