Species diversity and photobiont localization specificities in epigene lichens (on the example of the genus Cladonia)

The article describes the taxonomic composition and photobionts localization specificities in above-ground lichens of the genus Cladonia. Moreover it analyzes the amount and algal species in thallus homogenates due to their age: in zones of active growth, aging zone and destruction zone; alga cells in washings from surface of thalli. Also the article analyzes the influence of the mycobiont on the photobiont species and abundance of the photobiont. It gives the comparison analysis of these data in lichens in the north taiga zone (Murmansk Region) and steppe zone (on the example of Orenburg Region). The method of direct microscopy helped to determine the taxonomic affiliation of the photobionts to the genus. Here the authors mean the size, shape of the cells, the nature of the chromatophore, etc. The number of photobionts in samples was studied both by light microscopy and fluorescence microscopy. The paper presents the comparison results of the amount and algae diversity in in the thalli of the above-ground lichens of the genus Cladonia due to their geographical location and the specificity of the age dynamics of the podecium. The research shows the fact that Asterochloris alga was the dominant group in the actively growing lichen podecia. However geographical location is not important. Chlorella, Stichococcus, Pseudococcomyxa were found in lichens algae. The authors believe that the new information about the changes in the taxonomic composition of algae, due to the age of the thallus is important for science. Pseudococcomyxa algae dominated in the old parts of the north taiga lichens and Stichococcus dominated in the steppe areas. Moreover the authors give the attempt of resynthesize lichen tallium from previously isolated cultures of the mycobiotic and photobiont. This attempt was unsuccessful at the period of the research work.