"Lichens are the symbiotic phenotype of nutritionally specialized fungi that derive fixed carbon from green algae and/or cyanobacteria. The impact of nutrient availability and climate conditions on the growth and production of secondary metabolites is often discussed, especially that lichens produce an amazing diversity of secondary metabolites. Unfortunately, lichens are slow growing in nature and industrial-scale harvesting is not ecologically sensible and for some species not feasible, but lichen symbionts can be grown in cultures. However, the growth of the lichen fungi is relatively slow, especially when started from fungal spores. The project combines genetical, physiological and chemical analyses of lichen-forming fungi. The analysis of the breeding system of a very common lichen Protoparmeliopsis muralis may help us to understand why this lichen is so common in urban areas. Is it due to the high genetical variation caused by outbreeding or by self-fertility that could be advantageous in a particular environment? Moreover, the impact of strigolactones on the germination of fungal spores will be analysed in order to find potential stimulants for in vitro growth of the mycobiont. Moreover, the impact of the UV-light stress on the production of the secondary metabolites will be analysed. Investigation of the gene expression of mycobiont cultures will be performed in order to analyse genes potentially involved in the biosynthesis of certain secondary metabolites of lichen-forming fungi. An array of modern techniques will be used, including in vitro cultures of lichen-forming fungi, AFLP analysis, microsatellite markers analysis, MSAP, cloning, sequencing of fungal genes, HPLC and TLC analysis of the secondary metabolites. The expected results would contribute both to an understanding of lichen survival strategies and providing answers for basic questions about in vitro culturing and secondary metabolites biosynthesis."