Lichen photobionts of the rocky outcrops of Karadag massif (Crimean Peninsula)

Despite the fact that lichen algae have been explored for over100 years, their diversity, taxonomy and ecology still remains understudied. In present study we analyzed 114 specimens representing 72 lichen taxa collected on the Crimean Peninsula, culturing and sequencing their algal partners. In total we identified 26 taxa of photobionts representing 10 algal genera (Asterochloris, Chloroidium, Dilabifilum, Diplosphaera, Gloeocapsa, Myrmecia, Nostoc, Printzina, Stichococcus, Trebouxia). As most of the studied lichens (more than 80 % of studied lichen species) contained Trebouxia, for which morphology-based identification is often difficult and insufficient, we additionally used molecular methods. According to the molecular phylogeny of internal transcribed spacer (ITS) rDNA, Trebouxia species were related to three main clades: “Arboricola” (88.9 % of the investigated Trebouxia-containing lichens), “Impressa” (4.4 %) and “Simplex” (6.7 %). Based on results of molecular phylogeny and morphology three new species of Trebouxia, namely T. solaris, T. vagua and T. cretacea were described. In several lichens, two coexisting Trebouxia species were revealed in the same thallus.