Format: ORAL

Salvador Chiva1,2, Tamara Pazos1, Patricia Moya1, Eva Barreno1, Lucia Muggia2

1 Institut Cavanilles de Biodiversitat i Biologia Evolutiva (ICBIBE), Universitat de València, Spain 2 Department of Life Sciences, University of Trieste, Italy

Lichens are considered as microecosystems due to the great diversity of microorganisms that coinhabit their thalli. To encompass the microalgal diversity (including primary and non-primary phycobionts) associated with the lichen symbioses, the term phycobiota is currently used. Here we investigated how the diversity of lichen phycobiota correlates with lichen species and their growth form and ecology. Thalli of five lichen species were collected in a Mediterranean climate zone of the Iberian and Italic peninsulas. The selected species, i.e., Cladonia foliacea, Parmelia sulcata, Ramalina farinacea, Squamarina cartilaginea and Xanthoria parietina are widely distributed in these regions, have different thallus architectures and grow on different substrates. DNA from five thalli of the same species collected at each locality was extracted, amplified, pooled and DNA metabarcoded for the algal ITS2 marker using an Illumina sequencing approach. This allowed the estimation of the microalgae community present at a certain locality for each lichen species collected there. Furthermore, to corroborate the correct identifications of the lichen mycobionts, barcode identification (of the fungal ITS) by Sanger sequencing was performed. In addition, at each locality three samples of each substrate type present, adjacent to the collected lichens, i.e., soil, bark and rocks were sampled. The substrate samples were used to assess the microalgal background diversity in each locality, i.e., the whole set of algae potentially available for the establishment of lichen symbioses. Prometeo Excellence in Research Program (Generalitat Valenciana, Spain, PROMETEO/2021/005) and a postdoctoral contract (Next Generation EU, to SC) Ministry of Universities Universitat de Valncia (MS21-058).