Grube, Martin; Baloch, Elisabeth; Blaha, Julia; Wornik, Sabine. Photobiont selectivity in lichen symbioses. In: International Meeting on "Population and Evolutionary Biology of Fungal Symbionts", Ascona, Switzerland, 2007. AB-33.

Lichenized fungi can establish symbioses with diverse lineages of green algae and cyanobacteria. These symbioses are hard to culture, but molecular approaches help to understand the patterns of symbiont selectivity. Some lichen species associate with a narrow range of photobiont strains while others associate with a wider range of related algae or, in some cases, with both cyanobacteria and green algae in the same symbiotic thallus. Our studies, for example, show that euryoecious, wide-spread crustose lichen species can associate with coccale green algae (Trebouxiaceae) of varying  relatedness and with apparently different ecological preferences.  On the other hand, lichens forming symbioses with filamentous algae (Trentepohliaceae) seem to prefer strains which share growth form independent of their relatedness. We also investigated whether differences exist in the photobiont patterns among closely related lichens which differ in their propagation strategy. We found that both the asexual species, which propagates both symbionts jointly, and the sexually reproducing fungal species have similar levels of photobiont diversity in lichen populations. The results will be discussed.

Keywords: lichens, symbiont selectivity

*Institution: Institute of Plant Sciences

E-mail: martin.grube@uni-graz.at