AbstractsBiology & Animal Science

Lichens are symbiotic associations of heterotrophic fungi and photoautotrophic green algae or cyanobacteria. Bryoria is a lichenized euascomycete genus of approximately 50 currently accepted species. Although Bryoria is a conspicuous, easily recognized and frequently collected genus, species boundaries in this group are poorly known. This is especially the case with species in section Implexae where morphological and chemical variation is high even between individuals of the same species and genetic variation has been shown to be low in the examined markers. The aim of this study was to elucidate the taxonomic delimitation of the genus Bryoria, to examine the identity and selectivity of photobionts associated with Bryoria and to study the identity and phylogenetic placement of tremellalean fungi discovered from Bryoria. Possible correlations between the identity of the photobiont and the secondary chemistry of the lichen, and the identity of the secondary fungi and the secondary chemistry of the host lichen were particularly searched for. To study these questions, the taxon sampling focused on the chemically variable section Implexae. In addition, ecological characteristics and the distribution of Bryoria section Implexae species and their chemotypes in Finland were investigated to see if they corroborate recent taxonomic concepts. The results show that B. pseudocapillaris and B. spiralifera previously considered as members of section Implexae actually belong to the genus Sulcaria. Phylogenetic analyses also revealed that these two species are conspecific and thus a new combination, Sulcaria spiralifera, is introduced. In agreement with other studies, genetic differentiation in section Implexae was found to be minimal. Although most species of section Implexae are genetically indistinguishable, in this study, many of them were observed to have different ecological preferences. Bryoria capillaris favors managed stands in southern Finland whereas B. implexa and B. kuemmerleana prefer the habitats of long continuity of northern Finland. Bryoria vrangiana is a common species throughout the country but the three chemotypes of this species have slightly different habitat preferences chemotype lacking secondary substances being more common in the northern parts of the country, gyrophoric acid containing chemotype preferring the central parts of the country and fumarprotocetraric acid containing chemotype favoring the southern habitats. All Bryoria species studied here, except B. smithii, associate with a photobiont belonging to the Trebouxia simplex group. Selectivity of Bryoria spp. towards their photobiont varies among species. Bryoria bicolor, B. furcellata, B. smithii and B. tenuis are selective towards their photobionts whereas B. americana and B. fremontii seem to be less selective in their choice of a photobiont. All species in the section Implexae associate with the same photobiont making them selective at the section level. Lichen secondary chemistry was not found to correlate with the photobiont identity…