title: High cyanobiont selectivity of epiphytic lichens in old growth boreal forest of Finland.
abstract: Here, cyanobiont selectivity of epiphytic lichen species was examined in an old growth forest area in Finland. Samples of the eight lichen species were collected from the same aspen (Populus tremula) and adjacent aspens in the same stand. The cyanobionts of these samples were compared with free and symbiotic Nostoc obtained from other habitats and geographic regions. Our results, based on the phylogenetic analysis of a partial small subunit of the ribosomal DNA (16S rDNA) and the rbcLX gene complex did not show any correlation with the geographic origin of the samples at any spatial scale. Instead, there was a correlation between the cyanobionts and the alleged taxonomy of their mycobionts. The results indicate that the lichen species examined are highly selective towards their cyanobiont partners. Only Lobaria pulmonaria proved to be more flexible, being able to associate with a wide range of Nostoc. A same Nostoc strain was found to form associations with taxonomically unrelated lichens indicating that the cyanobiont-mycobiont associations as a whole were not highly specific in the examined species.
authors.affiliation: Botanical Museum, Finnish Museum of Natural History, PO Box 7, FIN-00014 University of Helsinki, Finland.
authors.forename: Leena
authors.initials: L
authors.lastname: Myllys
authors.affiliation: Botanical Museum, Finnish Museum of Natural History, PO Box 7, FIN-00014 University of Helsinki, Finland.
authors.forename: Soili
authors.initials: S
authors.lastname: Stenroos
authors.affiliation: Botanical Museum, Lund University, Östra Vallgatan 18, SE-223 61 Lund, Sweden.
authors.forename: Arne
authors.initials: A
authors.lastname: Thell
authors.affiliation: Ministry of the Environment, PO Box 35, FIN-00023 Government, Finland.
authors.forename: Mikko
authors.initials: M
authors.lastname: Kuusinen
mesh_terms: D004275:DNA, Ribosomal / Q000235:genetics; D005387:Finland; D017343:Genes, Plant; D008011:Lichens / Q000502:physiology*; D010802:Phylogeny; D032107:Populus / Q000254:growth & development / Q000502:physiology*; D013045:Species Specificity; D013559:Symbiosis; D014197:Trees / Q000254:growth & development / Q000502:physiology*
chemical_list: D004275:DNA, Ribosomal