Photobiont selectivity for lichens and evidence for a possible glacial refugium in the Ross Sea Region, Antarctica

摘要: Lichens are a symbiosis consisting of heterotrophic, fungal (mycobiont) and photosynthetic algal or cyanobacterial (photobiont) components. We examined photobiont sequences from lichens in the Ross Sea Region Antarctica using internal transcribed spacer region ribosomal DNA tested hypothesis that this extreme environment would demonstrate low selectivity their choice photobionts. Sequence data three targeted lichen species (Buellia frigida, Umbilicaria aprina decussata) showed all were associated with common haplotype (an unnamed Trebouxia species) which was present taxa at sites, suggesting lower selectivity. However, there also association unique, local photobionts as well evidence for species-specific selection. For example, cosmopolitan U. decussata two species, jamesii an species. The most commonly collected (B. frigida) had its highest diversity Dry Valley region, may have served refugium during glacial periods. conclude even these environments, still has influence on successful colonisation lichens. level is variable among be related to ability some (e.g. B. colonise wider range habitats.