Reproductive and dispersal strategies shape the diversity of mycobiont-photobiont association in Cladonia lichens

• Published in: Molecular phylogenetics and evolution 2019-05, Vol.134, p.226-237
• Main Authors: Steinová, Jana, Škaloud, Pavel, Yahr, Rebecca, Bestová, Helena, Muggia, Lucia
• Format: Article
• Language: English
• Subjects: Asterochloris; Distribution; Phylogeny; Specialist pattern; Specificity; Symbiosis
• ISSN: 1055-7903; 1095-9513
• DOI: 10.1016/j.ympev.2019.02.014

[Display omitted] •Dispersal strategy was shown to be the key factor shaping photobiont diversity.•Asexual Cladonia species are strongly selective towards their photobionts.•Sexually reproducing lichens were shown to be photobiont generalists.•A strict photobiont specialisation may lead to restricted lichen distribution. Ecological preferences, partner compatibility, or partner availability are known to be important factors shaping obligate and intimate lichen symbioses. We considered a complex of Cladonia species, traditionally differentiated by the extent of sexual reproduction and the type of vegetative propagules, to assess if the reproductive and dispersal strategies affect mycobiont-photobiont association patterns. In total 85 lichen thalli from 72 European localities were studied, two genetic markers for both Cladonia mycobionts and Asterochloris photobionts were analyzed. Variance partitioning analysis by multiple regression on distance matrices was performed to describe and partition variance in photobiont genetic diversity. Asexually reproducing Cladonia in our study were found to be strongly specific to their photobionts, associating with only two closely related Asterochloris species. In contrast, sexually reproducing lichens associated with seven unrelated Asterochloris lineages, thus being photobiont generalists. The reproductive mode had the largest explanatory power, explaining 44% of the total photobiont variability. Reproductive and dispersal strategies are the key factors shaping photobiont diversity in this group of Cladonia lichens. A strict photobiont specialisation observed in two studied species may steer both evolutionary flexibility and responses to ecological changes of these organisms, and considerably limit their distribution ranges.