High fungal selectivity for algal symbionts in the genus Bryoria

In this study we examined photobiont identity, diversity and selectivity in the genus Bryoria. We focused on B. fremontii and section Implexae in order to determine whether secondary chemistry is correlated with photobiont identity. DNA from two loci for photobionts and three loci for mycobionts was sequenced for both parsimony and Bayesian phylogenetic analyses. A comparison of photobiont and mycobiont phylogenies reveals that most Bryoria species associate exclusively with lineages of the Trebouxia simplex group; only B. smithii was associated with a different photobiont. We conclude that most Bryoria species included in our study are highly selective in their choice of algal partners and that the presence/concentration of different secondary compounds does not correlate with photobiont identity either in section Implexae or in B. fremontii.