Data from: Molecular phylogeny and symbiotic selectivity of the green algal genus Dictyochloropsis sensu lato (Trebouxiophyceae): a polyphyletic and widespread group forming photobiont-mediated guilds in the lichen family Lobariaceae

Dictyochloropsis s.l. is an ecologically important, common but
little-studied genus of green algae. Here, we examined the diversity and
host selectivity of algae attributed to this genus at both
species-to-species and species-to-community levels. We conducted a
molecular investigation of 15 cultured strains and several lichen
photobionts, using 18S rRNA, rbcL and ITS sequence data. We further used
seven alga-specific microsatellite markers to study algal sharing among
fungi of the family Lobariaceae in two populations in Madeira and Taiwan
(454 lichens). We found that the genus Dictyochloropsis s.l. is
polyphyletic. Dictyochloropsis clade 1 comprises only free-living algae
whereas Dictyochloropsis clade 2 includes lichenized algae as well as
free-living algae. Fungal selectivity towards algae belonging to
Dictyochloropsis clade 2 is high. Selectivity varies geographically, with
photobionts being restricted to a single region. Finally, we showed that
Dictyochloropsis clade 2 individuals are shared among different fungal
hosts in communities of lichens of the Lobariaceae. As for other green
algal lineages, there is a high amount of cryptic diversity in
Dictyochloropsis. Furthermore, co-evolution between Dictyochloropsis clade
2 algae and representatives of the Lobariaceae is manifested at the
community level, with several unrelated fungal species being horizontally
connected by shared photobiont clones.