Diversity and interactions of lichen mycobionts and photobionts in the Fildes Region,King George Island,maritime AntarcticaOA

Lichens,as dual organisms comprising a major mycobiont and a major photobiont,exhibit remarkable survival capabilities in extreme conditions,such as those found in Antarctica.Despite their adaptability,the diversity and distribution of lichen photobionts in the ice-free areas of maritime Antarctica remain less understood compared to their mycobiont counterparts.In our study,we investigated the diversity of both lichen mycobionts and photobionts in 56 samples collected from the Fildes Region on King George Island,maritime Antarctica.Through sequencing of the nuclear ribosomal internal transcribed spacer regions and subsequent phylogenetic analysis,we examined the relationships and association patterns between mycobionts and photobionts.Our findings revealed 19 taxa of lichen mycobionts across 13 families and seven orders,along with nine photobiont species within the class Trebouxiophyceae.These photobionts encompassed six Trebouxia species,one Asterochloris species,one Chloroidium species,and one Stichococcus species.In particular,a new Trebouxia lineage(Trebouxia sp.OTU D08)and a new Chloroidium lineage were found.The analysis indicated that many mycobionts could be associated with multiple photobiont species,a pattern also observed among the photobionts.These results contribute significantly to our understanding of the complex diversity of lichen mycobionts and photobionts in the ice-free areas of maritime Antarctica.