Diversity of Viridiplantae DNA present on rock surfaces in the Ellsworth Mountains, continental Antarctica

The Ellsworth Mountains experience frigid desert conditions. No macroscopic vegetation is present, with only very few published records of microalgae, and the range has received virtually no formal biological survey. Rocks, including gypsum crusts, were sampled from five specific locations in part of the region during the austral summer of 2012/13. These underwent DNA extraction and a metabarcoding approach using high-throughput sequencing, targeting plant DNA. This detected the presence of DNA assigned to a total of 48 taxa, including six Chlorophyta (green algae), four Bryophyta (mosses), and 40 Magnoliophyta (flowering plants). Cluster analyses suggested that the diversity found was not related to rock type or exposure age or sampling location, and there was limited similarity between locations. Thirty-four of the taxa assigned were consistent with a South American origin. The high diversity of DNA representing Poaceae (grasses; 12 taxa) is consistent with aerial transfer, most plausibly via pollen; this study provides an important means of better understanding the arrival and movement of biological material in Antarctica either through natural means or in association with human activities.