High levels of RAPD diversity in the moss Bryum argenteum in Australia, New Zealand, and Antarctica

Bryum argenteum sensu lato, is a cosmopolitan moss found in many countries of the world, and is one of only a few moss species present in continental Antarctica. We have used RAPD (Random Amplified Polymorphic DNA) technology to investigate how this moss has colonized and spread in Antarctica, and whether it is genetically similar to other populations in nearby temperate land masses. Our modified RAPD technique gave reproducible results for single two mm moss shoots; within-clump variation was observed in most isolates, making the use of single shoots essential for these studies. A comparison of B. argenteum isolates from continental Antarctica, as well as from locations in Australia and New Zealand revealed that isolates from Australia and New Zealand are more similar to each other than either population is to the isolates from Antarctica. The level of genetic variation was as high within Antarctic clumps as in those from more temperate regions, even though sexual reproduction has not been observed in the Antarctic populations.