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 count ries of the world, and is one of only a few moss species present in co ntinental 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 populati ons in nearby temperature land masses. Our modified RAPD technique gav e reproducible results for single two mm moss shoots; within-clump var iation was observed in most isolates, making the use of single shoots essential for these studies. A comparison of B. argenteum isolates fro m continental Antarctica, as well as from locations in Australia and N ew Zealand revealed that isolates from Australia and New Zealand are m ore similar to each other than either population is to the isolates fr om Antarctica. The level of genetic variation was as high within Antar ctic clumps as in those from more temperate regions, even though sexua l reproduction has not been observed in the Antarctic populations.