ISOZYME VARIATION IN THE MOSS MEESIA TRIQUETRA (MEESIACEAE)

Abstract

  Isozyme variation in eight enzyme systems in plants from 15 fens from three regions (boreal, subarctic, and high arctic) indicate that the gene diversity of Meesia triquetra, at 0.151, and genetic identity values (0.80-1.00) between populations of M. triquetra are comparable to those reported for many tracheophyte plant species. Gene diversity decreases significantly with increasing latitude, however patterns of gene diversity of the site level were more complex and suggest a highly dynamic species. In particular, subarctic sites have high between site gene diversity, while boreal sites have high within site gene diversity and high arctic sites are consistently low. Genetic identities are highest among the high arctic sites and lowest among the subarctic sites. The data suggest that the present-day regional gene diversity has evolved differently in each region.