N. Cronberg et al., GENETIC-VARIATION IN THE CLONAL BRYOPHYTE HYLOCOMIUM SPLENDENS AT HIERARCHICAL GEOGRAPHICAL SCALES IN SCANDINAVIA, Heredity, 78, 1997, pp. 293-301
The widespread bryophyte Hylocomium splendens was sampled in a hierarc
hical fashion from populations representing four Scandinavian vegetati
on zones. Allozyme electrophoresis revealed variation at 11 out of 13
screened loci, allowing accurate identification of genotypes. From a t
otal sample of 298 shoots 79 genotypes could be detected, giving the p
roportion of distinguishable genotypes (PD) of 0.265. The total alleli
c diversity (H-T) based on polymorphic loci was 0.274. The relative di
fferentiation among populations was low (G(ST) = 0.073), indicating a
high level of gene flow. Differences in population structuring occurre
d between a subarctic-alpine site vs. three lowland sites. The subarct
ic-alpine population had one widespread clone, which appeared to be pr
opagated by dispersal of vegetative fragments. That population also co
mprised many rare genotypes, often occurring together within 10 x 10 c
m patches. The lowland populations had genotypes that were locally com
mon and often dominant within the patches. When identical genotypes we
re observed in multiple patches within these populations, it was usual
ly statistically highly probable that they had arisen by independent s
exual recombinations.