Genetic structure, reproductive biology and ecology of isolated populations of Asplenium csikii (Aspleniaceae, Pteridophyta)

The potential for environmental heterogeneity to generate spatial structuring of genotypes in seedplant populations that occupy patchy habitats has been demonstrated by several studies, but little is known about the population structure of pteridophytes occupying patchy environments. In this study we have examined the genetic structure of isolated populations of the rock fern Asplenium csikii, an ecological specialist, growing almost exclusively on perpendicular walls of natural rock outcrops. All genetic variation observed in this taxon was partitioned between localities; no allozyme variation was found within a site and each site was colonized by a single multilocus phenotype (MLP). In total, ®ve di erent MLPs were recorded from the nine localities, with two MLPs present at more than one site