Allozyme Diversity and Geographic Variation among Populations of the Locally Endangered Taxon Carex magellanica subsp. irrigua (Cyperaceae)

Abstract

Carex magellanica subsp. irrigua is a wet habitat taxon that is extinct or declining in the Baltic States and Central Europe, but still quite common in northern areas, in Fennoscandia and Alaska. We investigated the extent of genetic variation within and among populations and geographic regions of this subspecies. Isozyme electrophoresis in polyacrylamide gels was applied to characterize genetic diversity with allozymes as genetic markers. Of the nine putative isozyme loci assessed, five (56%) were found to be polymorphic. The genetic diversity in small and fragmented Estonian populations was lower (H e?=?0.034) than in larger Fennoscandian and Alaskan populations (average H e?=?0.082). All standard genetic parameters (A e, H o, H e, P, F is, t) showed the lowest values in Estonian populations. The heterozygosity level in Fennoscandian populations was low (H o?=?0.01), whereas no heterozygotes were found in Estonian and Alaskan populations. High F is values indicate that C. magellanica subsp. irrigua is predominantly inbreeding. The main reason for its decline in Estonia is the destruction of suitable habitats. More attention to the protection of Estonian habitats is needed to maintain genetic diversity and stop further decline of this taxon.