Vplyv disperzie a lokálnych procesov na genetickú diverzitu populácií Daphnia curvirostris a Daphnia pulex v kontexte regionálnej štruktúry riečnej siete

Abstract

- 3 - Abstract Only a few studies have compared patterns of genetic variation among populations of different Daphnia species in the case of natural systems of river catchments. We assumed that as a result of dendritic nature of rivers and streams, the most genetic differentiation should be found between populations from different catchments and the least should be in the same sub-catchment. This is beacause it is much easier for animals restricted to passive dispersal via stream channel to disperse between adjacent streams in the same sub-catchment than between catchments. Using allozyme data based on six polymorphic enzyme loci, we present an analysis of genetic differentiation among 45 Daphnia curvirostris and 39 Daphnia pulex populations, separated by less than 100 m to more than 500 km from each other. The genetic population structure of the two species was strikingly similar, consistent with their similar metapopulation ecology. The mean FST value (differentiation within populations) was 0.32 and 0.30 and a hierarchical analysis showed that most genetic differentiation was between populations (68 and 70 %), less was present among populations within catchments (26 and 19 %) and the least was present among whole catchments (6 and 11 %). In spite of the large range of geographic distances, there was only...