Identifying hybridizing taxa within the Daphnia longispina species complex: a comparison of genetic methods and phenotypic approaches
Abstract
Daphnia galeata, D. longispina and D. cucullata are closely related species which often produce interspecific hybrids. Several marker systems are available for taxon determination in this hybridizing complex, but their performance and reliability has not been systematically assessed.
We compared results from identifications by three molecular methods. More than 1,200 individuals from 10 localities in the Czech Republic were identified as parental species or hybrids by allozyme electrophoresis and the analysis of the restriction fragment length polymorphism of the internal transcribed spacer (ITS-RFLP); over 440 of them were additionally analyzed and identified by 12 microsatellite loci.
Identification by microsatellite markers corresponded well with allozyme analyses. However, consistent discrepancies between ITS-RFLP and other markers were observed in two out of 10 studied localities.
These results warn against its use as a sole identification method in field studies.