Genetic polymorphism in nine clones of a parthenogenetic collembolan used in ecotoxicological testing

Ecotoxicological tests are increasingly being used to evaluate the toxicity of a substance or mixture of substances towards soil fauna. One of these uses the parthenogenetic collembolan Folsomia candida to test for soil contamination, and this has been standardised in Europe. However, in such studies, it is important to know whether different laboratories use genetically close clones. In this study, nine clones of the parthenogenetic collembolan F. candida, used in five laboratories, have been subtyped by amplification of random regions of genomic DNA using 10-base primers in the random-amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). This differentiated these clones into three groups of four, four and one, respectively. Several hypotheses can be envisaged to explain these divergences between the populations of this parthenogenetic collembolan, notably the history of interlaboratory exchanges of clones. Ecotoxicological tests (mortality and reproduction) were undertaken to test the sensitivities to cadmium and phenantrene of two clones from different RAPD defined groups. These showed minor differences in sensitivities to both, but more extensive testing with five cadmium concentrations showed that the genetic clone does not affect the LOEC determination. There is no evidence of significant differences between clones throughout a concentration gradient of cadmium. © 2000 Elsevier Science B.V. All rights reserved.