ALLOZYME VARIATION IN REFERENCE AND METAL-EXPOSED NATURAL-POPULATIONS OF ORCHESELLA-CINCTA (INSECTA, COLLEMBOLA)

Environmental pollution may affect genetic variation in populations inhabiting polluted sites. In this study, allozyme variation was studied in natural populations of the soil-dwelling insect Orchesella cincta. The populations originated from eight sites with different histories of metal contamination and natural enrichment in The Netherlands, Belgium and F.R.G. Slight but significant divergence was observed for four polymorphic loci; 18 loci were monomorphic at all sites. The highest mean values for heterozygosity (H), degree of polymorphism (P) and mean number of alleles per locus (A) were 0.090, 0.182 and 1.36, respectively. Geographic distance was not correlated to genetic divergence. Comparison of allozyme data from investigated populations and from a reference population in Italy showed a remarkable genetic homogeneity in this species, the highest value for Nei's genetic distance (D) being 0.035. Among NW European populations, a correlation between metal tolerance characteristics and allozyme frequencies was observed for glutamate-oxaloacetate transaminase (EC. 2.6.1.1).