Genetic variability of German and foreign common carp (Cyprinus carpio L.)populations

In order to describe their genetic variability the polymorphisms of 8 enzym atic systems representing 23 gene loci were studied in 11 German and 5 fore ign common carp lines using horizontal starch gel electrophoresis. The high est variability measured by the mean number of alleles per locus and the pe rcentage of polymorphic loci was observed in Vietnamese wild carp (1.9 and 50%, respectively) followed by carp from River Rhine (1.8 and 45%, respecti vely). The lowest variability was found in all domesticated stocks (1.4 to 1.5 and 25 to 40%, respectively) and could be attributed to a loss of rare alleles. The mean observed heterozygosities ranged from 0.112 to 0.256 for all populations examined. The calculation of Nei's unbiased genetic distanc es [Nei, M., 1978. Estimation of average heterozygosity and genetic distanc e from a small number of individuals. Genetics 89, 583-590] revealed three pairs of genetically identical populations. All of them were German mirror carp stocks. The largest genetic distance was found between Japanese Koi ca rp and German domesticated scaly carp (D = 0.133). A dendrogram based on th ese genetic distance measures showed that all populations could be assigned to two clearly distinct groups. One consisted of the German stocks and the Israeli Dor-70 carp (European group). The other one was formed by Koi carp , Vietnamese and River Amur wild carp, and the Ropsha carp (Asian group). W ithin the European group the carp from River Rhine were the most distinct o nes. Their relatively separate position was mainly caused by the presence o f alleles at four loci which could not be found in the majority of the dome sticated European stocks. (C) 1999 Elsevier Science B.V. All rights reserve d.