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

Abstract

In order to describe their genetic variability the polymorphisms of 8 enzymatic systems representing 23 gene loci were studied in 11 German and 5 foreign common carp lines using horizontal starch gel electrophoresis. The highest variability measured by the mean number of alleles per locus and the percentage of polymorphic loci was observed in Vietnamese wild carp (1.9 and 50%, respectively) followed by carp from River Rhine (1.8 and 45%, respectively). 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 distances [Nei, M., 1978. Estimation of average heterozygosity and genetic distance 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 carp and German domesticated scaly carp ( D=0.133). A dendrogram based on these 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). Within the European group the carp from River Rhine were the most distinct ones. Their relatively separate position was mainly caused by the presence of alleles at four loci which could not be found in the majority of the domesticated European stocks.