Genetic variability of German and foreign common carp (Cyprinus carpio L.) populations.
Polymorphisms of 8 enzymatic systems representing 23 gene loci were studied in 16 lines of common carp from Germany (11 lines), Japan, Russia (2 lines), Vietnam and Israel using horizontal starch gel electrophoresis. The number of carp examined per population ranged from 25 to 50. 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 the River Rhine (1.8 and 45%, respectively). The lowest variability was found in domesticated stocks (1.4-1.5 and 25-40%, respectively) and was 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 revealed 3 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 2 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 the River Rhine were the most distinct. Their relatively separate position was mainly caused by the presence of alleles at 4 loci which could not be found in the majority of the domesticated European stocks.