Biochemical genetic variation between four populations of Labeobarbus polylepis from three river systems in South Africa

摘要

The genetic variation within four Labeobarbus polylepis populations from both river and dam environments in the Limpopo, Incomati and Phongolo River systems was studied. Gene products of 22 enzyme-coding loci were resolved using horizontal starch gelelectrophoresis. Fourteen (64%) of the 22 loci were monoallelic in all populations. Levels of polymorphism (P_(0.95) ranged between 9.1% and 22.7%. The heterozygosity varied from 0.028 for the Westoe Dam population (Phongolo River system) to 0.093 in theSpekboom River population (Limpopo River system). The genetic distance, F_(ST) and N_(EM) values, as well as pair-wise contingency χ~2 analyses indicate a lack of gene flow between populations, as expected for isolated fish. Evidence of foreign geneticmaterial in one population was also observed.