DIVERSITY OF MITOCHONDRIAL DNA IN THE POPULATIONS OF SILVER CARP, BIGHEAD CARP, GRASS CARP AND BLACK CARP IN THE MIDDLE AND LOWER REACHES OF THE YANGTZE RIVER

Louis Bernatchez (Department of Biology, University Laval, Canada) RELP analysis of the mtDNA segment encompassing the ND5/6 and cytochromone b genes and D Loopregion was performed in Silver carp ( Hypophthalmichthys molitrix ), Bighead carp ( Aristichthys nobilis ), Grass carp ( Ctenopharyngodon idellus) and Black carp ( Mylopharyngodon piceus) from three sections (Shishou in Hubei Province, Jiujiang in Jiangxi Province, Wuhu in Anhui Province) along the middle and lower reaches of the Yangtze River. It was revealed that:(1) Silver carp, Bighead carp and Black carp showed a higher genetic diversity, whereas garss carp showed a lowergenetic diversity; The numbers of mtDNA haplotypes and the haplotype diversity indices for Silver carp, Bighead carp, Grass carp and Black carp were 28, 19, 27, 7 and 0 681, 0 583, 0 890 and 0 231 respectively. (2) The populations of Silver carp showed a significnat genetic diversity and a visible geographical distribution of genotypes; The populations of Bighead carp and Black carp had a significant genetic diversity but no visible geographical distribution of genotypes; The populations of Grass carp had neither significant genetic diversity nor visible geographical distribution of genotypes.