Isozyme variation of Lake Qinghai naked carp Gymnocypris przewalskii(Kessker)from five rivers

摘要

Samples of Lake Qinghai naked carp Gymnocypris przewalskii were collected from five distributaries of Lake Qinghai: Buha river(BH), Quanji river(QJ), Shaliu river(SL), Ganzi river(GZ) and Haergai river(HEG) in July, 2005. Thirteen isozymes coded by 26 gene loci were analyzed by starch gel electrophoresis, and allele frequencies of each locus in five populations were calculated. The results showed that six loci, ( Pgm , Hk , Cat , Gdh , Est-1 and S-Mdh) were polymorphic in five populations. The proportion of polymorphic loci was 23.08%, the results showed that samples from the five locations exhibit high genetic diversity. Average heterozygosities were 0.1161(HEG), 0.1178(GZ), 0.1304(SL), 0.1305(BH), 0.1287(QJ) respectively,and the average effective numbers of alleles were 1.3112(BH), 1.3069(SL), 1.2542(GZ), 1.2492(HEG), 1.2453(QJ). Buha River is the biggest of five rivers, and more genetic variation is shown in the BH population. Heterozygotis deficiency was detected in all populations except for the QJ population. A dendrogram was constructed with data derived from Nei’s genetic distance using UPGMA cluster analysis. Results showed that SL and QJ were clustered and then clustered with BH. GZ and HEG were clustered. Gene flow( N_m ) was 7.2013, indicating there was wide gene flow among the five populations. All these results indicate that the Lake Qinghai naked carp has high genetic variability and it is worthy of protection [ Acta Zoologica Sinica 53(5):892 – 898, 2007].