AFLP analysis of genetic structure and diversity in population of Schizothorax kolzovi from the Wujiang River

Abstract:

Schizothorax kolzovi, which belongs to Cypriniformes, Cyprinidae and Schizothoracinae, is a wild fish species of high economic value, distributed in the Jinsha, Yalong, and upper Wujiang Rivers of the Yangtze River system and the Beipan River in the Pearl River system in China. To assess the genetic diversity and germplasm resources of S. kolzovi in the Wujiang River, Guizhou, the genetic structure and diversity were analyzed in the 30 individuals of the species from the river by the methods of amplified fragment length polymorphism (AFLP). With 7 pairs of selected primers through the pre-experiment, 5~73 DNA fragments were amplified in the 30 individuals, ranging from 69 to 500 bp. A total of 856 loci were detected, including 796 polymorphic loci accounting for 92.99% of the total. The population contained 30 genotypes, and the mean values of the observed number of alleles (Na), effective number of alleles (Ne), Nei diversity index (H), and Shannon information index (I) were 1.933 6, 1.338 8, 0.212 2, and 0.338 7, respectively. The genetic distance between individuals ranged from 0.169 1 to 0.531 9, with an average of 0.306 8. The unweighted pair group method with arithmetic mean (UPGMA) and neighbor-joining (NJ) phylogenetic trees of the 30 individuals contained 2 branches and had the similar topological structure. The S. kolzovi population in the Wujiang River contained rich genetic diversity. However, hydropower station dams, river pollution, and overfishing have reduced the distribution of S. kolzovi, and its population size has declined. Therefore, this species is ecologically threatened, and the population and germplasm resources of S. kolzovi in the Wujiang River needs to be protected.