Ecologiсal and genetic changes in populations of silver (Hypophtalmichthys molitrix) and bighead (Aristichthys nobilis) carp

A comparative characterization of the genetic structure of populations of silver carp and bighead carp by four primers (CTC)6C, (GAG)6C, (AGC)6G, (AGC)6C was given. The average value of (Na) in silver carp and bighead carp was at the level of 45.7 and 42.7. In the bighead carp, the highest number of amplicons and the highest value of the effective number of alleles per locus were observed for primer (AGC)6C and were equal to 62 and 15.4, respectively. The least polymorphic in number of amplicons per locus was primer (CTC)6C, where the values were 29. According to the studied four primers, the effective number of alleles per locus ranged from 6.3 to 15.4. In silver carp, the largest number of amplicons and the highest value of the effective number of alleles per locus were observed with primer (GAG)6C and were equal to 57 and 18.5, respectively. The least polymorphic in the number of amplicons per locus was primer (CTC)6C, where the values were 34. According to the studied four primers, the effective number of alleles per locus ranged from 6.3 to 18.5. The comparative analysis of ecological and genetic changes allowed studying the genetic variability of silver and bighead carp at the population level. In addition to specific amplicons, unique DNA fragments inherent in populations at the species level have been found. Specific «species» and «population» polymorphic ISSR-markers, identified in this work, allow to use them as a basis for further comprehensive research for molecular labelling on the population level and to establish phylogenetic relationships, genomic profile of the species, as well as monitoring the genetic structure of fish. The optimized ISSR method can serve as an effective tool for further genetic studies of populations of silver carp and bighead carp. The obtained results allow controlling the selection and breeding work in the process of reproduction of the gene pool of existing fish populations. To increase the efficiency of selection and breeding work in fish farming, it is advisable to use genetic markers that have a high specificity to individual DNA fragments of fish.