In the present study, the genetic diversity of one selected strain (Pujiang No. 1), two domesticated populations (GA and
HX) and four wild populations (LZ, YN, SS and JL) of blunt snout bream (
Megalobrama amblycephala
) was analyzed using 17 microsatellite markers. The results showed that an average of 4.88-7.65 number of alleles (
A); an average of 3.20−5.33 effective alleles (
Ne); average observed heterozygosity (
Ho) of 0.6985−0.9044; average expected heterozygosity (
He) of 0.6501−0.7805; and the average polymorphism information content (
PIC) at 0.5706−0.7226. Pairwise F
ST value between populations ranged from 0.0307−0.1451, and Nei’s standard genetic distance between populations was 0.0938−0.4524. The expected heterozygosities in the domesticated populations (GA and HX) were significantly lower than those found in three wild populations (LZ, SS and JL), but no difference was detected when compared with the wild YN population. Likewise, no difference was found between the four wild
populations or two domesticated populations. The expected heterozygosity in Pujiang No. 1 was higher than the two domesticated
populations and lower than the four wild populations. Regarding pairwise F
ST value between populations, permutation test
P-values
were significant between the GA, HX and PJ populations, but not between the four wild populations. These results showed that the
expected heterozygosity in the selected strain of blunt snout bream, after seven generations of selective breeding, was lower than that
of wild populations, but this strain retains higher levels of genetic diversity than domesticated populations. The genetic differences
and differentiation amongst wild populations, domesticated populations and the genetically improved strain of blunt snout bream will
provide important conservation criteria and guide the utilization of germplasm resources.
