Genetic Diversity Of Dai-qu Pseudosciaena Crocea

Pseudosciaena crocea which were collected from Dai-qu Sea area played an importanteconomic position in the marine fisheries. They were valuable ocean marine resources andimportant economic fish in my province. The germplasm of Pseudosciaena crocea wasdegradating step by step along with the environmental degradation and overfishing. Therefore,carrying out the work to identify and protect croaker germplasm resources was quite urgent. Withthe help of mitochondrial DNA, RAPD and microsatellite these three molecular marker technology,this study compared and analysed the level of genetic diversity between Dai-qu stock and Min-yuestock, in order to reveal the genetic differentiation among populations, and then identified thegermplasm resources of Dai-qu stock effectively.The length of mitochondrial DNA control region sequence(Dai-qu stock) was from795bp to797bp and presented four haplotypes. The various parameters which can reflect the geneticdiversity indicated that compared to Min-yue Pseudosciaena crocea, the level of genetic diversity(Dai-qu stock) was lower; These two groups had similar relationship; However, neither of themwas stable, just was in a state of expansion.Using RAPD random primers to amplify genomic DNA of two large yellow croaker, theproportion of polymorphic loci (Dai-qu stock)was lower; The genetic similarity of them was0.9673. It indicated that their genetic variation was small and genetic relationship was quite close;The Shannon’s diversity index of Dai-qu stock was0.3930, and the Nei’s gene polymorphism indexwas0.3032, both of them were lower than Min-yue stock. It indicated that the level of geneticdiversity(Dai-qu Pseudosciaena crocea)was relatively low.By the use of Microsatellite loci, we detected49alleles in Dai-qu and Min-yue Pseudosciaenacrocea. The average allele of Dai-qu stock was less than Min-yue stock. The genetic differentiationindex of two population was0.0228. It indicated that the genetic difference between them wasweak, and the level of genetic diversity was low; The genetic similarity coefficient and geneticdistance were0.7838and0.2162, respectively. The genetic distance was at low level. It indicatedthat the degree of genetic variability between two large yellow croaker groups was low. Thegenetic relationship was quite close.