Comparative Studies On The Sequences Of Four Mitochondrial Genes Of Different Wild Populations Of Acanthopagrus Schlegelii In China

Acanthopagrus schlegelii has the characteristics of rapid growth,strong adaptability,small movement range,and high nutritional value.It is an important economic fish for marine aquaculture in recent years.Mitochondrial DNA is widely used in studies of genetic diversity and genetic differentiation of fishes because of its maternal inheritance,rich content,rapid evolution,and independent genetic behavior.Based on the four mitochondrial D-loop,Cytb,COI and 16 S rRNA gene sequences,this study investigated the genetic diversity and genetic differentiation of 80 individuals in 10 wild populations in coastal China.The results showed that:(1)Mitochondrial D-loop gene study revealed that there were 55 polymorphic loci and 36 haplotypes were defined.The haplotype diversity index Hd was 0.973 and the nucleotide diversity index Pi was 0.00843,10 in 10 populations.The population showed higher haplotype diversity and higher nucleotide diversity.Among them,Haikou population had the highest genetic diversity with a genetic distance ranging from 0.0062 to 0.106.The AMOVA analysis and phylogenetic tree showed that among 10 wild populations,There was no significant genetic differentiation.Neutral evolution tests showed that the Yantai and Zhanjiang populations deviated significantly from neutral evolution;(2)Cytomegalovirus Cytb gene research found 44 polymorphic sites,defining a total of 13 haplotypes,10 The haplotype diversity index Hd of the population was 0.664,and the nucleotide diversity index Pi was 0.02353,indicating that the 10 populations showed higher haplotype diversity and lower nucleotide diversity,including The population genetic diversity was the largest,and the genetic distance ranged from 0.0012 to 0.0490.The AMOVA analysis and phylogenetic tree showed that there was significant genetic differentiation between the Xiamen population and the other 9 populations,but there was no obvious genetic differentiation among the other 9 populations.The sexual evolution test showed that the Nanao Island population deviated significantly from neutral evolution;(3)The mitochondrial COI gene study found 63 polymorphic loci,defining a total of 9 haplotypes,and the haplotype diversity index Hd for 10 populations.0.509,the nucleotide diversity index Pi was 0.0537,indicating that the 10 populations showed higher haplotype diversity and higher nucleotide diversity,among which the Zhanjiang population had the highest genetic diversity and the genetic distance range was From 0.0003 to 0.0268,AMOVA analysis and phylogenetic tree showed that there was significant genetic differentiation between the Xiamen population and the other 9 populations,but there were no obvious genetic differentiation among the other 9 populations.The molecular neutral evolution test yielded 10 populations.Not significantly deviated from neutral evolution;(4)mitochondrial 16 S rRNA gene research,found that 16 polymorphic sites,defined a total of 9 haplotypes,10 population haplotypes Hidden index Hd was 0.393,nucleotide diversity index Pi was 0.00319,indicating that 10 populations showed lower haplotype diversity and lower nucleotide diversity,among which Zhanjiang population had the highest genetic diversity.The genetic distance ranged from 0.0000 to 0.0057.Both AMOVA analysis and phylogenetic tree showed that there was no significant genetic differentiation among the 10 wild populations.Neutral evolution tests showed that the Zhoushan population significantly deviated from neutral evolution.In summary,it was found that D-loop,COI,and Cytb genes can well reveal the genetic diversity of the population,but the 16 S rRNA gene has no obvious effect on revealing the genetic diversity of the A.schlegelii,and is not suitable for the black spine.The study of genetic diversity.It can be seen that the genetic diversity of the 10 populations of Chinese black sea locusts in China's coastal areas is generally at a medium level.Among them,the genetic diversity of Zhanjiang,Xiamen and Haikou populations is relatively high,which is related to their geographic location.The four gene segments all showed that there was no obvious genetic differentiation between the northern and southern populations in China and could be grouped into the same administrative unit.However,the COI and Cytb genes showed significant genetic differentiation between the Xiamen population and the other 9 populations.This may be related to the geographical isolation of Xiamen sea areas.The specific reasons have yet to be further verified.The genetic distance shows that none of the 10 populations reached the differentiation level of the subspecies,and there was no significant relationship between the genetic distance and the geographical location of the population.This study will provide important insights into the improvement of the germplasm,conservation of breeding and protection of germplasm of the A.schlegelii.