Genetic Diversity Analysis Of Culter Alburnus Basilewsky In Typical Waters In The Lower Yangtze River

The genetic diversity of C.alburnus Basilewsky,an economic fish species,is becoming more and more important as its resources are decreasing.Genetic diversity of C.alburnus Basilewsky is important to reduce the risk of species extinction.Fish mitochondrial DNA has become a hot research field due to its unique characteristics of maternal inheritance and simple genetic structure.Therefore this study using mitochondrial DNA as a molecular marker,with the Jiangsu section of the Yangtze river,Dianshan Lake,Changyang Lake,Changdang Lake,taihu Lake and Gaoyou Lake.The C.alburnus is investigate object,and utilization of cytochrome b(Cytb),cytochrome oxidase Ⅰ(COⅠ)and cytochrome oxidase Ⅱ(COⅡ)sequence gene sequence analysis,explore the genetic diversity of 6 C.alburnus groups,the main findings were as follows:1.Genetic Diversity Analysis of C.alburnus Basilewsky Different Populations Based on Cytochrome B(Cytb)GeneIn this study,based on the PCR amplification and sequencing of the mitochondrial DNA cytochrome b genes in the population of the four waters,A sequence of 1088 bp.Analysis shows,The A+T content in Cytb gene sequences was55%,G+C 45%.A total of 258 polymorphic sites were detected,211 samples obtained 46 haplotypes.The haplotype diversity was 0.849-0.946,of the four groups,the lowest haplotypes were found in the waters of Dianshan Lake,and Taihu Lake is the highest nucleotide diversity at 0.0083-0.174,The genetic diversity of the whole population is abundant.The interspecific genetic distance of four populations was0.052-0.152,and Taihu Lake population and Dianshan Lake population was 0.152.Dna SP analyzing the gene flow and genetic differentiation index of four geographical populations,it is concluded that the range of genetic differentiation index is0.197-0.646,and the range of gene flow value is 0.152-1.019.The minimum gene flow value of the Yangtze River and Dianshan Lake population is 0.152,and the maximum gene flow value of the Yangtze River and Changdang Lake population is1.019.The source of variation mainly comes from intergroup 211 Cytb gene sequences construction Neighbour-joining(NJ)phylogenetic tree shows that four geographic groups have geographical distinctions,but not very obvious.2.Genetic Diversity Analysis of C.alburnus Basilewsky in the Yangtze River and lakes Populations Based on COⅠ GeneIn order to understand the current situation of genetic diversity in the C.alburnus Basilewsky Populations of the Yangtze River and lakes.Genetic diversity analysis was carried out on four Populations from Dianshan Lake(DSH),Taihu Lake(TH),Changyang Lake(CYH)and Yangtze River(CJ)using the mitochondrial COⅠ gene sequence.The results showed that the average content of bases A,T,C and G in the COⅠ gene sequence of 816 bp was 26.3%,28.7%,26.8% and 18.2%,respectively,showed AT preference;A total of 43 haplotypes were defined among 293 sequences of 302 polymorphic sites.The haplotype diversity(Hd)and nucleotide diversity index(Pi)was 0.639-0.912,TH>CJ>DSH>CYH and 0.0052-0.0874,CJ>DSH>CYH>TH.The analysis of the genetic differentiation coefficient Fst and genetic distance between the Populations shows that there are significant genetic differentiation between the Taihu Population and other Populations,and the genetic distance between the other Populations is farther;AMOVA analysis showed that the variation between Yangtze River and Lake Populations was smaller,second only to genetic variation between 4 Populations,and the genetic variation was greatest in all sample C.alburnus Populations(10.16%<89.84%).The neutral tests for the Dianshan Lake Population,Tajima’s D and Fu Li F,were negative,indicating that the Dianshan Lake Population may have experienced Population outbreaks and expansion events,but no Population expansion occurred in the entire C.alburnus.The research shows that C.alburnus genetic differentiation has been formed in different geographical Populations,and the results provide a basis for the protection of the genetic diversity and breeding selection of the C.alburnus.3.Genetic diversity analysis of five C.alburnus groups in the lower Yangtze River based on COⅡ gene sequencesThe study is based on mitochondrial COⅡ gene sequence,analyzed the Yangtze river,Taihu Lake,Gaoyou Lake,Dianshan Lake and Changdang Lake five different geographic C.alburnus populations,the genetic diversity of different geographic population differences and group within the group were analyzed.By extracting the DNA and PCR sequencing,Sequence alignment and cutting were analyzed in softwares such as DNASP.The results of sequencing analysis for detection of total of425 bp COⅡ sequences to 31 mutation sites,two single mutation sites,29 simple information sites.The average content of Basic groups A,T,C and G was 24.19%,29.61%,28.03% and 18.17%,respectively.A+T(53.8%)was higher than C+G(46.2%),and 13 haplotypes were defined from 197 individuals in 5 geographic populations.The haplotype diversity ranged from 0.273 to 0.603,the Yangtze River population and Changdang Lake population were the highest,while the Taihu Lake population was the lowest.The nucleotide diversity ranged from 0.001 to 0.017,the lowest in Dianshan Lake and the highest in Changdang Lake.AMOVA analysis showed that the genetic variation was 10.47% between populations and 89.53%within populations(P<0.01)by using NJ(Neighbour-joining)build up C.alburnus different groups of molecular clustering tree 5 groups of individuals can be divided into two branchs,but five groups haploid type is not unique to the respective cluster form independent branch,but mutual crisscross complex cluster formation,differentiation between five become warped C.alburnus groups are not obvious.The analysis results show that on the whole C.alburnus groups of genetic diversity is rich,but a single lake of population genetic diversity,Changdang Lake group is the highest,lowest Taihu group.Follow-up studies will further understand the genetic background and germplasm resources of C.alburnus,and provide basic data for the conservation of its wild resources.Based on mitochondrial DNA,this study studied the genetic diversity of "five lakes and one river ".Based on the results of this study,we can simply evaluate the the results of this study,the-up study will use a combination of multiple markers to study its genetic diversity.A more comprehensive evaluation of germplasm resources provides a basic reference for the protection of seed resources and the breeding of improved varieties.