| In the present study,we screened 28 pairs of Monopterus albus polymorphic microsatellite by simplified genomic method,and analyzed the genetic diversity and genetic structure of 6 different Monopterus albus groups in Jiangxi by using 10 pairs of polymorphic primers.And the influence of the distance between the four water systems in Jiangxi on the genetic structure of the Monopterus albus is discussed.The main results of study are as follows:1.Isolation and characterization of microsatellite markers for Monopterus albusIn this paper,we analyzed the distribution of SSR by database method and simplified gene sequencing method,a statistical analysis was made on the advantage of a single repeating type.35 pairs of polymorphic primers were developed according to the available SSR sequences.Seven pairs of polymorphic primers were screened by database method,and 28 pairs of polymorphic primers were screened by simplified genome sequencing method.The polymorphic evaluation of the selected primer using 30 individuals.Among them,the simplified SSR derived from the genome sequencing method obtained 138 alleles,averaging 5.89 alleles per locus.The average observed and expected heterozygosity was 0.3559 and 0.6076.The average PIC value was 0.5623,indicating that these locis had good polymorphism.A total of 29 alleles were obtained from the EST-SSR of the database method,with an average of 4.14 alleles per locus.The average observed and expected heterozygosity was 0.2470 and 0.5674.The average PIC value is 0.4958.The total polymorphic level of the locus is medium.The simplified genome sequencing method used in this paper has become a new choice for developing SSR markers because of its simplicity,celebrityand low cost.2.The universal detection of EST-SSR between five different species13 pairs of primers were successfully amplified in the Monopterus albus tested in Carassius auratus,Cyprinus carpio,Misgurnus anguillicaudatus,Larimichthys polyactis and Siniperca chuatsi.Seven pairs of these primers were amplified between five different species,and five pairs of primers showed polymorphism among individual species.For the five species of molecular marker library to accumulate effective markers.And the seven pairs of primers have accumulated effective markers for the molecular markers library of the five species.3.Genetic diversity and genetic differentiation and structure analysis of the six groups in Monopterus albus1)Whether the group has a high reproductive capacity and the resistance of the disease is directly related to its diversity,which is also related to the growth ability of Monopterus albus.Using the 10 polymorphic loci,the genetic diversity of the sixpopulations of Jiangxi Monopterus albus was 0.5949,indicating that the diversity of these groups was at the high level.A total of 105 alleles were amplified from 10 loci,with an average of 10.5 alleles per locus.An null allele was present in all groups,among which Taojiang population was the most serious.2)In the genetic relationship between groups,JDZ group and DZ group were first clustered into one class,then clustered with JX and WD groups,and then clustered together with LH and TJ groups.The genetic distance between populations was related to river system distance,in particular,the DC population and other population on the tributaries of the Poyang lake river system.And the correlation coefficient was 0.6842.The mean Fis values of the 6 population showed that the TJ population had the largest inbreeding value(Fis).Population exists in multiple tributaries of the river system may affect the gene exchange between the DC population of Poyang Lake,which makes the WD population cluster with JDZ and DC after the JX population.3)The comparison of Fst value between two groups showed that the Taojiang group had a larger Fst value than other groups,and there was a trend of forming subspecies.The results of AMOVA showed that the variation among populations was mostly from different individuals within the groups.The 6 groups can be roughly divided into 4 genetic structures(from a genetic structure),not the only genotype we were all known.The LH and TJ populations were two different genetic structures,WD and LH populations were the other two genetic structures.4)Population genetic bottleneck analysis showed that WD,TJ,LH,JX population may have experienced genetic bottleneck.JDZ,DC,WD groups in the two models of the effective number of groups are more than 1000,indicating that these groups have a better resource state... |
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