Analysis Of Genetic Diversity For Different Popolation Of Apostichopus Japonicus

Apostichopus japonicusbelongs to Echinodermata, Eleutherozoa, Holothuroidea,Aspidochirota, Stichopodidae. It is normally restricted to the shallow sea of China, Korea andJapanese in the Western Pacific，and is liked by their people.Research of the genetic diversityof A. japonicus using molecular marker methods is developed in recentyears. In this paper,SSR and COⅠmolecular markers were used for research of genetic polymorphism andcomparison analysis of genetic structure of natural population and cultured population ofDalian A. japonicus.The results showed that SSR markers revealed the high genetic diversityof natural population. Thirty three pair primers were screened and the purpose fragment werebetween67and306bp. The allelic number was from3to8. The average number of effectivealleles was4.736, and expected heterozygosity and observed heterozygosity was0.270-0.8446and0.598-0.875. The average polymorphism information content was0.732in Dalian naturalpopulation, which showed abundant genetic diversity. A total of23pair of primers conformedto Hardy Weinberg equilibrium, and the testing locus which deviated Hardy Weinbergequilibrium existed generally. This may because the limited number and standard size of thesamples or the existence of invalid alleles.Sequencing, alignment, and counterpoint of wild and breeding population COⅠsequenceshowed that the homologous sequences were654bp. In the49individuals which from4groups, the variation point was found in40individuals, among which the polymorphic sitenumber was32, and there were29conversion and1transversion. Using MEGA3.0softwarewe construct the NJ tree and MP tree. From these trees we found that the wild and breedingpopulation got together respectively, which showed high genetic diversity within subgroup,and the genetic diversity between wild population and breeding population were closed.We took advantage of the microsatellite polymorphism and tried to identify the closelyrelated species.we selected a total of four single sites of Dalian A. japonicusbelongs. Becausea small scale change of the segments range is beneficial to the next identification, we can usethe different variation range of these sites in different sea cucumber to identify species. Thefour single site primers which we selected laid the foundation of subsequent identification.