22382.準噶爾雅羅魚遺傳多樣性及其同域同屬種間基因漸滲研究

1、石河子大學碩士學位論文準噶爾雅羅魚遺傳多樣性及其同域同屬種間基因漸滲研究姓名：涂著池申請學位級別：碩士專業(yè)：遺傳學指導教師：胡文革201106IIAbstractLeuciscusmerzbacheri(Zugmayer)isagenusoffishbelongingtoCyprinifmes，Cyprinidae，Leuciscinae，Leuciscuscuvier.Zugmayerisanindigenousmediumsized

2、freshbrackishfishothertwoLeuciscusspecies(L.baicalensisL.idus)distributedoverJunggarBasinofnthregionofXingjiangNthwestChina.Resentlymostpopulationsalloverdrainagessufferedseveredemographicdeclinehabitatfragmentationdueto

3、unreasonabledevelopmentutilization.Thusearlyin1998thenativefishspecieshavebeenlistedasvulnerablespeciesintheChinaRedDateBookofEndangeredAnimalsitwaslistedasXinjiangAquaticwildlifeprotectionlistin2004.Howeverlimitedgeicin

4、fmationisavailablefthisraredaceespeciallyatmoleculelevel.Soitisimminenttolaunchthiswk.HerewedescribethegeicdiversityintrogressionamongLeuciscusSubspeciesinSailimuLakebyintersimplesequencerepeatmarkers(ISSR).Indertoinvest

5、igatetheoptimalISSRPCRsystemfLeuciscusmerzabcheriftheISSRPCRapproachdefectedbyitsunstablewkingcondition.SoatfirstphagegenomeDNAofL.merzbacheriwereusedastemplateDNAL9（34）thogonaldesignwasadoptedtooptimizeISSRamplification

6、systemwhichinvolvedfourprincipalfactsTaqpolymeraseMg2dNTPsPrimersatthreelevelsrespectively.ThenwegainedtheoptimizedISSRPCRsystemwith1PCRbuffer0.5UTaqDNApolymerase3.0mMMgCl2250MdNTPs0.75Mprimer30ngtemplateDNAintotal25ulre

7、actionvolume.Furtherme，wescreeningamountof9primersfrom32primersobtainedtheirsuitableannealtemperatureobservedthissystem.Theresultssetabasicsteptoanalysisthegeicdiversityoftherarelyfishspecies.Furthmethegeicdiversityof91i

8、ndividualsfromsixwildpopulations(includingthreepopulationsofL.merzbacheritwopopulationsofL.idusonepopulationofL.merzbacheri)inJunngrBasinwasinvestigated.Usingthenineprimers193unambiguousDNAfragmentsweregeneratedwith178(9

9、1.75%)beingpolymphicindicatinganotablegeicvariationatthespecieslevel.Howeveratthepopulationlevelalowlevelpolymphismwiththepercentageofpolymphicbsrangingfrom9.28to47.94%.UndertheassumptionofHardyWeinbergequilibriumtheNei’

10、sgenediversity(Hpop)rangedfrom0.0384(SG)to0.1615(BG)withanaverageof0.0994atthepopulationlevelwhereasNei’sdiversityindex(Ht)valueis0.3352atspecieslevel.Shannonindex(Ipop)rangedfrom0.0561(BG)to0.2419(SG)withanaverageof0.14

11、96atthepopulationlevelatspeciesleveltheShannonindex(It)valueis0.4985.Thirdlyanalysisofmolecularvariance(AMOVA)wasusedtoapptionthevariationwithinbetweenpopulationsbothwithinbetweenspecies.AstheISSRmarkersrevealed45.36%oft

12、hetotalgeicdiversityresidedattheintraspecieslevelamongpopulationswhereas30%24.64%werepresentatinterspecieswithinapopulationrespectively.TheNei’sGst(0.7039)geneflowamongpopulations(Nm=0.2103)revealedseldomgeneexchangeshap

13、pensamongpopulations.ThedendrogramcreatedfromUPGMAanalysisbasedonNeiLi’scoefficientshowedthattheL.baicalensisLeuciscusmerzbacheriaggregateataclusterotherclustergatheredconfmingsignificantgeicdifferentiation.Thisisthefirs

14、treptofthepartitioningofgeicvariabilityofLeuciscusattheDNAlevel.TheISSRresultssuggestthereisalowlevelofgeicvariationpresentatLeuciscusspecies.ClusterofUPGMAanalysisindicateaslightcrossbreedingmightoccursbetweenthetwospec