Mapping And Genetic Effect Analysis Of QTLs Related To Growth Traits Of Olive Flounder (Paralichthys Olivaceus)

33family were built using the cross olive flounder from Japan×olive flounderfrom Korea.16family displaying a marked difference of growth among offspring werechosen, the parents of16family were analyzed by8SSR appearing polymorphism inother family.92F1individuals obtained from NO.1family that has the best Separationcondition were chose as the segregating population.Overall length, weight and body depth of92individuals were measured, the valueof Overall length ranged from19.3cm to28.0cm, mean+σ were23.67+2.12cm; thevalue of weight ranged from30.2g to207.0g, mean+σ were118.29+37.89g; the value ofbody depth ranged from6.4cm to10.0cm, mean+σ were8.36+0.87cm. Test of normality,correlation analysis, principal component analysis was handled with three sets of data.Results were that: Overall length was deflect from the normal distribution, weight andbody depth meet normal distribution. Overall length, weight and body depth weresignificantly related between each other, Pearson coefficient of correlation ranged from0.810-0.880. Finally,1set of data that can explain89.592%of the three charactersfeatures was obtained, which was named growth-trait, GT of flounder.After Polymorphism screening, PCR amplification,221SSR were left forconstructing genetic linkage map from400SSR.Llinkage analysis and Constructinggenetic linkage were through by joinmap4.0software.178SSR markers were linked to22linkage groups in female map, including a triplet and194SSR markers are linkedto23linkage groups in male map, including a triple. The Expected lengths of the femaleand male map are879.7cM and785.4cM respectively. The lengths of the female and male maps are599.0cM and693.4cM and covered76.27%and78.82%of the genome,respectively. The average map distance（s） of the female and male maps were3.84cMand4.05cM respectively. The map distance（s） of each linkage group of the female andmale maps ranged from6.1cM to59.5cM and from9.6cM to57.2cM, respectively. Thenumber of each linkage group of the female and male maps ranged from3to16.Based on the linkage maps, trait-marker regression and complexity intervalmapping were analyzed to fix QTLs related to growth traits by WinQTLCart2.5software, the experiential LOD-value of2.5was the threshold value of existing QTLs.Three QTLs related to growth traits were obtained from this research, qGT-f4,qGT-m20and qGT-f20, the variance explained by the three loci were27.60%，13.74%，10.27%,respectively. Twenty-two SSR makers related to growth traits （p<0.05） were obtainedfrom trait-marker regression analyzing. The variance explained by single SSR, ranged3.70%to11.26%. The four makers, scaffold558₅1720, scaffold558₂6183,scaffold903₆9232, scaffold485₄7120, scaffold1262₇7386and scaffold809₆5154were highly significantly （p<0.01） correlated with growth traits, the variance explainedby the six were10.42%,7.31%,10.07%,10.07%,8.39%,11.26%respectively.The research is the first time to fix QTLs related to olive flounder growth traits, usefor reference can be provided for the other good traits from this study, three QTLs andsix SSR related to growth traits were obtained from this research, which can lay thefoundation to molecular marker-assisted breeding. For moving forward a single step toachieve Fine Mapping QTL, the future work is that: build the permanent population ofolive flounder, increase the density of genetic linkage map so that reducing the areacontaining QTL, use the material in different growth periods and from differentenvironment in order to fix QTL Multilaterally.