Abstract:Common carp(Cyprinus carpio)is one of the most widespread freshwater teleost species in the world.It has been cultured as an important food fish worldwide,especially in China,for several thousand years.In the past decade,much research efforts have been made for the molecular breeding of common carp including development of polymorphic markers,linkage mapping,and quantitative trait loci(QTL)analysis.However,QTL researches of common carp have been limited by single family and small population size.Considering the ability to detect and identify QTL in single family is often limited and has obtained false positive locus.We conducted a whole genome scan on 522 progeny from 8 full-sib families using 250 microsatellites selected from high density genetic linkage map of common carp constructed by our lab.The genetic maps were constructed by use of the Cri-map program with genotypes of 8 families,and genetic distances were estimated by use of the Kosambi map function.A total of 233 markers were organized to 47 linkage groups and the linkage maps covered a genetic distance of 3 131.5 cM,with the average interval for markers within linkage group of 16.8 cM.The linkage map could be used for primary QTL analysis.QTL identification of standard length(SL)and body weight(BW)traits was carried out using half-sib mapping strategies by GridQTL software.We obtained 4 QTL distributed across 3 linkage groups(LG)during sire-based QTL analysis.For SL,3 QTL were identified,of which 1 QTL occurred at the 95% genome-wide level,and was located on LG24,accounting for 20.3% of phenotype variation.The remaining 2 QTL were at the 95% chromosome-wide level,explaining 11.9%(LG6)and 11.6%(LG30),respectively.For BW,1 QTL was identified at 99% genome-wide level,explaining 38.3% of phenotypic variance and overlapped with the SL QTL intervals on LG24.During dam-based QTL analysis,we identified 8 QTL that were distributed across 5 LGs.Five QTL were associated with SL,of which one was at 99% chromosome-wide level and located at LG8.The other 4 QTL were at the 95% chromosome-wide level,accounting for 9.6%-20.3% of phenotypic variance.QTLs on LG24 and LG30 were significant both the sire and the dam-based analysis.For BW,three QTL were detected and have a similar confidence interval with SL at LG24,LG30 and LG45.Among these,2 QTL were identified at the 99% chromosome-wide level,and 1 QTL at the 95% chromosome-wide level,explaining 10.8%-14.1% of phenotypic variance.The results showed that the most significant QTLs for SL and BW were located on LG24 and common to both sire and dam.The results of this study not only can supply more reliable markers for molecular breeding of common carp,but also provide reference data for exploring regularity of QTL variation among different populations and families.