Research Of Genomic Selection Apply In The Hybrid Population

With the development of chip and computer technology, a lot of single nucleotide polymorphism(SNP) covered over the whole genome was gained, the SNP markers formedlinkage disequilibrium(LD) with quantitative trait loci(QTL), genomic selection(GS) utilized SNP information appeared in the movement. The advantages of GS was that higher accuracy, shorten generation interval, reduced inbreedingcoefficient rising degree, accelerated genetic gains and realized selection at early stages. The methods of GS could be divide into a kind of best linear unbiased prediction(BLUP) method, and another way was Bayes method, the models of GS was single trait model and multiple trait model. Nowadays,the application of GS in animal breeding project, a great number of appliaction was in purebred, and GS single trait model was mainly used,the GS was less applied in crossed population, in particularly, the adhibitionof multiple trait model in crossed population was reported more rarely.In current study, we used the single trait model and multiple trait model of traditional BLUP, genomic best linear unbiased prediction(GBLUP) and genomic best linear unbiased prediction with genetic architecture(BLUP|GA) to 14 growth traits in hybrid chicken F2 population that was crossed between White Recessive Rock(WRR) and Xinghua(XH) chickens,the main purpose to research accuracy of GS and effect of selection at early stages in crossed chicken population, and explore the methods of evaluating GS. The According to the scheme to estimate breeding value(EBV) and genomicestimate breeding value(GEBV), and then tostatistic and analysis the results, we would summarize that:(1) The average accuracy of GS was higher than traditional BLUPas GS was used to growth traits in hybrid chicken population was 0.429、0.514 and 0.522, respectively, the regression coefficient of three methods was 1.016、1.027 and 0.913, respectively, the highest accuracy was BLUP|GA, the highest regression coefficient was BLUP.(2)Based on rank of EBV or GEBV estimated by different approaches, the common proportion of selected individual between GBLUP and BLUP|GA higher than between BLUP and GBLUP and between BLUP and BLUP|GA, average phenotypic value of selected individual of three methods was higher the whole population, average phenotypic value of selected individual was higher than traditional BLUP.(3) Results of genomic selection single trait model and multiple trait model used to growth traits of hybrid chickenpopulation, the accuracy of GBLUP multiple trait model was0.068 haigher than GBLUP single trait model, the accuracy of BLUP|GA multiple trait model was 0.068 haigher than BLUP|GA single trait model.(4) Selection at early stage could be used in hybrid chicken population via GS method, when the selection rate was lower, single trait model of genomic selection had obvious advantage; the multiple trait model of GBLUP, the best prediction of BW90 was BW77, and the multiple trait model of BLUP|GA, the best prediction of BW90 was BW56.