鲤饲料转化率性状的关联分析及优异等位变异挖掘

饲料转化率是鲤养殖重要的亟待改良的经济性状之一。本研究利用分布于鲤全基因组的1 536个SNP标记,分析68尾全同胞家系镜鲤Cyprinus carpio的基因分型,采用TASSEL软件的GLM和MLM模型检测与饲料转化率性状紧密关联的标记位点,发掘相关位点内的优异等位变异。本研究共获得17个与饲料转化率性状显著关联(P0.05)的SNP标记,贡献率在6.4%~16.6%之间,分布于鲤基因组第2、6、11、16、20、32、33、41,和42染色体以及Scaffold1032、1078和2323上,注释了一批饲料转化率相关的候选基因。从显著关联的标记位点内发掘了16种优异等位变异,其平均表型效应值较群体均值高6.2%,较非优势等位变异高12.5%。其中,SNP0919、SNP0167和SNP1016 3个标记的优异等位变异增减效差异最大,暗示这些标记对性状的选择效果明显。本研究发掘的饲料转化率相关的标记及优异等位变异可为鲤饲料转化率性状的分子标记辅助选择及分子设计育种提供依据。

Association Analysis of Feed Conversion Efficiency and Exploration of Elite Alleles in Common Carp

Feed conversion efficiency (FCE) is one of the important economic traits to be improved.In this study,a total of 1 536 SNPs were used to genotype a full-sib panel of 68 individuals of mirror carp (Cyprinus carpio) based on the Illumina GoldenGate assay.The association between SNPs and FCE phenotypic data was analyzed by general and mixed linear models (GLM and MLM) methods in software of TASSEL,and the significantly associated loci of FCE were analyzed for exploring the elite alleles.A total of 17 SNPs were found to be significantly associated with FCE at a threshold of P＜ 0.05 in nine chromosomes (2,6,11,16,20,32,33,41 and 42) and three Scaffolds (1032,1078 and 2323).The FCE associated loci had contribution varying from 6.4％ to 16.6％,and the phenotypic allele effect was estimated and then the average positive and negative allele effect of a locus was calculated over the phenotypic effects of all alleles.A total of 16 elite alleles were screened out among the 17 loci with repeated associations,with 6.2％ higher average phenotypic allele effect than that in the population mean and 12.5％ higher than the negative ones.Three loci such as SNP0919,SNP0167 and SNP1016 with the maximal differences in average phenotypic allele effect revealed the obvious effect on the selection of FCE trait.Meanwhile,17 candidate genes were scanned and annotated.The loci and elite alleles of FCE identified will provide important foundation for subsequent studies including molecular marker assisted selection and molecular breeding by design.