Gwas Analysis For Yield Traits Using Cultivated Varieties In Wheat

Wheat?Triticum aestivum L.?is one of the most important crops in the world.The productivity is very important for food supply in China.The development of high yield varieties is a basically object in wheat breeding programs.In the present study,Field trials were carried out at two sites using 107 varieties from the Yellow and Huai River Valley Facultative Winter Wheat Region.Combining with the data of 90 K SNP chip,we conducted the genome-wide association study?GWAS?for yileld traits to discover the important QTLs and their markers.This should be helpful for gene cloning of related traits and molecular marker-assisted selection?MAS?in breeding programs.The main results are as follows:?1?The variation of phenotype showed that the wide variations were detected,which the variation coefficients ranged from 7.35%?TSS in AV?to 248%?TSSS in DZ?for the targeted traits.The broad-sense heritability were 53.43?GY?-74.41 %?SL?.ANOVA analysis showed that the significant difference were detected between genotypes and envieonments for all the nine targeted traits,indicating the phenotype values were affected significant by both genotypes and envieonments.?2?The wheat 90 K chip was used to scan the 107 varieties.By removing the polymorphism SNPs with smallest allele frequency?MAF?less than 5%,and loss rate more than 15%,7090 SNPs were remained.According to the information published by Wang et al.?2014?,84.82%?6014/7090?of the SNPs has genetic location information,which distributed on 21 chromosomes.The number of SNPs on chromosomes ranged from 23?4D?to 551?5B?.The LD distance for A,B and D subgenome were 7.1 cM,7.1 cM and 27.1 cM,respectively,and the LD distance for whole genome was 13.5 cM.The results of group structure analysis showed that 107 varieties were divided into two subgroups,including respectively 29 and 78 varieties.?3?GWAS analysis detect out a total of 115 SNPs were significantly associated with wheat yield-related traits,and 99 SNPs had genetic location information,distributed on 111 sites of 16 chromosomes?1A,1B,1D,2A,2B,3A,3B,4A,4B,5A,5B,6A,6B,7A,7B,7D?,which explain 10.04-17.89% of the phenotypic variation;and 16 SNPs have no genetic location information.A total of 65 QTLs were detected.The individual QTL was explained 10.04% to 15.85% of the phenotypic variation.A number of 7,6,6,7,4,11,9,7 and 9 QTLs were detected for BSSS,FSS,GNS,GY,PH,SL,SN,TSS and TSSS,respectively.?4?A total of four QTL clusters were obtained,which the corresponding SNPs associated simultaneously with two or more traits.The SNP Excalibur_c105151₂00 on chromosome 1A at 38.1 cM,BS00111069₅1 on 2A at 47.2 cM,BS00111069₅1 on 2A at 92.2 cM,and Ex_c21738₁175 on 5A at 76.8 cM were all associated with FSS and GNS,explaining 11.82-12.72 %,12.44-15.00%,12.44-15.00% and 10.98-12.65 % of the phenotypic variation,respectively.