Genetic And Locational Analysis Of Zinc,Iron And Copper Contents In Common Wheat Grains

Zinc,iron and copper are 3 essential trace elements,which are all over the tissues and organs of the human body.They are of vital importance to human health.It is of great significance to increase the content of zinc,iron and copper in wheat grains to the people who live on wheat.In this paper,the content of zinc,iron and copper in grain of 243 Chinese wheat varieties（lines）in 3 environments were determined by atomic absorption spectrometry（AAS）.The results of phenotypic analysis showed that the variation range of Zn content in grain was from 22.99 to 87.57 mg/kg,with an average of 42.26 mg/kg.The variation range of Fe content in grain was 28.75-101.65 mg/kg,with an average of 5 1.02 mg/kg.The variation range of Cu content was 3.92-17.39 mg/kg,with an average of 9.23 mg/kg.Based on the 660K microarray genotyping results of wheat,this study used genome-wide association analysis（GWAS）method to identify the genetic regulatory sites of zinc,iron and copper content in 243 wheat seeds.The results are as follows:1.A total of 792 significant SNPs were detected in wheat grain zinc content,which can explain 4.8-16.5%of phenotypic variation,mainly distributed on chromosomes 1 A.2A,5A and 6B.Important gene loci regulating wheat GZnC may exist on chromosomes 2A,5A and 6B.Further analysis indicated that GZnC_Hap₅A may be an important gene locus in the regulation of wheat GZnC.2.A total of 245 significant SNPs were detected in wheat grain iron content,which could explain 7.3-30.3%of phenotypic variation,mainly distributed on chromosome 7B.Important gene loci regulating wheat GFeC may exist on chromosome 2A,5B and 7B.Further analysis indicated that GFeC_Hap₅A may be an important gene locus regulating wheat GFeC.3.A total of 489 significant SNPs were detected in wheat grain copper content,which could explain 1 0.1 to 32.6%of phenotypic variation,mainly distributed on chromosomes 2A and 5A.Further analysis showed that GCuC_Hap₂A,GCuC_Hap₃B and GCuC_Hap₅A may be important gene loci regulating wheat GCuC.In addition,187 F10 recombinant inbred line（RILs）populations with UC1110 and PI610750 as parents were used as materials in this study.The contents of zinc,iron and copper in grain were detected in the same environment in two years,and the QTLS were located.The results are as follows:Three QTLs controlling zinc content in wheat grain were identified and located on chromosomes 1B,4B and 7D,respectively,which explained phenotypic variation of 6.55%,5.46%and 6.74%.A QTL controlling iron content in wheat grains was identified,located on 1D chromosome,which explained 10.09%of the phenotypic variation.In addition,according to the GWAS detection results,two significant SNPs were located in 1D and within the interval of QGFeC-1D.It indicated that this locus plays an important role in the regulation of wheat GFeC.Four QTLs controlling copper content in wheat grains were identified,located on chromosomes 1D,6A,6B,and 7D,respectively,and explained phenotypic variation of 8.66%,7.55%,8.21%,and 4.71%.In addition,according to the GWAS test results,two significant SNPs were located on 1D chromosome and within the region of QGCuC-1D,indicating that this locus plays an important role in the regulation of wheat GCuC.This study analyzed the genetic mechanism of zinc,iron and copper content in wheat grain,and provided useful information for wheat quality breeding by using molecular marker-assisted selection of wheat germplasm resources with high zinc,iron and copper content.