Genome-wide Association Study Of Mixing Properties And SRC In Wheat(Triticum Aestivum L.)

Wheat?Triticum aestivum L.?is one of the world's main food crops,people's demand for quality of cooked wheaten food is constantly increasing with the improvement of living standards.Therefore,it is necessary to study the main quality characters of wheat,excavate the genetic genes controlling quality,and clarify the relationship between genes and traits.In the present study,a wheat association mapping population of 205 elite,winter wheat lines chosen from China winter wheat area since 1980 s was genotyped with high-density Illumina iSelect 90 K SNP assay.The natural population was regarded as experimental materials and performed genome-wide association study?GWAS?for wheat quality related traits.The results of mixing properties and solvent retention capacity?SRC?are summarized as follows:1.Phenotype analysis: The phenotypic variation analysis of mixing properties showed significant differences in the two environments,excluded MPT and MPW.The coefficient of variation of each parameter was different.The coefficient of variation of CTW,MTxV,MPT,SR and SL were more than 20% and others were in the range of 9.7%-20%.The results showed that the natural populations in the present study had a rich genetic variation in mixing properties,and it was of great potential to improve the quality of winter wheat.Analysis of the phenotypic variation of solvent retention capacity showed significant differences between sucrose SRC,sodium carbonate SRC,lactic acid SRC and water SRC in the two environments.The coefficient of variation of all traits showed differently.The coefficient of variation of lactic acid SRC and the water SRC in E1 environment was more than 10%,others were in the range of 7.9-9.11%,indicating that the improvement potential of the natural populations for solvent retention capacity was not great.2.Genome-wide association study of mixing properties: GWAS for 10 mixograph parameters were determined,and about 415 significant?p<0.001?marker-trait associations?MTAs?were identified,which spread over 20 wheat chromosomes.In the present study,important loci were identified on chromosomes 1B and 1D.among these,BS00022851₅1,Excalibur_c40993₁129 and RFL_Contig2826₅48 were associated with two or more traits on chromosomes 1B,and they were closely.The number of significant loci associated to more than one traits on chromosomes 1D were up to 30.Among these,D_GA8KES401EYUM8₁90was controlled MPT and CTW,and stable expressed in two environments with high phenotypic variance explained?PVE?of 15.9%.GENE-0511₁61 was major locus controlled MPT,MTxV and CTV at the same time,with high PVE of 16.3%.GENE-0511₄84 and Kukri_c6051₆40 were major loci controlled MPT,MTxV and CTV and stable expressed in two environments,with high PVE of 15.92%.BS00021702₅1 was major locus controlled MPT,MTxV and MTxW at the same time and stably expressed in two environments,with high PVE of 16.3%.3.Genome-wide association study of solvent retention capacity: GWAS for four solvent retention capacities?SRCs?were determined,and about 313 significant?p<0.001?markertrait associations?MTAs?were identified,which spread over 19 wheat chromosomes.GENE-3780₁31 was major locus associated with sucrose SRC in E2 with high PVE of20.0%.BS00021851₅1 was major locus associated with lactic acid SRC on chromosome 1D with PVE of 12.4%.IAAV1634 was stable expression and significant locus associated with water SRC.RFL_Contig29₁062 and BS00094342₅1 were major locus associated with water SRC.The loci associated with water SRC were almostly identified in E1 with low PVE.Seven major loci were identified to be associated with sodium carbonate SRC on chromosomes 7A.Among these,IACX72 and wsnp_Ex_c15988₂4402251 had the highest PVE of 11.1%,and BS00000010₅1 was the only locus identified in E2.4.Pleiotropic MTAs analysis: In the present study,a total of nine pleiotropic MTAs were identified to be associated with mixing properties and SRC.Among these,seven loci controlled two traits included EW and sucrose SRC were stable sites on chromosome 5A.GENE-3780₁31 were major locus and controlled four traits?MTx V,EW,CTV and sucrose SRC?,with high PVE of 20.11%.BS00022524₅1 were associated with EW,Lactic acid SRC and water SRC at the same time,but with low PVE.