Genome-wide Association Analysis Of Main Starch Quality And Dough Rheological Properties In Wheat

Wheat?Triticum aestivum L.?is one of the important cereal grains widely cultivated.Starch is the main component of wheat grain,which has an important influence on the quality of wheat.With the growth of population and the increasing demand for nutrition,people have brought forward more and more requests to the quality of wheat flour.Therefore,it is of great significance to study the main starch quality and dough rheological properties and to explore the wheat flour quality genes for improvement of wheat flour quality.In this study,genome-wide association analysis of dough rheological properties,pasting properties,starch granularity and starch content by natural group consisting of 205 wheat varieties.The main results were as follows: 1.Genome-wide association study of dough rheological properties192 significant?p<0.001?marker-trait associations?MTAs?of dough rheological properties were detected in two environments,which were distributed on other chromosomes except chromosomes 4D,5D and 6D and accounted for 6.44%-14.05% of the phenotypic variation.In this study,a number of important loci related to dough rheological properties were detected on chromosomes 1D and 7D.There are pleiotropic MTAs controlling development time and stability time up to 33 on chromosome 1D.wsnp_Ex_rep_c66423₆4641680 was simultaneously controlled development time and stability time,which was expressed steadily in two environments,explaining 11.40% of the phenotypic variation.IAAV7473 was highly significant and relative stable locus associated with stability time,with high PVE of 14.61%.wsnp_Ex_c16429₂4929065,Ra_c10518₇35 were pleiotropic MTAs controlled stability time and degree of softening on chromosomes 1D and 7D.2.Genome-wide association study of pasting properties320 significant?p<0.001?MTAs of pasting properties were detected in two environments,which were spread over other chromosomes except chromosomes 1D and accounted for 5.66%-13.01% of the phenotypic variation.A total of 57 pleiotropic MTAs was identified in this study,which are mainly related to the peak viscosity,trough viscosity,final viscosity and integral area.Among them,Kukri_c17417₂91 was relatively stable and highly significant locus controlling final viscosity,while controlling the trough viscosity and integral area.BS00040165₅1 and Tdurum_contig63207₈2 were associated with peak viscosity,trough viscosity,final viscosity and integral area with phenotypic variation higher than 10% on chromosomes 6A and 7B,respectively.3.Genome-wide association study of starch granularity87 significant?p<0.001?MTAs associated with starch granularity were detected on chromosomes 1A,1B,1D,2A,3D,4A,4D,5A,5B,6A,6D,7A,7B and 7D and explained 6.29%-14.56% of the phenotypic variance.In this study,a number of important locus related to starch granularity were detected on chromosomes 2A,7A and 7D.RAC875_c7019₇54 was major and significant locus controlling A-type starch granule content with PVE of 9.37%.There were eight pleiotropic MTAs of B-type starch granule content and A/B-type granule ratio on chromosomes 2A,7A and 7D.Excalibur_c14693₇24 was major and significant locus controlling B-type starch granule content on chromosomes 2A,explained 14.56% of PVE.4.Genome-wide association study of starch content37 significant?p<0.001?MTAs associated with starch granularity were detected on chromosomes 1A,1B,1D,2A,2B,2D,4B,5A,5B,5D,6D,7A and 7B,explaining 6.29%-14.56% of the phenotypic variance.BS00021851₅1 was major and significant locus controlling amylose content and explained 10.11% of PVE.Kukri_c43552₂38 was major locus associated with amylopectin content with PVE of 9.67% in E2.RAC875_c41415₄50 was main major locus controlling starch content and explained 11.10% of PVE.5.Pleiotropic marker-trait associations analysisIn the present study,a total of three pleiotropic loci were detected to be be relevant to pasting properties,dough rheological properties and starch granularity.Of them,wsnp_Ex_c17538₂6261053 were detected on chromosomes 2B,controlling peak viscosity,peak time and stability time,which explained 11.08% of high PVE.Two pleiotropic MTAs?wsnp_CAP11_c2839₁425826,CAP8_rep_c9420₁86?on chromosome 7D controlled breakdown,B-type starch granule content and A/B-type granule ratio,but with low PVE.