Genome-wide Association Analysis For Starch Pasting Properties Of Wheat

Wheat is one of the most widely grown cereals in the world.Starch,as a component of wheat grains,has an important impact on wheat quality.The gelatinization property of wheat starch is one of the most important indicators for evaluating the quality of wheat starch.It is closely related to the quality of foods such as noodles.Therefore,research on the gelatinization characteristics and genetic basis of wheat starch is of great significance for the improvement of wheat quality.In this study,208 natural population materials were genotyped by wheat 660 K gene chip.After 2 years of planting and starch gelatinization characteristics,the whole genome was analyzed by means of genome-wide association analysis.The main findings are as follows:1 The starch gelatinization characteristics of wheat starch are widely varied among the tested materials.Some southern varieties have better starch gelatinization properties,showing higher peak viscosity and higher lean value,such as Ningmai 14.Analysis of variance showed that the starch gelatinization properties of wheat were affected by genotype,environment and genotype and environment interaction.Peak viscosity,trough viscosity,lean value,final viscosity,rebound value,peak time and gelatinization temperature reached extremely significant levels in genotype,environment,and genotype-environment interactions,and the generalized heritability of gelatinization parameters was determined.The range of variation was 0.67-0.84,indicating that the genotype played a leading role in the gelatinization properties of wheat starch.Therefore,strengthening the genetic research on the gelatinization properties of wheat starch is of great significance to the quality improvement of wheat.2 By studying the correlation between different gelatinization parameters,it is found that the peak viscosity and the low valley viscosity,the lean value,the final viscosity,the rebound value and the peak time are significantly positively correlated,and the correlation coefficient with the low valley viscosity is the largest(r=0.883).The correlation between the lean value and the final viscosity is the largest,and negatively correlated with the peak time;the final viscosity,the low viscosity,the rebound value,and the peak time are significantly positively correlated,and the final viscosity has the highest correlation with the low valley viscosity;The gelatinization temperature is not correlated with other RVA parameters.3 genome-wide association analysis of wheat starch gelatinization characteristics,74 related sites were screened in four environments,distributed on 12 chromosomes: 2A,3A,3B,3D,4A,5B,5D,6A,6B,7A,7B,7D,the contribution rate of phenotypic variation of a single associated locus ranged from 5.57% to 26.27%,among which more related sites(24)were detected on chromosome 7A,which were detected on chromosome 3A.Five loci associated with multiplegelatinization parameters,which may be genetically enriched regions that control starch gelatinization properties,should be studied in depth.In addition,there are 36,26,and 16 sites associated with the lean value,peak time,and peak viscosity,respectively,and 12 and 8 sites associated with the final viscosity and the rebound value,respectively,and the gelatinization temperature.(2)and trough viscosity(1)have fewer associated sites.4 A total of 13 pleiotropic(at least two traits)association sites were detected,in which a related site was found on chromosome 7B(AX-108787075)while controlling peak viscosity,trough viscosity,final viscosity,rebound value and peak value.Time,the highest contribution rate of 25.25%,is an important associated site.Five pleiotropic sites for simultaneous control of two traits of starch gelatinization were detected,three pleiotropic sites controlling three traits of starch gelatinization and four pleiotropic effects of simultaneously controlling four traits of starch gelatinization Site.The KASP mark of AX-108787075 and AX-108926739 was developed and verified by another 124 related group materials provided by the research group.The main stable site detected in this study provides a theoretical basis for molecular marker-assisted selection breeding and starch quality improvement in wheat,and lays a foundation for excavating functional genes that control wheat starch properties.