| Wheat(Triticum aestivum L.)is one of the three major grains,as a staple food for 40% of the world’s population,wheat and its pasta products account for about 11% of the total food and provide 18.6% of the total calories for humans.It is of great significance to screen and cultivat high-amylose wheat varieties that are beneficial to human health.In this study,the content of starch components in the grains of natural population composed of 205 wheat varieties(lines)in two different environments(E1,E2)was measured,and the content of amylose and amylopectin,as well as the gene loci of total starch content in wheat was detected by whole-genome association analysis.It lays the foundation for the exploration of wheat amylose gene.Simultaneously determination of the starch components of360 wheat germplasm resources at home and abroad,and screen out germplasm with higher amylose content from natural population materials and 360 germplasm materials to provide parental resources for the selection and breeding of new varieties;correlation analysis between starch components of natural population materials and starch quality indicators,sedimentation value,starch gelatinization characteristics,starch granularity,and gluten under E1 environment,the main research results are as follows:1.The results of phenotypic analysis of starch components of 534 wheat materials showed that the ranges of amylose content,amylopectin content and total starch content(accounting for wheat grain)are 13.38%-24.24%,26.13%-54.16%,43.03%-72.16%.The wheat variety with the highest amylose content is W43 and the lowest is Chuanmai 8.The coefficient of variation of amylose content amylopectin content and total starch content are 9.60%,11.60%,6.60%,and the coefficient of variation of amylopectin content in the starch component is the highest,indicating that it has great potential for improvement.2.Correlation analysis found that the content of amylose has a very significant negative correlation with the stabilization time;the content of amylose has a significant positive correlation with type A starch;it has a very significant positive correlation with the degree of softening.The amylopectin content has a significant positive correlation with trough viscosity(TV);it has a very significant negative correlation with the degree of softening.The total starch content has a significant positive correlation with trough viscosity(TV);it has a very significant negative correlation with the degree of softening and peak time(PT).The content of amylose has a very significant negative correlation with amylopectin content and total starch content.There is no obvious correlation between starch components,gluten and sedimentation value.3.Through genome-wide association study,a total of 123 gene loci that are significantly associated with the target traits are detected,of them there are 32 SNP markers that are significantly related to amylose content,55 SNP markers that are significantly related to amylopectin content and 36 SNP markers that are significantly related to total starch content,the range of phenotypic variation explained(PVE%)is 5.80%-8.79%,5.99%-8.41%,6.08%-9.51%.In the two environments,the important association sites of amylose content detected are tplb0054d13＿2445(PVE%: 8.30%)and GENE-4944＿647,IAAV2921,Tdurum＿contig62981＿470(PVE%: 8.79%);important association sites of amylopectin content Excalibur＿c45968＿83(PVE%: 6.15%)and Tdurum＿contig7623＿392(PVE%: 8.41%);the important association sites of total starch content are TA005793-0515(PVE%: 6.85%)and BS00068779＿51(PVE%: 9.51%)A total of 18 pleiotropic association sites are detected,including 10 markers closely related to the content of amylopectin and the content of total starch,such as BS00068779＿51,GENE-4608＿569,Kukri＿c1853＿1975,Kukri＿c42522＿155,RFL＿Contig5005＿761;1 marker RAC875＿c76611＿364 that closely related to the content of amylose and the content of amylopectin;1 marker BS00106695＿51 that closely related to the content of amylopectin and the breakdown;3 markers BS00031057＿51,BS00067630＿51,RFL＿Contig5170＿1904 that closely related to the content of amylopectin and the breakdown;3 markers Excalibur＿c35611＿446,Kukri＿c29358＿277,Kukri＿c47664＿191 that control both the total starch content and integral area.4.According to amylose content,17 wheat varieties(lines)with amylose content more than 23% are selected,including W232,Xinmai 9,Lunxuan 987,Yumai 34,Zhongyu 01095,Zhoumai 32,Aifeng 3,W231,CENTAURD,W103,Panmai 5,Yunong 949,Zhengmai 7698,W125,W148,Zhenmai 18,W43. |
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