| Barley can be divided into palea barley and hulless barley according to palea segments.Hulless barley is naked barley,colored hulless barley is rich in a variety of nutrition and health components,is a special grain color germplasm resources.Starch is an important character of barley grain quality,which is not only the main energy substance,but also the main component affecting its nutrition,health and processing performance of grain crops.The grain color and starch components of barley are quantitative traits,which are easily affected by the environment.It is time-consuming and difficult to use traditional breeding methods to cultivate high-quality varieties,while molecular biology provides theoretical basis and practical significance for breeding excellent barley varieties.In this study,356 natural populations of barley with extensive genetic representation from many places were selected as research materials to determine and analyze the differences in grain color and starch content,and carry out genome-wide association analysis(GWAS).The results are as follows:1.The phenotypic analysis of grain color and starching-related traits of 356 barley materials showed that the variation ranges luminosity(L),chroma coordinate(a),chroma coordinate(b)and shade index(SI)were 28.50-58.00,0-6,0-19.75 and 0-0.36,respectively.The coefficients of variation were 13.34%,44.67%,49.56% and 59.97%,and the coefficients of genetic variation were 5.49%,20.89%,33.67% and 36.89%,respectively.The amplitude of amylose content,amylopectin content and total starch content were 10.45%-18.78%,23.95%-53.66% and 34.53%-68.68%,respectively,and the coefficient of variation were 10.61%,11.41% and 10.30%,respectively.The coefficient of genetic variation was 4.88%,4.87% and 4.32%,respectively.The coefficient of variation and genetic variation of shade index and chroma coordinate were large,and the luminosity was stable,which indicated that shade index and chroma coordinate had great improvement potential and abundant phenotypic variation.The variation coefficient of amylopectin was the highest,which indicated that amylopectin had great potential in quality improvement.2.The phenotypic analysis of 356 barley grain color and starching-related traits showed that the variation ranges of luminosity(L),chroma coordinate(a),chroma coordinate(b)and shade index(SI)were 28.50-58.00,0-6,0-19.75 and 0-0.36,respectively.The coefficients of variation were 13.34%,44.67%,49.56% and 59.97%,respectively.The amplitude of amylose content,amylopectin content and total starch content were 10.45%-18.78%,23.95%-53.66% and 34.53%-68.68%,respectively,and the coefficient of variation were 10.61%,11.41% and 10.30%,respectively.Among the grain color traits,the coefficient of variation of shade index and chroma coordinate was large,and the luminosity was stable,indicating that the shade index and chroma coordinate had great potential for improvement.Among the starch related traits,the variation coefficient of amylopectin was the highest,which indicated that amylopectin had great potential in quality improvement of starch components.3.According to the starch content of barley grains measured in different environments,we screened out white hulless barley and purple hulled hulless barley with high amylose content,shanqing 7 and WAS3 with low amylose content,Bailanglan and2009-119 with high amylose content,PY00954 and Nina with low amylose content.The highland barley varieties with high total starch content are 2009-119 and Purple hullss barley,while the hulless barley varieties with low total starch content are Zhagu and PY01181.4.Through genome-wide association analysis,a total of 38 SNPs associated with the color traits of barley grains were detected,including 5,3,21 and 9 significant loci associated with luminosity(L),chroma coordinate(a),chroma coordinate(b)and shade index(SI),respectively.8 loci/regions were identified by at least two traits.11 main correlation loci were found to be closely related to starch traits,among which there were 3,1,1 and 6 main correlation loci with amylose,total starch,amylopectin to amylose ratio and ratio of amylopectin to total starch,respectively.According to the functional annotation of genes in the region,6 hulless barley grain color loci and 7 candidate genes were screened out,namely loci S1H＿376415394,S2H＿582800461,S3H＿655280792,S2H＿676197102,S3H＿677552791 and S3H＿7467584.Candidate genes HORVU.MOREX.r3.1HG0053660,HORVU.MOREX.r3.2HG00173410,HORVU.MOREX.r3.3HG0313030,HORVU.MOREX.r3.2HG0188760,HORVU.MOREX.r3.3HG0322180,HORVU.MOREX.r3.3HG0221180 and HORVU.MOREX.r3.3HG0221210;Selected 2 hulless barley grain starch loci and 2 candidate genes,namely loci S4H＿623209802 and S3H＿40791106,candidate genes HORVU.MOREX.R3.4HG0410550 and HORVUMOREX.R3.3HG0235920. |
PDF Full Text Request