| Maize is one of the most important and widely cultivated crops in the world,and it plays an important role in ensuring world food security.The current main breeding goal of maize is to achieve high yield,stable yield and high quality,and quality traits directly or indirectly affect corn yield.Therefore,the study of maize quality traits has important practical significance for achieving high and stable corn yield.And with the rapid development of animal husbandry and processing industry,the demand for corn feed quality and processing value is increasing,so the study of corn quality traits has become an urgent task.With the development of whole genome sequencing technology,the development of massive single nucleotide polymorphism(SNP)molecular markers markers has provided great convenience for the use of whole genome association analysis technology to explore the genetic mechanism of complex traits.In this study,485 maize inbred line populations were used as research materials,and crude protein,crude starch,crude fat,lysine,corn kernel starch(optimal model)and corn kernels were calibrated by near infrared spectroscopy.The content of protein calibration(optimal model)was measured to obtain the phenotypic data of these quality traits.Then,558629 single nucleotide polymorphism(SNP)molecular markers covering the whole maize genome were used to analyze the whole-grain quality traits of maize,and 73 SNP sites were obtained,which were significantly associated with these grain quality traits.The main findings of this study are as follows:1.The analysis results of phenotypic traits show that these quality traits of corn kernels are all typical quantitative traits,and the variation range is relatively wide.The kurtosis value and skewness value of crude fat and the kurtosis value of corn grain starch calibration(optimal model)are all greater than 1,and the absolute values of kurtosis value and skewness value of other traits are both less than 1.Correlation analysis results show that all traits have significant correlations.The results of analysis of variance showed that the genotype effects,environmental effects,and genotype-environment interaction effects of these quality traits of corn all reached extremely significant levels.2.The general linear model(GLM)was used to analyze the correlation of maize grain quality traits.It was found that there were 15 SNP sites significantly correlated with the crude protein content of the grain;the SNP site on chromosome 2 explained 7.82%Phenotypic variation;through bioinformatics analysis of the 50kb sequence of significant SNP upstream and downstream,34 candidate genes involved in zinc ion binding,metabolism,transcriptional regulation,etc.were identified.A significant SNP locus was detected in the crude starch content of maize kernels,located on chromosome 6,this locus could explain 8.02%of the phenotypic variation;6 were selected to participate in DNA binding,membrane components,transcriptional regulation Candidate genes.Crude fat content detected 24 significant SNP sites,of which the SNP located on chromosome 3 explained the highest phenotypic variation of 9.44%;screened out 57 signals involving signal transduction,iron ion binding,metabolism,and transport proteins Candidate genes.There are 23 SNP sites that are significantly associated with the lysine content of the grain.Among them,the highest SNP on chromosome 7 explains 8.08%of the phenotypic variation;68 candidate genes such as ATP synthesis and potassium ion transport.Corn starch calibration(optimal model)and intact kernel protein calibration(optimal model)detected 7 and 3 significant SNP loci,respectively.The two SNPs located on chromosome 7 explained 7.49%of And 7.70%phenotypic variation;23 and 9 candidate genes were discovered through bioinformatics analysis,respectively,involved in lipid metabolism,iron ion binding,electron carrier activity,monooxygenase activity,nutrient storage,alcohol Protein and other physiological and biochemical metabolic processes. |
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