Foxtail millet(Setaria italica L.)is an important grain crop in northern China.The grain is rich in nutrients and many kinds of flavonoid,which plays an important role in growth and quality formation.At present,there are few studies on the regula-tory mechanisms of flavonoid synthesis and seed color formation in foxtail millet.The quantitative trait loci(QTL)analysis of flavonoid content and seed color traits in foxtail millet laid a foundation for fine mapping,cloning,and functional study of key genes for flavonoid synthesis,and it also provided technical support for revealing the mechanism of flavonoid synthesis and metabolism in foxtail millet and cultivating millet varieties rich in flavonoid.In this study,a recombinant inbred line(RIL)population consisting of 150 families was used as the experimental materials,which was constructed using a red seed-color high-flavonoid variety Jinmiaohongjiugu and a yellow seed-color low-flavonoid variety Yugu 28 as the parents.The related traits of seed color and flavonoid content were analyzed at maturity stage in foxtail millet.At the same time,composite interval map-ping(CIM)was used to locate and analyze QTL for seed color and flavonoid content,and the candidate genes within the QTL confidence intervals were predicted.Correlation analysis showed that flavonoid content was significantly positively correlated with seed color.A total four and eleven QTL associated with flavonoids content and seed color were located on chromosomes 1,2,5,6,7,8,and 9,respectively,and individual QTL phenotypic contribution rate was 2.01%-29.25%,six major QTLs were identi-fied,qSC1-2 and qFLA1-1,qSC7-1 and qFLA7-1,qSC9-3,and qFLA9-1 were co-localized QTL under both two traits.Through gene prediction and functional annotation,five candidate genes related to flavonoid synthesis and metabolism in the confidence interval of QTL were screened,indicating that the genes related to flavonoid synthesis,metabolism,and utilization were most probably to regulate the expression of these genes.15 QTL were clustered on seven chromosomes,respectively,and five candi-date genes related to flavonoid synthesis and metabolism were screened based on gene functional annotation,indicating that dif-ferent QTL loci were involved in the common genetic mechanism,and the pyramiding breeding of beneficial genes such as fla-vonoid synthesis and metabolism could be carried out through molecular marker-assisted selection.
维普
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