Soybean isoflavones are essential secondary metabolites synthesized in the phenylpropanoid pathway and benefit human health. In the present study, highresolution QTL mapping for isoflavone components was performed usi...Soybean isoflavones are essential secondary metabolites synthesized in the phenylpropanoid pathway and benefit human health. In the present study, highresolution QTL mapping for isoflavone components was performed using specific-locus amplified fragment sequencing(SLAF-seq) with a recombinant inbred line(RIL) population(F5:7) derived from a cross between two cultivated soybean varieties, Luheidou 2(LHD2) and Nanhuizao(NHZ). Using a high-density genetic map comprising 3541 SLAF markers and the isoflavone contents of soybean seeds in the 200 lines in four environments, 24 stable QTL were identified for isoflavone components, explaining 4.2%–21.2% of phenotypic variation.Of these QTL, four novel stable QTL(qG8, qMD19, qMG18, and qTIF19) were identified for genistin, malonyldaidzin, malonylgenistin, and total isoflavones, respectively. Gene annotation revealed three genes involved in isoflavone biosynthesis(Gm4CL, GmIFR, and GmCHR) and 13 MYB-like genes within genomic regions corresponding to stable QTL intervals, suggesting candidate genes underlying these loci. Nine epistatic QTL were identified for isoflavone components, explaining 4.7%–15.6% of phenotypic variation. These results will facilitate understanding the genetic basis of isoflavone accumulation in soybean seeds. The stable QTL and tightly linked SLAF markers may be used for markerassisted selection in soybean breeding programs.展开更多
基金supported by the National Key Technology R&D Program of China during the Twelfth Five-Year Plan Period of China (2014BAD11B01-x02)Beijing Science and Technology Project (Z16110000916005)+3 种基金National Science and Technology Major Project (2016ZX08004-003)National Key R&D Program of China (2016YFD0100504 and 2016YFD0100201)National Natural Science Foundation of China (31671716, 31171576)Agricultural Science and Technology Innovation Project of CAAS
文摘Soybean isoflavones are essential secondary metabolites synthesized in the phenylpropanoid pathway and benefit human health. In the present study, highresolution QTL mapping for isoflavone components was performed using specific-locus amplified fragment sequencing(SLAF-seq) with a recombinant inbred line(RIL) population(F5:7) derived from a cross between two cultivated soybean varieties, Luheidou 2(LHD2) and Nanhuizao(NHZ). Using a high-density genetic map comprising 3541 SLAF markers and the isoflavone contents of soybean seeds in the 200 lines in four environments, 24 stable QTL were identified for isoflavone components, explaining 4.2%–21.2% of phenotypic variation.Of these QTL, four novel stable QTL(qG8, qMD19, qMG18, and qTIF19) were identified for genistin, malonyldaidzin, malonylgenistin, and total isoflavones, respectively. Gene annotation revealed three genes involved in isoflavone biosynthesis(Gm4CL, GmIFR, and GmCHR) and 13 MYB-like genes within genomic regions corresponding to stable QTL intervals, suggesting candidate genes underlying these loci. Nine epistatic QTL were identified for isoflavone components, explaining 4.7%–15.6% of phenotypic variation. These results will facilitate understanding the genetic basis of isoflavone accumulation in soybean seeds. The stable QTL and tightly linked SLAF markers may be used for markerassisted selection in soybean breeding programs.
