College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
Plant Genetics, Gembloux Agro-Bio Tech, University of Liège, Gembloux, 5030, Belgium.
J Integr Plant Biol. 2019 Jun;61(6):675-690. doi: 10.1111/jipb.12811. Epub 2019 May 9.
As essential B vitamin for humans, folates accumulation in edible parts of crops, such as maize kernels, is of great importance for human health. But its breeding is always limited by the prohibitive cost of folate profiling. The molecular breeding is a more executable and efficient way for folate fortification, but is limited by the molecular knowledge of folate regulation. Here we report the genetic mapping of folate quantitative trait loci (QTLs) using a segregated population crossed by two maize lines, one high in folate (GEMS31) and the other low in folate (DAN3130). Two folate QTLs on chromosome 5 were obtained by the combination of F whole-exome sequencing and F kernel-folate profiling. These two QTLs had been confirmed by bulk segregant analysis using F pooled DNA and F kernel-folate profiling, and were overlapped with QTLs identified by another segregated population. These two QTLs contributed 41.6% of phenotypic variation of 5-formyltetrahydrofolate, the most abundant storage form among folate derivatives in dry maize grains, in the GEMS31×DAN3130 population. Their fine mapping and functional analysis will reveal details of folate metabolism, and provide a basis for marker-assisted breeding aimed at the enrichment of folates in maize kernels.
叶酸作为人体必需的 B 族维生素，在玉米籽粒等可食用作物部位的积累对人类健康至关重要。但其选育一直受到叶酸分析成本过高的限制。分子选育是叶酸强化的一种更可行和有效的方法，但受到叶酸调控分子知识的限制。在这里，我们报道了使用由两个玉米品系杂交而成的分离群体对叶酸数量性状位点（QTL）进行的遗传作图，这两个品系一个叶酸含量高（GEMS31），另一个叶酸含量低（DAN3130）。通过 F 全外显子测序和 F 核叶酸分析相结合，获得了 5 号染色体上的两个叶酸 QTL。这两个 QTL 已经通过使用 F 混合 DNA 和 F 核叶酸分析的大群体分离分析得到了验证，并且与另一个分离群体鉴定的 QTL 重叠。这两个 QTL 对 5-甲酰四氢叶酸（叶酸衍生物在干玉米籽粒中最丰富的储存形式）的表型变异的贡献率为 41.6%，在 GEMS31×DAN3130 群体中。它们的精细定位和功能分析将揭示叶酸代谢的细节，并为旨在富集玉米籽粒中叶酸的标记辅助选育提供基础。
