Abstract：
Enhancing maize kernel oil is vital for improving the bioavailability of fat-soluble vitamins. Here, we combined favourable alleles of dgat1-2 and fatb into parental lines of four multi-nutrient-rich maize hybrids (APTQH1, APTQH4, APTQH5 and APTQH7) using marker-assisted selection (MAS). Parental lines possessed favourable alleles of crtRB1, lcyE, vte4 and opaque2 genes. Gene-specific markers enabled successful foreground selection in BC1F1, BC2F1 and BC2F2, while background selection using genome-wide microsatellite markers (127-132) achieved 93% recurrent parent genome recovery. Resulting inbreds exhibited significantly higher oil (6.93%) and oleic acid (OA, 40.49%) and lower palmitic acid (PA, 14.23%) compared to original inbreds with elevated provitamin A (11.77 ppm), vitamin E (16.01 ppm), lysine (0.331%) and tryptophan (0.085%). Oil content significantly increased from 4.80% in original hybrids to 6.73% in reconstituted hybrids, making them high-oil maize hybrids. These hybrids displayed 35.70% increment in oil content and 51.56% increase in OA with 36.32% reduction in PA compared to original hybrids, while maintaining higher provitamin A (two-fold), vitamin E (nine-fold), lysine (two-fold) and tryptophan (two-fold) compared to normal hybrids. Lipid health indices showed improved atherogenicity, thrombogenicity, cholesterolaemic, oxidability, peroxidizability and nutritive values in MAS-derived genotypes over original versions. Besides, the MAS-derived inbreds and hybrids exhibited comparable grain yield and phenotypic characteristics to the original versions. The maize hybrids developed in the study possessed high-yielding ability with high kernel oil and OA, low PA, better fatty acid health and nutritional properties, higher multi-vitamins and balanced amino acids, which hold immense significance to address malnutrition and rising demand for oil sustainably in a fast-track manner.
摘要：
增强玉米仁油对于提高脂溶性维生素的生物利用度至关重要。这里,我们使用标记辅助选择（MAS）将dgat1-2和fatb的有利等位基因结合到四个富含多种营养的玉米杂交种（APTQH1，APTQH4，APTQH5和APTQH7）的亲本品系中。亲本系具有crtRB1，lcyE的有利等位基因，vte4和opaque2基因。基因特异性标记可在BC1F1，BC2F1和BC2F2中成功进行前景选择，而使用全基因组微卫星标记（127-132）的背景选择可实现93％的轮回亲本基因组恢复。所得自交系表现出显著较高的油(6.93%)和油酸(OA，40.49%)和低棕榈酸(PA，14.23％）与维生素原A（11.77ppm）升高的原始自交系相比，维生素E（16.01ppm），赖氨酸(0.331%)和色氨酸(0.085%)。油含量从原始杂种的4.80％显着增加到重组杂种的6.73％，使它们成为高油玉米杂交种。与原始杂种相比，这些杂种的油含量增加了35.70％，OA增加了51.56％，PA减少了36.32％，同时保持较高的维生素原A（两倍），维生素E（九倍），与正常杂种相比，赖氨酸（两倍）和色氨酸（两倍）。脂质健康指数显示动脉粥样硬化改善，血栓形成性,胆固醇血症，可氧化性，MAS衍生基因型相对于原始版本的过氧化性和营养价值。此外,MAS衍生的自交系和杂种表现出与原始版本相当的谷物产量和表型特征。研究中开发的玉米杂交种具有高籽粒油和OA的高产能力，PA低,更好的脂肪酸健康和营养特性，更多的多种维生素和平衡的氨基酸，这对于以快速的方式可持续地解决营养不良和不断增长的石油需求具有巨大的意义。
