Department of Plant Sciences, North Dakota State University, Fargo, ND, United States of America.
Department of Plant Pathology, North Dakota State University, Fargo, ND, United States of America.
PLoS One. 2019 Sep 18;14(9):e0221826. doi: 10.1371/journal.pone.0221826. eCollection 2019.
The genetic gain in yield and quality are two major targets of wheat breeding programs around the world. In this study, a high density genetic map consisting of 10,172 SNP markers identified a total of 43 genomic regions associated with three quality traits, three yield traits and two agronomic traits in hard red spring wheat (HRSW). When compared with six grain shape and size traits, the quality traits showed mostly independent genetic control (18% common loci), while the yield traits showed moderate association (53% common loci). Association of genomic regions for grain area (GA) and thousand-grain weight (TGW), with yield suggests that targeting an increase in GA may help enhancing wheat yield through an increase in TGW. Flour extraction (FE), although has a weak positive phenotypic association with grain shape and size, they do not share any common genetic loci. A major contributor to plant height was the Rht8 locus and the reduced height allele was associated with significant increase in grains per spike (GPS) and FE, and decrease in number of spikes per square meter and test weight. Stable loci were identified for almost all the traits. However, we could not find any QTL in the region of major known genes like GPC-B1, Ha, Rht-1, and Ppd-1. Epistasis also played an important role in the genetics of majority of the traits. In addition to enhancing our knowledge about the association of wheat quality and yield with grain shape and size, this study provides novel loci, genetic information and pre-breeding material (combining positive alleles from both parents) to enhance the cultivated gene pool in wheat germplasm. These resources are valuable in facilitating molecular breeding for wheat quality and yield improvement.
产量和品质的遗传增益是世界各地小麦育种计划的两个主要目标。本研究利用包含 10172 个 SNP 标记的高密度遗传图谱，共鉴定出与硬粒春小麦（HRSW）三个品质性状、三个产量性状和两个农艺性状相关的 43 个基因组区域。与六个粒形和粒长性状相比，品质性状表现出相对独立的遗传控制（18%的共同位点），而产量性状表现出中等程度的关联（53%的共同位点）。粒面积（GA）和千粒重（TGW）与产量的关联表明，通过增加 GA 可能有助于提高小麦产量。面粉提取（FE）虽然与粒形和粒长呈弱正表型关联，但它们没有共享任何共同的遗传位点。株高的主要贡献者是 Rht8 位点，矮化等位基因与穗粒数（GPS）和 FE 的显著增加以及每平方米穗数和容重的减少有关。几乎所有性状都鉴定到了稳定的位点。然而，我们在 GPC-B1、Ha、Rht-1 和 Ppd-1 等主要已知基因区域没有发现任何 QTL。上位性也在大多数性状的遗传中起着重要作用。除了增强我们对小麦品质和产量与粒形和粒长关联的认识外，本研究还提供了新的基因座、遗传信息和预繁殖材料（从双亲中结合阳性等位基因），以增强小麦种质资源中栽培基因库。这些资源对于促进小麦品质和产量改良的分子育种具有重要价值。
