Lopes M S, Dreisigacker S, Peña R J, Sukumaran S, Reynolds M P
CIMMYT, PO Box 39, Emek, Ankara, 06511, Turkey.
Theor Appl Genet. 2015 Mar;128(3):453-64. doi: 10.1007/s00122-014-2444-2. Epub 2014 Dec 25.
The wheat association mapping initiative is appropriate for gene discovery without the confounding effects of phenology and plant height. The wheat association mapping initiative (WAMI) population is a set of 287 diverse advanced wheat lines with a narrow range of variation for days to heading (DH) and plant height (PH). This study aimed to characterize the WAMI and showed that this diverse panel has a favorable genetic background in which stress adaptive traits and their alleles contributing to final yield can be identified with reduced confounding major gene effects through genome-wide association studies (GWAS). Using single nucleotide polymorphism (SNP) markers, we observed lower gene diversity on the D genome, compared with the other genomes. Population structure was primarily related to the distribution of the 1B.1R rye translocation. The narrow range of variation for DH and PH in the WAMI population still entailed segregation for a few markers associated with the former traits, while Rht genes were associated with grain yield (GY). Genotype by environment (G × E) interaction for GY was primarily explained by Rht-B1, Vrn-A1 and markers on chromosomes 2D and 3A when running GWAS with genotype scores from the G × E biplot. The use of PC scores from the G × E biplot seems a promising tool to determine genes and markers associated with complex interactions across environments. The WAMI panel lends itself to GWAS for complex trait dissection by avoiding the confounding effects of DH and PH which were reduced to a minimum (using Rht-B1 and Vrn-A1 scores as covariables), with significant associations with GY on chromosomes 2D, 3A and 3B.
小麦关联作图计划适用于基因发现，不受物候和株高的混杂效应影响。小麦关联作图计划（WAMI）群体由287个不同的高级小麦品系组成，抽穗天数（DH）和株高（PH）的变异范围较窄。本研究旨在对WAMI群体进行特征分析，结果表明，这个多样化的群体具有良好的遗传背景，通过全基因组关联研究（GWAS），可以在减少主要基因混杂效应的情况下，鉴定出有助于最终产量的胁迫适应性性状及其等位基因。使用单核苷酸多态性（SNP）标记，我们观察到D基因组上的基因多样性低于其他基因组。群体结构主要与1B.1R黑麦易位的分布有关。WAMI群体中DH和PH的变异范围较窄，但仍有一些与前一性状相关的标记发生分离，而Rht基因与籽粒产量（GY）相关。当使用G×E双标图中的基因型评分进行GWAS时，GY的基因型与环境（G×E）互作主要由Rht-B1、Vrn-A1以及2D和3A染色体上的标记解释。使用G×E双标图中的主成分（PC）评分似乎是确定与跨环境复杂互作相关的基因和标记的一个有前途的工具。WAMI群体通过避免DH和PH的混杂效应（将其降至最低，使用Rht-B1和Vrn-A1评分作为协变量），适用于GWAS对复杂性状的剖析，与2D、3A和3B染色体上的GY有显著关联。
